Relationship between molar dentoalveolar and craniofacial heights in children.

OBJECTIVES The relationship between posterior dentoalveolar heights and craniofacial vertical pattern has been matter of debate. Increased posterior dentoalveolar heights have been reported to be present in long face subjects, while in few studies the amount of molar dentoalveolar heights was negatively influenced by the divergence of the jaws. This, in turn, was interpreted as a dentoalveolar compensatory mechanism by which the teeth and the alveolar process adapt to jaw relationship in order to maintain a functional occlusion. Although this dentoalveolar compensatory mechanism has been reported to be present in adults and in subjects with permanent dentition, currently it is not known whether it might occur also in an early phase of growth, i.e. before growth spurts. In this study we tested the hypothesis that a dentoalveolar compensatory mechanism is absent in children with still unexpressed vertical growth potential. METHODS AND MATERIALS Cephalometric measurements obtained from 79 children younger than 9 were entered as independent variables in a multiple regression model. Maxillary and mandibular molar dentoalveolar heights were entered as dependent variables. RESULTS Approximately 54% of the total variability was explained by the variability in anterior lower facial height (ANS-Me) and mandibular palatal plane angle (PP-MP). Both maxillary and mandibular molar dentoalveolar heights were significantly influenced by the length of the anterior lower facial heights as measured by ANSMe, and by the mandibulopalatal plane angle (PP-MP). Increases of ANS-Me and PP-MP had opposite effects on the amount of molar dentoalveolar heights. CONCLUSION The findings suggest that an inverse relationship between posterior dentoalveolar heights and jaw divergence is already present when the vertical growth is stil incomplete.