Are temporomandibular disorders associated with facial asymmetry? A systematic review and meta‐analysis

Abstract

ObjectiveTo assess scientific evidence of the association between temporomandibular joint (TMJ) disorders and facial asymmetry (FA).MethodsA systematic review was performed in accordance with the PRISMA checklist. A search strategy was developed in electronic databases including MEDLINE, Scopus, Web of Science, Virtual Health Library and Cochrane Library until January 2020. Eligibility criteria included observational studies that investigated the occurrence of FA among patients with and without signs and symptoms of TMJ disorders. Risk of bias of individual studies was analysed after study selection and data collection processes according to Fowkes and Fulton guidelines. Four meta‐analyses (MA) were performed to evaluate the association between TMJ disorders and linear/angular menton deviation, subgrouping the studies into unilateral and bilateral cases. The evidence was certainty‐tested using the GRADE approach.ResultsThe search retrieved 2371 studies, 31 of which were eligible for full‐text reading. Seven cross‐sectional clinical studies met the eligibility criteria and were included in the qualitative synthesis, comprising a total of 621 subjects (345 with TMJ disease and 276 in control group), four of which were classified as being methodologically sound. Five studies were eligible for quantitative synthesis. Linear and angular menton deviation was greater in individuals with unilateral TMJ disorders than controls (MD = 2.41 [0.33, 4.50] P = .02; I2 = 86% and MD = 2.68 [0.99, 4.38] P = .002; I2 = 0%, respectively).ConclusionsDespite the low certainty in evidence, the present study indicated that unilateral TMJ disorders are associated with FA. However, longitudinal studies with greater certainty of evidence should be conducted to achieve a stronger estimate of this association.

Temporomandibular joint articular disc position and shape in skeletal Class III

“…36 Longitudinal studies with greater certainty of evidence should be conducted. 16 The articular disc is normally biconcave; therefore, changes in disc shape are attributed to internal TMJ disorders, and a disc that has lost its normal shape is more likely to be dislocated. 23 In the group with normal occlusion, no ADD was observed, and in 4 TMJs that 56 out of 60 TMJs (93.3%) had biconcave discs.…”

“…15 However, prospective and longitudinal studies are necessary to corroborate these findings. 16 Furthermore, conventional treatments, such as reverse maxillary protraction with or without mini-implants and chin cups, impact the TMJ. 14 Therefore, knowing the TMJ status, through physical examination and, eventually, by imaging tests, may provide information for diagnosis and treatment planning.…”

“…Disc displacement could be associated with changes in mandibular growth 15 . However, prospective and longitudinal studies are necessary to corroborate these findings 16 . Furthermore, conventional treatments, such as reverse maxillary protraction with or without mini‐implants and chin cups, impact the TMJ 14 .…”

Clinical relationship between maxillomandibular characteristics and temporomandibular disc conditions in female patients with a skeletal class III pattern

“…Among the various maxillomandibular classi cations in the sagittal facial planes, SKIII may be the one least related to articular disc displacement [18]. It is likely that a transversely deviated mandible is associated with articular disc displacement, given that clinical TMD symptoms are commonly seen in patients with skeletal facial asymmetry [19]. Therefore, in the present study, our objectives were to analyze the relationship between the antero-posterior and transverse maxillomandibular characteristics of SKIII patients and the patterns of disc conditions in the TMJ and to determine their relationship with the severity of TMD.…”

Optimal Use of a Panoramic Radiograph as a Screening Tool for Condylar Resorption in Patients Undergoing Active Orthodontic Treatment: A Case Series

“…[5] At the same time, there is enough evidence to support that internal derangements of TMJ can manifest altered craniofacial structures and may represent as facial asymmetry. [8][9][10][11][12][13][14] e cephalometric analysis in individuals with TMD as compared to control groups shows significant craniofacial differences. [11,[15][16][17][18][19][20] Panoramic radiographs are another readily available screening tool for observing condylar pathology.…”