Cephalometric evaluation of the short-term skeletal, dental and soft tissue changes in subjects with class II division 1 malocclusion treated with Invisalign® with mandibular advancement feature

Abstract

Aim: The aim of this study was to evaluate the short term skeletal, dental and soft tissue changes in growing subjects with Class II division 1 malocclusion treated with Invisalign mandibular advancement. Materials and methods: This was a retrospective study conducted on 15 growing subjects with Class II Division 1 malocclusion treated with Invisalign® Aligners with Mandibular Advancement Feature. Pre-treatment and post-treatment lateral cephalograms were collected from the Online Align Global Gallery and were traced using Dolphin Imaging Software. Paired Sample t-test was used to compare the measurements before and after treatment. Results: The average number of aligners used was 63.8 maxillary aligners and 61.47 mandibular aligners within a mean duration of 17.73 months treatment time. Statistically significant differences were observed in the ANB angle, facial convexity, and SNB angle in direction of Class II correction. Statistically significant changes were also seen in the interincisal and nasolabial angle. Counterclockwise rotation of the mandible was evident with decrease of mandibular plane to SN angle (mean difference -1.11 degrees; CI, -2.18 – -0.04 degrees). The upper incisors were retroclined (mean difference -7.03 degrees; CI, -10.94 – -3.11) while the lower incisors showed no significant changes after treatment. Conclusions: Invisalign® mandibular advancement was effective in treating mandibular retrusion with improvement in the anteroposterior jaw relationship, with good control of the vertical component and lower incisors inclination, and improvement of facial convexity and upper lip protrusion.