Roentgen stereometry in the study of craniofacial anomalies--the state of the art in Sweden.

The paper is a review of ten years' experience with the method for Roentgen Stereophotogrammetric Analysis (RSA) which was presented by Selvik in 1974. The RSA was developed for the study of bone displacement in three dimensions and intended for clinical use. The accuracy of the recordings is about 0.1 degrees for rotations about and 0.05 mm for translations along any one of the three cardinal axes of the head. The method, based on the use of metallic implants, is essentially individual. Some results from our stereometric studies of patients with cleft lip and palate, hemifacial microsomia, craniofacial dysostosis (Crouzon syndrome) and dysgnathia are presented. The recordings concern the direction, the rate, and the amount of articular growth in the craniofacial sutures and the temporomandibular joints (TMJs). The information obtained is thus highly relevant to treatment planning and follow-up in craniofacial anomalies.