A 6-year follow-up study of oral function in shortened dental arches. Part I: Occlusal stability.

In this clinical 6-year follow-up study subjects with shortened dental arches (SDA, n = 55), characterized by the absence of molar support, are compared with subjects with complete dental arches (CDA, n = 52) with respect to occlusal stability. In addition, a small group of subjects with SDA and removable partial dentures in the lower jaw (SDA+RPD, n = 19) is included in this study. The aim of this study was to describe effects regarding occlusal stability in subjects with SDA during a 6-year period. The applied parameters for occlusal stability are: number of occlusal contacts in the anterior region, overbite, interdental spacing and alveolar bone support. The results of this study show that: (i) SDA do provide durable occlusal stability; (ii) free-end RPD do not contribute to occlusal stability in SDA; and (iii) SDA with periodontally involved teeth show continuing periodontal breakdown.