Class III malocclusion: the post-retention findings following a non-extraction treatment approach

A retrospective, cephalometric study was made of a group of 28 successfully treated, Class III, Skeletal III children, who were considered suitable for orthodontic correction of their malocclusions. All had undergone non-extraction therapy, involving a combination of upper incisor proclination and headgear to an intact mandibular dentition and were available for review at least 2 years after all treatment and retention had ceased. Only girls over the age of 16 years and boys above 18 years of age at the post-retention recall were included. Data were examined at the beginning and end of active treatment, and at least two years out of retention. Where differences between the sexes were apparent, data for each sex were given separately. Where no significant differences were seen, data were pooled. Overjet correction was achieved by a combination of upper and lower incisor movement with no alteration in overbite. This was accompanied by a downward and backward repositioning of the mandible, redirecting, rather than restricting mandibular growth. Post-retention, demonstrable skeletal development occurred in both male and female faces. Normal patterns of facial growth reasserted themselves, reversing many treatment effects. The mandible reverted to a more horizontal direction of development, but because no growth restriction had occurred during treatment, no ‘catch-up’ growth of the lower jaw could be shown. Mandibular growth exceeded that of the maxilla, and since upper and lower incisor inclinations remained unaltered, both overbite and overjet reduced. Reflecting the underlying growth pattern, the lips became more retrusive.