Table 2 Qualitative analysis results of keratinized gingival width

Jing (2020) [38]

T: PAOO

n = 47

C: Conventional

Orthodontics

n = 13

T1: Full-thickness flaps were elevated on the labial aspect, and vertical alveolar decortication was performed with bone grafting.

T2: traditional orthodontic treatment

keratinized gingival width

More keratinized gingival gain was found in the T group, but the difference was not significant (0.34 vs. 0.17 mm).

PAOO guided tissue regeneration and increased keratinized gingival width, but the change between two groups was not significant.

Xu (2020) [39]

T: PAOO

n = 10

C: Conventional

Orthodontics

n = 10

T1Full-thickness flaps were elevated, and vertical interproximal cortical bone incisions were created with bone grafting.

T2: traditional orthodontic treatment

keratinized gingival width

More keratinized gingival gain was found in the T group, but the difference was not significant (0.35 vs. 0.25 mm).

Although the postoperative width was greater at 6 months, the changes in both groups were not statistically significant.