Jaw expansive lesions: population incidence and CT dentalscan role

Abstract

Aim: The aim of the study is to evaluate the incidence of different expansive lesions and the advantages of the clinical employment of Dentalscan to study bones lesions and to establish a common diagnostic path.

Materials and methods: Since January 2005 to November 2009, 3200 patients, not selected for sex or age, have undergone a CT "Dentalscan" in the department of Diagnostic Imaging, Tor Vergata University Hospital (PTV), a suspect bone pathology was found in 704 of them through the XR-orthopantomograpy (OPT). CT images were obtained with General Electric CT Light Speed multislice. Images were saved in the Advantage Workstation (GE) supported by the "Dentascan" dedicated software and by the 3D software (3D SSD). The protocol was : Slice thickness 1,25 mm, gap 0, matrix 512 × 512, 140 KV and 70 mA. All the lesions were also studied with the dedicated three-dimensional reconstructor 3D SSD. Biopsy for diagnosis was performed on all the lesions, except one (false positive with digital OPT). THE TECHNIQUE SENSITIVITY WAS ASSESSED FOR TWO IMPORTANT CLASSES: benign and malignant lesions.

Results: Through CT Dentascan a detailed evaluation of the jaws lesions and their extension was obtained. 656 patients (93.1 %) out of 704 examined for a suspicious lesion on the orthopantomography had a benign lesion: (127 follicular cysts (18.2 %), 181 radicular cysts (25.1%), 93 non odontogenic cysts (13.2%), 29 fibroma (4.2%), 198 odontomes (28.2%), 24 ameloblastoma (3.6%), 4 brown tumors (0.7%), 47 (6.9%) had malignant lesions: (12 carcinoma (1.7%), 29 metastasis (4.3%), 6 sarcoma (0.8%), 1 Dentascan CT resulted to be negative (1 false positive of digital OPT). The sensitivity of the technique for both groups was 99% for benign lesions and 98% for malign lesions.

Conclusions: CT Dentascan characteristics suggest to consider these techniques as the gold standard for the evaluation of jaw expansive lesions and the support of surgical planning.

Keywords: dentalscan; expansive lesions.

Figure 1

CT Dentascan exam using axial views (a), panorex reconstructions (b) and paragittal (c) shows an hypodense expansive lesion, monocamerated in the left portion of the lower jaw, that involves the radicular apex of the dental elements included from 33 and 36, with preserved cortex with an included dental element (38) mesioangled. The surgery assessed the histological nature of the lesion such as follicular cyst.

Figure 2

CT Dentascan exam using axial views (a), panorex reconstructions (b) and paragittal (c) and VR (d) shows a hypodense expansive lesion, multicamerated in the left portion of the lower jaw that swells the bone thining and interrupting the cortex on the lingual and marginal limit. It is not evident that the mandibular canal could be included in the lesion. The biopsy identified an ameloblastoma.

Figure 3

CT Dentascan exam using axial views (a), panorex reconstructions (b) and paragittal (c) shows an hypodense expansive lesion, monocamerated in the angle of the right lower jaw that undermines the cortex and seems to involve the nearer soft tissues. The complementary MR study, using T1w sequences (d), T2w (e) and T1w after contrast agent administration (f), shows a modified signal intensity SI with disomogeneous contrast enhacement, basically peripheral that involves like a sleeve the rising branch of the right lower jaw and the masseter muscle pterygoid muscle. The biopsy identified the histological nature as squamocellular carcinoma.

Figure 4

Digital OPT exam that shows radiotrasparent area periapex of 11–14. CT Dentascan exam using panorex reconstructions (b) and paragittal (c) shows regular bone structure in this site with regular trabecular network. VR reconstructions (d) support a bone without distorsion.