Cephalometric study on the influence of vertical traction of teeth on maxillofacial bones in young dogs.

Abstract

The influence of one-sided vertical traction of teeth on maxillofacial bones was investigated using cephalometric radiographs and tetracycline-labeling in young dogs. On the frontal view of the dry skull, traction resulted in a downward distortional deformity of the maxilla including the nasal floor. Cephalometry of radiographs revealed a downward displacement of the upper premolar and incisor teeth, medial maxillary region, and alveolar process of molar, canine and incisor on the right side, where traction was applied. Displacement was from 2.2 +/- 0.4 (mean +/- S.D.) mm at P3 to 0.8 +/- 0.2 mm at I1. In the control group without traction, it was 0.0 +/- 0.0 at P3 and 0.2 +/- 0.1 at I1. Tetracycline-labeling disclosed, in the frontal cut surface of maxillofacial bones at P3, that traction affected not only the periodontal tissue and alveolar processes, but also the neighboring bones and midpalatal suture. The ratio of the labeled area in the bone, measured using an image analyzer in 6 sectors of the cut surface, was 1.2 +/- 0.3% in the left upper sector to 13.0 +/- 4.3% in the right lower sector. In the control group, it was 1.2 +/- 0.4% in the left upper and 4.8 +/- 1.1% in the right lower sector. In conclusion, vertical traction of teeth induces a vertical deformation of the maxilla.