Abstract
OBJECTIVES: this study investigated the effects of growth and tooth loading on the structural adaptation of the developing alveolar bone adjacent to the tooth root as the tooth erupted into function. Growth and occlusal function were expected to lead to increased alveolar bone density. Meanwhile, the supporting alveolar bone was expected to develop a dominant trabecular orientation (anisotropy) only after occlusal loading. DESIGN: minipigs with erupting and occluding mandibular first molars (M(1)'s) were used to study the effects of growth and occlusal function on developing alveolar bone structure through comparison of alveolar bone surrounding M(1)'s. A second minipig model with one side upper opponent teeth extracted prior to occlusal contact with the M(1) was raised until the non-extraction side M(1)'s developed full occlusal contact. The comparisons between extraction and non-extraction side M(1) alveolar bone were used to emphasize the impact of occlusal loading on alveolar bone structure. Specimens were scanned on a Scanco Medical μCT 20 at a 22μm voxel resolution for structural analysis. RESULTS: with growth and occlusal function a distinct alveolar bone proper tended to develop immediately adjacent to the tooth root. The cancellous bone had thicker but fewer and more separated trabeculae after growth or occlusal loading. On the other hand, occlusal function did not lead to increased alveolar structural anisotropy. CONCLUSION: during tooth eruption, growth and masticatory loads effect structural change in alveolar bone. The impact of occlusal function on cancellous bone anisotropy may need a more extensive period of time to demonstrate.