Clinical Study Of Cone-beam Computed Tomography For Measuring The Hard Palate Mucosa Thickness In Han-nationality Adults Aged 20-69

Objective:In this study,cone-beam computed tomography was used to measure the thickness of the entire palatal mucosa of Han-nationality adults aged 20-69 with healthy periodontium,and to analyze its variation and relationship with gender and age,so as to provide more anatomical data for soft tissue grafts obtained from the hard palate mucosa during soft tissue augmentation surgery.Methods:Collecting 200 cases of cone-beam computed tomography scan images of Han-nationality adults aged 20-69 with healthy periodontium who visited the dental multidisciplinary Medical Centerof the First Hospital of Shanxi Medical University from October 2018 to December 2019,and divided them into 5 groups according to age,20-29 years old group,30-39 years old group,40-49 years old group,50-59 years old group,60-69 years old group,40 cases in each group,each group is divided into 2 groups according to gender,20 cases in each group.The thickness of hard palate mucosa from the cementoenamel junction(CEJ)to the mid-palatal suture of left maxillary canine to second molar was measured,and the measured values at each point were recorded.The change trend of hard palate mucosa thickness at each point was counted and analyzed,as well as its relationship with gender and age.Results:1.At 3 mm and 6 mm from CEJ,the thickness of hard palate mucosa in the canine and premolar areas is significantly greater than the molar area and the difference is statistically significant(P<0.05);At 9 mm from CEJ,the thickness of hard palate mucosa of the first molar is less than the second molar and the second premolar and the difference is statistically significant(P<0.05),the thickness of hard palate mucosa from the canine to the second premolar gradually increases,the thickness of hard palate from the second premolar to the first molar gradually decreases,the thickness of hard palate mucosa from the first molar to the second molar gradually increases again;At 12 mm,15 mm,and 18 mm from CEJ,the thickness of hard palate mucosa in the molar region is greater than the premolar region and the difference is statistically significant(P<0.05);At21 mm,24 mm,and 27 mm from CEJ,the thickness of hard palate mucosa of the second molar is greater than the first molar;From CEJ 30 mm or above,the thickness of hard palate mucosa is small.2.From CEJ to the mid-palatal suture,the thickness of hard palate mucosa in the canine area showes no significant change.The thickness of hard palate mucosa in the premolar area and the molar area increases first and then decreases.The first premolar has the thickest palate mucosa at 6 mm from CEJ,the second premolar has the thickest palate mucosa at 9 mm from CEJ,the first molar has the thickest palate mucosa at 12 mm from CEJ,and the second molar has the thickest palate mucosa at 15 mm from CEJ.3.At 6 mm,9 mm form CEJ in the canine,at 6 mm,9 mm,12 mm,15 mm form CEJ in the first premolar,at 6 mm,9 mm,12 mm,15 mm,18 mm form CEJ in the second premolar,at 6 mm,9 mm,12 mm,15 mm,18 mm,and 21 mm from CEJ in the first molar,at 6 mm,9 mm,12 mm,15 mm,18 mm,and 21 mm from CEJ in the second molar,The thickness of hard palate mucosa at the age of 40-49 years old group,50-59 years old group,60-69 years old group is thicker than the 20-29 years old group,30-39 years old group,the differences in the thickness of hard palate mucosa are statistically significant(P<0.05).4.There is no statistically significant difference in the thickness of hard palate mucosa between male and female in all age groups(P>0.05).Conclusion:1.From the direction of CEJ to the mid-palatal suture,the thickness of hard palate mucosa in the canine area is relatively constant in each age group,and the thickness of hard palate mucosa in the premolar area and the molars area is significantly different due to the influence of the submucosa,but the trend of change is the same,increasing first and then decreasing.2.The premolar area within 12 mm from CEJ is the preferred donor area of hard palate mucosa in soft tissue augmentation surgery.When there is a large number of grafts needed clinically,it may be considered to obtain the graft at a distance of CEJ12 to 18 mm from the molar area,but intraoperatively careful operation is required to prevent damage to the greater palatine neurovascular bundle.3.It was found that the thickness of palatal mucosa in Han-nationality adults aged 20-69 years is not related to gender by cone-beam computed tomography measurement.As a result of submucosal aging changes,some regions of the hard palate are thicker in the age group over 40 years old,compared with 20-29 years old group and 30-39 years old group.