A histological and ultrastructural study of wound healing after vomer resection in the beagle dog

Trauma to the vomer during cleft-palate surgery may impair anterior-posterior growth of the premaxilla and maxilla. The vomer was resected via a palatal flap in four 42-day-old beagle pups; four unoperated dogs served as controls. One experimental and one control animal was perfused at 2, 4, 8 and 12 weeks after surgery and specimens from the vomer-premaxillary suture and from the vomer at the level of the mid-palate were processed for light and electron microscopy. Measurements of maxillary casts showed retardation in anterior-posterior growth and development of an anterior cross-bite in all but one of the experimental animals. Microscopic examination of the healing wound showed granulation tissue and contractile fibroblasts, which were more numerous at the premaxilla-vomer suture than at the posterior site. Developing elastic fibres were also seen. Quantitation of fibroblasts revealed that 25-50 per cent in the control suture had the characteristics of contractile cells, but this reached 75 per cent in the resected group. These cells together with the elastin many constitute a system that retards anterior-posterior growth and leads to cross-bite.