Histologic and histomorphometric analysis of connective tissue grafts harvested by the parallel incision method: 
a pilot randomized controlled trial comparing macro- and microsurgical approaches

Objective: The aim of this pilot randomized controlled trial was to assess the efficacy of macro- and microsurgical procedures in removing the epithelial tissue layer of subepithelial connective grafts (SCTGs) harvested by the parallel incision method.
Method and materials: Sixteen patients were randomized to receive macro-SCTG harvesting (n = 10, control group) or micro-SCTG harvesting (n = 10, test group) by the parallel incision technique. Histologic and histomorphometric analysis of the SCTG evaluated the percentage remnant of epithelium and connective tissue. The presence of remnant portions of the epithelium was identified in eight samples (three in the macro- and five in the microsurgery groups).
Results: Sixteen participants with 20 sites were included and 20 SCTG were collected and analyzed. SCTG harvested by microsurgical approaches displayed more portions of remnant epithelium compared to the conventional removal (50% versus 30%). There were no significant differences in mean remnant epithelial thickness for test (147.3 ± 89.3 μm) and control (209.0 ± 127.5 μm) groups (P = .57). Likewise, nonsignificant differences were identified in terms of the connective tissue thickness (macrosurgery: 1,511.0 ± 1,160.0 μm; microsurgery: 1,472.0 ± 1,063.0 μm) between groups (P = .96).
Conclusion: The samples harvested by microsurgery had greater remaining epithelial portions than those harvested by macrosurgery, and similar connective layer thickness.