Changes in arch form and dimensions of cleft patients.

Abstract The photocopy method of cast analysis permits a better understanding of the dimensional changes occurring during various stages of arch development. The statistical evaluation of the measurements described, and the changes in arch dimension as a result of growth and surgery gave us a better understanding of cleft patients. We found a wide variation in initial arch form among the groups and a variable pattern of arch development from birth to age 5. Surgical closure of the lip had a significant effect upon reduction of the alveolar and palatal cleft and upon maxillary segmental relationships and positioning. The reduction of the palatal cleft after lip surgery was attributed to segmental repositioning, downward growth and change in angulation of the palatal shelves, and mesial growth of the palatal shelves of the lesser segment. A significant pattern of anteroposterior and lateral dimension retardation was noted immediately after surgical treatment. This lag appears to have diminished in most subjects after the age of 4 years. Maxillary width was affected more than length, and even though the cleft group had a reduced width as compared to the normal group at 5 years, a significant increase in this width was noted among the cleft subjects from year to year, suggesting that the type of surgery performed did not cause a major or persistent growth disturbance. In all CLP subjects at 5 years of age, the length measurements were similar to those of normal subjects. A constant change was observed in the relationship between the greater and the lesser segments during various stages of arch development. In the majority of patients in whom there was an overlap of the greater segment over the lesser segment, both before and after lip surgery, and even up to the age of 2 years, the segmental relationships began to change prior to the age of 3 years and assumed and end-to-end relationship after the eruption of the deciduous dentition. A study of cross-bite in the deciduous dentition in the CLP patients revealed that twelve subjects (40 per cent of the patients) did not have a cross-bite, seven subjects (23 per cent) had a cross-bite limited to the canine, eight subjects (26 per cent) had a complete buccal cross-bite, one had an anterior cross-bite, and two patients had an anterior and buccal cross-bite. These findings suggest that it may not be necessary to treat the arch in early infancy with a holding or an expansion appliance, since it appears that the arch and the segmental relationship will undergo favorable change with growth and with eruption of the deciduous dentition, provided that growth is not retarded by surgical intervention and scar tissue. It has been our opinion that the segments were able to assume a more favorable position because they were not locked in within the region of the alveolar cleft by any type of surgical intervention. Mandibular length and width were significantly smaller in the CP group than in the CLP and normal groups. This appears to suggest a definite tendency toward mandibular hypoplasia in CP subjects.