Mandibular bone invasion by gingival carcinoma on dental CT images as an indicator of cervical lymph node metastasis.
OBJECTIVE
To evaluate the significance of mandibular bone invasion by gingival carcinoma revealed by reformatted dental CT images as a prognostic indicator of cervical metastasis.


METHODS
Thirty-two patients with squamous cell carcinoma of the lower gingiva were examined by dental CT. Cervical metastases and survival rates of these patients were analysed in relation to their clinical characteristics, histologic grading based on gingival biopsy, and mandibular bone invasion using reformatted dental CT imaging diagnoses prior to surgery. The dental CT images were classified into four types: Class I, no bone invasion; Class II, invasion confined to the alveolus; Class III, invasion extending between the alveolus and the mandibular canal; and Class IV, invasion beyond the mandibular canal.


RESULTS
Logistic multivariate regression analysis showed that bony invasion identified on dental CT images was a significant prognostic factor in cervical metastases (P=0.028). The 5-year overall survival rates of Classes I, II, III, and IV were 100% (n=9), 76.2% (n=9), 71.4% (n=7), and 28.6% (n=7), respectively.


CONCLUSIONS
The evaluation of mandibular bone invasion using dental CT images is useful as a prognostic indicator of cervical metastasis for patients with gingival carcinoma.
Ogura
I
I
Oral and Maxillofacial Radiology, Graduate School, Tokyo Medical and Dental University, Japan. iogura@mascat.nihon-u.ac.jp
Kurabayashi
T
T
Amagasa
T
T
Okada
N
N
Sasaki
T
T
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000539:Alveolar Process / Q000000981:diagnostic imaging; D000541:Alveolectomy; D001706:Biopsy; D002294:Carcinoma, Squamous Cell / Q000000981:diagnostic imaging* / Q000556:secondary / Q000601:surgery; D016001:Confidence Intervals; D005260:Female; D005500:Follow-Up Studies; D005544:Forecasting; D005887:Gingival Neoplasms / Q000000981:diagnostic imaging* / Q000601:surgery; D006801:Humans; D007091:Image Processing, Computer-Assisted; D016015:Logistic Models; D008207:Lymphatic Metastasis / Q000000981:diagnostic imaging*; D008297:Male; D008334:Mandible / Q000000981:diagnostic imaging / Q000601:surgery; D008339:Mandibular Neoplasms / Q000145:classification / Q000000981:diagnostic imaging*; D008875:Middle Aged; D015999:Multivariate Analysis; D009333:Neck; D037981:Neck Dissection; D009361:Neoplasm Invasiveness; D016017:Odds Ratio; D011379:Prognosis; D015996:Survival Rate; D014057:Tomography, X-Ray Computed