Comparative study of TMJ for adolescent Angle II1 patients before and after Twin-block treatment

Abstract

Objective The aim of this study was to explore the changes of the skeletal structure of temporomandibular joint (TMJ) and the condyle-fossa relationships in teenage orthodontic patients with class Ⅱ1 malocclusions before and after twin-block treatment by using cone-beam computered temography (CBCT) and Anatomage Invivo5 software, thus further understand the twin-block treatment's effects on morphology and structure of TMJ. Methods Twenty-seven class Ⅱ1 malocclusions patients with mandibular retrusion were included in this study. They were at or just before the peak phase of pubertal growth, and were scanned by CBCT before and after the Twin-block treatment. The three-dimensional images were reconstructed with Anatomage Invivo5 software, and linear and angular parameters were measured. Paired t-test was used. Results Condylar anterior-posterior diameters and condyle height increased after treatment in both sides, and showed statistical significance (P 0.05), and about parameters of joint space(P>0.05). Conclusions Twin-block can stimulate condylar reconstruction by increasing condylar anterior-posterior diameters and condyle height in adolescent patients with class Ⅱ1 malocclusions. The changes of glenoid fossa of temporomandibular joint and the condyle-fossa relationships have no significant differences before and after Twin-block treatment. Key words: CBCT; TMJ; Class Ⅱ Division 1 malocclusion; Twin-block