Changes in the vertical position of the anterior teeth after surgical correction of mandibular protrusion.

A group of patients who had undergone an oblique vertical ramus osteotomy for correction of mandibular protrusion was examined 2 years postoperatively in order to clarify whether the treatment resulted in vertical changes of the front teeth. 1. The results indicate an extrusion of both the upper and lower anterior teeth, as the distance from the upper and lower incisors to the NL and ML lines increased postoperatively (0.3 to 2.3 mm.). 2. The clinical crown height increased (0.3 to 0.4 mm.). 3. The root length decreased (0.5 to 0.9 mm.). 4. There were only insignificant changes in the height of the interproximal marginal bone. 5. There was no significant correlation between the changes in crown height and the amount of tooth extrusion; nor was there any correlation between these changes and the changes in mandibular inclination or root length reduction.