Craniofacial morphology of skeletal class III patients before treatment and growth-related changes during treatment with a maxillary protraction appliance: a comparison of orthodontic and surgical cases.

ABSTRACT

AIMS: To examine differences in the craniofacial morphology of skeletal Class III patients before treatment and growth-related changes during treatment with a maxillary protraction appliance (MPA) between patients who were treated only orthodontically (orthodontic group) and those who eventually received orthognathic surgery (surgical group). METHODS: The orthodontic and surgical groups consisted of 6 boys and 9 girls and 4 boys and 6 girls, respectively. Lateral cephalograms taken at the first visit and at the end of treatment with the MPA were measured. The Mann-Whitney U test and Wilcoxon signed-rank test were used. RESULTS: Before treatment, the Wits appraisal was significantly smaller and the gonial angle was significantly larger in the surgical group. During treatment, both the SNA and ANB angles were significantly increased in the orthodontic group, whereas only the SNB angle was significantly increased in the surgical group. Moreover, significant lingual inclination of the mandibular incisors was found in the orthodontic group. CONCLUSION: The Wits appraisal and gonial angle were useful for distinguishing between the two groups at the first visit. Facilitation of forward maxillary growth, modification of the direction of mandibular growth, and lingual tipping of the mandibular incisors may be important ways to avoid orthognathic surgery.