Impact of surgically assisted rapid mandibular expansion on the temporomandibular joint - A retrospective study

This study evaluates the impact of tooth-borne Surgically Assisted Rapid Mandibular Expansion (SARME) on the temporomandibular joint (TMJ) function and condylar morphology. Medical records of patients who received a SARME between 2014 and 2018 are retrospectively reviewed concerning functional problems. Morphological changes of the condyles are analyzed by means of surface registration of 3D reconstructed CBCT scans preoperatively and one-year postoperatively, and correlated to functional outcome. In 68 patients data are complete. The risk of TMJ dysfunction is slightly increased from 18 to 25% at a mean of 14 months after SARME. This is attributed to an increase in the number of minor problems (75-82%). The presence of complaints before SARME is the only identifiable risk factor for also having complaints after the intervention (p = 0.0019). In one patient with pre-existent TMJ dysfunction complaints deteriorated after SARME. After SARME no cases of extended condylar resorption are described. There is no correlation between morphological condylar changes and the prevalence of TMJ dysfunction (p = 0.7121 for appositional and p = 0.3038 for resorptive changes). However, appositional and resorptive changes at the condylar head appear to correlate with growth potential, based on age, gender and skeletal deformity (p < 0.0001 and p = 0.0154 respectively). Within the limitations of the study it seems that SARME does not have a negative impact on TMJ function or condylar integrity and, therefore, the choice for or against this approach can be made without considering consequences for TMJ a major issue for the decision.