Validity of the computer-assisted cephalometric growth prognosis VTO (Visual Treatment Objective) according to Ricketts.

Abstract

The computer-assisted growth prognosis "Visual Treatment Objective" (VTO) according to Ricketts gives an individual prediction based on empirically obtained mean growth rates and includes the expected influence of orthodontic treatment. The objective of the present study was to investigate the validity of the VTO over a period of 2 and 5 years. For this purpose, lateral teleradiographic images of 180 patients were analyzed before the start and after the completion of active treatment, and the actual outcome was compared with the prognosis. For both prognostic periods, the VTO yielded a satisfactory prognosis of maxillary inclination, of the anteroposterior position of the maxilla, of growth in mandibular length, of the anteroposterior position and rotation of the mandible, of the positional relation of the mandible and maxilla, of basicranial configuration, and of vertical craniofacial development. For neither of the 2 prognostic periods did the VTO give a satisfactory prognosis of dental relations, of dentoskeletal relations or of soft-tissue configuration. The VTO is capable of giving a largely valid prognosis of skeletal growth tendencies. However, in view of the large number of parameters affected by therapeutic measures, the VTO prognosis must be expected to differ from the actual treatment outcome.