Alveolar and skeletal dimensions associated with lower face height.

In this study, the relationships between the lower face height and the structure of the frontal alveolar and basal bone were investigated. The areas and the dimensions of the anterior alveolar and basal midsagittal cross-sectional bone from the maxilla and the mandible were recorded on lateral cephalograms from 460 untreated adults. An index was calculated dividing the sagittal by the vertical dimension of the midsagittal cross-sectional area. The subjects with a normal overbite between 0.5 and 4 mm (N=165) were divided into three groups according to the lower face height. A larger lower face height coincided with a larger maxillary alveolar and basal area and with a smaller mandibular alveolar index. Correlations between the lower face height and the maxillary alveolar index and the mandibular alveolar and basal area were low. It is concluded that long-faced subjects have a large mandibular alveolar height, which is more associated with a narrowed shape than with a large volume of the symphysis.