Occlusal stability in shortened dental arches

Shortened dental arches consisting of anterior and premolar teeth have been shown to meet oral functional demands. However, the occlusal stability may be at risk as a result of tooth migration. The aim of this nine-year study was to investigate occlusal stability in shortened dental arches as a func tion over time. Occlusal stability indicators were: 'interdental spacing', 'occlusal contacts of anterior teeth in Intercuspal Position', 'overbite', 'occlusal tooth wear', and 'alveolar bone support'. Subjects with shortened dental arches (n = 74) were compared with subjects with complete dental ar ches (controls, n = 72). Repeated-measurement regression analyses were appl ied to assess age-dependent variables in the controls and to relate the occ lusal changes to the period of time since the treatment that led to the sho rtened dental arches. Compared with complete dental arches, shortened denta l arches had similar overbite and occlusal tooth wear. They showed more int erdental spacing in the premolar regions, more anterior teeth in occlusal c ontact, and lower alveolar bone scores. Since the differences remained cons tant over time, we conclude that shortened dental arches can provide long-t erm occlusal stability. Occlusal changes were self-limiting, indicating a n ew occlusal equilibrium.