Morphological changes in alveolar bone thickness and height after orthodontic proclination or labial movement combined with autogenous soft tissue grafting: a CBCT evaluation

BACKGROUND

Autogenous soft tissue grafting is indicated in thin gingival biotypes before orthodontic proclination or labial movements to increase the keratinized gingiva and prevent gingival recession. However, its effect on local alveolar bone remodeling is unclear. The aim of this study was to investigate the effects of autogenous soft tissue grafting on local alveolar bone after orthodontic proclination or labial movements.

METHODS

Sixteen patients with a thin scalloped gingival biotype, narrow keratinized gingiva, or thin cortical bone requiring orthodontic proclination or labial movement of teeth were included. Cone-beam computed tomography (CBCT) images were obtained before grafting and at least 6 months after surgery. Sixty mandibular teeth were included, and the vertical bone level and horizontal labial bone thickness were measured. The results were compared using paired t-tests or Wilcoxon signed-rank test.

RESULTS

The horizontal labial bone thickness increased, especially at 6 mm below the cementoenamel junction (CEJ) in the mandibular central and lateral incisors (P < 0.05). The total alveolar bone area of the canines, first premolars, and second premolars increased at 3, 6, and 9 mm below the CEJ, respectively, and the differences were statistically significant (P < 0.05). Additionally, vertical bone height increased minimally on the labial side, but the differences were not statistically significant (P > 0.05).

CONCLUSIONS

New bone regeneration was observed on the labial (pressure) side after autogenous soft tissue grafting, which may represent a mechanism to effectively prevent gingival recession and maintain periodontal health.

IRB APPROVAL

All the experimental procedures involving humans in this study were approved by the Medical Ethics Committee of Xiangya Stomatological Hospital, Central South University ( No. 20190048).

[Efficacy of tunnel technique for treatment of gingival recession of upper adjacent teeth with noncarious cervical defect]

OBJECTIVE

To evaluate the efficacy of tunnel technique (TUN) in treatment of teeth with adjacent gingival regression (GR) combined with noncarious cervical lesions (NCCL).

METHODS

We collected data from 21 patients (79 teeth) undergoing TUN surgery for GR combined with NCCL. According to GR depth (GRD) and lesion depth (LD) of NCCL, the teeth were divided into group 1 with GRD≤3 mm and LD≤1 mm; group 2 with GRD≤3 mm and LD>1mm; group 3 with GRD>3 mm and LD≤1 mm; and group 4 with GRD>3 mm and LD>1 mm. The mean root coverage (MRC) rate, complete root coverage (CRC) rate, keratinized gingival width, and keratinized gingival thickness were compared among the 4 groups after TUN surgery.

RESULTS

The keratinized gingival width and thickness were significantly improved after the surgery in the 4 groups. When the GRD was below 3 mm, the MRC was not significantly different between group 1 and group 2 (8.55% vs 95.45%, P>0.05); When the GRD was beyond 3 mm, the MRC and CRC rates were both decreased in group 3 and group 4, especially in group 4, where the CRC rate (25%) was significantly lower than those in the other 3 groups (P < 0.01).

CONCLUSION

In patients with GR combined with NCCL, TUN surgery can obviously improve keratinized gingival width and thickness. GRD has a greater effect on the outcome of root coverage than LD, suggesting that NCCL restoration before TUN surgery may not be necessary. Both GRD and LD should be considered in the evaluation of the clinical efficacy of TUN surgery.