Evaluations of the morphology and position of condyle and fossa of adolescent temporomandibular joint with Class IIsubdivision malocclusions

Purpose To evaluate the morphology and position of condyle and fossa and joint space of adolescent temporomandibular joint with Class Ⅱ subdivision malocclusion, in order to provide a reference for diagnosis before treatment. Methods The study sample consisted of 30 adolescent patients with Class Ⅱ subdivision malocclusions(9 males, 21 females, mean age 12.5 years) as the experimental group and 30 adolescent patients with Class Ⅰ malocclusions (11 males, 19 females, mean age 12 years) as the control group treated from June 2018 to December 2019 in Suzhou Stomatological Hospital. The long axis of condyle, short axis of condyle, the distance from the outer pole of condyle to sagittal midline, horizontal angle of condyle, Joint space(medial, inner, outer, anterior, superior, posterior), vertical height of condyle, width of joint fossa, depth of joint fossa, angle of posterior wall of the articular tubercle and vertical distance of bilateral condyle to horizontal line were measured on cone-beam CT(CBCT) images and analyzed with Dolphin Imaging 11.95. SPSS 23.0 software package was used for statistical analysis of the data. Results In Angle Class Ⅱ subdivision malocclusion patients, there were significant differences in posterior joint space, horizontal angle of condyle, vertical height of condyle, width of joint fossa, depth of joint fossa and angle of posterior wall of the articular tubercle between neutral side and distal side(P 0.05). Conclusions There may be differences in condyle position, condyle shape and joint fossa shape between patients with Class Ⅱ subdivision malocclusions and Class Ⅰ malocclusion patients. More attention should be paid to the temporomandibular joint in initial clinical examination and clinical orthodontic treatment.