Cephalometric Evaluation of Maxillary Incisors Inclination, Facial, and Growth Axes in Different Vertical and...

The aim of this study was to evaluate the inclination of the maxillary incisors (I), facial axis (FA), and growth axis (GA) in different vertical and sagittal patterns.

A total of 498 consecutive orthodontic patients, with an average age of 18.87 years (range = 5-63 years), were grouped based on their vertical and sagittal patterns. Maxillary incisors, FA, and GA axes were traced and their corresponding angles to nasion-basion and true horizontal lines were measured. The sample was divided into three groups based on the mandibular divergence (mandibular plane-MP/sella-nasion [SN]): Group 1-hypodivergent pattern (MP/SN ≤ 27; n = 30), Group 2-normodivergent pattern (27 < MP/SN <37; n = 254), and Group 3-hyperdivergent pattern (MP/SN ≥ 37; n = 214); the sample was then divided into three groups based on the sagittal pattern (ANB, angle between points A, Nasion and B): Group I-skeletal CLI (Class I) (0 n = 228), Group II-skeletal CLII (ANB ≥ 4; n = 216), and Group III-skeletal CLIII (ANB ≤ 0; n = 54). Group differences were evaluated using the analysis of variance and post hoc tests. Chi-square tests were used for testing relationships between categorical variables.

FA/nasion-basion (NBa) and GA/NBa were different among the vertical groups (P < 0.001). FA/NBa was found significantly different in the sagittal groups, whereas GA/NBa was only different between CLII and CLIII groups. Compensation in maxillary incisors' inclination was present in the sagittal groups, but not in the vertical ones. CLI patients when stratified in vertical groups showed FA/NBa and GA/NBa to be different across the three vertical groups.

FA/NBa was found different in the vertical and the sagittal groups. Maxillary incisors compensation was only found in the sagittal and not in the vertical groups.