Faculty Bibliography

This study evaluated photodensitometry as a noninvasive method for quantitating bone mineral content (BMC) and osseous repair after Le Fort I osteotomy. Le Fort I osteotomies were performed on 6 Macaca fasicularis monkeys; maxillas were either advanced (Group I, n = 3) or impacted and advanced (Group II, n = 3). Postoperative, standardized lateral cephalometric films were taken at weekly intervals up to 25 weeks and osteotomy site repair was studied using photodensitometry. Segment stability was also evaluated and correlated with measured densities. In both experimental groups, clinical stability occurred at about the same time (45.7 and 48.7 days postoperatively) despite large differences in the size of the initial surgical defects. The net rate (slope) of osteotomy site remineralization was significantly different (Group II greater than Group I), but the relative difference in film absorbance between the osteotomy site and adjacent bone at the time of clinical stability was the same. This difference can be extrapolated from early postoperative films and may constitute a useful parameter for predicting when clinical stability will be achieved

This study establishes the existence of a mammalian buccal mucosal wound hyaluronidase (hyaluronate 4-glycohydrolase; EC 3.2.1.35) having properties distinct from those of the endogenous lysosomal hyaluronidase of normal (uninjured) buccal mucosa. A time-dependent change in hyaluronidase activity was measured, with the highest specific activity occurring on post-wound day 4 (7.7 +/- 1.3 units/mg protein), followed by consecutive decreases until activity was no longer discernible by day 21. Mucosal wound hyaluronidase closely resembled a previously described integumentary wound endoglycosidase in terms of a high pH optimum (5.0-6.0), distinct (but non-exclusive) substrate preference for hyaluronic acid, and ability to generate saturated depolymerization products by an endoglycosidic hydrolysis

This study establishes the existence of a mammalian buccal mucosal hyaluronidase having properties typical of a lysosomal enzyme. Mucosal hyaluronidase exhibited a distinct substrate preference for hyaluronic acid, generated saturated de-polymerization products by endoglycosidic hydrolysis, and possessed a pH optimum of 3.5 and an isoelectric point of 5.9