The Accuracy of Lateral Cephalogram in Representing the Anterior Maxillary Dentoalveolar Position

Abstract

Background: To evaluate the dentoalveolar position and root diameters of the maxillary incisors from cone beam computed tomograms (CBCT) compared with cephalometric tracings. Methods: A total of 64 sets of initial lateral cephalograms and CBCT images were enrolled. Measurements of dentoalveolar position included bone thicknesses and heights of alveolar, cortical, and cancellous bone. Root diameter and total root-bone thickness were also evaluated. All measurements were performed on cephalograms and CBCT images of the maxillary central incisor (U1CT) and maxillary lateral incisor (U2CT). The data were statistically analyzed using one-way ANOVA and Bonferroni tests (p < 0.01) to compare the cephalograms, U1CT, and U2CT. Results: The cephalograms presented thicker alveolar bone (labial: 0.20–0.67 mm, palatal: 0.41–0.60 mm; p < 0.001) and cortical bone (labial: 0.20–0.67 mm, palatal: 0.41–0.52 mm; p < 0.001) as well as higher alveolar crest (labial: 0.23–0.27 mm, palatal: 0.15–0.17 mm; p < 0.001) and cortical height (labial: 0.35–0.47 mm; p = 0.051, palatal: 0.14–0.18 mm; p < 0.001) than the CBCT images on both the labial and palatal sides, whereas palatal cancellous thickness was not significantly greater (p > 0.01). The cephalograms presented a greater total root-bone thicknesses (0.80–1.08 mm; p < 0.001), whereas the cephalograms traced thinner roots than the CBCT images (0.36–0.52 mm; p < 0.01). Conclusion: Routine lateral cephalograms are not suitable for alveolar bone evaluation in orthodontic treatment due to errors in representing dentoalveolar thicknesses and heights.

The Accuracy of Lateral Cephalogram for Measuring Alveolar Bone Thickness and Root Diameter on Mandibular Incisors

“…Previous studies reported bone thickness tended to have a smaller value at the mid-root level than at the coronal third, especially in mandibular lateral incisors with the most prevalent location of fenestration at the mid-root level [ 22 , 23 ]. Labial alveolar bone in Ceph was thicker than L1CT and L2CT at all levels which was similar to a study by Teerakanok et al [ 13 ]. A possible explanation comes from two reasons.…”

“…The study is a retrospective study that recruited patients from two sources. The first source included subjects who participated in past research [ 13 , 16 , 17 ]. The second source included patients who required both types of radiographs for treatment planning.…”

“…The reference line was the long axis of the tooth ( Figure 1 A). Thicknesses, including total root-bone thickness, alveolar bone, cortical bone, and cancellous bone at the labial and lingual sides, and the root diameter of the cephalometric mandibular central incisor were measured perpendicular to the long axis at 3, 6, and 9 mm apical to the cemento-enamel junction (CEJ) ( Figure 1 B and Figure 2 ) [ 13 , 19 ]. Heights including labial bone height and lingual bone height were measured parallel to the tooth axis ( Figure 2 ).…”

“…The sample size calculation followed a study by Teerakanok et al [ 13 ] to detect a difference between lateral cephalograms and CBCT radiographs with a power of 80%. The calculation indicated that 15 subjects were required.…”

“…Comparisons between cephalograms and CBCT images of the skull and facial bones were conducted and indicated that the values from a cephalogram could be either greater or less than the results from CBCT [ 9 , 10 , 11 , 12 ]. The only study that compared conventional cephalograms and CBCT images of dentoalveolar areas was a study by Teerakanok et al [ 13 ], which found that cephalograms presented thicker bone and higher bone height than the CBCT images. However, the study was performed on maxillary incisors.…”