Jacobs Journal of Anatomy and Physiology

The Incidence of Temporomandibular Joint Structural Abnormalities in Orthodontic Pretreatment Patients

Published on: 2017-03-21


Objectives Structural variations of the temporomandibular joint (TMJ) will affect orthodontic treatment. So we analyzed common issues of TMJ structure among patients with different types of malocclusions. Methods 312 orthodontic pretreatment patients were randomly selected as subjects. Conventional anteroposterior and lateral cephalometric radiographs, panoramic radiographs, TMJ magnetic resonance images were obtained and the subjects’ TMJ structures were assessed. Results Among all the 312 pretreatment patients, 206 patients (66.03%) presented with TMJ structural variations, and for male patient Class I patients, 72.97% of skeletal Class II patients, 64.04% of skeletal Class III patients. Horizontal analysis indicated that a varied TMJ structure was present in 78.18% of patients with mandibular deviation to the left, 60.87% of patients without mandibular deviation, 85.19% of patients with mandibular deviation to the right. Vertical analysis revealed that a varied TMJ structure was present in 77.12% of high-angle patients, 56.88% of average-angle patients, 70.59% of low-angle patients. Conclusions TMJ structural variations were present in a high proportion of orthodontic pretreatment patients. Although most of these patients did not present clinical symptoms, orthodontists should pay more attention to such potential risk.


Orthodontic, Temporomandibular Joint, Malocclusion, Structural Variations