A Morphometric Analysis of Intra-Articular Disc of Temporomandibular Joints in Cadavers

Abstract

Introduction: Temporomandibular Joint (TMJ) has been a controversial topic in Oral and Maxillofacial Surgery speciality especially regarding temporomandibular joint disorders and internal derangement of articular disc. The aetiology behind it has been related to the anatomic variations of the disc and its impact on the functioning of the articular disc. To understand such anatomic variation, the study has been conducted that will help future maxillofacial surgeon’s in designing accurate prosthetic articular disc that will improve the overall mechanics of the functioning of the prosthetic disc. Aim: To analyse the morphometric variations of the intraarticular disc in terms of circumference of the disc, perforations and their thickness within the disc in cadavers. Materials and Methods: The present observational study was carried out on cadavers in the Department of Anatomy. SBKS Medical College and Research Centre, Sumandeep Vidyapeeth University, Gujarat, India. The study was done from January 2017 to October 2018. Temporomandibular joints were dissected bilaterally from 10 human cadavers, i.e., 20 articular discs. The disc was removed and was measured with the help of thread, vernier callipers and standardised metallic scale and the circumference and thickness in the disc were evaluated. Descriptive statistical test was used and Chi-square test was applied. Results: Mean thickness of disc, both in males as well as females ranged from 1.4-2.0 mm in the Posterio-Medial (PM) and Posterio-Lateral (PL) region, while in Anterio-Medial (AM) and Anterio-Lateral (AL) region it ranged from 1.6-1.8 mm. Maximum length of disc ranged from 12-13 mm in anterioposterio dimension while in Medio-Lateral (ML) it was 22-23 mm. Conclusion: The study gives an indepth knowledge about the various morphometric variations of articular disc and also shows its impact on the functioning of the disc. The study also directs maxillofacial surgeons to design prosthetic articular disc with greater accuracy and anatomical knowledge so that the procedures like surgical replacement of the disc can be carried out with greater potency and efficacy for the betterment of the patient.

Keywords

• articular surface variations
• bilateral diarthroidial joint
• perforations
• thinning of disc