Journal of Dental Research, Dental Clinics, Dental Prospects
Volume:2 Issue: 3, Summer 2008

Background and aims. Radiography is used to diagnose the demineralization process and carious lesions; however, conventional radiography and direct digital images do not show these lesions when the amount of demineralization is less than 40%. Digital subtraction radiography has recently been used to improve the diagnostic quality of these lesions. The purpose of this study was to compare the caries depth estimated by digital subtraction radiography in combination with barium sulfate in diagnosing proximal dental caries with histopathologic evaluation.Materials and methods. In this study 30 molars and premolars (24 demineralized lesions with cavity, 8 without cavity) were studied. Direct digital images were taken (kVp: 68, mA: 8; t: 0.12 for premolars and t: 0.16 for molars) whereas the position of X-ray tube and CCD receptor and teeth was fixed. To prepare the second images 135 gr/L barium sulfate was used. The images obtained with the same exposure and geometry and then subtracted. The depth of the lesions in direct digital and subtracted images were assessed and compared with the depth measured in histopathologic assessments.Results. The mean depths (± SD) of the lesions were 1.80 ± 0.77 mm in direct digital radiography, 2.32 ± 0.76 mm in subtracted images after barium sulfate treatment, and 2.51 ± 0.43 mm in histopathologic sections. The statistical difference between direct digital radiography and the other methods was significant (P < 0.05). However, the differences were not statistically significant between subtracted images and histopathologic sections. The average intra-class correlation coefficient was 0.7241 (CI: 95%).Conclusion. The present study has demonstrated that digital subtraction radiography images have the potential to measure the depth of proximal caries with no significant difference with histopathologic evaluation.

Background and aims. Salivary glands are very susceptible to radiation and any disturbances in their function are detrimental to the hard tissues in the oral cavity. The aim of this study was to evaluate posterior class V dental caries in patients with head and neck cancers undergoing radiotherapy.Materials and methods. In this study, twenty seven patients undergoing conventional radiotherapy were included. Class V dental caries of posterior teeth in these patients were evaluated in three intervals: before treatment, 3 weeks after the initiation of the treatment, and at the end of the treatment. Differences of mean caries activity between intervals were evaluated using paired sample t-test.Results. There were no class V decays prior to radiotherapy. Mean percentage of class V caries three weeks after radiotherapy and at the end of radiotherapy were 28.42% ± 14.41 and 67.05% ± 19.02, respectively. There were statistically significant differences in mean values among three stages (P = 0.00025).Conclusion. The results of the present study revealed that radiotherapy in patients with head and neck cancers causes class V dental caries on posterior teeth.

Background and aims. This study observed occlusal contacts and their area on the teeth during lateral mandibular movements. The percentage of each occlusal pattern was determined. Materials and methods. Fifty subjects (male: 27, female: 23), aged 20-29 years, were included in the study. The criteria for selection were as follow: all subjects (i) were in their twenties; (ii) had normal occlusal alignment, no temporomandibular signs and symptoms with Angle’s Class I relationship; (iii) had full dentition except for third molars; (iv) had no history of orthodontic therapy; and (v) had no restorations involving a cusp. The occlusal contacts were recorded with occlusion foil in three lateral excursions: 1, 2 and 3 mm from the maximum intercuspation. Data were analyzed with chi-square test. Results. Most of working-side contact patterns were classified as group function (60%). Canine protection was rare (17%). Contact patterns other than canine protection and group function were found in 23% of the contact patterns on the right side. On the left side, group function was seen in 51%, canine protection in 21% and others patterns in 28% of the studied subjects. Conclusion. On laterotrusion, most subjects had group function on the working side but canine protection was rare.

Background and aims. The anatomical features of gingiva are important in appropriate periodontal treatment planning. This study was designed to determine the anatomic features of gingival in a group of dental students in Tabriz, Iran.Materials and methods. One-hundred healthy subjects (aged 20-24 years old) with no history of periodontal or orthodontic treatment and a gingival index of zero or one were included. The following measurements were made using a periodontal probe: the distance between the gingival margin and base of gingival sulcus (depth of sulcus); the distance between the gingival margin and mucogingival junction (keratinized gingiva); and the distance between base of gingival sulcus and mucogingival junction (attached gingiva). Existence of free gingival groove was also recorded by observation. Mean values of collected data were calculated.Results. The widest attached gingiva and keratinized gingiva on the buccal aspect was seen in upper lateral incisor and their minimum in lower premolars. The maximum depth of sulcus on the buccal surface was recorded in upper right molar and its minimum on the buccal surface was found in lower left canine. All of the studied students had free gingival groove on the buccal or oral aspect of at least one tooth.Conclusion. The anatomic features found in this study were similar to those of the previous studies. However, mild variations with regard to race differences were observed.

Background and aims. While the use of X-ray is increasing, professional responsibility of dentists entitles them to have sufficient and correct knowledge of using radiographs. The aim of this study was to assess the level of knowledge of correct prescription of radiographs among dentists in Yazd, Iran. Materials and methods. This was a descriptive cross-sectional study including 134 general dentists and dental specialists. A self-administered questionnaire was used to assess their level of knowledge in various sections pertaining to prescription of radiographs. Their level of knowledge was compared in each section on the basis of gender and educational status. Results. Participants showed a high level of awareness in prescription of panoramic, periapical radiographs, and computerized tomography, whereas it was moderate in the field of occlusal radiographs, susceptible patients to caries, patients with periodontal diseases, evaluation of growth condition and dental crypts and weak in the fields of bitewing radiographs and insusceptible patients to caries. There was no difference in level of knowledge between genders. The level of knowledge in specialists was higher than general dentists except for using X-ray for susceptible patients to caries where no significant difference was observed.Conclusion. Specialist dentists were more knowledgeable than general dentists in prescribing radiological examinations.

Background and aim. Knowledge of the common radiographic errors and their prevention could prevent imposing redundant radiation, time and money to patient and the dentist. The aim of this study was to assess the common radiographic errors on panoramic radiographs in a radiology department. Materials and methods. 250 panoramic radiographs (100 male and 150 female; mean age, 24.3) taken at the Department of Oral and Maxillofacial Radiology were evaluated. Radiographs were categorized into five groups according to the type of errors (patient positioning errors, darkroom errors, failure to remove metallic accessories, equipment setup errors, and patient movement during exposure).Results. There were19 error-free radiographs. The number of radiographs with errors was 231, of which 26 were unacceptable and had to be retaken. Errors of patient positioning were observed in 78% of cases, film development in 69.2%, equipment setup in 3.2%, failure to remove metallic accessories in 3.2% and patient movement during exposure in 2.4% of cases. Conclusion. The errors seen on panoramic radiographs were relatively high with errors in patient positioning being the most frequent error.

Elongation of the styloid process or stylohyoid ligament calcification is a well recognized finding of dental practice, and an incidence of 4 to 30 percent has been reported on radiographs. Rarely, complete mineralization of the stylohyoid ligament or elongation of styloid process has been associated with difficulties in intubation and significant clinical symptoms, which is termed Eagle’s syndrome, and it exhibits dull or sharp intermittent pain felt along the glossopharyngeal nerve that is located in the hypopharynx and at the base of the tongue and recurrent throat pain or foreign body sensation, dysphagia, or facial pain. Additional symptoms may include neck or throat pain with radiation to the ipsilateral ear. In the case presented, the elongated process caused a broad tenderness in left lateral and posterior cervical as well as temporal regions.

Squamous cell carcinoma (SCC) is the most common malignant tumor of the oral cavity and one of the ten most common causes of death. It arises from dysplastic oral squamous epithelium. Considering the pathogenesis of SCC, a smooth and intact surface in this lesion is not a usual finding.In this paper, we report an extremely rare case of oral SCC in buccal mucosa presenting as an exophytic lesion with smooth and intact surface, very unusual for oral SCC.