The Application Of CBCT Combined With Oral Scan To Measure Palatal Mucosa Thickness Of Maxillary Posterior Teeth In Connective Tissue Graft

Objective:Oral CBCT combined with digital oral scanning technology was used to measure and analyze the variation rule of palatal masticatory mucosa thickness in maxillary posterior region and its correlation with gender,gingival biotype and palatal bone plate,providing theoretical reference for the preparation of palatal connective tissue grafts in incremental soft tissue surgery.Methods:A total of 57 patients(342 dental positions)with digital oral scanning were selected from December 2020 to March 2022 in the implant Department of Shandong University Stomatological Hospital.Among them,25 were males and 32 were females,ranging in age from 18 to 70 years old,with an average age of 36 years old.CBCT imaging and CS 3600 intraoral scanning were performed in all patients.A fitting data model was formed in the maxillary posterior region through tooth spot registration.Games-Howall test was performed to analyze the difference in the thickness of masticatory mucosa from the first premolar to the first molar area on both sides of the maxilla.Independent sample t test was used to analyze the difference of the mucosal thickness of both sides of the maxillary palate,the gingival thickness corresponding to different genders,different ages and gingival biological types.The correlation between the thickness of palatal mucosa in the maxillary posterior region and the corresponding palatal bone plate was examined by Pearson.Results:(1)There was no significant difference in the thickness of palatal mucosa on both sides of the maxillary posterior region(P>0.05).(2)In the same dental position at different levels,the thickness of 14,15 and 25 teeth was the highest at the 12mm level,and the thickness of other teeth was the highest at the 14mm level;All teeth were thinnest at the 2mm level.The overall palatal mucosa thickness in the premolar region increased firstly and then became thinner with the increase of the gingival margin distance,while the palatal mucosa thickness in the first molar region increased continuously with the increase of the gingival margin distance.(3)The mucosa thickness of premolars and molars was similar at 2mm,4mm,and 12mm at the same level.At the level of 6mm,8mm,10mm,the second premolar was the thickest;At 14mm,the first molar is thickest.In this study,it was also found that the first molar was the thinnest at the level of 2mm,12mm and 14mm,and other horizontal teeth were the first molar.(4)Only the second premolar 14mm from the gingival margin had a statistically significant difference in palatal mucosa thickness(P<0.05),but no statistically significant difference was found at other dental sites(P>0.05).(5)Only the second premolar was 2mm from the gingival margin,and the first molar was 2mm and 4mm from the gingival margin.There were no statistical differences in the thickness of palatal mucosa between the middle-aged and young groups(P>0.05),and there were statistical differences in the measurement sites of other dental positions(P<0.05).(6)Only the first molar 2mm from the gingival margin had a statistically significant difference in the palatal mucosa thickness corresponding to the gingival biological type(P<0.05),but no statistically significant difference was found at other dental position measurement sites(P>0.05).(7)At the same level,there was a weak correlation between the plate of the palate and the thickness of the mucosa of the side of the palate(0≤| r |≤0.5).Conclusion:It is feasible to measure maxillopalatal mucosa thickness by CBCT combined with digital oral scan.The bilateral palatial masticatory mucosa in maxillary posterior region is basically symmetrical.The thickness of palatal mucosa of maxillary second premolars was the thickest at 6mm-10mm from the gingival margin.The second premolar is the most suitable donor area for autologous soft tissue transplantation,but the large palatal neurovascular bundle should be avoided during the preparation.There was no significant correlation between palatal mucosa thickness and sex,gingival biotype and palatal plate thickness.The palatal mucosa of middle age group was thicker than that of youth group.