Influence of lip retraction on the cone beam computed tomography assessment of bone and gingival tissues of the anterior maxilla

Objective. To evaluate the influence of lip retraction on cone beam computed tomography (CBCT) assessment of bone and gingival tissues on the labial surface of the anterior maxilla. Study Design. A retrospective study was conducted using measurements of bone and gingival tissues collected from 120 maxillary incisors. The thicknesses of the bone and gingival tissues of different regions were measured on CBCT images, with and without a lip retractor. The thicknesses of the gingival tissues obtained from CBCT were correlated with measurements performed by clinical probing. Results. The thickness of bone in the more cervical region presented a higher mean value for exams performed with a lip retractor (P = .021). The thickness of bone found a significant correlation with the thickness of the gingiva (P = .020) with a lip retractor in CBCT exams. The thickness of the gingival tissue obtained from CBCT scans with lip retraction found significant correlations with those obtained clinically (P = .001). Conclusions. The use of lip retractors is a simple and reliable practice that allows the measurement of gingival tissues on CBCT images. This practice can exempt a patient from an invasive clinical procedure for measuring the thickness of the gingival tissue for implant cases of the anterior segment.