Class III malocclusion: a comparison of extraction and non-extraction techniques.
A retrospective cephalometric study was made of the hard tissue changes in a group of 90 Class III, Skeletal III children, diagnosed as suitable for treatment by orthodontic means alone. Thirty-two were treated by a combination of upper incisor proclination and headgear to an intact mandibular dentition (Group 1), while in 28 the overjet was corrected with mid-arch extractions and Edgewise mechanics (Group 2). The remaining 30 children acted as controls (Group 3). Children were initially examined as male and female subgroups, and where no significant differences were seen data were pooled. In order to standardize the results, treatment/observation effects were presented as average changes per year. The three groups were essentially comparable pretreatment. Following overjet correction, the lower incisors uprighted in both groups, with an improved relationship to the A-Po line: the upper incisors were proclined in Group 1 only. Underlying skeletal changes were restricted to the mandible, which showed a downward and backward hinging, and an increase in lower face height. The improved mandibular position was significantly greater in the non-extraction group and was accompanied by an improvement in facial convexity. In addition, treatment could be started earlier and was completed in a significantly shorter time (Table 1). It would, therefore, appear that, in the short term at least, a non-extraction/headgear approach has advantages over a standard mid-arch extraction/Edgewise technique.
Department of Child Dental Health, London Hospital Medical College, Dental School, England.
J M
JM
Battagel
H S
HS
Orton
D000293:Adolescent; D000704:Analysis of Variance; D001641:Bicuspid / Q000601:surgery; D002508:Cephalometry; D002648:Child; D005115:Extraoral Traction Appliances; D005260:Female; D006801:Humans; D007180:Incisor / Q000473:pathology; D008297:Male; D008313:Malocclusion, Angle Class III / Q000473:pathology / Q000628:therapy*; D008334:Mandible / Q000254:growth & development / Q000473:pathology; D008445:Maxillofacial Development; D012189:Retrospective Studies; D012690:Serial Extraction; D012737:Sex Factors; D014087:Tooth Movement Techniques