Noninvasive evaluation of the correlation between thickness of the buccal bone and attached gingiva of maxillary premolars

Objective To noninvasively determine the relationship between the thickness of the buccal bone and attached gingiva of the maxillary premolars. Material and Methods 128 maxillary premolars in 32 patients were assessed for measurement of buccal bone thickness and corresponding attached gingival thickness at 3 mm apical to cemento-enamel junction. Buccal bone thickness was measured on cone-beam computed tomography scans and attached gingival thickness by ultrasound unit. Pearson's correlation coefficient was calculated to assess the correlation between buccal bone and attached gingival thickness at each tooth type. Results The mean buccal bone thickness at the maxillary premolars was 1.07 mm. The 1st premolars had a buccal bone thickness < 1 mm at 68% of all sites, and the 2nd premolars had a buccal bone thickness of 1.0-2.0 mm at 32% of all sites. The 1st premolars had a gingival thickness > 1.2 mm at 55% of all sites, and the 2nd premolars had a gingival thickness of 1.1-1.3 mm at 45% of all sites. The correlation between buccal bone and attached gingival thickness was moderately positive (r = 0.406; P < .001). Conclusions The relationship between buccal bone thickness and gingival thickness is independent of each other in the maxillary right first premolar, whereas a moderate correlation with a dependent relation exists in the maxillary right second premolar, maxillary left first premolar, and maxillary left second premolar. Clinical Significance Soft tissue and hard tissue associated with volumetric changes in maxillary premolar region can be unfavorable for both aesthetic and implant placement. In fact this study highlighted the relationship between the thickness of attached gingiva and corresponding buccal bone in maxillary premolar region so to enable for proper planning of implant therapy following extraction.