ABSTRACT
Objective@#To study the effect of orthodontic traction on the roots and periodontal soft and hard tissues of buried obstructed upper incisors.@*Methods@#This study was reviewed and approved by the ethics committee, and informed consent was obtained from the patients. From January 2018 to December 2022, 40 patients who underwent orthodontic traction on impacted upper incisors were selected; those whose contralateral homonymous apical foramen was not developed were placed in group A (23 cases), and those whose contralateral homonymous apical foramen was developed were placed in group B (17 cases). Software was used to measure the root length of the impacted upper incisors in groups A and B on cone beam CT (CBCT) images before and after traction and compare the changes in alveolar bone (alveolar bone width, labral bone plate thickness, and horizontal height of alveolar bone) and keratinized gingival width between each impacted upper incisor and the corresponding contralateral tooth immediately and one year after traction@*Results@#The root length of the impacted upper incisors increased after traction compared to before traction (P<0.05). The width of the alveolar bone at the completion of traction in group A was similar to that of the contralateral homonymous tooth (P>0.05), whereas the width of the alveolar bone at the completion of traction in group B did not reach that of the contralateral homonymous tooth, with a significant difference in width (P<0.05). Neither the labial bone plate height or width in group A or B reached that of the contralateral homonymous tooth after traction (P<0.05). The keratinized gingival width on the affected side was also significantly smaller than that on the contralateral side (P<0.05), but it was increased significantly in group A at the one-year follow-up visit (P<0.05).@*Conclusion@#Tooth traction is conducive to impacted upper incisor root growth, alveolar bone reconstruction and keratinized gingival growth but cannot produce complete symmetry with respect to the contralateral side.
ABSTRACT
PURPOSE: To evaluate the morphology and position of condyle and fossa and joint space of adolescent temporomandibular joint with Class â ¡ subdivision malocclusion, in order to provide a reference for diagnosis before treatment. METHODS: The study sample consisted of 30 adolescent patients with Class â ¡ subdivision malocclusions(9 males, 21 females, mean age 12.5 years) as the experimental group and 30 adolescent patients with Class â 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 â ¡ 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<0.01). In Angle Class â malocclusion patients, there was no significant difference in joint fossa morphology, condyle morphology and condyle position between right side and left side (P>0.05). CONCLUSIONS: There may be differences in condyle position, condyle shape and joint fossa shape between patients with Class â ¡ subdivision malocclusions and Class â malocclusion patients. More attention should be paid to the temporomandibular joint in initial clinical examination and clinical orthodontic treatment.
