Riga-Rostock 2022 abstracts 01.06.2022..pdf - Agnese Ķirse

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16TH JOINT SYMPOSIUM OF ROSTOCK UNIVERSITY AND RIGA STRADIŅŠ UNIVERSITY AND 10TH CONGRESS OF BALTIC ASSOCIATION FOR MAXILLOFACIAL AND PLASTIC SURGERY EMERGING TECHNOLOGIES IN ORAL AND MAXILLOFACIAL SURGERY ABSTRACTS JUNE 03-04 2022 RIGA, LATVIA 16TH JOINT SYMPOSIUM OF ROSTOCK UNIVERSITY AND RIGA STRADIŅŠ UNIVERSITY AND 10TH CONGRESS OF BALTIC ASSOCIATION FOR MAXILLOFACIAL AND PLASTIC SURGERY 03-04 JUNE 2022 Oral Presentation TELOMERE LENGTH SCREENING IN YOUNG PATIENTS WITH HEAD AND NECK CANCER IS SUITABLE TO DETECT UNDERLYING INHERITED TELOMERE BIOLOGY DISORDERS* Birte Julia Siegmund1,4, Fabian Beier2,4, Benjamin Rolles2,4 , Maurice Klein1,4, Mark Ooms1,4, Philipp Winnand1,4, Eva Simons3,4, Marcel Bourgeois2,4, Gerrit Spanier5, Simon Laban6, Manuel Weber7, Carolin Goetz8, Falk Birkenfeld9, Kim Kricheldorf2,4, Susanne Isfort2,4, Martin Kirschner2,4, Stephan Hackenberg3,4, Frank Hoelzle1,4, Tim H. Brümmendorf2,4 , Mareike Tometten2,4 1Department of Oral and Maxillofacial Surgery, University Hospital RWTH Aachen, Aachen, Germany 2Department of Hematology, Oncology, Hemostaseology and Stem Cell Transplantation, University Hospital RWTH Aachen, Aachen, Germany 3Department of Otorhinolaryngology, Head and Neck Surgery, University Hospital RWTH Aachen, Aachen, Germany 4Center for Integrated Oncology - Aachen Bonn Cologne Duesseldorf (CIO-ABCD) 5Department of Oral and Maxillofacial Surgery University Hospital Regensburg, Regensburg, Germany 6Department of Otorhinolaryngology, Head and Neck Surgery, University Hospital of Ulm, Ulm, Germany 7Department of Oral and Maxillofacial Surgery, University Hospital of Erlangen, Erlangen, Germany 8Department of Oral and Maxillofacial Surgery, Klinikum rechts der Isar, Technical University Muenchen, Muenchen, Germany 9Department of Oral and Maxillofacial Surgery, University Hospital Schleswig-Holstein, Kiel, Germany * Encore-Abstract: Parts of the work were presented at the DGHO annual meeting 2021 and DOESAK-Meeting 2021; the project is still in progress Keywords. Screening for underlying inherited Telomere biology disorders (TBD) in young patients with squamous cell cancer of the head and neck (SCCHN) Introduction. Telomere biology disorders (TBD) are hereditary disorders characterized by impaired telomere maintenance. TBD patients are predisposed for hematologic and solid cancers at early age, squamous cell carcinoma of the head and neck (SCCHN) represents the most frequent solid tumor entity. Functional TBD read-out is prematurely shortened telomere length (TL). We systematically analyzed TL in a young cohort of SCCHN patients to identify the frequency of underlying TBD cases. 2 16TH JOINT SYMPOSIUM OF ROSTOCK UNIVERSITY AND RIGA STRADIŅŠ UNIVERSITY AND 10TH CONGRESS OF BALTIC ASSOCIATION FOR MAXILLOFACIAL AND PLASTIC SURGERY 03-04 JUNE 2022 Methods. All patients (pts) were included in the Aachen TBD registry based on clinical suspicion for TBD. Pts < 50y at initial cancer diagnosis with or without missing risk factors (RF) were eligible. Lymphocyte (L) and granulocyte (G) age-adjusted (aa) TL were analyzed by flow-FISH, next generation sequencing (NGS) for telomere maintenance gene mutations performed in cases with TL below the 10th percentile. Results. Six German centers included 40 pts in this ongoing study. Mean age at initial diagnosis was 42.0 ± 7.2 y. Major site and histology was lingual and squamous cell cancer, respectively. Tumor stage and RF available in 29 pts showed 18 (62%) with stage III or IV, smoking in 13 (45%), alcohol abuse in six (20%) and 10 (34%) with no history for both RF. HPV/p16 status was negative in all analyzed cases (15/15). AaTL in L was significantly lower (-0.59 (p= 0.017)) compared to healthy controls, while aaTL in G was normal (0.45 (p= 0,059)) representing premature aging. TL in L was below the 10th and 1st percentile in five and two pts, respectively. NGS screening revealed variants in two cases affecting the telomere maintenance genes CTC1 and NHP2 which were both classified as variants of uncertain significance and likely pathogenic. Conclusion. Pending validation in a larger pts cohort, this pilot study establishes systematic TL screening in young SCCHN pts for underlying inherited TBD. 3 16TH JOINT SYMPOSIUM OF ROSTOCK UNIVERSITY AND RIGA STRADIŅŠ UNIVERSITY AND 10TH CONGRESS OF BALTIC ASSOCIATION FOR MAXILLOFACIAL AND PLASTIC SURGERY 03-04 JUNE 2022 Oral Presentation THE ROLE OF VIRTUAL PLANNING IN THE TREATMENT OF EXTENDED MANDIBLE CHONDROSARCOMA Zaleckas Linas, Assoc. Prof. 1, 2, Rutkūnas Vygandas, Prof1, Gendviliene Ieva DD, PhD1, Sun Yi, PhD3,4, Simonaitis Tomas5, Kaupas Simonas, MD6 1Institute of Odontology Faculty of Medicine Vilnius university, Vilnius, Lithuania 2Centre of Oral and Maxillofacial Surgery Vilnius university hospital Zalgiris clinic, Vilnius, Lithuania 3OMFS-IMPATH Research Group, Department of Imaging and Pathology, Faculty of Medicine, University of Leuven, Leuven, Belgium 4Department of Oral and Maxillofacial Surgery, University Hospitals Leuven, Leuven, Belgium 5DigitorumLAB, Vilnius, Lithuania 6Medical diagnostic and treatment center, Vilnius, Lithuania [email protected], [email protected] Aim. To present the treatment case of the patient with extended mandible chondrosarcoma and to reveal the role of virtual planning and digital technologies in the rehabilitation of masticatory function. Methods. Patient suffered from mandible swelling since 2006. After the surgery on 2007 pathological examination showed no signs of malignancies (mandible chondroma). 10,5 years later, at the patient’s age of 63 years, the symptoms recurred. The biopsy confirmed the diagnosis of mandible chondrosarcoma (G1). The virtual planning of mandible resection from angle to angle and reconstruction with vascularized fibula free-flap using surgical cutting guides was performed. After the successfully surgery and healing period the virtual planning of fully guided implant placement and dental restorations was done. Results. The surgical treatment was successful, final pathological diagnosis - bilateral mandible chondrosarcoma pT2N0, LVI (1) (G2), radical resection of chondrosarcoma. The virtual planning of fully guided implant placement allowed implant placement without removing of reconstruction plate and osteosynthesis screws. Final full-arch full-contour screw-retained zirconia restoration of the mandible was done and masticatory function was completely restored using digital workflow. During the 3-years follow-up period the patient is disease – free. Conclusions. Virtual planning and digital technologies enables and facilitates the complete restoration of the mandible and masticatory function in severe clinical cases. 4 16TH JOINT SYMPOSIUM OF ROSTOCK UNIVERSITY AND RIGA STRADIŅŠ UNIVERSITY AND 10TH CONGRESS OF BALTIC ASSOCIATION FOR MAXILLOFACIAL AND PLASTIC SURGERY 03-04 JUNE 2022 Oral Presentation ALUMINA-REINFORCED ZIRCONIA CERAMIC TITANIUM HYBRID IMPLANTS – A GAME CHANGER IN DENTAL IMPLANTOLOGY? Michael Dau1, Andreas Methner1, Mohamed Elhensheri1, Vivien Engel1, Nadja Engel1, Bernhard Frerich1 1 Department of Oral, Maxillofacial and Plastic Surgery, University Medical Center Rostock, Rostock, Germany [email protected] Keywords. dental implant, hybrid implant, animal model, mini pig, titanium, alumina reinforced zirconia ceramic Aim. Ceramic dental implants might provide an alternative to the typical titanium implants and are mainly made of aluminum oxide. Alumina is prone to fracture due to its high hardness and modulus of elasticity but relatively low bend strength and fracture toughness, which can lead to implant fractures. Combining titanium and ceramic in a hybrid implant might a good way to address the disadvantages of both materials. Methods. In an animal model four different dental implant types (a pure titanium; a pure zirconium dioxide ceramic; two different designs alumina-reinforced zirconia ceramic with pure titanium core) were inserted in each side of the mandible in adult mini pigs via submandibular approach. After 2, 8, 12 and 26 weeks the animals were scarified and the mandible was harvested. The decalcified specimens were evaluated histomorphometrically using the software Photoshop CS (Adobe Systems) regarding the bone implant contact (BIC, %). Results. For all animals, postoperative healing was uneventful and no complications were observed. Light microscopic analyses showed that all implants were well tolerated. Osteoblast seams as well as newly formed blood vessels, connective tissue, and some multinuclear giant cells on the surface of the implants were observed in all groups at each point in time. The BIC increased overtime in all groups with a slightly bigger BIC in the pure titanium group. Conclusions. Overall, the Alumina-reinforced zirconia ceramic titanium hybrid implants showed similar healing like classical pure titanium implants and might be a good candidate to overcome the limitations of pure zirconia ceramic implants. Funding. This research project was supported by Tizio Hybrid Implants GmbH (Germany). 5 16TH JOINT SYMPOSIUM OF ROSTOCK UNIVERSITY AND RIGA STRADIŅŠ UNIVERSITY AND 10TH CONGRESS OF BALTIC ASSOCIATION FOR MAXILLOFACIAL AND PLASTIC SURGERY 03-04 JUNE 2022 Oral Presentation USING PLATELET RICH FIBRIN TO ENCOURAGE WOUND HEALING IN LOWER THIRD MOLARS’ EXTRACTION SITES Kristina Kull, Resident of Maxillofcial Surgery, Tiia Tamme, MD PhD Maxillofcaial Surgeon, Janne Tiigimäe-Saar, PhD Maxillofacial Surgeon Department of Maxillofacial Surgery, Tartu University Hospital, Tartu, Estonia [email protected] Background. Third molar removal is one of the most common procedures performed by oral and maxillofacial surgeons. Pain, swelling and infection are most common complications after third molar extraction. Platelet-rich fibrin is second generation autologous biomaterial that polymerizes slowly. Slow polymerization accelerates wound healing. The aim of this study is to assess the effectiveness of PRF in wound healing by evaluating pain, swelling and bone density after lower third molar removal. Methods. 20 patients (10 male, 10 female) participated in the study. Lower third molars were removed bilaterally during single appointment. Control site was used to evaluate swelling. The Numerical Pain Rating Scale (NRS) was used to evaluate pain. Panoramic dental X-rays were used to evaluate bone density. Results. The pain at the control site was more intensive and lasted longer than at the PRF site. The swelling was more intensive at the control site. Bone density was higher at Conclusion. PRF seems to be effective material to encourage wound healing after third molar removal. PRF could be used routinely after third molar removal. Keywords. Third molar, PRF, Swelling, Pain, Platelet-rich fibrin, wisdom teeth removal 6 16TH JOINT SYMPOSIUM OF ROSTOCK UNIVERSITY AND RIGA STRADIŅŠ UNIVERSITY AND 10TH CONGRESS OF BALTIC ASSOCIATION FOR MAXILLOFACIAL AND PLASTIC SURGERY 03-04 JUNE 2022 Oral Presentation LONG-TERM RESULTS IN PRE-ADOLESCENT PATIENTS HAVING U-CLAP. THE BALTIC CLEFT NETWORK STUDY Jan-Hendrik Lenz1, Ilze Akota2, Linas Zaleckas3, Marianne Soots4, Ieva Bagante2, Irena Rogovska5, Bernhard Frerich1, Karsten Gundlach1 1Dept. for Oral and Maxillofacial Plastic Surgery (chair: Prof. Dr. Dr. Bernhard Frerich), Rostock University, Rostock, Germany 2Dept. for Oral and Maxillofacial Surgery (chair: Prof. Dr. Ilze Akota), Riga Stradins University, Riga, Latvia 3Centre of Oral and Maxillofacial Surgery (chair: Assoc. Prof. Dr. Zaleckas), Institute of Odontology, Faculty of Medicine Vilnius University, Vilnius University Hospital Zalgiris Clinic, Vilnius, Lithuania 4Institute of Dentistry (chair: Assoc Prof. Dr. Ülle Voog-Oras), Tartu University, Medical Faculty, Tartu, Estonia 5Dep. of Doctoral Studies (chair: Prof. Dr. Sandra Lejniece) Riga Stradins University, Riga, Latvia [email protected] Aim. This multicenter study aimed at comparing different techniques of lip and nose repair with or without NAM and primary anterior rhinoplasty in pre-adolescent children. Material and Methods. Patients with unilateral clefts of lip, alveolus, and palate who had undergone cleft lip and nose repair (from 2001 to 2018) were evaluated in a prospective three-centre study using standardized monochromatic, cropped photographs. Four cleft surgeons evaluated the aesthetics of the central part of the face when the patients had reached age ten years. Results. Seventy-six sets of photographs out of 87 patients were evaluated. The overall ratings of lips and noses did not differ much between centres. However, noses of centres 1 (mean 0.74; SD 0.57) and 2 (mean 0.76; SD 0.60) had been rated better than centre 3 (mean 1.32; SD 0.78; p = 0.0078), especially “Deformation of upper part of nostril rim or poor position of alar cartilage”. Centre 3 had produced better looking scars (mean 0.33; SD 0.48); p = 0.0036. Conclusions. Apparently better noses are to be found following either NAM or primary anterior rhinoplasty plus postoperative nasal stents. The latter seems to be particularly favorable and reduces the number of secondary interventions. Different techniques result in minor lip differences. 7 16TH JOINT SYMPOSIUM OF ROSTOCK UNIVERSITY AND RIGA STRADIŅŠ UNIVERSITY AND 10TH CONGRESS OF BALTIC ASSOCIATION FOR MAXILLOFACIAL AND PLASTIC SURGERY 03-04 JUNE 2022 Oral Presentation ORTHODONTIC FINDINGS AND SPEECH OUTCOMES IN PATIENTS WITH UNILATERAL CLEFT LIP AND PALATE Ann Dieckmann1, Susanne Josko1, Karsten Gundlach1 , Franka Stahl 2, Bernhard Frerich 1, Jan- Hendrik Lenz 1 1Department of Oral and Maxillofacial and Facial Plastic Surgery, University of Rostock, Rostock, Germany 2Department of Orthodontics, University of Rostock, Rostock, Germany Aim. To evaluate malocclusion in the primary dentition and speech in patients with unilateral cleft, lip, alveolous and palate and compare speech with dynamic and static orofacial dysfunctions Material. 50 patients with unilateral total clefts of lip, alveolus and palate (Q.37.5) from 2 different European cleft palate centers at the age of 5 years with a self developed protocol for minimal documentation. Methods. To determine malocclusions with 5-year-old Index according to Mars and evaluate primary orofacial functions (like breathing, sucking, chewing, biting, swallowing and tongue rest position) as well as secondary functions (like speech and voice) with standardized objective tests: payne- technique according to Garliner, functional tonometer according to Thiele, articulation test according to Dieckmann/Dieckmann and A-I-check according to Gutzmann. Pearson’s chi square test was used for statistical analysis and p≤0.05 was defined as significant. Results. The frequently most found category of the 5-year-Index was category II in both cleft centers. Open mouth posture (40%), unphysiological tongue rest position (37%) and visceral swallowing pattern (79%) were the most frequently diagnosed primary orofacial dysfunctions with all test persons. There were no significant differences between the participating cleft palate centers. Malarticulation and hypernasality (being secondary orofacial dysfunctions) were diagnosed in 35% and 82% of all subjects respectively with significant differences between the 2 cleft palate centers. This can be explained by the differences in treatment plans. Non significant differences in velopharyngeal function were found among these two groups at 5 years of age. Conclusions. The high frequency of malocclusions and primary and secondary orofacial dysfunctions in patients with unilateral clefts of lip, alveolus and palate require an early finding, treatment and intervention. 8 16TH JOINT SYMPOSIUM OF ROSTOCK UNIVERSITY AND RIGA STRADIŅŠ UNIVERSITY AND 10TH CONGRESS OF BALTIC ASSOCIATION FOR MAXILLOFACIAL AND PLASTIC SURGERY 03-04 JUNE 2022 Oral Presentation RIGA CLEFT LIP AND PALATE CENTRE LONG-TERM EXPERIENCE OF ALVEOLAR BONE GRAFTING Julianna Muceniece, Ilze Akota, Ieva Bagante, Inese Maulina, Ieva Maulina, Inta Zepa Cleft Lip and Palate Centre, Riga Stradins University Institute of Stomatology, Riga, Latvia [email protected] Aim. The objectives of this study was to evaluate the outcome of the alveolar bone grafting in unilateral complete cleft lip, alveolus and palate (UCLP) patients in our centre performed from January 2000 to December 2019. Methods. Data were collected from the medical records, 2D x-rays, photos and casts. The results were analyzed with respect to the height of the bone in grafted area, wound healing, condition of erupting teeth and the space closure in the dental arch. Results. Out of 90 operated patients, 76 (47 male and 27 female) patients were included in the study. Left side was mostly affected ( 54 vs 22). The average age of the patients at bone grafting was 10.00 years (range 6.9 - 30.3). The primary healing was observed in 73 (96.06%) patients while wound dehiscence occurred in 3 (3.94%) cases. The intra-oral radiographic observation period was 7.9month (range 5month to 2.11years). Eighty eight percent of our patients had alveolar bony height between the teeth bordering the former cleft more than 75% of the normal height of the alveolar process. If bone grafting was perform before canine or second incisor eruption, in 89% of cases alveolar arch was closed by orthodontic means. Prosthodonticaly closure was observed in 11% of our patients. Conclusion. Long term results of bone grafting showed high rate of success. Gap closure by orthodontic means was achieved in 89% of our patients with bone grafting performed before adjusted teeth eruption. 9 16TH JOINT SYMPOSIUM OF ROSTOCK UNIVERSITY AND RIGA STRADIŅŠ UNIVERSITY AND 10TH CONGRESS OF BALTIC ASSOCIATION FOR MAXILLOFACIAL AND PLASTIC SURGERY 03-04 JUNE 2022 Oral Presentation PEER-ASSISTED ASSESSMENTS IN AN ELECTRONIC OBJECTIVE STRUCTURED CLINICAL EXAMINATION (E-OSCE) OF PRE-FINAL YEAR STUDENTS Jan-Hendrik Lenz1,2, Steffen Emmert 2, Anke Busse3, Anne Port4, Susanne Fröhlich5, Bernd Romeike2, Juliane Kröplin1, Cadja Bachmann2 1Department of OMF and Facial Plastic Surgery, Rostock Medical Faculty 2Deans Office for Student Affairs, Rostock Medical Faculty 3Department of Radiology, Rostock Medical Faculty 4Department of Forensic Medicine, Rostock Medical Faculty 5Department of Orthopedics, Rostock Medical Faculty Rostock University, City of Rostock, Germany [email protected] Aim. Peer-assisted learnings (PAL) are well known in higher education and implemented in many medical curricula. COVID-19 pandemic derived effects have promoted an increase of digital educational assessments (i.e. E-OSCE). This study examined the assessment of medical peer-tutors in an interdisciplinary clinical E-OSCE. Methods. 24 peer-tutors (qualified in teaching, feedback and rating of clinical skills) applied PAL with first clinical year students regularly in internal medicine and surgery over 2 years. Then nine tutors acted as raters in an E-OSCE for pre-final year medical students covering analysis of doctor- peer-patient consultations, videotaped physical examinations (PE) and clinical findings of PE´s, X- ray´s and death certificates. 247 pre-final year students took part in the E-OSCE: First of all they received video-links, videos and diagnostic findings for preparation. Then students performed E-OSCE examinations and documented the results via an intranet-gateway. Assessments were evaluated by peer-tutors using a five-point scale after secondary training supervised by clinical experts Results. Peer-assessments showed minimum differences due to individual variances, students´ results varied from good (PEs:mean 1.86) to very good (PE-documentations:mean 1.44). Technical as staff efforts (e.g. matching of results) were extensive. Finally students evaluation showed high acceptance of the E-OSCE. Conclusions. E-OSCE rating by peer-tutors seems to be a reliable method for futural PAL-studies. The E-OSCE seems to be valuable tool regarding students learning outcomes. Intranet-based gateways seem to be a basic precondition for all E-OSCE observations. Increased IT support and an increased number of peer-tutors are recommendable for futural E-OSCE´s. 10 16TH JOINT SYMPOSIUM OF ROSTOCK UNIVERSITY AND RIGA STRADIŅŠ UNIVERSITY AND 10TH CONGRESS OF BALTIC ASSOCIATION FOR MAXILLOFACIAL AND PLASTIC SURGERY 03-04 JUNE 2022 Oral Presentation EVOLUTION OF ORAL HEALTH PROFESSIONAL’S EDUCATION IN EUROPE: THE O-HEALTH-EDU PROJECT OUTCOMES Ilze Akota1, Julia R. Davies2, Jonathan Dixon3, James Field4, Gabor Gerber5, Maria-Cristina Manzanares-Cespedes6, Denis Murphy7, Corrado Paganelli8, Barry Quinn9, Valerie Roger-Leroi10, Stephanie Tubert-Jeannin10, Sibille Vital11 1Riga Stradins University, Riga, Latvia, 2Malmö University, Malmö, Sweden, 3University of Sheffield, Sheffield, UK 4University of Cardiff, Cardiff, UK, 5Semmelweis Egyetem, Budapest, Hungary, 6Universitat de Barcelona, Barcelona, Spain, 7Association of Dental Education in Europe, Dublin, Ireland, 8University of Brescia, Brescia, Italy, 9University of Liverpool, Liverpool, UK, 10Clermont Auvergne University, Clermont-Ferrand, France, 11Université de Paris, AP-HP, Paris, France Numerous projects (DentEd, Dent CPD) and other activities have been carried out to harmonise dental education and quality assurance systems in Europe. The Association for Dental Education in Europe (ADEE) has played an important role by enhancing the quality of education, advancing the professional development of dental educators, and supporting research in education and training of Oral Health Professionals (OHPs). Currently work continues on the EU Erasmus + project entitled O-Health-Edu “Advancing Oral Health: A vision for dental Education”. This project is coordinated by the University of Clermont Auvergne (France) with the Association for Dental Education in Europe (ADEE) and 8 other university partners, including Riga Stradins University. The objectives of this project are to gain a valid understanding of the realities of dental education within Europe, to enable a shared understanding and a common vision for the future of OHP Education among European stakeholders and policy makers, and finally, to define priorities for a strategic vision and support changes for OHP education. A recent scoping review revealed significant gaps in our knowledge of how education of OHPs is implemented and delivered across Europe, being both limited and somewhat outdated (Dixon et al., 2021). One specific outcome of the project is created resource where terms specifically related to OHPs education are clearly defined and explained, called “Articulate”. The resource is now freely available online and feedback from the OHP education community is expected. This can be found, with free online access, at https://o-health-edu.org/articulate 11 16TH JOINT SYMPOSIUM OF ROSTOCK UNIVERSITY AND RIGA STRADIŅŠ UNIVERSITY AND 10TH CONGRESS OF BALTIC ASSOCIATION FOR MAXILLOFACIAL AND PLASTIC SURGERY 03-04 JUNE 2022 The process of collection of programme-level data on OHPs Education across Europe is underway. Outcomes will also improve the visibility of OHP programmes across Europe, to all interested stakeholders. The O-Health-Edu data hub presents a ‘summary card’ for each institution that has completed the survey and created a profile. This information is accessible at https://o-health- edu.org/ohe-datahub-directory. O-Health-Edu’s longitudinal vision for the education of OHPs in Europe into the future, to 2040 acts in the best interests of both students and patients, and sits within the context of a wider strategy for general health. The involvement of multiple stakeholders (educators and clinicians, international and national bodies, regulators and students) has enabled the creation of a shared vision, built through consensus. The Vision is now freely available online (Field et al 2022) and a representative visual can also be accessed at www.adee.org/ohe/vision-and-charter 12 16TH JOINT SYMPOSIUM OF ROSTOCK UNIVERSITY AND RIGA STRADIŅŠ UNIVERSITY AND 10TH CONGRESS OF BALTIC ASSOCIATION FOR MAXILLOFACIAL AND PLASTIC SURGERY 03-04 JUNE 2022 Oral Presentation AUTOMATED VIRTUAL PLANNING OF MANDIBULAR RECONSTRUCTIONS WITH MICROVASCULAR FIBULA FLAPS Igors Litvinovs1, Ali Modabber1, Frank Hölzle1, Florian Peters1, Ezgi Cevik1, Tobias Pankert1, Thomas Roth1, Stefan Raith1. 1Department of Oral and Maxillofacial Surgery, RWTH Aachen University Hospital, Pauwelsstraße 30, 52074 Aachen, Germany [email protected] Aim. Restoration of the mandible in cases of extensive continuity defects is an extremely difficult task. Due to the variety of applications, the autologous fibula flap is often the graft of choice. The aim of study was to develop and evaluate software capable of providing individualized planning of mandibular reconstruction using a fibula flap graft, considering the individual geometric specificities of the patient. Methods. The algorithm developed is based on curves following characteristic anatomical features. The geometric data of the physiological mandible and fibula were used to create different defects, and the geometric correspondence was investigated to demonstrate the applicability of the method with different reconstruction parameters. Results. It has been shown that the present method can be used by surgeons as an automated planning tool with the ability to account for individual geometric parameters. In addition, the study showed that the approach could be easily integrated into a highly automated process. The usability of the presented software was found to be excellent, given the fact that surgeons could work with the software directly after a brief introduction. Conclusions. A new algorithm for computer-guided planning of mandibular reconstruction using fibular grafts proved to be applicable to the desired goal while meeting stringent requirements. Parametric studies with different segment lengths have shown that the approach is able to automatically generate reconstruction proposals that can be critically evaluated by experienced surgeons and used as a template for subsequent planning of mandibular reconstructions. 13 16TH JOINT SYMPOSIUM OF ROSTOCK UNIVERSITY AND RIGA STRADIŅŠ UNIVERSITY AND 10TH CONGRESS OF BALTIC ASSOCIATION FOR MAXILLOFACIAL AND PLASTIC SURGERY 03-04 JUNE 2022 Oral Presentation IMPLEMENTATION OF 3D-PRINTED PERFUSION BIOREACTORS FOR STEM CELL SEEDING IN BONE SCAFFOLDS FOR FUTURE CHAIRSIDE APPLICATIONS Nadja Engel1, Carsten Fechner1, Robert Ott2, Paul Cherkasov3, Valeria Khaimov2, Stefan Siewert2, Klaus-Peter Schmitz2, Bernd Joachim Krause4, Bernhard Frerich5* 1Experimental research laboratory, Department of Oral and Maxillofacial Surgery, Facial Plastic Surgery, Rostock University Medical Center, Schillingallee 35, D-18057 Rostock, Germany. 2Institute for ImplantTechnology and Biomaterials e.V., Friedrich-Barnewitz-Str. 4, D-18119 Rostock, Germany. 3RoweMed AG – Medical 4 Life, Juri-Gagarin-Ring 4, D-19370 Parchim, Germany. 4Department of Nuclear Medicine, Rostock University Medical Center, Gertrudenplatz 1, D-18057 Rostock, Germany. 5Department of Oral and Maxillofacial Surgery, Facial Plastic Surgery, Rostock University Medical Center, Schillingallee 35, D-18057 Rostock, Germany. [email protected] Aim. There undoubtedly is a substantial need for new regenerative strategies in the management of craniofacial bone deficits, for example before implantation in dental surgery. Regardless of which approach is used, devices and methods are required to ensure effective, homogeneous, and reproducible seeding of scaffolds or carrier materials with stem cell or other endogenous material. A clinically acceptable seeding system should be self-contained, and the process should be completed within a defined short period of time. In this study we aimed to design a 3D-printable perfusion bioreactor for chairside applications in terms of a fast and homogeneous stem cell distribution within approved bone substitute materials (Fig. 1). Methods. Different bioreactor geometries with varying connector geometries were numerically modelled and thereafter printed with a Formlabs Form2 3D printer. Perfusion experiments were performed with adipose-derived stem cells, isolated from lipoaspirate samples which were collected from patients undergoing liposuction or lipofilling procedures. Using the combination of positron emission tomography (PET) and computed tomography (CT) within a micro-PET/CT, [18F]FDG- labeled stem cells can be monitored during perfusion processes to assess both, the colonization in three dimensions and the vitality of the cells within opaque scaffolds. Initial cell attachment and spreading within the scaffold was visualized by scanning electron microscopy. Osteogenic differentiation was proven by immunohistochemistry and osteogenic marker expression. 14 16TH JOINT SYMPOSIUM OF ROSTOCK UNIVERSITY AND RIGA STRADIŅŠ UNIVERSITY AND 10TH CONGRESS OF BALTIC ASSOCIATION FOR MAXILLOFACIAL AND PLASTIC SURGERY 03-04 JUNE 2022 Results. In our experiments, we could show that numerical modelling is able to predict the homogeneity and efficiency of seeding depending on defined parameters such as bioreactor geometry, perfusion rate and cell density of the perfusate. A particular challenge poses the imaging of seeded cells in opaque scaffolds, which could be reliably realized with dynamic micro-PET/CT. Compared to conventional histological or laser scanning microscopic imaging, this method saves time, is non-destructive and allows a higher throughput of experiments. By testing different geometries for the in- and outlets of the bioreactor, the conical form proved to be the most effective for homogeneous colonization. Furthermore, the encasement of scaffolds plays an important role to prevent leakage flow around the scaffolds. Consequently, a silicone encasement for individually structured scaffolds was generated. However, through the combined use of conical inlets and a custom-made silicone encasement the cell seeding homogeneity was significantly increased. If an oscillating perfusion mode is additionally used, the homogeneity of the cell distribution can be further increased resulting in a low Hoover coefficient of 0.24. In summary, this study shows that an individual bioreactor can be easily and quickly generated with a conventional 3D printing process, which can also be adapted to the individual geometry of the patient's bone substitute material. Conclusions. This bioreactor is enables homogeneous seeding of individual scaffolds with stem cells in less than an hour. The following four parameters were decisive for efficient cell colonization of the scaffold in the present investigations: 1. cell concentrations of 0.5 to 1.0 × 106 cells/ml, 2. a low perfusion rate of 0.5 – 1.0 ml/min, 3. scaffold encasement with a silicone sleeve, and 4. an oscillating perfusion mode. Fig. 1 Schematic graphical presentation of a 3D-printed perfusion bioreactor with subsequent PET/CT or histological analysis of cell homogeneity and cell spread. LSM: laser scanning microscopy. IHC: immunohistochemistry. 15 16TH JOINT SYMPOSIUM OF ROSTOCK UNIVERSITY AND RIGA STRADIŅŠ UNIVERSITY AND 10TH CONGRESS OF BALTIC ASSOCIATION FOR MAXILLOFACIAL AND PLASTIC SURGERY 03-04 JUNE 2022 Oral Presentation A DEEP LEARNING APPROACH FOR OSTEOPOROSIS IDENTIFICATION USING CONE-BEAM COMPUTED TOMOGRAPHY Laura Neimane1,2, Anda Slaidiņa3, Oskars Radziņš2,4, Ivars Namatēvs5, Kaspars Sudars5 1Department of Conservative Dentistry and Oral Health, Riga Stradins University, Riga, Latvia 2Baltic Biomaterials Centre of Excellence, Headquarters at Riga Technical University, Riga, Latvia 3Department of Prosthodontics, Riga Stradins University, Riga, Latvia 4Riga Stradins University Institute of Stomatology, Riga, Latvia 5Institute of Electronics and Computing Science, Riga, Latvia Aim. To develop a method to identify osteoporosis risk for postmenopausal women in the jawbones region, create an end-to-end deep learning prototype model, and apply quantitative and qualitative radiology bone density indices in cone beam computed tomography (CBCT) examinations. Methods. In the present study are planning to included 220 postmenopausal females aged 55-95 years who underwent CBCT (i-CAT Next generation, Kavo, Germany) examinations due to implant planning. Bone mineral density measurements of lumbar spine and both femoral necks by dual energy X-ray absorptiometry (DEXA) (Lunar DEXA DPX-NT, GE Medical Systems) will be performed. The worst T-score readings will be taken into account. The CBCT images are analyzed with OnDemand3D Dental, Kavo, Germany software. By analysing CBCT images and threshold values we will develop an osteoporosis risk identification method, followed by indexing mental and mandibular cortical indices. Based on the image analysis dataset, the deep neural network training will be performed by using existed (3D U-Net, V-Net) and new (Visual Transfomer) deep neural network architectures. Results. Using a Deep Learning (DL) approach, a Computer Vision method will be elaborated which can identify more quickly and accurately the risk of osteoporosis in women. Consequently, it facilitates the early treatment of the disease as well as prevents osteoporotic fractures. Conclusions. DL approach is is a perspective tool that could be used to identify osteoporosis risk for postmenopausal women in the jawbones region examined by CBCT. Funding. This work was supported by the “Fundamental and Applied Research Projects”, grant number: lzp-2021/1-0031 16 16TH JOINT SYMPOSIUM OF ROSTOCK UNIVERSITY AND RIGA STRADIŅŠ UNIVERSITY AND 10TH CONGRESS OF BALTIC ASSOCIATION FOR MAXILLOFACIAL AND PLASTIC SURGERY 03-04 JUNE 2022 Oral Presentation EMPIRICAL FINDINGS OF A 7-YEAR TMJ ARTHROSCOPY SURGERY EXPERIENCE Marijus Leketas PhD, DDS, MD1, Vykintas Pliavga SDS2, Abdulla Varoneckas DDS1 1Lithuanian University of Health Sciences, Department of Maxillofacial Surgery, Kaunas, Lithuania 2Lithuanian University of Health Sciences, Faculty of Odontology, Kaunas, Lithuania [email protected] Aim. To present the achievements of a 7-year clinical experience along with conducted research in the field of TMJ arthroscopy. Methods. Clinical experience of 7 years, case-control studies, RCTs, and systematic reviews in Kaunas Clinics were summarized. Results. Clinical practice of TMJ arthroscopy has started in Kaunas Clinics by performing first arthroscopic surgery in 2014 October. Since then, more than 300 successful TMJ arthroscopies were performed. Later, a systematic review comparing different intraarticular injection substances (PRFG and HA) followed by TMJ arthroscopy. The results showed a tendency towards the superiority of PRFG over other treatments in pain management. However, a lack of randomized controlled trials (RCTs) that compared both substances made it hard to conclude which substance enhances recovery and effectiveness the most, therefore this was followed by a RCT that compared the effect of HA and PRGF injections on the early postoperative period after TMJ arthroscopy in 77 patients. Lately, the object of interest has become the most advanced procedure in TMJ arthroscopy surgery – discopexy. A systematic review was carried out evaluating the effectiveness of different TMJ arthroscopic discopexy techniques. Conclusions. TMJ arthroscopy surgeries have proven themselves to be a successful way of helping particular TMD patients. Despite that, to this day, the scientific field of TMJ arthroscopy has shown us that this procedure is not extensively researched. 17 16TH JOINT SYMPOSIUM OF ROSTOCK UNIVERSITY AND RIGA STRADIŅŠ UNIVERSITY AND 10TH CONGRESS OF BALTIC ASSOCIATION FOR MAXILLOFACIAL AND PLASTIC SURGERY 03-04 JUNE 2022 Oral Presentation TEMPOROMANDIBULAR JOINT SURGERY FROM ARTHROCENTHESIS TO ALLOPLASTIC RECONSTRUCTION- IS THERE AN ALGORITHM? Birte Julia Siegmund, Ali Modabber, Frank Hölzle Department of Craniomaxillofacial and Facial Plastic Surgery, University Hospital of RWTH Aachen, Germany [email protected] Keywords. Temporomandibular diseases and disorders, TMJ reconstruction, surgical therapy of temporomandibular joint, alloplastic prosthetic total joint systems Aim. Treatment of temporomandibular disorders and diseases is commonly based on conservative therapy (physical therapy, splint therapy, botulinum toxin). The number of patients treated surgically is on rise. Depending on the entity of TMJ disease and the severity of TMD, treatment varies in the degree of surgical invasion and should be regarded as a kind of level scheme. Methods. Patients with different TMJ disorders and diseases where treated successfully in the last years two years in our department. Surgical intervention, combined with conservative and orthognathic methods has to be regarded as a kind of algorithm for successful treatment and stable results. Results. Especially surgical treatment of the temporomandibular joint has many different aspects and should be selected for every patient individually. Regarding the invasiveness and the irreversibility of this approach, the use of alloplastic total systems is still under debate and should be seen as an ultima ratio in TMJ surgery as the top of a level scheme. Conclusion. For successful and stable results, surgical treatment has to be seen as one part in a combination of surgical and conservative treatment methods. The top of a level scheme is the alloplastic reconstruction using prosthetic total joint systems. This is a very promisingly approach and results of stock systems are comparable with CAD/CAM-Systems. Nevertheless, indication has to be made carefully regarding medical history and risk factors. In some cases CAD/CAM- systems are recommended and should stay as a gold standard. Regarding diagnostics, it is necessary to reevaluate the effectiveness and the diagnostic accuracy of MRI and compare the results to clinical and surgical findings. 18 16TH JOINT SYMPOSIUM OF ROSTOCK UNIVERSITY AND RIGA STRADIŅŠ UNIVERSITY AND 10TH CONGRESS OF BALTIC ASSOCIATION FOR MAXILLOFACIAL AND PLASTIC SURGERY 03-04 JUNE 2022 Oral Presentation ADVANCED HIGH HYDROSTATIC PRESSURE BASED PROCESSING OF TISSUE GRAFTS Michael Dau1, Janine Waletzko-Hellwig1, Michael Sämann2, Christoph Drobek3, Anika Jonitz- Heincke2, Hermann Seitz3, Rainer Bader2, Bernhard Frerich1 1Department of Oral, Maxillofacial and Plastic Surgery, University Medical Center Rostock, Rostock, Germany 2Biomechanics and Implant Technology Research Laboratory, Department of Orthopedics, University Medical Center Rostock, Rostock, Germany 3Department of Mechanical Engineering, University of Rostock, Rostock, Germany [email protected] Keywords. high hydrostatic pressure, devitalization, decellularization, cleaning, allograft, regenerative medicine, bone regeneration Aim. Reconstructing severe bone defects is a clinical challenge. While the use of autografts is still considered as the gold standard, the available amounts of autograft and the donor site morbidity are limiting factors. Following the processing, allografts often lose the mechanical properties and the extracellular matrix shows signs of damage. Tissue processing using High Hydrostatic Pressure (HHP) might be able reduce chemical use in order to maintain the tissue integrity and mechanical strength. Methods. To evaluate the quality of HHP processing human osteoblasts were treated with various MPa levels each analyzed regarding metabolic activity, cell death by flow cytometry and the state of the cells. Additionally, bone cylinders – based of HHP treated bone cells – were formed and histologically analyzed for quality of the extracellular matrix and mechanical strength. Results. In brief, the level of the applied hydrostatic pressure correlated with the decrease of metabolic activities of human osteoblasts and an increase of apoptotic cells as well as an increase of necrotic cells. A graft processing using HHP of 250 to 300 MPa seems to be the optimal level to avoid high levels of cell necroses. The mechanical strength of the human bone cylinders was not affected by the HHP treatment using 250 MPa respectively 300 MPa. Conclusions. High hydrostatic pressure treatment of allogenic bone grafts seems to be a reliable method to devitalize allografts without losing the mechanical stability of the tissue and therefore an interesting approach for processing of bone allografts without using chemical agents. Funding. This joint research project HOGEMA is supported by the European Social Fund (ESF), reference: ESF/14-BM-A55-0012/18, and the Ministry of Education, Science and Culture of Mecklenburg-Vorpommern, Germany. 19 16TH JOINT SYMPOSIUM OF ROSTOCK UNIVERSITY AND RIGA STRADIŅŠ UNIVERSITY AND 10TH CONGRESS OF BALTIC ASSOCIATION FOR MAXILLOFACIAL AND PLASTIC SURGERY 03-04 JUNE 2022 Oral Presentation CURRENT RESEARCH APPROACHES FOR INNOVATIVE PROMOTION OF RESIDENTS AND YOUNG FELLOWS IN ORAL AND MAXILLOFACIAL SURGERY – A LITERATURE REVIEW OF THE STAUS QUO IN GERMANY Juliane Kröplin1, Fabian Kurosch Nokodian1, Jan-Hendrik Lenz1, Bernhard Frerich1 1Department of Oral and Maxillofacial Surgery, University Medical Centre Rostock, Rostock, Germany Aim. Aim of this paper is to present current research approaches to support adequate competence development in further training in oral and maxillofacial surgery. Methods. A selective pubmed-based literature review of content on research approaches in further training in oral and maxillofacial surgery was carried out. Papers from residents and young fellows of the German Society of Surgery and its associated societies from the years 2020 to 2022 were taken into account. Results. A total of n=7 publications were considered. Among these, n=4 are interdisciplinary. Only publications with at least one oral and maxillofacial surgical author were analysed. A total of n=37 authors have contributed to the publications. N=11 of them have an oral and maxillofacial surgical affiliation. Five main topics could be identified. The results show in particular research efforts in the areas of Digitalisation, Simulation-based training, Social media, 3D-printing and Leadership. Conclusion. Technical and scientific progress requires innovative training strategies in order to meet the challenges of future healthcare. The literature review reveals research approaches that could be of great importance in the further training of oral and maxillofacial surgeons in the future. Consideration of this content could also support innovative promotion of residents and young fellows in oral and maxillofacial surgery. This might lead to an improvement in the quality of patient care. 20 16TH JOINT SYMPOSIUM OF ROSTOCK UNIVERSITY AND RIGA STRADIŅŠ UNIVERSITY AND 10TH CONGRESS OF BALTIC ASSOCIATION FOR MAXILLOFACIAL AND PLASTIC SURGERY 03-04 JUNE 2022 Oral Presentation CUSTOMIZED SURGICAL APPROACH FOR PATIENTS WITH MANDIBLE OR MAXILLARY TUMOR ASSOCIATED BONE DEFECTS Janis Zarins1,2, Kristaps Blums1,2, Oskars Radzins2, Renars Deksnis3, Atis Svare3, Santa Salaka3 1Microsurgery Centre of Latvia, Riga Eastern University Hospital Gailezers, Riga, Latvia 2Baltic Biomaterials Centre of Excellence, Headquarters at Riga Technical University, Riga, Latvia 3Oncology Centre of Latvia, Riga Eastern University Hospital Gailezers, Riga, Latvia [email protected] Aim. The aim is to introduce pre-operative 3d virtual planning for mandible and maxillary bone defects in patients after oral cavity oncology or osteoradionecrosis and develop customized surgical approach. Methods. Thirteen patients underwent mandible (n=11) and maxillary (n=2) reconstructions during the period of 2021 to 2022. Eleven patients had active oncology, while two patients had osteradionecrosis associated bone defect of mandible. All patients underwent one stage resection and reconstruction with microvascular bone flaps. All cases were 3d virtually preplanned and surgical cutting guides were prepared using 3d printers and sterilized. Results. Preoperative 3d virtual planning matched surgical plan in all cases. Three out of 11 mandible reconstructions underwent also temporomandibular joint reconstruction due to the bone collapse – two with additional lateral femoral condyle flow through microvascular flap and one as an extraskeletal reposition on-table of the remaining joint to fibula flap. All patients recovered well and was discharged from the hospital totally independent from nasogastric tube and tracheostomy. All patients achieved intelligible speech. Nevertheless, all patients except one were satisfied with cosmetic outcome. Mouth opening for all except one patients was over 3 cm. Flap harvest and on- table osteotomies were done simultaneously to tumor or tissue excisions. Conclusions. Preoperative 3d virtual planning provides more accurate surgical outcome similar to patient’s natural anatomy which provides good functional outcome and better cosmetic result. Moreover, surgical cutting guides for donor and recipient area allows two team approach thus decreasing the total time of surgery and patient recovery. This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the grant agreement No 857287. 21 16TH JOINT SYMPOSIUM OF ROSTOCK UNIVERSITY AND RIGA STRADIŅŠ UNIVERSITY AND 10TH CONGRESS OF BALTIC ASSOCIATION FOR MAXILLOFACIAL AND PLASTIC SURGERY 03-04 JUNE 2022 Oral Presentation 3D PRINTING AND PLANNING IN PRIMARY RECONSTRUCTION OF ISOLATED ORBITAL FLOOR FRACTURE Ieva Bagante1, Oskars Radziņš2, Uldis Spulle3 1RSU Institute of Stomatology, BBCE, Pauls Stradins Clinical University Hospital 2RSU Institute of Stomatology, BBCE 3Stradins Clinical University Hospital [email protected] Aim. Aim of the study was to analyze experience with 3D printing and 3D surgical planning with a pre-bended titanium mesh in patients with isolated orbital floor fracture. This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the grant agreement No 857287. Methods Five consecutive patients with isolated orbital floor fracture who were treated in Pauls Stradins Clinical University Hospital in 2022 were included in the study. In-house 3D-printed anatomical prototypes, natural and mirrored around the midsagittal plane, were used as bending guides. Open reduction with a transconjunctival or subciliar approach and orbital floor reconstruction with a pre-bended titanium mesh was performed. The outcomes were analysed quantitatively with Mimics (Materialise, Leuven, Belgium) by measuring the volumes within the bony orbit using computer tomography images. Results. All patients before surgery were presented with enophthalmos and/or diplopia and were operated within 4-14 days of the trauma. The mean difference between the affected and healthy orbital volumes were 1823 ± 716 mm3 before and 454 ± 316 mm3 after surgery. The mean difference in affected orbital volume before and after surgery was 1908 ± 1051 mm3. Interrater mean difference between volumetric measurements was 3%. Post operative relative mean difference between orbits was 2.4%. Clinically and radiologically all orbital floor reconstructions were successful with no post operative ophthalmic complications. Conclusions. 3D-printed orbital prototypes seem to be accurate for orbital floor reconstruction planning and give acceptable symmetry of orbital volumes. The study should be continued with more patients. Prototypes were helpful in educating the patients and explaining the surgical procedure. 22 16TH JOINT SYMPOSIUM OF ROSTOCK UNIVERSITY AND RIGA STRADIŅŠ UNIVERSITY AND 10TH CONGRESS OF BALTIC ASSOCIATION FOR MAXILLOFACIAL AND PLASTIC SURGERY 03-04 JUNE 2022 Oral Presentation IMMATURE THIRD MOLAR AUTOTRANSPLANTATION WITH A PRINTED REPLICA. CASE REPORT Miks Lejnieks1,2, Ilze Akota1, Gundega Jakobsone1 Oskars Radzins1,2, Uldis Spulle1, Laura Neimane1,2 1Riga Stradins University Institute of Stomatology, Riga, Latvia 2Baltic Biomaterials Centre of Excellence, Riga, Latvia [email protected] One of Biomaterials Centre of Excellence project (BBCE) objectives is to promote PhD students integration in the international scientific environment and to develop the research capabilities. The use of donor tooth printed replica is described in literature as valuable to reduce total surgery time, donor extra-alveolar time and the number of donor tooth fitting attempts. Planning and replica printing for surgeries were supported by BBCE. Aim. The aim of the study was to demonstrate immature third molar autotransplantation with and without use of a printed donor tooth replica. Methods. All surgeries were done in Rigas Stradins University, Institute of Stomatology. Two immature third molar autotransplantation case reports were described, one conventional (Patient A) and one with a printed donor tooth replica. (Patient B) Total surgery time from first incision to last suture, donor tooth extra- alveolar time and donor tooth fitting times were monitored. Results. Patient A. female, 16 years old. Indicated for d26 extraction, (periodontitis chronica), and to transplant d28 (root development ½- ¾) to region d26. Total surgery time- 60 minutes, donor tooth extra alveolar time 120 seconds, fitting attempts – 3. Patient B. male, 17 years old. Indicated for d26 extraction, (unrestorable dental crown), and to transplant d18 (bifurcation not formed) to region d26. Total surgery time- 45 minutes, donor tooth extra alveolar time 60 seconds, fitting attempts – 1. Conclusions. The use of a replica made the procedure less traumatic, reduced the total surgery time, the donor extra-alveolar time and the number of times of fitting the donor tooth. The study with the aim to investigate efficiency of cone-beam replicas is under way. Acknowledgments. The authors acknowledge financial support from the European Union's Horizon 2020 research and inovation programme under the grant agreement No 857287 23 16TH JOINT SYMPOSIUM OF ROSTOCK UNIVERSITY AND RIGA STRADIŅŠ UNIVERSITY AND 10TH CONGRESS OF BALTIC ASSOCIATION FOR MAXILLOFACIAL AND PLASTIC SURGERY 03-04 JUNE 2022 Oral Presentation METHOD FOR VOLUMETRIC ANALYSIS OF MALAR REGION AFTER AUGMENTATION Martins Lauskis1,2, Ģirts Šalms2, Oskars Radziņš1, Ingus Arnolds Apse1 1Baltic Biomaterial Centre of Excelence 2Riga Stradins University Institute of Stomatology [email protected] Introduction. High and prominent cheekbones have long been considered a standard of beauty in many cultures. Different materials have been used to augment the malar region, hydroxyapatite granules being one of them. Volumetric stability is one of the key factors for predictability and patient satisfaction. Main disadvantage of using hydroxyapatite granules mixed with collagen is the decrease of implant volume. To counteract this volume loss, it is required to use excessive amount of material initially. Aim. To evaluate volumetric changes of malar implants over 12-month period after surgery. Methods. Volumetric analysis was performed on CBCT images of patients that received HAP/collagen implants to augment malar region during orthognathic surgery. To find volumetric changes and the corresponding areas in which they occur, superimpositions of the examination data were done. The superimpositions used a voxel-based method with the cranial base region above the condylar heads as the reference. To calculate volumetric differences the areas of interest were segmented to form a closed area and then filled to form solid objects followed by Boolean operations to determine the changes quantitatively and qualitatively. Results. Volume loss was most prominent during first 4 months after surgery, resorption rate after 4 months was minimal. Conclusion. Volume loss of hydroxyapatite/collagen implants can be detected. This method of CBCT analysis provides valuable info about volumetric stability of implants. Acknowledgment. This project has received funding from the European Union’s Horizon 2020 research and innovation program under the grant agreement No 857287. 24 16TH JOINT SYMPOSIUM OF ROSTOCK UNIVERSITY AND RIGA STRADIŅŠ UNIVERSITY AND 10TH CONGRESS OF BALTIC ASSOCIATION FOR MAXILLOFACIAL AND PLASTIC SURGERY 03-04 JUNE 2022 Oral Presentation THE EVALUATION OF MANDIBULAR CONTOUR DEFECT AFTER BILATERAL SAGITTAL SPLIT OSTEOTOMY: CASE SERIES Lana Mičko1,2,3, Ilze Šalma1,2,3, Ingus Skadiņš2,4, Ģirts Šalms1,3, Arita Dubņika2,5, Karina Egle2,5 1Institute of Stomatology, Riga Stradins University, Riga, LV-1007, Latvia 2Baltic Biomaterials Centre of Excellence, Headquarters at Riga Technical University, Riga, Latvia 3Riga Stradins University, Department of Oral and Maxillofacial surgery, Riga, Latvia 4Riga Stradins University, Department of Biology and Microbiology, Riga, Latvia 5Rudolfs Cimdins Riga Biomaterials Innovations and Development Centre of RTU, Faculty of Materials Science and Applied Chemistry, Institute of General Chemical Engineering, Riga Technical University, Pulka 3/3, Riga, Latvia [email protected] Introduction. The bilateral sagittal split osteotomy (BSSO) is the most commonly performed lower jaw surgery for the correction of mandibular deformities. Despite careful surgery planning to get predictable outcomes, some adverse results may remain after jaw repositioning. After large mandibular movement, insufficient bone contact may result in compromised bony union which may create unpleasant mandibular contour defect. The application of platelet rich fibrin may promote bone healing in sites of osteotomy. Aim. The aim of the study is to evaluate mandibular contour defect development in patients undergo conventional and modified BSSO with Choukroun’s PRF. Methods. Test group patients undergo BSSO with PRF used to fill osteotomy gaps near mandibular border. Control group patients undergo conventional BSSO. Cone beam computed tomography (CBCT) is done to all patients undergo BSSO 10 days and 12 months after surgery. The osteotomy gaps are measured in time and compared. Using superimposition of CTs the volume of osteotomy gap at mandibular border is measured. Results. Osteotomy gap in mandible is various in size in each patient depending on severity of dentofacial deformities. Patients undergo BSSO using PRF showed smoother line of mandibular border in osteotomy sites. Conclusions. PRF is autologous material with promising potential to be used for bone tissue formation in bilateral sagittal split osteotomy. Acknowledgement. The Latvian Council of Science research project No. lzp-2020/1-0054 “Development of antibacterial autologous fibrin matrices in maxillofacial surgery (MATRI-X)”. This project has received funding from the European Union’s Horizon 2020 research and innovation program under the grant agreement No 857287. 25 16TH JOINT SYMPOSIUM OF ROSTOCK UNIVERSITY AND RIGA STRADIŅŠ UNIVERSITY AND 10TH CONGRESS OF BALTIC ASSOCIATION FOR MAXILLOFACIAL AND PLASTIC SURGERY 03-04 JUNE 2022 Poster Presentation THE ROLE OF TISSUE BIOPSY IN CONFIRMING A RARE CASE OF PEDIATRIC PAROTID MALT-LYMPHOMA Dovile Proskute, MD1, Violeta Panaviene, MD, PhD, Assoc.Prof.2, Monika Kapitancuke, MD3 1Department of Maxillofacial surgery and Department of Pediatric Otorhinolaryngology, Vilnius University Hospital Santaros Klinikos, Vilnius, Lithuania 2Department of Specialized Pediatric Diseases, Vilnius University Hospital Santaros Klinikos, Vilnius, Lithuania 3Department of Pediatric Oncology and Hematology, Vilnius University Hospital Santaros Klinikos, Vilnius, Lithuania [email protected] Aim. The aim of this poster is to present a rare case of an 8-year-old girl with a bilateral parotid swelling of unknown origin. With other diagnostic tests being non-informative, we were able to confirm the diagnosis of MALT lymphoma and apply treatment only after performing a parotid tissue biopsy. Case presentation (methods + results). An 8-year-old girl complained of bilateral parotid swelling for more than 1 year. Consultations with various specialists as well as multiple laboratory and visual tests did not confirm any specific diagnosis. Inflammatory changes of both parotid glands in an MRI scan and elevated serum Pm-Scl levels suggested a diagnosis of Sjögren’s syndrome, however, we decided to perform a parotid tissue biopsy before starting any treatment. The histological result of a biopsy revealed extranodal marginal zone B-cell (MALT) lymphoma. In addition, repeated immunological analysis confirmed Sjögren’s syndrome. Multiple tests for disease staging detected stage II MALT lymphoma. The patient received four cycles of rituximab combined with methylprednisolone pulse once-weekly. After four courses of therapy, we see positive clinical and radiologic changes in both parotid glands. Conclusion. Even though children usually develop more aggressive non-Hodgkin lymphomas, rare indolent type MALT-lymphoma is also possible, particularly in association with Sjögren’s syndrome. We would like to pay attention to the rare hematological diagnoses in a pediatric population and emphasize the importance of a tissue biopsy and histological examination in unclear cases. 26 16TH JOINT SYMPOSIUM OF ROSTOCK UNIVERSITY AND RIGA STRADIŅŠ UNIVERSITY AND 10TH CONGRESS OF BALTIC ASSOCIATION FOR MAXILLOFACIAL AND PLASTIC SURGERY 03-04 JUNE 2022 Poster Presentation THE ROLE OF EXPRESSION OF SOLUBLE CD44 IN SALIVA AND CD44 ANTIGEN IN ORAL LEUKOPLAKIA Madara Dzudzilo1, Ingrīda Čēma1, Regīna Kleina2, Guntars Selga1, Šimons Svirskis3 1Department of Maxillo-Facial Surgery and Oral Medicine, Rīga Stradiņš University, 16 Dzirciema Str., LV-1007 Rīga, Latvia 2Department of Pathology, Rīga Stradiņš University, 16 Dzirciema Str., LV-1007 Rīga, Latvia 3Institute of Microbiology and Virology, Rīga Stradiņš University, 5 Rātsupītes Str., LV-1067 Rīga, Latvia [email protected] Aim. The aim of this study was to determine whether and how the CD44 protein expression in leukoplakia tissues correlates with positive SolCD44 test presence and their role in oral leukoplakia. Methods. SolCD44 and total protein expression in saliva were determined using an OncAlert® Oral Cancer Rapid test. Immunohistochemical visualization of the researched antigens was performed on the formalin-fixed paraffin-embedded oral leukoplakia and control tissue. CD44 and CD9 proteins were assessed by a standard polymer-based visualization En-vision method by Dako Denmark. Statistical processing of data has been performed. Results. Comparison of paired associations of total protein, SolCD44, mean number of CD44 expressed epithelial layers in leukoplakia tissue, and macrophages below the basement membrane between control group and patients with leukoplakia showed statistically significant results (p < 0.0001). It is shown that the total protein indicates low or elevated risk of possible malignant transformation processes in leukoplakia. Statistically significant differences between higher total protein level and clinical forms of oral leukoplakia (p < 0.0001), as well as CD44-labeled epithelial cell layer decrease (p < 0.0001), were found. This possibly points to the onset of the stemness loss in leukoplakia tissue. CD9 antigen expression in the exosomes of the oral epithelium explained the intercellular flow of SolCD44 and other fluids in the leukoplakia area. Conclusion. The OncAlert® Oral Cancer Rapid test is a valuable screening method in daily clinical practice, in terms of complementing clinical diagnostics methods and to assess the potential for early malignancy. 27 16TH JOINT SYMPOSIUM OF ROSTOCK UNIVERSITY AND RIGA STRADIŅŠ UNIVERSITY AND 10TH CONGRESS OF BALTIC ASSOCIATION FOR MAXILLOFACIAL AND PLASTIC SURGERY 03-04 JUNE 2022 Poster Presentation MULTIPLE INFLAMMATORY MYOFIBROBLASTIC TUMORS OF THE FACE: CASE REPORT AND LITERATURE REVIEW Vainermanas Gabrielius, MD, DD, Zykute – Bruziene Indre MD, DD, Zaleckas Linas MD, PhD, Assoc.Prof. Centre of Oral and Maxillofacial Surgery Institute of Dentistry, Faculty of Medicine, Vilnius university Lithuania Vilnius University hospital Zalgiris clinic, Vilnius, Lithuania [email protected] Aim. To present treatment results of a rare clinical manifestation of the inflammatory myofibroblastic tumors (IMT) in the facial region of a 25 year old patient. IMTs are very rare soft tissue tumors, which usually affect the lungs, pelvis and retroperitoneum. The head and neck region involve about 14-18 % of extra-pulmonary IMTs. Methods. Patient with no underlying diseases was referred to the Department of maxillofacial surgery Vilnius University hospital Zalgiris clinic with three painless masses of the face. The patient noticed the tumors about a year ago and was examined by a dermatologist and plastic surgeon - both of whom referred the patient to our surgery department for treatment. On clinical examination three painless egzofitic tumors of the face were seen: on the right side temporal and buccal regions and on the left side buccal region. MRI scan revealed that the temporal tumor has grown invasively onto temporal muscle. Other tumors did not penetrate deeper than subcutaneous tissue. Results. After the biopsy diagnosis of the IMT was confirmed. Complete surgical excisions of the tumors and skin plasty were performed. No recurrence of IMT was seen after more than 9 months, CT scan showed no metastasis of IMT to the lungs. Conclusions. Only few case reports were found with IMT manifestation in the oral and maxillofacial region, moreover - none with multiple manifestations in the region of the face. The reviewed literature showed that the treatment of choise for non-recurring IMTs is surgical excision. 28 16TH JOINT SYMPOSIUM OF ROSTOCK UNIVERSITY AND RIGA STRADIŅŠ UNIVERSITY AND 10TH CONGRESS OF BALTIC ASSOCIATION FOR MAXILLOFACIAL AND PLASTIC SURGERY 03-04 JUNE 2022 Poster Presentation SECONDARY ALVEOLAR BONE GRAFTING USING PLATELET-RICH PLASMA IN ALVEOLAR CLEFT PATIENTS - TWO CASE REPORTS Julianna Muceniece, Ilze Akota, Ieva Bagante, Inese Maulina, Ieva Maulina, Inta Zepa Cleft Lip and Palate Centre, Riga Stradins University Institute of Stomatology, Riga, Latvia Baltic Biomaterials Centre of Excellence, Riga, Latvia [email protected] Aim. Cleft lip and palate is the most common congenital deformity affecting craniofacial region. Bone grafting of the alveolus is an essential part of the treatment protocol for cleft patients. Autogenous bone is still a gold standard for secondary bone grafting in alveolar clefts. The worldwide use of platelet-rich plasma (PRP) therapy shows good results in their intrinsic growth factors to stimulate and accelerate a healing response. Aim of this report was to demonstrate 2 cases with autogenous cancellous bone and PRP use in bone grafting procedure in cleft children. Methods. Two patients 8 and 9 years of age with complete unilateral cleft lip, alveolus and palate and unilateral cleft lip and alveolus were described. Both underwent secondary bone grafting with autogenous cancellous bone graft harvested from tibia and additionally PRP. Results. Early postoperative period and bone healing 6 month after operation were observed. Primary wound healing was seen in both patients with no significant pain and swelling postoperatively. PRP use is a relatively simple procedure to be performed simultaneously with secondary alveolar bone grafting. Conclusion. Non-complicated wound healing occured. Procedure with PRP demands either additional personal to make preparations or longer operation time. Long term observation is necessary to confirm the effectiveness of PRP use in secondary bone grafting for cleft children patients. 29 16TH JOINT SYMPOSIUM OF ROSTOCK UNIVERSITY AND RIGA STRADIŅŠ UNIVERSITY AND 10TH CONGRESS OF BALTIC ASSOCIATION FOR MAXILLOFACIAL AND PLASTIC SURGERY 03-04 JUNE 2022 Poster Presentation PAX7, PAX9 AND RYK EXPRESSION IN CLEFT AFFECTED TISSUE Mārtiņš Vaivads1, Ilze Akota2,3, Māra Pilmane1 1Institute of Anatomy and Anthropology, Riga Stradins University, Kronvalda Boulevard 9, Riga, Latvia, LV-1010 2Department of Oral and Maxillofacial Surgery, Riga Stradins University, 16 Dzirciema Street, Riga, Latvia, LV-1007 3Cleft Lip and Palate Centre, Institute of Stomatology, Riga Stradins University, 20 Dzirciema Street, Riga, Latvia, LV-1007 [email protected] Aim. Craniofacial clefts are one of the most common types of congenital malformations. Transcription factors paired box 7 and 9 (PAX7, PAX9) and receptor-like tyrosine kinase (RYK) have been previously associated with the formation of orofacial clefts but their exact involvement and interactions in cleft-affected tissue remains uncertain. This study analyses the presence of PAX7, PAX9 and RYK immunopositive cells within different cleft affected tissue to assess their possible involvement in cleft morphopathogenesis. Methods. The cleft affected tissue was collected from non-syndromic orofacial cleft patients during cleft correcting surgery (36 patients with unilateral cleft lip, 13 patients with bilateral cleft lip, 26 patients with cleft palate). Control group tissue was obtained from 7 patients without cleft lip and palate. To evaluate the number of immunopositive structures in the cleft affected tissue and the control group a semiquantitative counting method was used. Non-parametric statistical methods (Kruskal-Wallis H test, Mann–Whitney U test, and Spearman’s rank correlation) were used. Results. Statistically significant differences for the number of PAX7, PAX9 and RYK positive cells were notified between the controls and the patient groups. Multiple statistically significant correlations between the factors were found in each cleft affected tissue group. Conclusions. PAX7, PAX9 and RYK have a variable involvement and interaction in postnatal morphopathogenesis of orofacial clefts. PAX7 is more associated with the formation of unilateral cleft lip, while PAX9 relates more towards the isolated cleft palate. The stable presence of RYK in all cleft types indicates its possible participation in different facial cleft formation. 30 16TH JOINT SYMPOSIUM OF ROSTOCK UNIVERSITY AND RIGA STRADIŅŠ UNIVERSITY AND 10TH CONGRESS OF BALTIC ASSOCIATION FOR MAXILLOFACIAL AND PLASTIC SURGERY 03-04 JUNE 2022 Poster Presentation CHARACTERISATION OF OPN, OC, ßdef-2, bFGF AND MMP-2 IN BONE OF CLEFT LIP PALATE (CLP) PATIENTS FROM FIRST TIME PLASTIC ALVEOLAR OSTEOPLASTY Dace Buile1 , Māra Pilmane2 , Ilze Akota3 1Department of Morphology, Institute of Anatomy and Anthropology, Riga Stradiņš University, 9 Kronvalda Str., LV-1010, Riga, LATVIA. 2Department of Morphology, Institute of Anatomy and Anthropology, Riga Stradiņš University, 9 Kronvalda Str., LV-1010, Riga, LATVIA. 3Department of Maxillofacial Surgery, Institute of Stomatology, Riga Stradiņš University, 20 Dzirciema Str., LV-1007, Riga, LATVIA. [email protected] Aim. Cleft lip palate (CLP) is a disruption of facial structure. The aim of our study was to determine appearance of the tissue factors in bone of patients with CLP during first time plastic alveolar osteoplasty. Methods. Immunohistochemistry was performed with osteopontin (OPN), osteocalcin (OC), beta- defensin-2 (βdef-2), basic fibroblast growth factor (bFGF) and matrix metalloproteinase-2 (MMP- 2). For the quantification of structures, the semi-quantitative census method was used. Spearman rank order correlation coefficient and Mann-Whitney U test were used for the statistical analysis. Results. A significantly higher number of OPN positive osteocytes (U=28,000; p=0.002) and MMP-2 positive osteocytes (U=26,000; p=0,012) was observed in the CLP group when compared to the control group. The number of OC positive osteocytes (U=15,000; p=0.000), bFGF positive osteocytes (U=21,500; p=0,005) and βdef-2 positive osteocytes (U=50,500; p=0.003) was significantly lower in the CLP group in comparison to the control group. Strong, positive correlation between βdef-2 and bFGF (rs=0.610; p=0.002) was detected in the CLP group. Conclusions. Increased appearance of OPN positive osteocytes shows increased bone homeostasis which may be a possible compensatory reaction to decreased quality of postsurgical bone. Increased MMP-2 positive osteocytes could suggest that bone of patients with CLP is more requisite for tissue repair. Decreased appearance of bFGF and OC positive osteocytes possibly indicate reduced abilities for bone tissue repair and regeneration, together with the low appearance of βdef-2, which indicates a tendency for reduced anti-inflammatory mechanism, could suggest the possibility of decreased wound healing properties in bone of patients with CLP after primary osteoplasty. 31 16TH JOINT SYMPOSIUM OF ROSTOCK UNIVERSITY AND RIGA STRADIŅŠ UNIVERSITY AND 10TH CONGRESS OF BALTIC ASSOCIATION FOR MAXILLOFACIAL AND PLASTIC SURGERY 03-04 JUNE 2022 Poster Presentation OUTCOME OF BONE REGENERATION AFTER APICAL SURGERY USING PLATLET-RICH-FIBRIN Aleksandra Karkle1, Zanda Bokvalde1, DDS, Laura Neimane1,2, DDS, MSc, Dr Med 1RigaStradins University, Department of Conservative Dentistry and Oral Health 2Baltic Biomaterials Centre of Excellence, Headquarters at Riga Technical University, Riga, Latvia [email protected] Aim. To assess and report the regenerative potential of PRF following apical surgery. Evaluate ultrasonography investigations advantage in oral surgery practice. Methods. Case reports are presented in which apical surgery was required, because of failed endodontic therapy. By randomization principle patients were distributed into two groups: Group I - autologous platelet-rich fibrin membrane (PRF) was used to stimulate bone regeneration and Group II – control group without PRF application. Patients were radiologically, ultrasonographycally and clinically examinated before apical surgery procedure and at recall visits. Radiological images were analyzed using i-Dixel, Moritta, Japan. Ultrasound imaging investigation was performed using a high frequency hockey stick linear transducer with a 20 mm width scan (frequency 15-18 MHz, Apolio a550, Canon). Results. The six-month review post apical surgery showed good bone regeneration and healing in Group where PRF was used. Ultrasound imaging investigation shows the advantages in determinating the size of bone defect. Conclusion. The report showed that using of PRF is effective way of achieving bone regeneration after apical surgery. 32 16TH JOINT SYMPOSIUM OF ROSTOCK UNIVERSITY AND RIGA STRADIŅŠ UNIVERSITY AND 10TH CONGRESS OF BALTIC ASSOCIATION FOR MAXILLOFACIAL AND PLASTIC SURGERY 03-04 JUNE 2022 Poster Presentation ODONTOGENIC SINUSITIS – CASE SERIES Ilze Prikule1, Irina Vasilcenko2 1Faculty of Residency, Maxillofacial Surgery, Riga Stradins University, Riga, Latvia 2Pauls Stradins Clinical University Hospital, Maxillofacial Department, Riga, Latvia [email protected] Aim. Odontogenic unilateral maxillary sinusitis is a well-known condition that is often overlooked due to unspecific symptoms and lack of tooth-related problems. 10-40% of all unilateral sinusitis cases are odontogenic etiology. The aim of this report is to highlight the importance of the multidisciplinary approach in the case of a suspect of odontogenic sinusitis. Methods. Four patients between 15.06.21 and 21.12.21 who underwent surgical treatment at our department were included. The preoperative diagnoses and symptoms, kind of operation, length of hospital stay, and outcome has been taken from medical records. Results. Our four presenting patients had a delayed diagnosis of odontogenic sinusitis. Mild irregular facial pain for a period of time from 6-12 months treated by the dentist or general practitioner was observed before they were referred to the maxillofacial surgeon. Destruction of maxillary sinus wall was observed in all patient cases. All patients required surgical treatment that resulted in a positive patient outcome. Histological evaluation revealed that three patients had an odontogenic cyst and one patient had sinus fungal infection. Intrahospital stay warried from 3 to 7 days. Conclusions. The delayed referral leads to severe disease form with bone destruction that requires hospitalization and surgery. A meticulous dental history and examination as well as collaboration between the dentist, the otorhinolaryngologist, and the maxillofacial surgeon in difficult cases is important. 33 16TH JOINT SYMPOSIUM OF ROSTOCK UNIVERSITY AND RIGA STRADIŅŠ UNIVERSITY AND 10TH CONGRESS OF BALTIC ASSOCIATION FOR MAXILLOFACIAL AND PLASTIC SURGERY 03-04 JUNE 2022 Poster Presentation EXPERIENCE OF BURNING MOUTH SYNDROME TREATMENT IN ORAL MEDICINE CENTER Guntars Selga, Viktors Jankovskis Oral Medicine Center, Riga Stradiņš University Institute of Stomatology Introduction. Burning mouth syndrome (BMS) is a state where patients experience a burning, scalding, painful sensation in the oral cavity, most often affecting the tongue, without a clear clinical presentation. It more often affects females after the age of 50. At the moment there are yet to be fully standarized and validated methods of diagnosis and classifications for BMS. Aim. The objectives were to gather data before and after treatment for patients with burning mouth syndrome using vitamin B complex and zinc supplements. Methods. Overall 98 patients took part in the study. Pain burning level was determined using Visual analogue scale, anxiety and depression levels – using Hospital Anxiety and Depression scale and salivary flow levels were determined before and after treatment. Results. Our data presents an increase of burning/scalding sensation throughout the day, from morning till evening with a score rising from 2.5 to 5 before the treatment and 1 to 3 after the treatment, but overall data shows lowered pain/burning sensation levels for more than 50% of the patients in all 3 time periods after receiving the treatment. Conclusions. Vitamin B and zinc supplement therapy shows an effective way to minimize pain/burning sensation levels among patients with BMS. 34 16TH JOINT SYMPOSIUM OF ROSTOCK UNIVERSITY AND RIGA STRADIŅŠ UNIVERSITY AND 10TH CONGRESS OF BALTIC ASSOCIATION FOR MAXILLOFACIAL AND PLASTIC SURGERY 03-04 JUNE 2022 Poster Presentation MANAGEMENT OF ANTLEY - BIXLER SYNDROME: A CASE REPORT Prof. Ģirts Šalms1, Dr. Agnija Tāluma1, Dr. Lana Mičko1 1Pauls Stradiņš Clinical University Hospital, Department of Oral and Maxillo Facial Surgery, Latvia Key words. Antley–Bixler syndrome, craniosynostosis. Introduction. Antley –Bixler Syndrome is a rare genetic disorder based on complex disturbance of craniofacial growth due to premature synostoses of the cranial base and vault. Both autosomal dominant and autosomal recessive inheritance are possible. It is characterized by many musculoskeletal, craniofacial anomalies, urogenital and cardiac malformations. We present a clinical case of Antley–Bixler syndrome patient with characteristic phenotype - midfacial hypoplasia, dysplasia of ears and nose, radiohumeral synostosis, upper airway obstruction and urogenital malformations -, necessitating multi-disciplinar management. Materials and methods. Patient was evaluated by multidisciplinar team, computed tomography was done. CT-scanning revealed premature synostosis of both coronal sutures as well as lambdoid and sagittal sutures. Surgical treatment consisted of anterior and posterior cranioplasty at age of 9 month, which was performed in Finland. Surgical treatment was continued by otopasty at age of 7 years. At age of 12 patient had impaired breathing. Le Fort III osteotomy was considered with RED distractor. Individual hemlet was designed and 3D printed for application of distractor pins. Results. Using surgical treatment was achieved satisfactory outcome. Due to succesful cranioplasty ICP remains in normal range and lead to age-related intellectual, psychomotoric and social development. After Lefort III osteotomy notable respiratory improvement was achieved, no apnoe epysodes. 20 cm of advancement was achieved – improved maxillar – mandibular relationship. There is remarkable improvement of facial easthetics, but still remains radix nasi region defect. Correction of the residual craniofacial deformity and jaw deformity by conventional orthognatic surgery is still required at the end of growth.Self confidence was improved. Conclusion. Craniomaxillofacial surgical correction in case of Antley –Bixler syndrome should be performed to compensate growth deficiency. Interdisciplinary treatment approach using modern craniofacial surgical techniques to Antley – Bixler Syndrome patients and could be used in similar syndromes with craniofacial involvement. 35 16TH JOINT SYMPOSIUM OF ROSTOCK UNIVERSITY AND RIGA STRADIŅŠ UNIVERSITY AND 10TH CONGRESS OF BALTIC ASSOCIATION FOR MAXILLOFACIAL AND PLASTIC SURGERY 03-04 JUNE 2022 Poster Presentation CASE REPORT OF LATE POST-TRAUMATIC ORBITAL WALL RECONSTRUCTION WITH INDIVIDUAL 3D PRINTED TITANIUM IMPLANT Associate professor Dalius Sakavičius, Vaidas Grimuta Department of Maxillofacial Surgery, Hospital of Lithuanian University of Health Sciences Kauno klinikos, Kaunas, Lithuania Aim. Purpose of these case report is to highlight the precision and accuracy obtained with patient specific implants for orbital reconstruction designed on the basis of 3d analysis of orbital computed tomographic scan (CT) using virtual planning, computerised designing, 3d printed stereo- lithographic models and 3d printed titanium orbita implants to correct late post traumatic orbital deformities which causes enophthalmos, diplopia and facial deformity. Material and methods. These 2 cases report describes a patients who came to our clinic for correction of enophthalmos, persistent diplopia in upward gaze and facial deformities, more than twelve months post trauma. Three dimensional (3D) virtual treatment planning was carried out by using the 3D CT data. The unaffected orbit of the contralateral side was superimposed on the deformed orbit to highlight the defect and a customized implant was designed in the desired size and shape on 3d planning program and they were printed with 3d printer for precise anatomic orbital reconstruction. Results. There was a marked improvement in the diplopia, in upward gaze, enophthalmos and facial deformities post surgery when the individual orbital implants printed with 3d technology was used. Conclusion. The concept of 3D virtual treatment planning, 3D stereolithographic models, individual printed with 3d printer titanium mesh implants, greatly improves the correction of extremely difficult late post- traumatic orbital deformities. 36 16TH JOINT SYMPOSIUM OF ROSTOCK UNIVERSITY AND RIGA STRADIŅŠ UNIVERSITY AND 10TH CONGRESS OF BALTIC ASSOCIATION FOR MAXILLOFACIAL AND PLASTIC SURGERY 03-04 JUNE 2022 Poster Presentation ORBITAL FLOOR FRACTURE: COMPLICATION FROM TITANIUM IMPLANT. A CLINICAL CASE Agnija Tāluma, Ieva Bāgante, Ģirts Šalms Pauls Stradiņš University Hospital, Rīga, Latvia Rīga Stradiņš University Institute of Stomatology Baltic Biomaterials Excelence centre Riga Technical University [email protected] Introduction/aim. Orbital floor fractures are a common result of orbital injury. Sequelae of orbital floor fractures include enophtalmus, diplopia, infraorbital nerve anaesthesia. Possible rare complication could be local spread of infection and granulation tissue or cyst formation around the implant. Titanium mesh and other alloplastic implants could encapsulate with a fibrous capsule. It can be due to sinus infection or haemorrhage. The aim was to present rare clinical case with complication from titanium mesh. Methods. A 51-year-old man presented to the Maxillofacial surgery department with complains of a bulge under left eye, exophtalmus and narrowed field of view. 3 years ago patient had undergone left orbital fracture repair with titanium mesh. A CT scan revealed well –defined round shape formation in left maxillary sinus and orbital floor 2,5x3x4cm in size. Intraorbital part of the formation is dislocating the eye ball cranially and lateraly. The treatment included removal of the titanium mesh and cyst around it. The orbital floor was not reconstructed immediately. After operation patient had enophtalmus and diplopia. The secondary orbital floor reconstruction was after 10 months with 3D orbital prototype printing and 3D planning with pre-bended titanium mesh. Results. After secondary orbital floor reconstruction there was no enophtalmus after 1 week, diplopia disappeared after 1 month. The patient was pleased with the cosmetic result. Conclusions. The secondary orbital floor reconstruction with 3D printing and 3D planning with pre- bended titanium mesh showed good functional and cosmetic results. It was useful tool, especially in secondary orbital floor repair. 37 16TH JOINT SYMPOSIUM OF ROSTOCK UNIVERSITY AND RIGA STRADIŅŠ UNIVERSITY AND 10TH CONGRESS OF BALTIC ASSOCIATION FOR MAXILLOFACIAL AND PLASTIC SURGERY 03-04 JUNE 2022 Poster Presentation ODONTOMAS AND SUPERNUMERARY TEETH IN LATVIAN ADOLESCENCE Dita Bisane1, DDS, Laura Neimane1,2, DDS, MSc, Dr Med 1RigaStradins University, Department of Conservative Dentistry and Oral Health 2Baltic Biomaterials Centre of Excellence, Headquarters at Riga Technical University, Riga, Latvia [email protected] Aim. To investigate the prevalence of supernumerary teeth and odontomas among 11–14-year-old Latvian adolescents attending Riga Stradins University Institute of Stomatology. Methods. A cross- sectional study of panoramic X-rays of 11–14-year-old adolescents taken between August and December 2020 was performed. Data of supernumerary teeth and odontomas were registered. IBM SPSS 27 was used for statistical analysis. Chi square tests were performed to assess association between supernumerary teeth, odontomas and gender. Results. A total of 1005 patients were analysed; 993 met inclusion criteria (M=12 years 11 months (SD=13 months)) with 404 males (40.7%, M=13 years (SD=14 months)) and 589 females (59.3%, M=12 years 11 months (SD=13 months)). Total prevalence of supernumerary teeth was 1.6% (N=16; 0.8% males, 0.8% females). No statistically significant difference was found between genders (p = 0.444). In 16 patients we found 19 supernumerary teeth, 57% of them were located in upper incisor area. 8 out of 19 teeth were not erupted. Total prevalence of odontomas was 0.4% (N=4; 0.1% males, 0.3% females) with no statistically significant difference between genders (p = 0.522). 2 out of 4 odontomas were associated with tooth impaction. There were two cases of concomitant supernumerary tooth and hypodontia and one case of odontoma impacting a supernumerary tooth. Conclusion. Prevalence of supernumerary teeth in our sample was 1.6 %. Prevalence of odontomas was 0.4 %. There was no statistically significant difference between genders. 38