The relationship between lip pressure and facial growth after cleft lip repair: an experimental study.

Two different methods of lip repair were used on rabbits with surgically created unilateral clefts of the lip, alveolus, and palate. Control groups involved both unoperated animals and those with unrepaired surgically created clefts. The resulting lip pressure in the rabbits with repaired cleft lips was found to be significantly higher than in the control groups. Direct skull measurements showed that the rabbits whose lips had been surgically repaired also had significantly shorter maxillae that did the control groups. The correlation found between the amount of lip pressure and the degree of growth inhibition indicated a causal relationship.