Effects of bone grafting, performed with corticotomies and buccal tooth movements, on dehiscence formation in dogs

- Archwire expansion after corticotomy produces similar amounts of tooth movement, whether or not grafting was performed.
- Although tipping was controlled, all teeth had large bony dehiscences on both roots, with about 30% less bone loss in the graft+ than the graft− side.
- After corticotomy-facilitated dental expansion, grafted bone was evident in host bone, with most new bone formed apically.
- Soft tissue was not detrimentally affected by corticotomies, despite the large bony dehiscences.
- Root resorption occurred especially when the premolar was close to the cortex.

IntroductionA randomized split-mouth experiment was performed in dogs to determine the effects of bone grafting, together with corticotomies and buccal tooth movements, on dehiscence formation.MethodsBilateral full-thickness mucoperiosteal buccal flaps were raised, and corticotomies were performed with a piezosurgery unit adjacent to the maxillary second premolars in 7 dogs. The experimental (graft+) side received a demineralized freeze-dried allograph and a resorbable collagen membrane. The second premolars were expanded with archwires for 9 weeks, followed by 3 weeks of consolidation. Soft tissue measurements included probing depths, attachment loss, and recession. Tooth movements were monitored using intraoral, radiographic, and model measurements. Bone surrounding the second premolars was evaluated with microcomputed tomography. New bone formation was analyzed histologically using calcein and alizarin fluorescent labels, and hematoxylin and eosin stains.ResultsPostsurgical healing progressed normally with no signs of infection. The graft+ and control (graft−) second premolars underwent similar amounts of expansion (about 2.5 mm intraorally; about 1.7 mm radiographically) and tipping, with no statistically significant side differences. The soft tissue periodontium was not affected on either side. There were bony dehiscences on both the graft+ and graft− sides, with slightly but significantly (P = 0.038) more bone loss over the mesial root on the graft− side. Bone material density was significantly (P = 0.028) greater on the graft+ side. Buccal bone apposition was evident surrounding graft particles, and mineralized particulate graft material was present at the apical aspect of the roots on the graft+ side.ConclusionsBone grafting does not prevent dehiscence formation because only a limited amount of new bone is formed, primarily at the more apical aspects of the tooth's roots.