SU-E-I-06: Measurement of Skin Dose from Dental Cone-Beam CT Scans.

PURPOSE: To directly measure skin dose using point-dosimeters from dental cone-beam CT (CBCT) scans. To compare the results among three different dental CBCT scanners and compare the CBCT results with those from a conventional panoramic and cephalomic dental imaging system. METHODS: A head anthropomorphic phantom was used with nanoDOT dosimeters attached to specified anatomic landmarks of selected radiosensitive tissues of interest. To ensure reliable measurement results, three dosimeters were used for each location. The phantom was scanned under various modes of operation and scan protocols for typical dental exams on three dental CBCT systems plus a conventional dental imaging system. The Landauer OSL nanoDOT dosimeters were calibrated under the same imaging condition as the head phantom scan protocols, and specifically for each of the imaging systems. Using nanoDOT dosimeters, skin doses at several positions on the surface of an adult head anthropomorphic phantom were measured for clinical dental imaging. RESULTS: The measured skin doses ranged from 0.04 to 4.62mGy depending on dosimeter positions and imaging systems. The highest dose location was at the parotid surface for all three CBCT scanners. The surface doses to the locations of the eyes were ∼4.0mGy, well below the 500mGy threshold for possibly causing cataract development. The results depend on x-ray tube output (kVp and mAs) and also are sensitive to SFOV. Comparing to the conventional dental imaging system operated in panoramic and cephalometric modes, doses from all three CBCT systems were at least an order of magnitude higher. No image artifact was caused by presence of nanoDOT dosimeters in the head phantom images. CONCLUSIONS: Direct measurements of skin dose using nanoDOT dosimeters provided accurate skin dose values without any image artifacts. The results of skin dose measurements serve as dose references in guiding future dose optimization efforts in dental CBCT imaging.

Case report. Diagnosis and management of an anterior lingual mandibular salivary gland defect.

OBJECTIVES: To describe an anterior lingual mandibular salivary gland defect (ALMSGD). A review of the literature shows only twenty-five previously reported cases. METHODS: A twenty-six-year-old female was examined for comprehensive dental treatment when a well-circumscribed, corticated 1.5 cm diameter radiolucent lesion was noted in the mandibular left cuspid region. The patient's previous panoramic radiographs demonstrated that the lesion was present nine years ago and had not changed in size during this interval. RESULTS: The radiographic and clinical findings support the diagnosis of ALMSGD. Surgical intervention is not indicated due to the lack of symptoms and stability of the lesion. CONCLUSIONS: This case is unique because the patient is the youngest reported. It also supports the significance of a radiological diagnosis in the management of hard tissue lesions of the jaws and the importance of access to previous radiographs.

Generalized radiopacities.

Lesions are grouped together based on their radiographic appearances. Although similar in radiographic appearance, lesions often are differentiated by the age of the patient when first detected, sex of the patient, and site predilection. In some cases, lesions can be differentiated further by their prevalence rates or unique radiographic signs.

Controversies in the diagnosis and treatment of temporomandibular disorders: an updated review of the literature.

The purpose of this literature review is to examine some of the controversies related to the diagnosis and treatment of temporomandibular disorders. The main issues are the role of occlusion as an etiologic factor of temporomandibular (TM) disorders and the diagnostic significance of various radiological findings with respect to TM disorders. Only further research by scientific methodology into these complex areas will aid in resolving these issues.

A possible late onset variation of Papillon-Lefèvre syndrome: report of 3 cases.

Three unusual cases of Papillon-Lefèvre syndrome with late onset of features and relatively mild periodontal disease are presented. These examples confirm some of the late onset of features and mild periodontal presentation of a previous case report. Bacteriologic associations, polymorphonuclear leukocyte chemotactic, phagocytic, and bactericidal activity, and therapeutics with regard to this syndrome are discussed.

Helicobacter pylori infection in dental workers: a seroepidemiology study.

The finding of Helicobacter pylori in dental plaque suggested that dental workers may be at increased risk of acquiring H. pylori infection from occupational exposure. A cross-sectional survey of 239 dental workers from 37 Texas cities (including 89 dentists, 44 dental hygienists, 98 dental assistants, and eight dental students) was conducted. H. pylori infection was determined by the presence of IgG antibodies to H. pylori, using a specific and sensitive ELISA. Participants ranged in age from 19 to 72 yr (mean 34 yr) and the duration of dental practice ranged from 1 to 48 yr (mean 12 yr). Type of dental occupation, duration of practice, type of practice (public or private), instrument used for cleaning teeth (ultrasonic scaler or curette), and prevalence of upper gastrointestinal symptoms were determined by self-administered questionnaires and interviews. Eighty-two percent had no symptoms referable to the upper gastrointestinal tract. The overall prevalence of H. pylori infection was 24%: 17% in dentists, 18% in dental hygienists, 34% in dental assistants, and 25% in dental students. The prevalence increased significantly with age (p < 0.05). The prevalence of H. pylori infection was significantly higher in non-whites, 29 of 63 (46%), than whites, 29 of 176 (16%) (p < 0.001). Logistic regression analysis (dependent variable H. pylori) revealed no significant association between H. pylori infection and the type, duration, or volume of practice, or the type of cleaning instrument used. We conclude that dental workers are not at increased risk to H. pylori infection.