RÉSUMÉ
Objective To analyze the clinical effect of both micro-implant anchorage and selective extracting maxillary first molar to correct the failure of orthodontics.Methods From January 2006 to June 2012,24 cases who suffered from failure of orthodontics were treated in this department.To all patients,bilateral maxillary first molars were extracted,and micro-implant anchorage were planted into maxilla from buccal alveolar ridge to correct malocclusion acting as anchorages.Lateral cephalometric radiographs,intraoral photograph and facial photograph of every patient were taken before and after treatments; Their over bite and overjet molar relationship and incisors retraction were compared before and after treatments.Methods All the micro implant anchorages were sucessfuly implanted except two patients who experienced second operation owing to luxation of three implants.All the molars were strengthed and the profile improved along with their normal over bite and overjet.Conclusions The treatment of using micro-implant anchorage and selective extracting maxillary first molar is an ideal option of second orthodontics.Unconventional tooth extraction is used in this treatment.Micro implant anchorages are stable,acceptable and effective in clinical application.
RÉSUMÉ
Objective To study the effects of different sources of dendritic cells (DCs) on root resorption and healing after allo-geneic tooth transplantation in rats .Methods The BN rats and Lewis rats were respectively used as the donor and recipient teeth for establishing the animal experimental transplantation models and randomly divided into 4 groups ,20 cases in each group :the syn-geneic transplantation group(A) and the allogeneic transplantation groups(B ,C ,D) .The group A and B were infused with PBS buffer solution 0 .5 mL on 7 d before operation .The group C and D were infused with 1 × 106 donor or recipient tolerogenic DCs on 7 d before operation .5 rats randomly selected from each group were sacrificed for performing the pathological examinations of transplanted teeth at the end of 1 ,2 ,4 and 8 weeks .Results The inflammatory cellular infiltration was most severe in the group B , slightest in the group A and moderate in the group C and D .The root resorption was minimal in the group A ,maximal in the group B and moderate in the group C and D (P0 .05) ,but which at 8 weeks in the group D was lower than that in the group C .The periodontal membrane healing points at 8 weeks in the group C and D was less than that in the group A ,but more than that in the group B (P<0 .05);the inflam-matory absorption was highest in the group B(P<0 .05);the alternative absorption was lowest in the group A (P<0 .05) .Conclu-sion The two different sources of tolerogenic DCs all could reduce the rejection reaction of allogeneic tooth transplantation ,reduce the root resorption and promote the healing of periodontal membrane .Recipient tolerogenic DCs could reduce the root resorption in late stage even more .