Background. Temporomandibular disorders (TMD) are the most common reason of non-dental pain in the orofacial region. A clinical examination of the temporomandibular joint (TMJ) with additional imaging is the most recommended procedure for TMD diagnosis. Objectives. The objective of this study was to evaluate the association between TMD and the condylar position in the glenoid fossa by examining a group of patients suffering from TMD compared with a control group of patients without TMD. In this study, we used cone-beam computed tomography (CBCT) images for measurements. Material and methods. Sixty-five symptomatic joints were selected from 48 patients with TMD. Sixtyfive joints were selected from a total of 96 asymptomatic joints in the control group. The superior, anterior and posterior area of the joint, and the steepness of the articular eminence were measured on the CBCT images. The data was analyzed using Pearson's χ 2 test. Results. The position of the condyle was significantly more posterior in the joints with TMD, and more anterior and centric in the asymptomatic joints. Statistically, the vertical position of the condyle and the steepness of the articular eminence had no significant relation with the occurrence of TMD. Conclusions. In this study, we observed that the posterior condylar position is more common in TMD patients, but it is not the reason for diagnosing TMD, and the reason of the posterior position of the condyle should be investigated before any decisions pertaining to treatment are made. In future, studies should focus on evaluating how the position of the condyle will change after the treatment of patients with TMD.
PurposeThis study aimed to evaluate the effect of field-of-view (FOV) size on the gray values derived from conebeam computed tomography (CBCT) compared with the Hounsfield unit values from multidetector computed tomography (MDCT) scans as the gold standard.Materials and MethodsA radiographic phantom was designed with 4 acrylic cylinders. One cylinder was filled with distilled water, and the other 3 were filled with 3 types of bone substitute: namely, Nanobone, Cenobone, and Cerabone. The phantom was scanned with 2 CBCT systems using 2 different FOV sizes, and 1 MDCT system was used as the gold standard. The mean gray values (MGVs) of each cylinder were calculated in each imaging protocol.ResultsIn both CBCT systems, significant differences were noted in the MGVs of all materials between the 2 FOV sizes (P<.05) except for Cerabone in the Cranex3D system. Significant differences were found in the MGVs of each material compared with the others in both FOV sizes for each CBCT system. No significant difference was seen between the Cranex3D CBCT system and the MDCT system in the MGVs of bone substitutes on images obtained with a small FOV.ConclusionThe size of the FOV significantly changed the MGVs of all bone substitutes, except for Cerabone in the Cranex3D system. Both CBCT systems had the ability to distinguish the 3 types of bone substitutes based on a comparison of their MGVs. The Cranex3D CBCT system used with a small FOV had a significant correlation with MDCT results.
More than 75% of dental caries in children and adolescents occurs in occlusal surfaces [1]. Studies over the past two decades have shown that a significant portion of occlusal caries could not be diagnosed in the early stages because of various reasons including dentists' carelessness and inappropriate instruments [2]. Researchers believe that the diagnosis of occlusal caries was more difficult
AbstractBackground. Recent Studies have shown that a significant portion of occlusal caries could not be diagnosed in the early stages because of various reasons. Early detection of superficial caries is important for preventive dentistry. Objectives. This study aims to compare the quality of occlusal caries detection using digital phosphor storage plate (PSP) and cone beam computed tomography (CBCT). Material and Methods. For this experimental study 88 human molars were used. The clinical appearances of the occlusal surfaces of the teeth ranged from sound to discolor with no macroscopic cavitation. They were imaged using a digital system (PSP) and CBCT (NewTom 3G). Three independent observers assessed the images twice. ROC curve was used for assessment of the imaging systems accuracy for the detection of caries. A histological investigation was used as a gold standard. Methods were analyzed by ANOVA and t-test with p value of 0.05. Tests were performed with STATA software (version 11). Intra and inter observers agreement for each image set was assessed by ICC. Results. The average of observers results in caries detection with PSP images was 0.34 (P value = 0.208) and with CBCT images was equal to 0.45 (P value = 0.722). This showed that the diagnostic accuracy of CBCT and PSP was not acceptable compared with the gold standard. Although CBCT was a little higher than PSP on ROC curve, statistically there were no significant differences between both images in detecting occlusal caries. The ICC results showed acceptable agreement between observers in caries detection by CBCT and PSP, but the agreement between observers using these image modalities and the gold standard was poor. Conclusions. The accuracy of NewTom 3G CBCT for detecting occlusal caries was slightly better than PSP (not significantly), but none of them had the sufficient diagnostic accuracy for detecting incipient occlusal caries. Therefore, in these cases it is necessary to use other methods to improve detection (Dent. Med. Probl. 2016, 53, 2, 186-192).
Desmoplastic ameloblastoma (DA) is one of 6 subtypes and also a rare variant of ameloblastoma. It is not recognized perfectly up to now. Although most of the conventional ameloblastomas can be diagnosed in posterior of the mandible, DA more transpires in anterior of the jaws. Our patient was a 57-year-old man with swelling in the right side of the anterior maxilla. In the medical examination bone expansion was detected with a normal covering mucosa and no discoloration. This paper provides more information about cone beam computed tomography image features of DA.
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