Application of cultured dermal substitute for amelioration of maxillary bone growth suppression after cleft palate operation in rats.

The growth and development of maxillary bone and dentition is often impaired in patients who have undergone the cleft palate operation (push back method). Wound contraction exerts adverse effects on maxillary bone growth. The present study investigates the ability of cultured dermal substitute (CDS) to ameliorate maxillary bone growth suppression in experimental animals. We prepared CDS by incorporating rat fibroblasts into a matrix comprising a spongy hyaluronic acid (HA) sheet combined with collagen gel. The number of fibroblasts in the CDS was adjusted to 1.0 x 10(5) cells/cm(2). Wistar rats were randomly assigned to one of the following groups: I, control (no operation); II, surgically exposed bone without matrix or CDS; III, surgery with matrix; IV, surgery with CDS. Under pentobarbital anesthesia, about 2 x 4 mm of the mucosa and periosteum was surgically removed from the left half of the palate. A silicone sheet was placed on the matrix or CDS and affixed with superglue. The palatal width was measured 9 weeks later in skull preparations as the distance between the cheek side cusps of the second molar. The palates in group IV were significantly wider than those in groups II and III, and did not significantly differ from that in the control group. These findings indicated that CDS has the ability to promote wound healing and reduce scar formation through the synergic effects of fibroblasts and the matrix, and thereby to ameliorate indirectly the growth of maxillary bone.