Surgical control of mandibular growth: test of a recent biomechanical hypothesis

It has been suggested that, by changing the orientation (and hence the function) of the condyle/ascending ramus segment, surgical control of mandibular growth rotation is possible in growing children. To test one aspect of this hypothesis--the effect of changes in condylar orientation--one condyle in each of thirty-five young male rats was rotated surgically, either clockwise or counterclockwise, and then wired to the ramus to preserve the new orientation. Amalgam implants and lateral cephalograms were used to measure the subsequent pattern of mandibular growth. The findings revealed that surgical rotation of the condyle and the subsequent pattern of mandibular displacement are poorly correlated (r = 0.1-0.3). It was concluded, therefore, that changes in the pattern of mandibular rotation that may follow early mandibular advancement are the result of factors other than the orientation of the condyle following surgery.