Effect of metal artifact removal modes on the accuracy of linear measurement around titanium implants by applying different voltages: an original article.

BACKGROUND: This study aims to evaluate the effects of the artifact removal algorithm on linear measurements of the buccal cortical plate by altering the voltage. METHODS: Ten titanium fixtures were inserted at the site of central, lateral, canine, premolars and molars of dry human mandibles. Vertical height of buccal plate was measured using a digital caliper as a gold standard. Mandibles were scanned with 54 and 58 kVp. Other parameters were constant. Images were reconstructed with none, low, medium and high artifact removal modes. Two Oromaxillofacial radiologists evaluated and measured the buccal plate height using Romexis software. Statistical package for the social sciences (SPSS) version 24 was used for data analysis. RESULTS: In medium and high modes, the difference between 54 and 58 kVp was significant (p < 0.001). No significance was noted by using low ARM (artifact removal mode) at the 54 kVp and 58 kVp. CONCLUSION: Using artifact removal in low voltage decreases the accuracy of linear measurement and buccal crest visibility. By using high voltage, artifact removal would have no significant effect on accuracy of linear measurements.

Cytotoxicity, genotoxicity, and immunohistochemical expression of p53 in the oral mucosal epithelium of adults following cone-beam computed tomography.

This study sought to assess the cytotoxicity, genotoxicity, and immunohistochemical (IHC) expression of p53 in the oral mucosal epithelium of adults following cone-beam computed tomography (CBCT). This before-and-after observational study evaluated 30 patients (15 males and 15 females); mean age 35 years, who required CBCT. Exfoliating epithelial cells of the buccal mucosa were collected with a cotton swab immediately before and 10 days after CBCT. Following Papanicolaou staining, genotoxicity was evaluated by the micronucleus assay. The frequencies of pyknosis, karyorrhexis, karyolysis, budding and binucleation as cytotoxicity factors were also recorded. Expression of p53 was evaluated by IHC staining. Data were analyzed by paired samples t-test. Micronucleated cells, pyknosis, karyorrhexis, karyolysis, budding, cytotoxicity, and expression of p53 increased significantly after CBCT. CBCT exerts genotoxic and cytotoxic effects and leads to overexpression of p53 protein in the oral buccal mucosal cells.

Correlation between the Opacification Degree of Paranasal Sinuses on CT, Clinical Symptoms and Anatomical Variations of the Nose and Paranasal Sinuses in Patients with Chronic Rhinosinusitis.

Objectives: This study aimed to evaluate the correlation between the opacification degree of the paranasal sinuses on computed tomography (CT) with clinical symptoms, and anatomical variations of the nose and paranasal sinuses in patients with chronic rhinosinusitis (CRS). Materials and Methods: This descriptive prospective study evaluated 100 patients (60 males and 40 females), who were diagnosed with CRS by ENT specialists according to the clinical findings, and were scheduled for a CT scan. The patients were requested to express the severity of their symptoms using a visual analog scale. The CT scans of the paranasal sinuses were assessed for the presence of anatomical variations and scored using the modified Lund-Mackay scoring system for the opacification degree of each sinus. The correlations between the anatomical variations and sinusitis, and also between the severity of symptoms/disease severity and CT scores were statistically analyzed. P<0.05 was considered statistically significant. Results: The most common symptoms were purulent (discolored) nasal drainage and nasal obstruction. Septal deviation was the most common anatomical variation. The maxillary and anterior ethmoid sinuses were the most commonly involved areas. The Spearman's correlation coefficient showed a significant correlation between the sinus involvement and some of the evaluated symptoms, as well as certain types of anatomical variations (P<0.05). Conclusion: Some specific anatomical variations of the paranasal sinuses may predispose them to sinusitis. The CT scan score can predict the severity of many symptoms such as purulent (discolored) nasal drainage, nasal obstruction, hyposmia/anosmia, halitosis, cough, and fatigue, among the other symptoms of CRS.