Objective:To assess the efficiency of orthodontic management in the treatment of impacted tooth in dentigerous cyst.Methods:Nine cases of dentigerous cysts with impacted teeth were treated with fixed appliances, surgical exposure, scrape of cyst and orthodontic traction to assist eruption of impacted teeth.Results:After treatment the panoramic radiographs revealed that radiolucent lesion disappeared with full bone regeneration, and the lesion was replaced by normal bony density and structure. Roots of impacted teeth normally developed. Impacted teeth were orthodontically brought into their proper position with normal alignment, normal overjet and overbite. Normal occlusion was found in all the cases. Mean total active orthodontic treatment time was 21.25 months,varying from 14 to 36.Conclusion:Orthodontic management combined with surgical approach is effective in the treatment of impacted teeth in dentigerous cyst.

Objective To study the pre-and post-surgical orthodontic treatment methods of patients with skeletal malocclusion treated through combined orthodontic-orthognathic surgery,and to set some guidance for the future clinical Work.Methods Twenty-five skeletal malocclusion patients in our clinic aged from 17 to 36 were treated by presurgical orthodontic treatment,orthognathic surgery and postsurgical ortho dontic treatment.Presurgical orthodontic treatment included alignment of dental arches,leveling of arches,elimination of rotations,coordination of the arches,and decompensation of anterior and posterior teeth.The postsurgical orthodontic treatment included closing residual spacing,final tooth alignment,maximum interdigitation,finalizing torque,artistic positioning,ideal overjet/overbite relationship and establishment of correct root parallelism.Results The duration of presurgical orthodontic treatment was 14.41 months on average(2～23 months),and the postsurgical orthodontic treatment time was 6.94 months on average(1.5～13.5 months).The duration for the whole active treatment was 21.35 months on average(7～35 months).The maxilla was moved back on an average 5.00 mm in maxillary protrusion cases.The mandible was moved anteriorly on an average 7.25 mm in mandibular retrusion cases.The mandible was moved back on an average 6.55 mm in mandibular protrusion cases.The chin was moved anteriorly on an average 5.33 nan in retrusion of chin cases.Conclusions Pre-and post-surgical orthodontic treatments are important procedures to the surgical treatment for skeletal malocclusion and basic needs to obtain successful treatment results.

OBJECTIVETo investigate the correlative factors influencing the stability of orthodontic treatment out of retention.

METHODSPre-treatment, post-treatment and 2 approximately 8 years out of retention study models of 74 cases with malocclusion were assessed by the PAR (Peer Assessment Rating) index.

RESULTS(1) Out of retention, the relapse rate was 13.01% in weighted PAR total scores and the relapse rate was 6.38%, 15.56%, 28.86%, 22.41% in alignment, overjet, overbite and transverse buccal occlusion respectively. (2) The rate of great improvement was decreased from 77.03% after treatment to 64.86% out of retention. The PAR score increased in 53 cases (71.62%), unchanged in 6 cases (8.11%) and reduced in 15 cases (20.27%) out of retention. (3) The weighted total scores in the Begg appliance were higher than that in Edgewise out of retention (P < 0.05). (4) The alignment and PAR total scores out of retention were higher in class II malocclusion than in class I malocclusion (P < 0.05). (5) The weighted PAR total scores post-retention were higher in unilateral extraction than in other groups (P < 0.01).

CONCLUSIONS(1) There was a trend that teeth relapsed to original position out of retention. The relapse rate was greater in alignment, overjet, overbite and transverse buccal occlusion. (2) The stability out of retention was not related to patient's age and sex, but was related to the types of appliance, malocclusion and extraction.

Adolescent ; Adult ; Age Factors ; Child ; Female ; Follow-Up Studies ; Humans ; Male ; Malocclusion ; pathology ; therapy ; Orthodontics, Corrective ; methods ; Recurrence ; Sex Factors ; Time Factors ; Treatment Outcome