Kalaitsidou, IoannaIoannaKalaitsidouGass, MathieuMathieuGassTatsis, DimitrisDimitrisTatsisKhalil, SherinSherinKhalilSchedeit, ChristianChristianSchedeitMarjanowski, Simon DavidSimon DavidMarjanowskiWiegner, SarahSarahWiegnerSchaller, BenoîtBenoîtSchaller2025-06-262025-06-262025-05-28https://boris-portal.unibe.ch/handle/20.500.12422/212057Background: Trismus, or restricted mouth opening, can present significant challenges in oral and maxillofacial surgery and trigger substantial functional and psychosocial disabilities. Intra-articular causes, such as temporomandibular joint ankylosis and arthritis, are thoroughly described; however, extra-articular pathologies like neoplastic, traumatic, infectious, and fibrotic conditions of adjacent soft and hard tissues are less frequently reported and present distinct diagnostic complexities and therapeutic hurdles. This retrospective study aims to investigate the difficulties encountered in diagnosis and surgical interventions associated with rare extra-articular causes of trismus. Material and Methods: This article describes five rare causes of extra-articular trismus. The cases range from benign pathologies like coronoid hyperplasia and osteomas to more complex diagnoses of myositis ossificans, external auditory canal abscess, and chronic osteomyelitis. A thorough diagnostic workup was performed for each patient, and specific surgical interventions were administered based on their pathology. Results: All five patients showed significant improvements in mouth opening after surgery. Diagnostic accuracy was ensured with advanced imaging modalities and innovative surgical techniques, and adequate postoperative care translated the favorable outcome. Conclusions: Although based on individual case descriptions, this study emphasizes the potential importance of early diagnosis, a multidisciplinary approach, and individualized treatment planning in managing rare extra-articular causes of trismus. These cases suggest a basis for a more organized system for the timely identification and treatment of such conditions. Additional research is needed to improve diagnostic accuracy, optimize surgical management, and develop evidence-based aftercare treatment to improve patient care and quality of life.enabscessear canalhyperplasiamyositis ossificansosteomaosteomyelitistrismus600 - Technology::610 - Medicine & healtharticle10.48620/888034050693210.3390/diagnostics15111360