Adult Dentition in Relation to the Palate and the Cranium: Reference from the head length and the head breadth

The purpose of this study was to elucidate the relation of dentition to the palate and the cranium in Japanese adults to serve as fundamental material for considering the morphology of dental arch well fitted to each person. In 168 Japanese male adults with no history of orthodontic treatment (mean age of 25 years and 5 months), the dental arch length and width, basal arch length and width, palate depth and volume as well as biometric head length and breadth were measured using a set of dental casts. From the determined values thus obtained, the correlative coefficient was calculated and tested for comparison. The results of this study reveal as follows : 1. The maxillary arch length and the width of inter-1 st molars tended to become larger with more deepened palate, indicating a tendency of larger volumes of the palate. 2. The larger the head length was, the larger the width of inter-maxillary 1 st molars became. 3. The larger the head breadth was, the larger the width of inter-1st molars of both arches became. 4. The maxillary protrusion tended to have a larger head length as compared with the mandibular protrusion. From the results mentioned above, the dentition was revealed to closely relate to the palate and the cranial size, and it was thus suggested that not only the harmonized size of the tooth and alveolar base but also the cranial size should be considered when the teeth are aligned.