Determination of the palatal masticatory mucosa thickness by dental MRI: a prospective study analysing age and gender effects

The aim of this prospective study was to evaluate age and gender effects on the palatal masticatory mucosa thickness by using non-invasive and non-ionizing MRI. 40 periodontally healthy participants of five gender-balanced age groups (20-29, 30-39, 40-49, 50-59 and 60-69 years, respectively) underwent dental MRI at 3 Tesla using a contrast-enhanced, high-resolution 3D-sequence. The palatal masticatory mucosa was measured at 40 standard measurement points by two independent observers. Statistical analysis was performed by using intraclass correlation coefficient (ICC), Shapiro-Wilk test, two-way analysis of variance and post-hoc Tukey HSD test. Measurements of the palatal masticatory mucosa thickness were highly reliable with a mean intraobserver ICC of 0.989 and a mean interobserver ICC of 0.987. Mean palatal masticatory mucosa thickness increased with the distance from the gingival margin in all tooth regions. Molars showed a considerably lower average palatal masticatory mucosa thickness at intermediate heights in comparison to canines and premolars. Average palatal masticatory mucosa thickness continuously increased with age and significantly differed between age groups (p < 0.01). A significant increase was observed between the age groups of 30-39 years and 40-49 years (p = 0.04). Gender had no significant effect on average palatal mucosa thickness (p = 0.19). However, there was a tendency towards thicker mucosa in males (mean ± SD, 3.36 mm ± 0.47) compared to females (3.23 mm ± 0.44). In the present study, dental MRI allowed for a highly reliable determination of the palatal masticatory mucosa thickness. Considerable intra- and interindividual variations in palatal masticatory mucosa thickness were observed. Average palatal masticatory mucosa thickness was dependent on age but not on gender.