[Computed tomographic features of desmoplastic ameloblastoma of the jaw]

OBJECTIVE

To retrospectively analyze the clinical and CT imaging features of desmoplastic ameloblastomas (DA) in comparison with other types of ameloblastomas.

METHODS

Patients diagnosed with ameloblastoma histopathologically in Peking University School and Hospital of Stomatology from July 2000 to August 2017 were reviewed to analyze the constituent ratios and characteristics of DA. CT imaging features of DA (28 cases) were investigated in comparison with consecutive cases of solid/multicystic and unicystic ameloblastomas. The following imaging perspectives were analyzed: the border, internal structure, three-dimensional shape, tooth, the periodontium, the cortex and the expansion of the tumors. CT values were measured in the region of interest for quantitative analysis.

RESULTS

Among the 1 269 cases of ameloblastomas, 50 (3.9%) were DA, which showed predilections for males (74.0%). The average age of DA was about 43.9 years old, which was higher than the other two types. The anterior incisorcanine region (62.0%) and premolar region (30.0%) were most frequently affected. The incidence rate of DA in mandibule was 56.0% (28/50), which was slightly higher than that of maxilla (44.0%). The DA characteristically showed scallop border and honeycomblike or soapbubble internal structure with bone formation on CT. The mean ratios of height to mesiodistal and buccal-lingual to mesio-distal distances were 0.76 and 0.63, which were higher than the other two types. According to the degree of internal bone formation, three subtypes of DA could be observed: densely ossifying type (I), honeycomb/soap bubble type (II) and sparsely ossifying type (III). The means and standard deviations of CT values of DA were significantly higher than those of the other two types, which were (488.8±164.0) HU (type I), (171.7±102.8) HU (type II), (42.1±8.8) HU (type III).

CONCLUSION

CT is helpful for diagnosis of DA, which shows as solid tumor with varying degrees of internal ossification.

[Cone-beam CT features of ameloblastomas]

OBJECTIVE

To summarize and analyze the cone-beam CT (CBCT) imaging features of ameloblastomas for clinical preoperative diagnosis.

METHODS

Thirty-seven cases with complete data proven by pathology were retrospectively studied for distinct CBCT features.

RESULTS

Of the 37 cases, 31 were primary and 6 were recurrent. On CBCT images, the 37 cases were composed of 36 cases (97.3%) of intraosseous lesions (17 cases of multilocular lesions, 17 cases of unilocular lesions, and 2 cases of honeycomb lesion) and 1 case (2.7%) of extraosseous lesion (soft tissue lesion). Of the 17 multilocular cases, 15 (88.2%) showed tongue-shaped crests in lesions. Thirty-four cases (94.4%) showed apparent expansible change toward lip/buccal and (or) palatal/lingual sides ofjaw, with partialcortical erosion.

CONCLUSION

CBCT imaging yields accurate three-dimensional images of lesion shape and structure. Therefore, CBCT can be usedfor the clinical diagnosis and surgical assessment of ameloblastoma.