An orthodontic and cephalometric study on the results of the combined surgical-orthodontic approach of the protruded premaxilla in bilateral clefts.

The anatomical aberration of the premaxilla in bilateral cleft lip and palate (BCLP) gives rise to many problems. Orthodontic and orthopaedic treatment alone often fail to correct this deformity. In this study, the results of a combined surgical-orthodontic approach were analysed. 22 BCLP-patients, who had undergone an osteotomy of the premaxilla in combination with secondary or tertiary bone grafting, were involved in this study. Two cephalograms were analysed from each patient, one prior to and one after osteotomy. Dental casts were made prior to orthodontic treatment, prior and after osteotomy of the premaxilla and after final orthodontic treatment. As a control group, BCLP-patients treated by the cleft palate centre, Oslo were used. Treatment planning of these two teams is comparable, except for the fact that in Oslo surgical repositioning of the premaxilla is never performed. Cephalometric values before and after osteotomy of the premaxilla were calculated. These values were corrected for growth by means of the Oslo-data. Differences before and after osteotomy were tested statistically with a paired t-test. After osteotomy, good arch form was achieved, the premaxilla was positioned more superiorly and normal inclination of incisors was achieved. It was not possible, however, to lower a high-positioned premaxilla to a normal vertical relationship.