Is there a correlation between vestibular depth and shrinkage of free gingival graft:  A descriptive-correlational study

Abstract

Background: The purpose of the present study was to evaluate the correlation of vestibular depth (VD) with Free Gingival Graft (FGG) dimensional shrinkage.Methods: This study was a descriptive-correlational study which was performed on twenty patients with insufficient attached gingiva width (AGW). Under local anesthesia, a partial thickness bed with sub-marginal incision was created. An FGG was prepared from the palate and sutured to the prepared bed. Clinical parameters including VD, probing depth (PD), keratinized gingiva width (KGW), AGW, vertical graft dimension (VGD), horizontal graft dimension (HGD) and graft area (GA) were evaluated preoperatively and after one, three, and six months postoperatively. The distribution of data was normal. Repeated measures ANOVA, Repeated measures with covariance, Pearson correlation coefficient and linear regression were performed to analyze the data.Results: One patient was excluded from the study, therefore, the obtained data of 19 remaining patients were analyzed. Six months after FGG surgery, AGW and KGW raised to 6.15±1.01 mm and 7.55±1.1 mm, which were statistically significant (p <0.001). The shrinkage rate of HGD, VGD, and GA were 13%, 34%, 42% respectively after 6 months. The VD was increased 2.05 mm compared to baseline which was statistically significant (p<0.01). Pearson correlation coefficient showed that there was a statistically significant correlation between VGD shrinkage (r=-0.614, p=0.005) and GA shrinkage (r=-0.476, p=0.039) with VD. The correlation of Horizontal shrinkage with VD was not statistically significant (r=0.065, p=0.792).Conclusions: It was concluded that the shrinkage of FGG was influenced by VD and a negative moderate correlation was existed between VD and shrinkage of VGD and GA. Trial registration: This study was retrospectively registered by Iranian Registry of Clinical Trials (IRCT) with the number: IRCT20101204005305N18. Registered 22 September 2019. https://irct.ir/trial/41736