Reduction of midfacial periosteal perfusion failure by subperiosteal versus supraperiosteal dissection.

PURPOSE: Detachment of soft tissue is a prerequisite for cleft repair. Recent experimental studies have indicated that supraperiosteal rather than subperiosteal soft tissue detachment causes midfacial hypoplasia, although, the cause has not been clarified yet. We hypothesized that microcirculatory dysfunction may be responsible for hypoplasia development, and established in rabbits an experimental model to study the differences in nutritive perfusion of midfacial periosteum in dependency on the applied technique of soft tissue detachment.

MATERIALS AND METHODS: In anesthetized New Zealand White rabbits a cranially broadly based rectangular soft tissue flap was intraorally circumcised on the anteromedial aspect of the maxilla. After either supraperiosteal or subperiosteal soft tissue detachment fluorescence microscopy allowed quantitative in vivo analysis of the nutritive perfusion of midfacial periosteum.

RESULTS: Microscopic analysis of individually perfused capillaries showed that blood flow was comparable in supraperiosteally and subperiosteally dissected maxillary periosteum. Nonetheless, both dissection techniques were associated with a remarkable capillary perfusion failure. However, the functional capillary density, which indicates the number of perfused capillaries per tissue area and thus the overall quality of capillary perfusion, was found significantly ( P < .05) lower in supraperiosteally than in subperiosteally dissected periosteum.

CONCLUSION: Using a new model for in vivo quantification of periosteal perfusion in the maxilla of rabbits, periosteal perfusion was found significantly more deteriorated after supraperiosteal compared with subperiosteal soft tissue detachment. The marked reduction of periosteal microcirculatory perfusion failure after subperiosteal soft tissue detachment may contribute to the clinically observed protection from manifestation of midfacial hypoplasia after cleft repair.