Vascular changes following mucoperiosteal flap surgery: a fluorescein angiography study in dogs.

This study was undertaken to determine the vascular changes which occur following mucoperiosteal flap surgery where two different suturing techniques were employed. In four healthy adult mongrel dogs, buccal and lingual full-thickness envelope flaps were reflected in the mandibular quadrants following intravicular incisions from the first premolar to the first molar. The flaps were immediately readapted and primary closure was achieved by the horizontal mattress suturing technique in one quadrant and the direct interrupted suturing technique in the contralateral quadrant of each dog. A simple photographic system was developed for recording the in vivo gingival circulation depicted by fluorescein angiography just prior to surgery and then after surgery on days 1, 3, 7, 10, 14, and 21. The flaps were divided into three interproximal and two mid-buccal sites for analysis and the intracapillary and diffusion extent of dye fluorescence was accurately quantified by computerized planimetry. As healing progressed, longitudinal changes relative to presurgical baseline were analyzed by paired t-test. Cross-sectional comparisons utilizing Student t-test allowed for evaluating differences between the two suturing techniques as well as differences between interproximal versus mid-buccal sites at each postsurgical day. It was found that the simple act of raising a mucoperiosteal envelope flap initiates significant vascular trauma. Statistically significant reductions in flap circulation relative to presurgical baseline lasted for at least 3 days but persisted for 7 days at the interproximal sites. Flap diffusion (extravascular leakage) recovered sooner and extended over a significantly greater area of the flap than did intracapillary flap circulation during the early period of healing.(ABSTRACT TRUNCATED AT 250 WORDS)