Brad J. Potter

Measurement of endodontic file lengths: calibrated versus uncalibrated digital images.

This in vitro study compared the accuracy of file length measurements made on calibrated and uncalibrated direct digital images. Endodontic files of known lengths and ISO sizes were used in 10 single-rooted, relatively straight teeth within cadaver specimens. The crowns of the teeth were ground flat and an orthodontic wire of known length was secured to the coronal surface. This wire was placed mesiodistally and perpendicular to the root and served as the reference point for the file measurement and as a calibration reference length. A #20 file was hand-measured to a length that reached the apical third of each tooth. It was inserted and a radiographic image was secured. The instrument was remeasured three additional times at different lengths on the same tooth and reinserted before each image acquisition. Thus 40 digital images were acquired using a GE X-ray unit and a Schick Computed Dental Radiography (CDR) #2 sensor. These images were placed in random order, and an independent, blinded investigator determined the file lengths using on-screen calibrated and uncalibrated measurement of the CDR image with a straight-line and multiple-line measuring technique. The experimental measurements were compared with each other and with the known clinical measurements. A two-way analysis of variance indicated that there was a statistically significant difference showing that the calibrated measurements were more accurate than the uncalibrated measurements (p = 0.0001), and there was no significant difference between the straight-line and multiple-line measuring techniques (p = 0.14).

Implant site assessment using panoramic cross-sectional tomographic imaging

OBJECTIVES The purpose of this study was to evaluate the ability of two different panoramic imaging systems to produce cross-sectional images with accurate vertical dimensions of the posterior mandible. STUDY DESIGN Three partially edentulous human cadaver mandibles were used for this study. On each mandible, three potential implant sites were arbitrarily identified in an area between the mental foramen and the ascending ramus. Each site was imaged using two different panoramic machines. Using each image, the mandibles outline, cortical thickness, and position of the mandibular canal were traced on clear acetate film. The mandibles were then sectioned at each site to serve as a gold standard. The cadaver sections and tracings (corrected for magnification) were measured, recording the overall mandibular height, distance from the crest of the ridge to the superior aspect of the mandibular canal, and the thickness of the cortical bone at the most inferior aspect of the mandible. RESULTS There were no significant differences between either of the systems image measures and the gold standard when considering the distance between the crest and the mandibular canal. Differences were noted between the systems measures and the gold standard in the assessment of the cortical bone thickness and the overall mandibular height. CONCLUSIONS Both imaging systems can be useful for vertical measurements of a potential implant site in the posterior mandible.

Cutaneous draining sinus tract of odontogenic origin: unusual presentation of a challenging diagnosis.

A 44-year-old woman presented with a chronically draining lesion on her cheek just lateral to the nasofacial sulcus. The lesion was refractory to treatment with oral antibiotics. Physical examination revealed poor dentition, and a panoramic radiograph demonstrated periapical abscesses in the maxillary right lateral incisor and canine. A diagnosis of cutaneous fistula of odontogenic origin was made, and the patient was treated with tooth extraction. The cutaneous fistula subsequently resolved. Intraoral examinations and radiographs are critical for making the diagnosis of cutaneous draining sinus tract of odontogenic origin. Many patients undergo unnecessary surgical therapies before having the correct diagnosis made, but root canal therapy or surgical extraction is the treatment of choice. A dental origin must be considered for any chronically draining sinus of the face or neck.

Reproducibility of beam alignment using different bite-wing radiographic techniques

Longitudinal radiographic assessment of crestal alveolar bone plays an important role in the diagnosis and long-term evaluation of periodontal disease in patients. Because practitioners use several radiographic techniques to obtain bite-wing radiographs, horizontal and vertical alignment errors could adversely affect the diagnostic impression gained from this type of radiographic examination. The objective of this study was to determine the alignment reproducibility of three different clinical techniques used to acquire bite-wing radiographs. Patients who require bite-wing radiographs as part of a dental school screening process were radiographed with modified standard bite-wing tabs and two different intraoral positioning devices. Horizontal and vertical angular deviations were measured and alignment errors were calculated for each radiograph. The mean total angular alignment error for the standard bite-wing tab technique was 6.2 degrees, whereas the mean alignment error for both positioning devices was less than 1.8 degrees. The results of this study suggest that an intraoral positioning device for acquiring bite-wing radiographs should be used.

Central giant cell granuloma : report of a case

The central giant cell granuloma is a tumor that has great potential for the displacement of teeth and the development of a facial deformity. Although its cause and behavior are still matters for discussion, its early diagnosis and treatment are a priority. We describe a patient with a large benign central giant cell granuloma of the anterior mandible. The clinical, radiographic, and histologic appearance, as well as the appropriate treatment, are discussed in light of the current literature.

Impact of dental devices on cochlear implants.

A cochlear implant (CI) converts mechanical sound energy into electrical signals that can be delivered to the cochlear nerve of profoundly deaf patients. The purpose of this study was to investigate whether electromagnetic interference with the CI occurs during the operation of the electric pulp tester, apex locator, electrocautery unit, electrosurgery unit, or panoramic radiograph machine. A mastoidectomy and cochleostomy were performed on a cadaver, and a CI was implanted. The dental devices were used intraorally, and the implants circuitry was tested after each trial. A second CI was implanted in a human skull, which was then exposed to 50 panoramic radiographs, testing the implants circuitry after each exposure. The probability of damage to the CI by any of the devices was negligible, except for the electrosurgery unit operated at level 7, which destroyed the CIs circuitry. Therefore, although the other devices seem safe, it is recommended that the electrosurgery unit not be used on a CI patient.

A case report of subpontic osseous hyperplasia in the maxillary arch.

Subpontic osseous hyperplasia has been portrayed in both the historical and the current literature as occurring exclusively in the mandibular posterior region. This article presents the clinical, radiologic, and microscopic documentation of subpontic osseous hyperplasia occurring in the maxillary first molar region.

Measurement of Endodontic File Lengths: A Density Profile Plot Analysis

The purpose of this study was to evaluate measurements of endodontic files of known length and diameter using a density profile plot analysis of digital images. Ten single-rooted teeth with relatively straight roots in cadaver specimens were used. The crowns of the teeth were removed and a rectangular orthodontic wire, 5.13 mm in length, was placed horizontally on the occlusal surface to serve as a calibration reference point. The #8, #10, #15, and #20 FlexOFiles were measured to the nearest 0.5 mm and then placed to four working lengths that terminated within the apical third of each root. A GE X-ray unit and a Schick CDR #2 sensor were used to digitally acquire 160 images. The digital images were placed in random order and an independent, blinded investigator determined the file length using a density profile plot analysis. The measurements generated by the histogram analysis (experimental) were compared with the original clinical measurements. The paired t test, intraclass correlation coefficient, and the Bradley-Blackwood test were used to assess reliability. The results revealed that the means of the experimental measurements of all file sizes were within 0.5 mm of the known lengths and were always shorter than the known lengths. Also, the larger the file size the less deviation from the known lengths: #20, -0.16 mm (p = 0.0001); #15, -0.21 mm (p = 0.0001); #10, -0.34 mm (p = 0.0001); and #8, -0.45 mm (p = 0.0001). This study demonstrated that the density profile plot analysis might be a useful adjunct for the measurement of endodontic file lengths on a digital image.

Morphologic operations used to distinguish between two patient populations differing in periodontal health

OBJECTIVES This study was conducted to determine whether morphologic operation procedures applied to digitized, non-standardized, clinical radiographs of mandibular alveolar bone could be used to distinguish between a population of patients diagnosed with periodontitis and a population of patients either diagnosed with gingivitis or having healthy gingivae. STUDY DESIGN Two groups, one consisting of 29 patients who either had healthy gingivae or had been diagnosed with gingivitis and the other consisting of 32 patients who had been diagnosed with periodontitis, were compared. Pre-existing clinical radiographs were digitized, and for each patient three to six regions of interest were placed on an image of the mandibular posterior region of the interdental bone. The regions of interest were processed under two morphologic-operations protocols, and a mean density (referred to as an MO number) was calculated for each patient. With paired t-tests, the resulting MO numbers for the two groups were compared. RESULTS The two populations were statistically different (p < 0.05). CONCLUSION The results of this study indicate that morphologic operations have the potential to differentiate between patient groups differing in periodontal health.

Utilization of radiographs for a state dental board examination

A survey of 97 dentists who had recently taken a state dental board examination was completed to document the use of radiographs for the screening and treatment of their patients. The response rate was 53%. Candidates spent on average 14.25 hours screening a mean of 18 patients to identify the dental pathoses necessary to take the examination. Candidates took a mean of 28.9 (+/- 25.8) radiographs for screening purposes and during the examination with a range of 3 radiographs to a maximum of 141 radiographs. Time in practice and specialty status did not affect the total number of radiographic exposures made. The majority of radiographs taken (53%) were unlikely to be used in the direct care of the patients dental needs. The results of this survey indicated that efforts to minimize administrative radiographs should be increased.