Timing of cleft palate closure should be based on the ratio of the area of the cleft to that of the palatal segments and not on age alone.

BACKGROUND: Retrospective and prospective serial spatiotemporal investigations were carried out primarily to determine whether the ratio of the size of the posterior cleft space relative to the palatal surface area limited laterally by the alveolar ridges can be used to select the appropriate time for surgical closure of the palatal cleft space. Two subsamples were compared to determine whether the size of the palate and velocity of palatal development in well growing cases differ from those in cases treated by vomer flap surgery. The prospective investigation asked whether presurgical orthopedics increases the rate of palatal growth and palatal size. METHODS: Using the palatal casts of 242 male and female individuals from eight institutions in the United States and Western Europe that followed a variety of treatment protocols, separate serial analyses were conducted of well growing cases with excellent aesthetics, dental occlusion, and speech and a control series of 17 cases of various clefts of the lip and alveolus and/or soft palate but no clefts in the hard palate. Twelve groupings of cases were established depending on their institutional location and type of cleft. RESULTS: Among the various institutions in the study, palatal growth rates and size were statistically similar. Growth in the various clinical series (size, mm2) was less than that of the control series. The ratio of cleft space size to palatal surface area medial to the alveolar ridges was 10 percent or less at 18 months of age in most cases. There was no statistical difference in total surface size between groups, except for one series whose total growth size was least of all. Right and left lateral palatal segments, whether large or small, grew at the same rate. The sample of bilateral cases was too small for statistical comparisons. Presurgical orthopedics did not stimulate palatal growth. The coefficient of variance was less than 10 percent in all measurements. CONCLUSIONS: Delaying all cleft closure surgery until 5 years of age and older is unnecessary to maximize palatal growth. The best time to close the palatal cleft space is when the palatal cleft size is 10 percent or less of the total palatal surface area bounded laterally by the alveolar ridges. The 10 percent ratio generally occurs between 18 and 24 months but can occur earlier or later. There is more than one good type of palatal cleft closure surgery.