Prognosis of primary and secondary insertions of orthodontic miniscrews: What we have learned from 500 implants

Dynamics of alveolar bone healing after the removal of orthodontic temporary anchorage devices

“…4‐8 weeks of lag period is recommended clinically to allow for sufficient bone formation and to utilize accelerated osteoblast activity before reinsertion to replace an unstable miniscrew, and bone formation and enhanced regional osteoblastic activity were both confirmed during the initial 2‐6 weeks of healing in our beagle dog model. Histologically, however, the removal site was composed mainly of abundant woven bone rather than lamellated cortical bone even after 13 weeks.…”

“…However, unlike the initial peak of MAR and BFR, the latter cycle of bone formation may only involve an increase in the number of osteoblasts (BFR) rather than an increase in individual osteoblast activity (MAR). 18 4-8 weeks of lag period is recommended clinically to allow for sufficient bone formation and to utilize accelerated osteoblast activity before reinsertion to replace an unstable miniscrew, [11][12][13]23 and F I G U R E 4 Dynamics of alveolar bone formation after TAD removal; bone histomorphometry. Quadruple (C2, X2, Ot, and Ac) or triple labels (X2, Ot, and Ac) were frequently observed in the control site of maxilla (A) and mandible (D) representing mineral apposition at 6, 8,10, and 12 wk after TAD removal, respectively.…”

“…Alveolar bone healing after TAD removal holds significance especially for reinsertion procedures when primary stability of the TADs is not obtained. Since the stability of TADs, especially miniscrews, depends mainly upon bone quality and mechanical interdigitation with that bone, 4–6 weeks are recommended to allow sufficient healing of the alveolar bone prior to reinsertion in the same or an adjacent site after primary failure . However, TADs reinserted into the initial failure sites even after 4‐8 weeks of latency period reportedly showed lower stability than the initial stability, also suggesting differences in quality of bone at the removal site …”

“…Since the stability of TADs, especially miniscrews, depends mainly upon bone quality and mechanical interdigitation with that bone, 9,10 4-6 weeks are recommended to allow sufficient healing of the alveolar bone prior to reinsertion in the same or an adjacent site after primary failure. [11][12][13] However, TADs reinserted into the initial failure sites even after 4-8 weeks of latency period reportedly showed lower stability than the initial stability, also suggesting differences in quality of bone at the removal site. 12,13 Although more than 20 years have passed since the introduction of TADs, 14 detailed information on the natural healing and long-term remodeling of alveolar bone after TAD removal is lacking in the literature.…”

“…[11][12][13] However, TADs reinserted into the initial failure sites even after 4-8 weeks of latency period reportedly showed lower stability than the initial stability, also suggesting differences in quality of bone at the removal site. 12,13 Although more than 20 years have passed since the introduction of TADs, 14 detailed information on the natural healing and long-term remodeling of alveolar bone after TAD removal is lacking in the literature. The aim of this study was thus to investigate the dynamics of alveolar bone healing after the removal of TADs.…”