The relations between alveolar ridge and the teeth located in neutral zone.

The neutral zone is defined as the area where the forces of the tongue pressing outward are neutralized by the forces of the cheeks and lips pressing inward. In this study records of neutral zones of 30 edentulous patients were used to establish the relation between teeth arrangement according to neutral zone principles and teeth arrangement according to crest of ridge. These 30 patients were classified according to their ages, edentulous periods and denture experience. The results have shown that the lower molars were positioned a little bit closer to lingual with respect to crest of ridge; premolars were positioned either close to crest of ridge or they were coincided on it. In the anterior zone, the teeth were in accordance with known principles of positioned of anatomic landmarks.