Detection of bone invasion by gingival carcinoma of the mandible: a comparison of intraoral and panoramic radiography and computed tomography.
OBJECTIVE
To assess the diagnostic accuracy of panoramic radiography (PR), panoramic radiography combined with intraoral radiography (PR+IR), and CT in detecting the supero-inferior extent of tumor invasion of the mandible by gingival carcinoma.


METHODS
PR, PR+IR, and CT images of the mandible in 37 patients with gingival carcinoma were evaluated by five oral radiologists for the supero-inferior extent of bone invasion using ROC analysis. The mean ROC curve area (Az) of each observer for the different imaging modalities was analysed by nonparametric two-way ANOVA. P<0.05 was considered statistically significant.


RESULTS
The mean Az for the detection of bone invasion were 0.88+/-0.03 for PR, 0.77+/-0.12 for PR+IR, and 0.87+/-0.03 for CT (P=0.0907). The mean Az for the detection of bone invasion beyond the alveolus was 0.89+/-0.07 for PR, 0.85+/-0.08 for PR+IR, and 0.83+/-0.06 for CT (P=0.5438). The mean Az for the detection of bone invasion beneath the mandibular canal were 0.94+/-0.04 for PR, 0.94+/-0.02 for PR+IR, and 0.91+/-0. 04 for CT (P=0.2466). No statistically significant differences were observed in Az between PR, PR+IR, and CT.


CONCLUSIONS
We consider that PR+IR should be adopted as the initial imaging modality to determine the extent of supero-inferior invasion of the mandible in gingival carcinoma.
Nakayama
E
E
Department of Oral and Maxillofacial Radiology, Faculty of Dentistry, Kyushu University, Fukuoka, Japan.
Yoshiura
K
K
Yuasa
K
K
Tabata
O
O
Araki
K
K
Kanda
S
S
Ozeki
S
S
Shinohara
M
M
D000704:Analysis of Variance; D002294:Carcinoma, Squamous Cell / Q000000981:diagnostic imaging / Q000473:pathology*; D005887:Gingival Neoplasms / Q000473:pathology*; D006801:Humans; D008339:Mandibular Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology*; D009361:Neoplasm Invasiveness / Q000000981:diagnostic imaging*; D023861:Photography, Dental; D012372:ROC Curve; D011862:Radiography, Panoramic; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D018709:Statistics, Nonparametric; D014057:Tomography, X-Ray Computed