Search

BACKGROUND The aim of this study was to determine if image enhancement improves a clinician's ability to identify the presence of calculus on digital radiographs. METHODS Seventy-one hopeless teeth were collected from 34 patients. Teeth were stained with 1% methylene blue, the largest interproximal calculus deposit was scored, and photographs of each interproximal root surface were taken. The surface area of calculus deposit was determined as a percentage of the total interproximal root surface area. Digital radiographs of teeth taken before extraction were modified using the following enhancements: auto-contrast, emboss, invert, and sharpen. Radiographic presence of calculus was determined by two examiners. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated for each examiner and enhancement. A receiver operating characteristic curve was used to compare differences between the image enhancements in the detection of dental calculus. The kappa statistic was used to compare ratings between examiners. RESULTS None of the enhanced images were statistically superior to original images in identifying radiographic calculus (P > 0.05). The average sensitivity of digital radiography was 50%, average specificity was 82.2%, PPV was 94%, and NPV 23.2%. A threshold of >30% of interproximal root surface covered with calculus and increasing size of deposits were associated with improved detection (P < 0.05). CONCLUSIONS Digital enhancements do not significantly improve radiographic detection of dental calculus. As area of calculus on the root surface and size of calculus deposits increased, sensitivity of detection also increased.

PubMedID: 25427616 The aim of this study is to evaluate the reliability of the avascular exposed root surface area (AERSA) as a prognostic test for gingival recessions (GRs) and to compare the predictive value of the avascular root surface area calculation and Miller classification on the final rootcoverage outcomes. Methods: Ninety-one patients with 91 isolated single GRs (32 Miller Class I, 29 Miller Class II, and 30 Miller Class III defects) located at the upper and lower incisors and canines were treated with a laterally positioned flap. Clinical parameters were recorded and correlated with the achievement of complete root coverage (CRC) after 6 months. Results: From all clinical parameters used, AERSA showed the highest sensitivity and specificity for predicting CRC. Receiver operating characteristic curves analyses revealed three acceptable cutoff points based on baseline AERSA for achieving CRC with higher sensitivity and specificity values compared to GR depth, GR width, and gingival thickness. Both univariate and multiple linear regression analyses reported that the models could explain the 86% of the mean root coverage with AERSA. Conclusions: This prospective longitudinal study indicates that AERSA may be used to classify GR defects. The newly developed prognostic model may be used to predict the final root coverage outcomes.

Several animal studies have shown a positive correlation between aging and alveolar bone loss (ABL). The purpose of this study was to develop a model for the study of ABL in mice and aging.Mucoperiosteal flap surgery (MFS) was performed on the buccal aspect of the left side of the mandible (BL) in 72 CF(1) Mus domesticus mice and divided into three groups as follows: males, breeding (non-virgin) females, and virgin females. The MFS was performed in 3-, 6-, 9-, and 12-month-old animals under anesthesia. The buccal aspects of right hemimandibles were used as controls (BR). Animals were sacrificed under anesthesia 21 days after surgery. Mandibles were removed, defleshed, stained with toluidine blue, and photographed in a microscope. The photographs were digitized, and ABL was measured as the exposed root surface area (mm(2)). Blinded measurements were performed using a computer-assisted image analysis system.In terms of alveolar bone loss, the BL (operated) area showed a significant difference (paired Student t test; P0.001) when compared to the BR area in all three groups. Sex and breeding differences were not observed in this experiment. ABL in the left hemimandibles was significantly larger in 3- (mean: 0.70; 95% confidence interval [CI]: 0.59 to 0.80) and 12-month-old animals (mean: 0.58; 95% CI: 0.46 to 0.71) than in 6- (mean: 0.39; 95% CI: 0.33 to 0.46) and 9-month-old animals (mean: 0.42; 95% CI: 0.35 to 0.48); P0.001.The results suggest that 3-month-old CF(1) mice, in a sex and breeding independent process, could be a useful model for provoked alveolar bone loss studies in aging.

Background: The purpose of this study was to determine the total root surface area of extracted teeth by computerized image analysis and the amount of remaining attachment area assuming various amounts of bone loss due to periodontal disease. Methods: One hundred fifty extracted mandibular teeth were evaluated, and measured from cusp tip to the cemento-enamel junction (CEJ), CEJ to root apex, and cusp tip to root apex. The fulcrum point of the tooth was also measured, along with the total root surface area of attachment and total surface area of attachment remaining following simulation of attachment loss in 2 mm increments. Measurements were made on 80 teeth on one proximal surface and either the buccal or lingual surface and multiplied by a factor of 2. Measurements on 70 teeth were made on all 4 root surfaces to predict the accuracy of measuring only 2 surfaces to determine root surface area. Images of the tooth surfaces were obtained by video camera and converted to computer image with measurement of the surface areas. Results: The total root surface area for the mandibular cuspids and first and second bicuspids was 275.88 mm 2 , 251.45 mm 2 , and 271.81 mm 2 , respectively. The 2-sided and 4-sided measurements for the mandibular first bicuspid were 252.55 mm 2 and 247.02 mm 2 , respectively (P >0.05). Conclusions: This study found the total root surface area to be greater than that in most previous studies. Increasing attachment loss is related to decreasing root surface area; however, this relationship is not directly proportional. No statistical difference was found between measuring 4 surfaces versus only 2 surfaces. J Periodontol 2002;73:1095-1100.

The prognosis of a tooth affected by periodontitis might depend on the amount of bone remaining around the root surface. The surface area of a single tooth root relates to a simulated x-ray projection.The aim of the study was to determine root surface area from radiographs. Two methods were used. In the first, cross-sections of a single-tooth root were simulated using ellipses with different eccentricities. Projection data from 90 directions at 1 degrees intervals were obtained, which were then used to estimate circumferences that were then compared with the known circumference. In the second model, circumference was estimated from projection data derived from the projection of an ellipse with the central ray parallel to the long axis. The estimated circumference was compared with possible circumferences resulting from this projection data.In the first model, all estimated circumferences are less than the true circumferences. The largest error in each case decreased rapidly as the eccentricity of the simulated ellipse decreased. Less than 6% of the largest errors were found when the eccentricity is 0.83. In the second model, the estimation should be within less than 2% of error when the asymmetry factor is less than 0.6.The circumference of an elliptical object can be approximated from the projection data of this ellipse. Therefore, the surface area of a single tooth root may be estimated with clinically useful accuracy from the projection data.

The prognosis of a tooth with periodontitis is affected by the amount of supporting bone. A key factor in retaining a tooth is the ratio of supported root surface. Currently, root surfaces cannot be accurately measured using conventional dental radiographs, which only measure the length of bone support on proximal surfaces.Eight extracted, single-rooted teeth were 3-dimensionally digitized using a contact technique for true surface area measurements. Root length, projection area, and pixel values were then measured on digital radiographs. The accuracy of the ratio estimation of supported surface area from linear, area, and pixel values was calculated and compared.The mean error from linear estimation was 7.9%; the mean error from area estimation was 1.0%; and the mean error from pixel value estimation was 1.3%. One-way analysis of variance (ANOVA) showed significant differences in all estimations while Scheffé's analysis further revealed significant differences only in the linear estimation.A three-dimensional digitizing device could be used as a non-destructive method of measuring root surface area. The ratio of supported single-root surface area could be estimated with high accuracy from the projected area data acquired on the digital dental radiographs. The thickness data as reflected from the pixel values in the digital images did not improve the estimation accuracy. Estimations using only length data yielded significantly less accuracy. Digital dental x-ray images provide the potential for estimating the ratio of supported root surface efficiently.

The assumption that the palatal (PAL) root of maxillary molars has significantly greater attachment area than either the mesiobuccal (MB) or the distobuccal (DB) root was tested by documenting the root surface area of the individual roots and root trunks of 20 extracted maxillary first molars. Each molar was cross sectioned every millimeter, and the circumference of each root and root trunk section was measured with a calibrated opisometer. Mean circumferential measurements from each 1-mm section were summed to give the surface area for each root and root trunk. The DB root had significantly less surface area than either the MB or PAL root or the root trunk. There was no significant difference between the surface areas of the MB and PAL roots. The surface area of the root trunk, which was significantly greater than that of any of the three individual roots, averaged 32% of the total root surface area of the maxillary first molar.

Nine lower first bicuspid teeth were mounted in blocks of plastic and their roots were serially sectioned and photographed. Data from the photographs were compiled by a digitizer and a digital computer, which calculated the cumulative root surface area for each millimeter of root height. From these data, three variables, which relate root surface area to root height, were calculated. It was found that if one-half of the height of attachment to the root were lost due to periodontal disease, a mean of 61.5% of the actual attachment area to the root is lost. If a mean of 5.72 mm of root attachment height is lost, or if a mean of 60.6% of the same root height remains, only one-half of the total root attachment area remains to provide tooth support.

The variation of root surface area (RSA) in 1-mm increments from the cementoenamel junction (CEJ) to the apex was determined for the maxillary first molar. Twenty extracted maxillary first molars were cross sectioned every millimeter, and each section was photographed, projected and measured with a calibrated opisometer. The RSA and percentage of RSA were calculated for each 1-mm section. The location of furcation entrances, root separations and roofs of the furcations was also determined. Analysis of the mean measurements demonstrated that (1) the largest per cent of RSAs were found in the furcation area; (2) the mean distance from the CEJ was 3.6 mm for the mesial furcation entrance, 4.2 mm for the facial furcation entrance and 4.8 mm for the distal furcation entrance; (3) the mean distance from the CEJ to the point at which the roots separate from the root trunk was 5.0 mm for the mesiobuccal root and 5.5 mm for the distobuccal root; (4) in 11 of the 20 teeth the roof of the furcation was coronal to all root separations, forming a concave dome between roots. According to the individual and mean measurements, horizontal attachment loss of 6.0 mm or greater would have resulted in Grade III furcation involvement in all the teeth studied.