Evaluation of the effect of periapical lesions and other odontogenic conditions on maxillary sinus mucosal thickness characteristics and mucosal appearance: A CBCT study.

Background. This retrospective study aimed to investigate the effect of various dental and maxillary sinus variables on maxillary sinus mucosal thickness (MT). The variables included periodontal bone loss (PBL), periapical status, dental restorations of posterior maxillary teeth, and the distance from the root apices to the sinus mucosa. Methods. Cone-beam computed tomography (CBCT) images of the maxillary sinuses (n = 600) in 300 patients were examined. The sinus MT and the distance of the roots from maxillary sinuses were measured. Apical lesions of the roots, PBL, and situations of adjacent teeth were recorded. The relationships between these conditions and MT and characterization of MT were evaluated. The Kruskal-Wallis H test was used to compare groups due to the non-normal distribution of the data. The relationship between categorical variables was analyzed using chi-squared test. Results. There was a significant correlation between maxillary sinus MT and periapical lesions, PBL, and restorations (P < 0.05). MT increased as the apical lesions of premolar teeth enlarged (P < 0.05, P = 0.022). MT increased in cases of mild PBL of molar teeth (P = 0.041). Conclusion. In this retrospective study, the MT significantly increased in patients with periapical lesions, inadequate endodontic treatment, increased PBL, and inadequate dental restorations.

Root canal length measurement of molar teeth using conebeam computed tomography (CBCT): comparison of two dimensional versus three-dimensional methods.

PURPOSE: This study aimed to evaluate the validity of 2-dimensional (2D) and 3-dimensional (3D) cone-beam computed tomographic (CBCT) root canal length measurements of molar teeth compared with actual root canal lengths and the influence of canal curvature on the accuracy of CBCT measurements. MATERIALS AND METHODS: Seventy root canals of 24 molar teeth were scanned using CBCT, and the root canals were categorized as; 'straight/curved,' 'highly curved,' and 'multiple curved.' The 2D measurements were performed within a suitable slice between the major foramen and the corresponding cusp. The 3D measurements were performed within the slices in regular intervals of axial planes in between the same reference points. The reproducibility and reliability of the methods were analyzed by intraclass correlation coefficient. Differences between the actual and CBCT root canal lengths were evaluated by chi-square and McNemar tests if the measurements were within acceptable limits of ±0.5 mm. RESULTS: Both methods were found to be reproducible and presented excellent reliability. However, the 3D method was significantly more accurate, with an 85.7% frequency of measurements within acceptable limits (p<0.05). In 'multiple curved' root canals, the 3D method presented more reliable measurements than the 2D method. For 'straight/curved' root canals, the 2D method gave results significantly closer to the actual root canal length in comparison with 'highly curved' root canals (p<0.05). CONCLUSION: The 3D measurements are more accurate than 2D measurements. If an already existing CBCT is present, it could be an alternative method for predetermination of root canal lengths in molar teeth.

Evaluation of Mandibular Third Molar Region in a Turkish Population Using Cone-Beam Computed Tomography.

OBJECTIVES: To evaluate impacted mandibular third molar tooth region and obtain linear measurements using CBCT images and to assess the relationship between the impacted third molar and the mandibular canal. METHODS: CBCT scans of 351 patients (208 females, 143 males) were assessed. Age, gender, and impaction site were recorded for each patient. The relationship of third molars with the vertical axis of second molars, 2nd molar resorption and the relationship between third molar apices and the mandibular canal were assessed. In addition, the distance between ramus and second molar, mesiodistal width of the third molar, the angle between third molar and second molar, and width of the third molar capsule were measured. Binary Logistic Regression, Chi-Square Test, and General Linear Model were used for statistical analysis. RESULTS: The highest percentage of impaction was found for mesioangular followed by transversal and vertical. The transversal impacted third molars revealed a significant association with adjacent second molar root resorption (p<0.001). There was a statistical significance between the second molar resorption and distance between ramus and second molar (p<0.001). The mesioangular impacted third molars revealed significant relation with the mandibular canal (p<0.05). The most frequent variation found was the dental canal followed by the retromolar canal. In general, higher measurement values were obtained for men when compared to women (p<0.05). CONCLUSION: CBCT assessment of the third molar region provided useful information regarding impacted mandibular third molar surgery operations.

Age estimation based on pulp/tooth volume ratio measured on cone-beam CT images.

OBJECTIVES: After tooth eruption, the size of the pulp cavity decreases with age owing to deposition of secondary dentine. The aim of this study was to investigate the relation between the chronological age and the ratio of pulp volume (PV) to tooth volume (TV) measurements using CBCT images of single rooted teeth. METHODS: Maxillary anterior, canine and mandibular canine/premolar CBCT scans of patients older than 15 years of age were collected from the archives between 2013 and 2015 years. Patients with CBCT scans of teeth were seen in detail and patients with known chronological age were included. Teeth with caries, filling or crown restorations, periapical pathologies or pulps that could not be identified were excluded. Consequently, 204 patients with 655 teeth were evaluated. The PV and the TV of each tooth was measured and then the PV/TV ratio was calculated. Simple linear regression analysis was performed in order to predict age estimation by using PV/TV. RESULTS: The PV/TV of all teeth ranged between 0.01 and 0.08. A negative correlation was found between the PV/TV ratio and age (p < 0.05). The regression analysis showed the highest Pearson correlation (0.532) for the maxillary central incisor tooth. Considering measurements of the PV/TV of all assessed teeth, there was no significant difference in the intercept between both gender (p > 0.05). CONCLUSIONS: This study revealed that PV/TV ratio was not gender dependent and the strongest correlation was found between the age and PV/TV ratio measured on maxillary central incisors than other teeth.

Change in Periapical Lesion and Adjacent Mucosal Thickening Dimensions One Year after Endodontic Treatment: Volumetric Cone-beam Computed Tomography Assessment.

INTRODUCTION: Changes in periapical lesion dimensions along with mucosal thickening after endodontic treatment have not been studied yet. Therefore, the objectives of this study were (1) to obtain linear and volumetric measurements of lesion dimensions in maxillary first molars with periapical pathology and (2) to measure maxillary sinus mucosal thickening in the vicinity of periapical lesions before and 1 year after endodontic treatment by using cone-beam computed tomography (CBCT). METHODS: Twenty-one maxillary first molar teeth of 21 patients (14 female and 7 male) with periapical lesion that had local mucosal thickening in the vicinity of the periapical lesion were endodontically treated. A total of 21 maxillary first molar roots (8 mesiobuccal roots, 6 distobuccal roots, and 7 palatal roots), each one from different patients, was included. Pretreatment and 1-year post-treatment CBCT images of each tooth were obtained by using Kodak CS 9300 3D CBCT unit. Width, height, surface area, and volume measurements of periapical lesions and mucosal thickening of the maxillary sinus mucosa in the vicinity of the periapical lesion were measured before and 1 year after endodontic treatment. General linear model (analysis of variance) was used for the comparisons between measurements, and significance was set at P < .05. Regression analysis was also used to test the correlation between different measurements. RESULTS: We found statistically significant differences between mean pretreatment and mean post-treatment measurements conducted by using CBCT images (width, P = .002; height, P < .001; maximum mucosal thickening, P < .001; medium mucosal thickening, P < .001; minimum mucosal thickening, P < .001; surface area, P = .032; and volume, P = .034). Considering gender, age, and root-type variables, no significant differences were found for all the measurements conducted (P > .05). There were 36%, 41%, 53%, 54%, 53%, 73%, and 75% mean reductions in lesion width, lesion height, maximum sinus mucosal thickness, medium sinus mucosal thickness, minimum sinus mucosal thickness, lesion surface area, and lesion volume, respectively, before and 1 year after endodontic treatment. Regression analysis of pretreatment lesion volume versus percentage of post-treatment lesion volume change revealed a low regression coefficient (R2 = 16.7%, P > .05), showing a weak linear relationship. CONCLUSIONS: CBCT assessment of changes in periapical lesion and mucosal thickening dimensions may reveal useful information regarding endodontic treatment success.

Volumetric Evaluation of Safe Zone for Bone Harvesting From Symphysis Region by Using Cone Beam Computed Tomography.

OBJECTIVES: The aim of the present study was to retrospectively make a volumetric evaluation of symphysis sites of patients by the use of cone beam computed tomography (CBCT). METHODS: This retrospective study evaluated dentate symphysis region of the mandibles in CBCT scans taken for different reasons in 90 patients (45 women and 45 men). Three-dimensional (3D) data were obtained using a CBCT device Kodak 9000 3D CMOS sensor with optical fiber. CBCT images were then transferred as digital imaging and communications in medicine files and imported into a volumetric-rendering software 3D DOCTOR (Able Software Corp., Lexington, MA) capable of measurements of vector based-segmentation technology for volumetric measurements. RESULTS: The total average bone volume is 2616.45 mm. Significant differences in average bone volume were found between group I and group IV (P < 0.001). Higher bone volume was obtained in the male groups (2903.01 mm) than in the female groups (2329.88 mm). CONCLUSIONS: CBCT is a good candidate for 3D assessment of high-contrast structures in the oral region. We suggest that the use of 3D computed tomography in combination with a software program is a dependable means of measuring the volume of the symphysis bone graft.

Efficacy of Combined Use of Different Nickel-Titanium Files on Removing Root Canal Filling Materials.

INTRODUCTION: The aim of this study was to estimate the remaining amount of residual filling materials in root canals after retreatment using ProTaper Universal Retreatment (PTUR) files (Dentsply Maillefer, Ballaigues, Switzerland) alone or with the additional use of the Self-Adjusting File (SAF; ReDent-Nova, Ra'anana, Israel), Reciproc (VDW, Munich, Germany), or Hedström-files (H-file; VDW, Antaeos, Munich, Germany) with volumetric estimation using the stereologic method via cone-beam computed tomographic images. METHODS: Forty-eight mandibular premolars with single canals were used. The canals were instrumented with ProTaper rotary instruments up to F4 and filled with gutta-percha and AH26 sealer (Dentsply De Trey, Johnson City, TN). All the samples were placed into the silicone models. Samples were scanned with cone-beam computed tomographic imaging and assigned into 4 groups (n = 12) according to retreatment files: the PTUR system group, the PTUR system plus SAF group, the PTUR system plus Reciproc group, and the PTUR system plus H-file group. The specimens were rescanned after retreatment procedures, and the volume estimations of the remaining filling materials were performed using the stereologic method. Data were analyzed using Kruskal-Wallis and Dunn tests. RESULTS: There was no significant difference among the groups regarding mean percentage volumes of the filling materials before retreatment procedures (P > .05). None of the retreatment procedures provided complete removal of the filling materials. The additional use of the SAF did not significantly improve the removal of filling materials when compared with the PTUR system alone (P > .05). However, the additional use of Reciproc or hand H-files significantly improved the removal of filling materials when compared with the PTUR system alone (P < .05). CONCLUSIONS: The additional use of files with different motion kinetics improved the removal of root canal fillings; however, none of the systems completely removed the root canal filling material from the root canals.

Effect of voxel size on accuracy of cone beam computed tomography-aided assessment of periodontal furcation involvement.

OBJECTIVE: To assess the accuracy of cone beam computed tomography (CBCT) images obtained at different voxel sizes in detecting ligature-induced furcation involvement. STUDY DESIGN: Furcation lesions were prepared in 36 molar teeth in rats, and 24 intact teeth served as controls. CBCT Kodak 9000 images at three different voxel sizes were acquired: 0.076 mm, 0.100 mm, and 0.200 mm. Four observers assessed 3 sets of images using a 5-point evaluation scale. κ-Coefficients were calculated for intra- and interobserver agreement. Receiver operating characteristic analysis measured the true positive rate (TPR), true negative rate (TNR), and area under the curve (AUC). Accuracy values were compared by using Mood's Median Chi-Square (α<0.05). RESULTS: Intra- and interobserver agreement ranged from 0.600 to 0.999 and from 0.366 to 0.573, respectively. Highest median AUC and true positive rate (TPR) values were obtained for voxel size of 0.076 mm. The highest median TNR values were obtained for the voxel size 0.1 mm. There were no significant differences (P≥.05) among the median AUC, TPR, or TNR values for the 3 different CBCT voxel sizes. CONCLUSIONS: Given the limitations of this study, all voxel sizes performed similarly in the detection of furcation involvement.