Importance of vertical dimension and cant of occlusal plane in craniofacial development
PURPOSE: In order to examine the relationship between the vertical dimension change and the growth of the maxillo-facial complex in the mixed dentition, we applied a denture frame analysis including the measures of vertical dental and skeletal height, and maxillo-mandibular growth. MATERIALS AND METHODS: The materials used in this study consisted of 225 pair of dental casts in occlusion and serial lateral cephalograms of 25 children. We observed their occlusion and growth in the initial stage (Stage 1), beginning of exchange of the buccal segment (Stage 2), end of exchange of the buccal segment (Stage 3), and final stage (completion of occlusion, Stage 4). RESULTS: Most of the dentition (58%) became Class I molar relation before Stage 2 and almost all of the Class II at Stage 2 remained as Class II occlusion at the final occlusion (Stage 4), indicating rarely available Lee way space for obtaining Class I molar relation. The skeletal Class II group showed a significantly higher eruption of the lower first molar in Stages 2 and 3, while Class III skeletal group showed a significantly higher eruption of upper first molars at Stage 4. There were significant differences of posterior occlusal plane (POP) in different skeletal frames. CONCLUSION: The results suggested that the increase in vertical dimension and inclination of the POP influence the growth of the mandible in obtaining Class I molar relation and that improper vertical dimension and inclination of POP are related to the development of skeletal malocclusions.