The purpose of this study was to evaluate, using dental, skeletal and soft tissue cephalometric analyses, a group of Class III patients clinically diagnosed as maxillary deficient and treated with orthognathic surgery. The preoperative cephalograms of 50 patients treated with maxillary advancements were hand-traced by the same operator. Cephalometric analyses were performed and mean values for each measurement were compared with the norms using t test for a mean ( p < 0.05). Results showed an increased inclination of the upper incisors was found, with a mean U1-NA angle of 27.58° and a mean U1-PP angle of 116°. Lingual inclination of the lower incisors was also observed, with a mean L1-NB angle of 22.53° and a mean IMPA of 83.13°. 70% of patients presented labial inclination of the upper incisors, and 56% presented lingual inclination of the lower incisors. Results also showed significantly increased values for anteroposterior measurements of the mandible, such as mandibular length, Pg-NPerp and SNB. In male patients, maxillary length and Nperp-A were decreased, while in female patients NPerp-A was similar to the normative value. SNA was normal in both genders. Soft tissue measurements suggested normal antero-posterior position of the maxilla and an anteriorized mandible in both genders. In conclusion: (1) remaining dental compensations were found in most patients and the lower incisors were more frequently decompensated than the upper incisors; (2) most skeletal and soft tissue cephalometric measurements showed little correlation with the clinical diagnosis and actual surgery performed in this sample of Class III patients.

Conflict of interest : None declared.