Dentition, Bone Loss, and the Aging of the Mandible

Abstract

Facial aging is a dynamic process with impact on both the soft tissues and the bones. Despite a growing body of evidence, controversy still exists regarding absolute characteristics of the aging facial skeleton. The purpose of this study was to investigate various mandibular measurements in different age groups and to delineate the relation of the dentition to these parameters. Ninety Caucasian mandibles were assessed for the following distance landmarks: gonion-gonion, infradentale-gnathion, mental foramen-mandibular crest, mental foramen-inferior mandibular border, gnathion-gonion, condyle-gonion, and gonial angle. The measurements were compared according to age, sex, and dentition. The number of teeth decreased significantly with increasing age in males (P = .002) and females (P < .001). There were no other statistically significant differences between age groups for the rest of the parameters. The infradentale-gnathion distance (P = .005) and the mental foramen-mandibular crest distance (P < .001) was found to increase with total number of teeth. Other parameters did not show a significant relation to dentition. All parameters were significantly larger in the male subgroups with the exception of gnathion-gonion distance and gonial angle. Bilateral mandibular measurements were symmetric except for the gonial angle, which was more obtuse on the right side in males (P = .007) and females (P = .018). Our findings support previous evidence that dentition is the main determinant of the morphology of the mandible. The skeletal characteristics are variable among individuals, and a longitudinal study is required to better understand age-related changes of the mandible.