Kahn, Sérgio

This study aimed to determine whether administering botulinum toxin type A (BT) prior to surgery would stabilize surgical lip repositioning. A randomized controlled parallel-group clinical trial was performed. A total of 18 participants with excessive gingival display (EGD) were divided into two groups. For the test group (TG), BT was injected into the smile muscle locations 15 days before the surgical procedure. For the control group (CG), only lip repositioning surgery was performed. Gingival display (GD) and upper lip displacement (LD) were measured 3 and 6 months postoperatively. Data were submitted to ANOVA, Tukey, and t tests. For GD and LD, the changes were statistically significant between the measurements taken at the baseline, 3-month, and 6-month marks. The GD presented a reduction of 5.2 ± 1.1 mm in TG and 3.2 ± 1.4 mm in CG after 6 months. The LD measurements reduced 45% for TG and 26% for CG in 6 months. The injection of BT 15 days before lip repositioning surgery provided more stable results and effectively reduced the GD at 6 months.

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. Keywords: gingival recession, histology, microsurgery, plastic surgery

Gingival biotype is a clinical term used to describe the thickness of the gingiva. It has been classified as being thick or thin and may be related to the clinical outcome of root coverage procedures. This study evaluated the impact of gingival biotype on the clinical outcome of root coverage procedures following subepithelial connective tissue graft plus coronally positioned flap. A total of 19 patients, 10 with thin and 9 with thick gingival biotype, were treated for localized Miller Class I or II gingival recessions. After 6 months, 14 patients achieved complete root coverage, 7 from each group. The overall mean pooled root coverage rate was 90.93%. The thin biotype cases yielded a reduced mean root coverage of 88.51% compared with 93.63% for patients who had the thick biotype classification. Although the thin gingival biotype may impair the clinical outcome of root coverage procedures, this limitation does not appear to have a strong influence on the success of the root coverage therapy when subepithelial connective tissue graft was associated with the coronal positioning of the flap.

The aim of this study was to evaluate whether there is a positive correlation between the width of the zone of gingival keratinized tissue and its thickness. Maxillary right canines, lateral incisors, and central incisors of 60 patients (30 men, 30 women) between the ages of 20 and 35 years were examined. Using an endodontic spacer with a rubber cursor and a digital caliper of 0.01-mm resolution, the values of the width of the zone of gingival keratinized tissue and gingival thickness were obtained. It was observed that the lateral incisor has the largest mean zone of gingival keratinized tissue (5.54 ± 1.09 mm), followed by the central incisor (4.62 ± 1.02 mm) and canine (4.32 ± 1.33 mm). The mean gingival thickness was greater in the central incisor (1.17 ± 0.20 mm), followed by the lateral incisor (1.04 ± 0.24 mm) and canine (0.87 ± 0.27 mm). No statistically significant difference was verified for the mean width of the zone of gingival keratinized tissue and gingival thickness between men and women. A positive correlation between gingival thickness and width of the zone of gingival keratinized tissue was observed in the maxillary canine (Pearson r = 0.398, P .05), lateral incisor (Pearson r = 0.369, P .05), and central incisor (Pearson r = 0.492, P .05). In patients 20 to 35 years of age, there was a positive correlation between gingival thickness and width of the zone of gingival keratinized tissue for the maxillary right canine, lateral incisor, and central incisor.

Periodontal reconstructive surgery procedures seek to correct mucogingival defects, including gingival recession. This case report describes the use of a subepithelial connective tissue graft (SCTG) associated with root-end fillings using mineral trioxide aggregate (MTA) for the treatment of Miller Class II recession with root apex exposure. A partial-thickness double pedicle flap was made, followed by root preparation with curette and bur finishing. The exposed root apex was removed and the canal was filled with MTA. An SCTG taken from the palate was placed over the root surface and covered with the double pedicle flap. Twelve months after treatment, a reduction from 11 mm to 1 mm in gingival recession was achieved, covering 91% of the root. Repair in the periapical region was determined with radiographs. A 1.0-mm probing depth was measured, and no bleeding was observed on probing. There was an adequate keratinized tissue band, along with esthetic tissue contour and coloration. This case report serves as an example of how the grafting of subepithelial connective tissue can be successfully accomplished in tandem with MTA for the treatment of isolated Miller Class II gingival recession with root apex exposure.