[Postoperative follow-up after extraction of an impacted lower third molar]. / Controllo post-chirurgico nella avulsione del terzo molare inferiore incluso.

BACKGROUND: On the basis of an anatomo-surgical classification adopted in our Department, that divides impacted lower third molars into (1) ectopic, (2) dystopic and (3) in the proper anatomical site, and the latter into Class A (complete bone impaction without pathology of the second molar), Class B (mucosal impaction with pathology of the second molar: Subclass B1, if the mucosa distal to the second molar is of a normal amount; Subclass B2, if the retromolar mucosa is plentiful), and Class C (mucosal semi-impaction), the authors carried out a comparative study on 20 patients who underwent extraction of both Class C lower third molars. METHODS: These operations were performed, in each patient, on one side raising an Archer's flap and on the other introducing a modification of the incision lines using Z-plasty for flap design. The patients were examined from the first postoperative hours up to the 7th day following a protocol aimed at monitoring the postoperative variables pain, edema, trismus, infection and healing time. RESULTS AND CONCLUSIONS: The preliminary results, analyzed by Student's "t"-test, are statistically significant (p < 0.05), and favour the hypothesis that the technical modification proposed for the flap, by permitting a better closure of the socket, involves a lesser incidence of postoperative complications and in any case a more comfortable postoperative course.

Molecular approach to the nucleo-melanosomal interaction in human melanoma cells.

This paper presents evidence that L-tyrosine oxidation products and 5,6-dihydroxyindole, an intermediate of melanin synthesis bind to and modify DNA structure, as tested by extracting cell DNA, using topoisomerase I and denaturation assays. When supercoiled plasmid pCU18 or pBR322 DNAs are treated with 5,6-dihydroxyindole the supercoiled species disappear and are converted to species less mobile in a gel retardation test with respect to relaxed DNA, 5,6-Dihydroxyindole causes an easier acid denaturation of the double helix. The results, that are dose dependent, would point to both intercalation and cross-linking of DNA by 5,6-dihydroxyindole and its oxidation product(s). 3H-L-tyrosine deriving radioactivity, bound to nuclear DNA, is higher at low pH, (5.6) if compared to pH 6.8. The highest radioactivity bound to cell DNA is found during the transition from the amelanotic to the melanotic phenotype in human melanoma cell lines. As a control, the binding of 3H-L-tyrosine radioactivity to human prostate fibroblast DNA was investigated.