The effect of buccal shelf miniscrew retraction techniques on alveolar bone remodeling of mandibular anterior area

Bone remodeling is considered the main process occurred during orthodontic tooth movement especially affecting the alveolus. This process may be a risk factor for the development of gingival recessions, which are 5.8-11.5% common in orthodontically treated patients. The purpose of our study was to assess the changes in the alveolar bone at the level of lower central incisors in adolescent and adult patients after orthodontic tooth movements using CBCT (Cone beam computed tomography) scans. This review's criteria were met by 20 pts out of a total of 47. Retraction of lower incisors was carried out utilizing buccal shelf miniscrews by two en masse retraction techniques to assure full control of tipping movements during orthodontic treatment, the distance from the cementoenamel junction to marginal bone crest was measured before starting space closure and after 6 months. In both types of retraction techniques, the difference in the bone loss was greater on the lingual side of the incisors, especially in Group 1 which utilized a continuous elastomeric chain extended along the main archwire it was comparable to the retraction of lower anteriors within the chain connected to a hook attached to the wire at the level of the centre of resistance of lower anterior teeth between lower lateral and canine although the G1 had a higher retractive effect on lingual bone as compared to G2 (P value= 0.036). The lingual bone movement after retraction showed no statistically significant difference between both groups.