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The aim of this study was to apply low-dose CT scans to evaluate the treatment and post-retention effects of RME on nasal cavity and periodontal effects.CT scans of 17 subjects (7 males 10 females, mean age 11.2 years) were taken before RME (T0), at the end of the expansion phase (T1), and after a retention period of 6 months (T2). Measurements were performed on axial scans and on 3 different coronal scans. Statistical analysis was performed with ANOVA for repeated measures with post-hoc tests.Transverse dimensions of nasal cavity showed statistically significant T0-T1 increments at all the 3 coronal scans. All T0-T1 increments at the nasal levels showed a decrease in magnitude from the anterior to the posterior measurements. In the evaluation of T0-T1 changes, periodontal measurements were significant on the buccal aspect of banded teeth with a reduction in alveolar bone thickness. In the evaluation of T0-T2 changes, the lingual bone plate thickness resulted significantly increased.RME therapy induces a significant increase in the transverse dimension of the nasal cavity without permanent injuries to the periodontal bony support discernible at CT imaging. After six months the expansion of the nasal cavity results stable.

With our study we wanted to compare the diagnostic accuracy of conventional radiography (orthopanoramic and intraoral radiography) and Cone Beam CT (CBCT) for the diagnosis of periapical lesions on the posterior elements of the upper maxilla endodontically treated.The images were analyzed by a radiologist and an endodontist whose interpretation of radiological examinations is unique. Were examined 34 molars (23 first molars and 13 second molars) with a total of 102 roots. The CBCT detected a significantly higher number of lesions (43%, p0.001) compared to conventional radiography. Our results demonstrate that the CBCT can be inserted into the diagnostic routine for the evaluation of all pre-prosthetic posterior elements of the upper jaw endodontically treated in addition to the diagnostic techniques 2D, especially when in the treatment plan is provided the realization of an abutment. The CBCT, which has reduction of cost and absorption of radiation with respect to the conventional CT, is also very useful even when there is a need to perform a surgical treatment-endodontic (apicectomy) of a lesion diagnosed with 2D techniques.

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.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.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.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.

TO CORRELATE DIFFERENT CT SYSTEM: MSCT (multislice computed tomography) with different acquisition parameters (100KV, 80KV), different reconstruction algorithm (ASIR) and CBCT (cone beam computed tomography) examination in terms of absorbed X-ray dose and diagnostic accuracy.80 KV protocols compared with 100 KV protocols resulted in reduced total radiation dose without relevant loss of diagnostic image information and quality. CBCT protocols compared with 80 KV MSCT protocols resulted in reduced total radiation dose but loss of diagnostic image information and quality although no so relevant.In addition the new system applies to equipment ASIR applicable on MSCT allows 50% of the dose without compromising image quality.

The aim of this study is to describe the current role of imaging in pre-surgical planning, reporting 25 cases of paranasal sinus tumors examined in our Institute. Between June 2006 and May 2008, we identified 25 patients with malignant tumors of the paranasal sinuses. All of the patients were evaluated with CT and/or MR exams. US were used to assess regional lymph node involvement. When necessary CT-PET scanning using FDG, was done. Diagnostic imaging is essential during the initial work-up of a patient suspected of having a paranasal sinus tumor. The role of imaging is to define the tumor extension, nodal involvement, metastases and recurrences in the postoperative patient. CT and MR imaging are the primary modalities employed; each have advantages and disadvantages but tend to be complementary. The involvement of fine bone structures is best evaluated with CT. In assessing the extent of the tumor, MR provides excellent soft tissue detail, allowing for delineation of neoplasm from surrounding inflammatory tissue and secretions. For evaluation of lymph node enlargement color-Doppler US, CT and MR provide morphologic data, while CT-PET provides metabolic data. CT-PET can be used to stage nodal and metastatic disease and for assessing the efficacy of therapy or recurrent disease.

The aim of this prospective study was to evaluate the effects of rapid maxillary expansion (RME) on the palatal area as assessed by low-dose CT before treatment (T0), at the end of active expansion (T1) and after a retention period of 6 months (T2).The study sample comprised 17 prepubertal subjects (mean age 11.2 years) with constricted maxillary arches. Total amount of expansion was 7 mm in all subjects. Multi-slice low-dose CT scans were taken at T0, T1, and T2. On axial CT scanned images a circle line corresponding to the palatal area was drawn and the area inside the circle registered at all three observation times. The area was measured in mm². Statistical comparisons were carried out with Friedman test with post-hoc tests (P0.05).The palatal area showed a significant increase from T0 to T1 and from T0 to T2 as a consequence of the opening of the midpalatal suture after RME.Opening the midpalatal suture by using orthopedic forces allowed to extend the area of the maxilla. After a 6-months retention period the palatal area demonstrated a stable increase due to a bone deposition along the midpalatal suture in both the anterior and posterior parts of the maxilla.

The aim of this study was to investigate pharyngeal size differences between pre- and posttrials of a Mandibular Advancement Device (MAD), using a computed tomography (CT),in the treatment of Obstructive Sleep Apnea (OSA) adult patients.Eighteen patients with mild to moderate OSA (mean Apnea/Hypopnea Index, AHI, of 16.7) were treated with a MAD to wear at night only. After 3 months of treatment, three-dimensional changes in pharyngeal dimensions were measured on CT images performed with a sixteen detector-row CT scanner (Light Speed Plus; GE Medical Systems). Two consecutive axial sections from the hard palate to the epiglottis were obtained with and without the appliance. Measurements were made of the following airway areas (mm2) and lengths (mm): RF (nasopharynx); ROF (naso-oropharynx); OF (oropharynx); IPF (hypopharynx); SPL (soft palate length); SPT (soft palate thickness); Rgn (retrognation)-hyoid bone; hyoid bone-C2; Rgn-C2; PhL (oropharynx length); pharynx posterior wall thickness at three level. The angle between the hard and the soft palate (APDM) was also calculated.AHI improved significantly (from 16.7 to 11.2) when the appliance was used. Measurements from CT scans showed statistically significant expansion in the naso-oropharynx area (RF p.014; ROF p.050), in the Rgn-C2 length (p.005) and in the angle between the hard and the soft palate (APDM p.001).Our findings confirm the effectiveness of MAD in the treatment of patients with mild to moderate OSA. The use of MAD significantly expands the areas of the upper airway lumen most involved in the collapse.

This was to correlate the dosimetric evaluation with high diagnostic accuracy by suggesting a protocol that significantly reduces the dose administered by a Dentascan exam without affecting diagnostic accuracy.17 patients were selected consecutively (7 males and 10 females) of a mean age of 11.2 (8-14 years) who sought orthodontic treatment. They needed CT control before and after treatment with RME to evaluate impacted canines. The study was performed using a multidetector 16-rows CT with two protocols that provided 2 different KV acquisition parameters: 80 KV or 120 KV. Radiation dose was evaluated in two ways: CTDI and DLP. Image quality was rated and the results were compared to identify significant differences in terms of image quality, radiation exposure and presence of artefacts.The 80 KV scanning has a significantly lower effective radiation dose compared to the 120 KV scanning (p0.05). The images of all patients were used for comparing the protocols in terms of image quality. The mean scores for the 80 KV scanning images were 4.18 +/-0.81 and 4.41 +/-0.80 for dose obtained by 120 KV scanning. The median image quality was 4 (good) for both protocols. The 80 KV protocol allowed, as well as the 120 KV, a careful analysis by the orthodontist and the dental surgeon that together, based on this images, can choose the best line of treatment between several available options.80 KV protocols compared with 120 KV protocols resulted in reduced total radiation dose without relevant loss of diagnostic image information and quality. The images were good enough to obtain information about the exact position of impacted teeth and to plan the best line of surgical treatment and mechanotherapy strategy.