An evaluation of cross-bite ridge relationships. A study of articulated jaw records of 150 edentulous patients.

Data were collected from 150 men and women complete-denture patients. Their jaw records were evaluated with a specially designed instruments. The extent of deviation of the maxillary and the mandibular ridges in the horizontal plane was calculated at various interridge distances, at a constant interalveolar crest-line angle of 80 degrees. It was found that: 1. Most patients of both sexes revealed a normal horizontal ridge relationship. 2. Next to the normal ridge relationship, there was a tendency for a unilateral cross-bite ridge relationship on the left sides of those patients who had recent extractions (up to 6 months previously). 3. True bilateral cross-bite ridge relationships were found only in those patients who gave a history of prolonged edentulousness. 4. The decision to arrange the posterior teeth in normal or cross-bite ridge relationship should take into consideration the deviations in the ridge relationship as well as the interridge distance. A method of evaluating interridge deviations in the horizontal plane in the posterior region of articulated jaw records of edentulous patients was developed.