Morphological changes in temporomandibular joint dysfunction and effectiveness of different treatment methods

Abstract

Objectives: Temporomandibular joint dysfunction (TMD) results in changes in anatomical structures. The aim of this study was to examine the morphological changes using magnetic resonance imaging (MRI) and evaluate the effectiveness of different treatment methods in patients with TMD. Methods: 34 TMD patients (18–62 years of age) were randomly divided into two treatment groups. Group A (n=18) was subjected to dry needling (DN) and mobilization for 10 sessions, Group B (n=16) was instructed to use occlusal splint with home exercises for one month. The control group included MRIs of 17 healthy adults that were randomly selected from the archives of Radiology Department of Mustafa Kemal University. The length and width of the masseter, lateral and medial pterygoid muscles and the depth of the mandibular fossa were measured and mandibular condyle types were recorded. Range of motion of each temporomandibular joint was evaluated in pre- and post-treatment periods to test the effectiveness of the treatment methods. Results: The size of the masticatory muscles in TMD group was significantly smaller than the control group (p<0.05). The depth of the mandibular fossa was significantly shallower in the TMD group (p<0.05). The most commonly encountered condylar shape was convex in the TMD group (63.6%), but flat (58.8%) in the control group. No statistically significant relationship was observed between condyle type and fossa depth (p>0.05). However, the fossa depth showed a significant correlation with muscle size (p<0.05) and this correlation decreased with dysfunction. Dry needling and mobilization significantly decreased pain and increased mandibular movements (p<0.05); however, there was no significant change for Group B. Conclusion: The anatomical structures associated with the temporomandibular joint seems to be affected in patients with TMD. We suggest that the limited movement of the temporomandibular joint may cause atrophy of the masticatory muscles, affecting the range of motion of the joint. Dry needling and mobilization techniques might be a more effective alternative than occlusal splint in the treatment of TMD.

Correlation Between the Masticatory Muscle Dimensions and Internal Derangement of Temporomandibular Joints Based on Magnetic Resonance Imaging

“…All masticatory muscle dimensions were significantly greater in males than females (P < 0.05), except for the width of the medial pterygoid muscle (P = 0.064), which suggested no sex differences. According In this regard, Duman et al (17) reported that the length and width of the masticatory muscles reduced dramatically in TMD patients, resulting in muscular atrophy, which might cause limited jaw mobility. Due to restricted jaw mobility, the masticatory muscles may no longer operate within their normal range, leading to their long-term atrophy.…”

“…The medial pterygoid muscle was also evaluated using the coronal T1W sequence by measuring its height and width (Figure 2). Besides, the lateral pterygoid muscle (superior and inferior heads) was evaluated by measuring its height and length in the sagittal T1W closed mouth position (Figure 3) (17). To increase the reliability of measurements, they were repeated twice and reexamined for possible associated anatomical features in the sagittal T2W sequence.…”

“…The relationship between joint structures and ID has been investigated in several studies, with contradictory results reported in different populations. Some studies reported a reduction in the dimensions of the masticatory muscles in TMD patients, while some others reported their hypertrophy in patients with ID (14,(16)(17)(18).…”

Use of &#8220;Bicondylar&#8221; as a Descriptive Term for the Temporomandibular Joint: A Scoping Review

“…The temporomandibular joint (TMJ) is the joint between the mandibular condyles with the mandibular fossa and the articular tubercle of the temporal bone (Duman et al, 2020). TMJ is a ginglymoarthrodial joint formed by the glenoid fossa of the temporal bone and the mandibular condyle; it is a composite anatomical joint that allows both hinge motion (inferior joint between the articular disc and condyle) and gliding motion (superior joint between articular disc and temporal bone) (Moore et al, 2014;Baral et al, 2020).…”

“…A bicondylar joint is usually considered when two convex surfaces slide together, as it happens in TMJ and the knee joint (Sakul et al, 2019). However, the term "bicondylar" is used in multiple contexts in the current scientific literature reporting dissimilar forms and disagreements in the correct use of the term; while for some authors this term refers to two ellipsoidal condyles facing each other in the same joint (Sakul et al, 2019;Meyvaci et al, 2020), for others "bicondylar" refers to a TMJ is composed by right and a left condyle (Pai et al, 2019;Duman et al, 2020;Veras et al, 2021).…”