An autologous connective tissue graft from the palate is one of the most predictable donor sites for mucogingival periodontal surgery. The thickness of palatal mucosa varied among ethnicity could dictate the treatment outcome.

This study aimed to analyze the palatal masticatory mucosal thickness variation in maxillary first premolars by using cone-beam computed tomography (CBCT) images in a group of Thai participants.

From 900 CBCT images, there were only 20 cases included in this retrospective study. The systematic measuring of 160 points of the palatal mucosal thickness was performed at four points (3-, 6-, 9-, and 12-mm) both left and right sides of the maxillary first premolar on the CBCT images, starting from 3 mm below cementoenamel junction (CEJ) and in 3-mm intervals (3-, 6-, 9-, and 12-mm) from the CEJ of permanent maxillary first premolars. The radiographic measurements were performed by calibrated experience oral radiologist and periodontist. Descriptive data were analyzed to determine the differences in the mucosal thickness according to the sides of the palate and gender. Independent T-test and ANOVA were utilized to analyze the thickness related to the gender and differences in thickness interval.

There was a perfect agreement of inter-rater reliability between observers (>0.9). The means of the right palatal mucosal thickness at 3-, 6-, 9-, and 12-mm were 3.03 ± 0.82, 3.79 ± 0.53, 3.97 ± 0.91, and 3.74 ± 1.02, respectively, and on the left side were 3.48 ± 0.76, 4.10 ± 0.49, 4.51 ± 0.81, and 3.94 ± 1.11, respectively. There was no statistical difference in the mucosa thickness observed by side and gender. On the contrary, the palatal masticatory mucosa significantly increased gradually from the CEJ toward the apical region (p<0.05). The maximum palatal mucosal thickness was at 9-mm on both left and right sides and declined at 12-mm.

The palatal mucosal tissue from the maxillary first premolars represented uneven thickness that increased gradually from the CEJ toward the apical region. There was no difference by side and gender.