Treatment outcome in cleft lip and palate: issues and perspectives.

In the last 40 years, great progress has been made toward a better understanding of many aspects of the cleft lip and palate defect, but there is still a long way to go before there is agreement on the optimal treatment procedures. With regard to the primary operations, it can be stated, in a somewhat simplified form, that there are two main schools of thought in cleft treatment. One advocates early closure of the lip and palate, a procedure which imparts a high priority to early speech function. The other recommends delayed closure of the hard palate, thereby according a high priority to the growth of the maxilla. A number of intercenter and multicenter studies have been carried out recently in an effort to elucidate which procedures give the best result, both esthetically and functionally. The results are ambiguous, and this has led a number of researchers to suggest that the randomized clinical trial is the only way to resolve the ambiguity. The fact that it has proved difficult to identify the optimal procedures in the field of cleft lip and palate treatment need not only be due to a less than optimal research design; a contributory factor might also be the great variability in craniofacial morphology and in the response to treatment in patients who have exactly the same cleft lip and palate diagnosis. Intensive research has made it possible to state categorically that clefts occur due to many different factors in an interplay between genetics and environment. Therefore, it is not likely that a single gene can be responsible for clefting. Since scar tissue presents many problems-for instance, impairment of growth-the reduction or prevention of scar formation has long been a desirable goal. The discovery that a fetus can heal without scar formation has led to many animal experiments. The timing of the surgical intervention on fetuses is critical, since late-gestation fetuses heal with adult-like scarring. There are still many unsolved problems connected with fetal surgery, and at present prenatal surgery for repair of cleft lip and palate is not ethically defensible in humans. On the other hand, it appears that there are considerable possibilities for the reduction of human scarring after surgery with the introduction of various wound-healing medications.