Dentoalveolar compensation in negative overjet cases.

The purpose of this study was to investigate dentoalveolar compensation in negative overjet cases. Eighty-eight adult females with either skeletal Class I or skeletal Class III jaw relationships were examined. Of the total, 44 cases showed anterior crossbite and the remaining 44 cases had normal incisor relationships. Four cephalometric parameters were measured: the sagittal jaw relationship, maxillary and mandibular incisor inclination, and the occlusal plane angulation. In the negative overjet cases, correlation analysis was performed between the skeletal and dental measurements. Stepwise discriminate analysis was carried out to separate the negative and normal overjet cases. Compensatory changes for sagittal jaw discrepancies in the negative overjet cases were statistically confirmed for both incisor inclination and occlusal plane angulation. However, the compensatory effects were weaker than in the normal overjet cases. The discriminate analysis successfully separated the normal and negative overjet cases, suggesting that negative overjet results from insufficient dentoalveolar compensation for variations in the sagittal jaw relationships.