Date of Graduation


Document Type


Degree Type



School of Dentistry



Committee Chair

Peter Ngan

Committee Co-Chair

Chris Martin

Committee Member

Bryan Weaver


Introduction: Class II malocclusions can be treated with appliances such as the pendulum appliance or distal jets to distalize maxillary molars to achieve a Class I molar relationships. It is not clear in the literature whether these clear aligners can distalize maxillary molars, dental tipping, or translation. The objective was to evaluate the dental and skeletal changes in three planes spaces using CBCT scans and compare the treatment changes with a control group of subjects. Methods: Eight Class II division 1 malocclusions patients treated with maxillary molar distalization using clear aligners. Twelve molars were evaluated for tooth movement in three planes of space using CBCT scans. Patients were compared with a control group of untreated subjects from the Bolton Brush study; matched in craniofacial morphology, gender, and treatment length. Sagittal and vertical changes were measured using the Pancherz analysis (Pancherz, 1982). Transverse changes were measured by intermolar widths of the maxillary and mandibular molars. Results: Significant sagittal changes were found with the change in molar relationship (-2.3mm), forward movement of the mandibular incisors (+3.4mm), and mandibular molars (+3.6mm). The treatment changes were compared to control subjects, significant differences were found with the mesial movement of the maxillary molars (0.5mm vs. 5.0mm, Conclusions:Significant dentoalveolar changes including restraint in the forward movement of the maxillary molars can be expected with sequential molar distalization with clear aligners.