Growth characteristics of the premaxilla and orthodontic treatment principles in bilateral cleft lip and palate.

Sixty-three individuals with complete bilateral cleft lip and palate (BCLP) were studied. In 51 of these subjects no surgical set-back or early bone grafting procedures were done. In the other 12 subjects early surgical procedures to reduce the prominence of the premaxilla had been done. In the larger group the premaxilla was, on the average, protrusive until age 12, after which it gradually became more retrusive. By the end of the growth period the premaxilla was not excessively protrusive in any of these subjects. It was concluded that it is advantageous for the premaxilla in individuals with BCLP to be protrusive during most of the growth period, since the premaxilla grows forward at a slower rate than the mandible. In the 12 subjects with premaxillary surgery, midface retrusion was demonstrated at an early age. The forward growth of the premaxilla in these individuals was slower than in the BCLP without premaxillary surgery and all 12 subjects developed rather severe midface retrusion. Orthodontic treatment principles for four different stages of craniofacial and dental development have been outlined.