[Posttreatment stability of four first bicuspid extraction cases treated with the Alexander technique--model analysis].
OBJECTIVE
To evaluate the posttreatment stability of four first bicuspid extraction cases with the Alexander technique.


METHODS
Fifteen patients, 8 males and 7 females in the permanent dentition were selected. The age range of the patients was 10.3 to 16.2 years old. Four first bicuspids of every patient were extracted and all patients were treated with the Alexander technique. The study casts were taken before (T(1)), after treatment (T(2)) and 27.8 months averagely follow-up (T(3)). Data were correlated by means of paired t tests.


RESULTS
Although maxillary and mandibular intercanine widths were increased by 0.98 mm and 0.87 mm, respectively, during treatment, they were decreased by 0.37 mm and 0.72 mm, respectively, during follow-up period. Maxillary and mandibular crowding were increased by 0.53 mm and 0.98 mm, respectively, during follow-up period. No statistical significance were found. Upper and lower arch depth were decreased significantly due to retraction of anterior teeth and remained stable during follow-up period.


CONCLUSIONS
According to this study, the design of the Alexander appliance and the Alexander technique are helpful for stability of extraction therapy. Follow-up is still necessary to evaluate the long-term stability.
Wei
Song
S
Department of Orthodontics, Peking University School of Stomatology, Beijing 100081, China.
Fu
Min-kui
MK
D000293:Adolescent; D001641:Bicuspid / Q000601:surgery*; D002648:Child; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008311:Malocclusion, Angle Class I / Q000628:therapy*; D008312:Malocclusion, Angle Class II / Q000628:therapy*; D003765:Models, Dental; D009971:Orthodontics, Corrective / Q000379:methods*; D014081:Tooth Extraction; D016896:Treatment Outcome