Dentoalveolar development in subjects with normal occlusion. A longitudinal study between the ages of 5 and 31 years

TLDR

The study aimed to examine dentoalveolar development in individuals with ideal occlusion across ages 5 to 31. Using 436 dental casts from 436 Swedish subjects (189 male, 247 female) with no orthodontic history, the authors measured tooth width, arch dimensions, and palatal height and analyzed the data with Student’s t‑tests. Results showed continuous arch changes from primary to adult, with biological migration causing anterior crowding even in the mandible, a dynamic occlusion that must be considered in treatment planning, and a gradual increase in palatal height attributable to slow tooth eruption, which also explains implant crown infraposition.

Abstract

The aim of the present study was to examine dentoalveolar development in subjects with an ‘ideal’ (normal) occlusion. The material comprised 436 study casts of 189 male and 247 female subjects of Swedish origin between the ages of 5 and 31 years with no history of orthodontic treatment. Tooth width, and arch length, width, and depth, as well as palatal height were measured. The data were analysed with a Student's t-test. The results verified that continuous changes of the dental arches occur from the primary until the adult period, with individual variations. This change could be interpreted as a biological migration of the dentition, resulting in anterior crowding especially in the mandible, even in subjects with congenitally missing third molars. The occlusion should be regarded as a dynamic rather than a stable interrelationship between facial structures. This natural development has to be considered in orthodontic treatment planning as well as in assessment of stability following orthodontic treatment. A continuous increase of palatal height up to adulthood seems to be an effect of a slow continuous eruption of the teeth. This finding is also of significance in explaining the infraposition of implant-supported crowns.