Morphology and morphometry of the foramen venosum: a radiographic study of CBCT images and literature review.

PURPOSE: The goal of this study was to assess the morphological variations, location, and morphometric measurements of the foramen venosum (FV) and analyse its interrelationships with other foramina on cone-beam computed tomography (CBCT) scans. METHODS: A total of 269 individual CBCT scans were evaluated retrospectively. The presence or absence of FVs and their diameter, shape, and confluence to foramen ovale were recorded. The distances between anatomic structures and the FV were calculated. Appropriate statistical analysis was performed for the collected data. RESULTS: Of the 269 cases studied, nine were excluded due to duplicate foramina that made statistical analysis difficult. In the 260 evaluated scans, the FV was identified in 190 individuals (73.1%). The incidence was 148 (56.9%) on the right side and 152 (58.5%) on the left side. The FV was present unilaterally in 80 (30.8%) and bilaterally in 110 (42.3%) out of the 260 individuals. The mean maximum diameter of FV was 1.75 ± 1.27 mm, and no significant differences related to gender and age were detected (p < 0.05). The most prevalent foramen shape was the oval type (45.9% on the right side and 40.8% on the left side). CONCLUSION: FV is a very frequent anatomical variation. This foramen can exist either bilaterally or unilaterally. No significant differences related to sex, side, or age could be found in the present study. The anatomic characteristics of FV should be considered during interventions in the middle cranial fossa. CBCT imaging with lower radiation doses and thin slices may prove useful before surgical skull-base procedures.

CBCT quantitative evaluation of mandibular lingual concavities in dental implant patients.

PURPOSE: The purpose of this study was to evaluate the prevalence of mandibular lingual concavities and to measure them using CBCT (Cone-Beam Computerized Tomography). METHODS: In this study, CBCT scans of 200 patients requiring dental implants were assessed for lingual concavities. Reconstructed CBCT images were transferred as DICOM files to the 3D DOCTOR software program, and metric, volumetric, and surface area measurements were obtained. Two-way mixed ANOVA was used to model side (left/right, anterior), measurement type, and gender with side and type taken as within-subject variables, gender as between-subject variables, and age as a covariate. A comparison between the dentate and edentulous groups in the samples with lingual concavities was performed using an unpaired Student's t test. RESULTS: Submandibular concavity mean depth and volume were found to be 2.4 mm and 130.7 mm(3), whereas mean depth and volume of sublingual concavities were found to be 1.3 mm and 26.5 mm(3). Significant inverse ratios were found between age and volume and between age and surface area (p < 0.05). All measurements were higher in males than females, but the differences were not statistically significant. The differences between the presence of concavity (sublingual, right, and left submandibular) and dental status (dentate/edentulous) were statistically insignificant (p > 0.05). CONCLUSION: Mandibular lingual concavity dimensions were found to vary by age, location, and the presence/absence of teeth. Third party software can be used to generate 3-dimensional models that provide useful information about shape, size, and location of sublingual and submandibular concavities prior to implant placement.

A comparison of peripheral marginal bone loss at dental implants measured with conventional intraoral film and digitized radiographs.

The purpose of the present study was to examine the effects of conventional and bone-condensing implantation techniques and time (6 and 12 months after implantation) on levels of marginal bone surrounding implants and to assess the level of agreement between measurements made using digitized intraoral images and film. The study group consisted of 14 healthy patients (9 female, 5 male; age range, 23-59 years; mean age, 41.1 years) with 28 single-tooth dental implants. In each patient, an implant was placed on one side using a conventional technique and on the opposite side using a bone-condensing technique. Film radiographs were taken at 6 and 12 months following implant placement and were digitized at 300 dpi and 600 dpi using a laser scanner. All scanned images were stored as both TIFF and JPEG files. A single observer twice measured distal and mesial marginal bone loss from film and digitized images. At the mesial site, there was a significant main effect of time (6 and 12 months after implantation) on the measurement of bone loss, F(1, 26) = 6.08, P = .02, but no significant main effect of implantation technique, F(1, 26) = 1.56, P = .223, and no significant interaction between time and technique, F(1, 26) = 2.09, P = .160. Similarly, at the distal site, there was a significant main effect of time on the measurement of bone loss, F(1, 26) = 14.1, P = .001, but no significant main effect of implantation technique, F(1, 26) = 1.21, P = .281. However, in contrast to the mesial site, there was also significant interaction between technique and time on the distal site, F(1, 26) = 4.974, P = .035. Intraobserver intraclass correlation coefficients and repeatability measurements showed high agreement for all image types. The bone-condensing technique resulted in greater marginal bone loss. Marginal bone measurements made using digitized intraoral images and conventional film showed high levels of agreement.

Accuracy of CBCT measurements of a human skull.

The purpose of this study is to assess the accuracy and reproducibility of cone-beam computed tomography (CBCT) measurements of a human dry skull by comparing them to direct digital caliper measurements. Heated gutta-percha was used to mark 13 specific distances on a human skull, and the distances were directly measured using a digital caliper and on CBCT images obtained with Iluma (3M Imtec, OK, USA) and 3D Accuitomo 170 (3D Accuitomo; J Morita Mfg. Corp., Kyoto, Japan) CBCT imaging systems. Iluma images were obtained at 120 kVp and 3.8 mA and reconstructed using voxel sizes of 0.2 and 0.3 mm(3). Accuitomo images were obtained at 60 kVp and 2 mA and a voxel size of 0.250 mm(3). In addition, 3-D reconstructions were produced from images obtained from both systems. All measurements were made independently by three trained observers and were repeated after an interval of 1 week. Agreement between observers and image type was assessed by calculating Pearson correlation coefficients, with a level of significance set at p < 0.05. Pearson correlation coefficients between readings ranged from 0.995 to 1 for all image types. Correlations among observers were also very high, ranging from 0.992 to 1 for the first reading and from 0.992 to 1 for the second reading for the different image types. All CBCT image measurements were identical and highly correlated with digital caliper measurements. Accuracy of measurements of various distances on a human skull obtained from different CBCT units and image types is comparable to that of digital caliper measurements.

Evaluation of bifid mandibular canals with cone-beam computed tomography in a Turkish adult population: a retrospective study.

PURPOSE: Knowing the anatomic location and also variations of the mandibular canal is especially important for surgical procedures on mandible such as dental implant surgery, impacted molar extraction and sagittal split ramus osteotomy. The purpose of this study was to clarify the incidence and location of bifid mandibular canals in an adult Turkish population to avoid complications during surgical procedures. METHODS: A retrospective study using cone beam CT images was performed to evaluate bifid mandibular canal in mandible of 242 patients. Both right and left sides were studied (n = 484). Axial, sagittal, cross-sectional and panoramic images were evaluated, and three-dimensional (3D) images were also reconstructed and evaluated, as necessary. The course and length of bifid mandibular canals and the superior and inferior angles between canals were measured. RESULTS: Bifid mandibular canals were observed in 225 (46.5%) of 484 sides examined. The most frequently encountered type of bifid canal was the forward canal (29.80%), followed by the retromolar (28.10%) the buccolingual (14.50%) and the dental canal type (8.30%). Mean lengths of bifid canals were 13.6 mm in the right side and 14.1 mm in the left side. Mean superior angles were 139° on the right and 141° on the left side, whereas mean inferior angles were 38° on the right side and 32° on the left side. No statistically significant differences were found in the lengths or angles between the right and left sides and also for gender (p < 0.05). CONCLUSIONS: This study, which utilized CBCT images, uncovered a higher prevalence of bifid mandibular canals than what has been reported in previous studies using conventional radiography techniques.

Assessment of zygomatic bone using cone beam computed tomography in a Turkish population.

OBJECTIVE: To provide linear and volumetric measurements of zygomatic bone using cone beam computed tomography (CBCT) images. STUDY DESIGN: CBCT images were assessed for 198 patients. Posterior and anterior zygomatic bone widths (M1 and M2), zygomatic bone projection (M3), zygomatic bone height (M4), combined zygomatic arch diameter (M5), maximum cortical thickness (M6), gray value obtained from maximum cortical thickness region (M7), minimum cortical thickness (M8), and gray value obtained from minimum cortical thickness region (M9) were measured. Volume and surface area measurements of the zygomatic bone were also conducted. Sex, age, and side were recorded for each patient. General linear model analysis of variance (ANOVA) was performed (P < .05). RESULTS: Age (P < .001) and gender (P = .001) significantly affected M1. Gender significantly affected M3 (P = .003) and M4 (P = .000), with higher values for men. Gender (P = .000) and age (P = .000) significantly affected M5 variation. Only age had a significant effect on M6 variation, with an increase with age (P < .015). Only gender had a significant effect on M7 (P = .005), M8 (P = .000), and M9 (P = .004), with higher values for men. All the factors significantly affected zygomatic bone volume variation (gender, P = .000; age, P = .000; and side, P < .004). CONCLUSION: Detailed examination of the zygomatic bone region can be performed with CBCT images.

Occlusal caries detection by using a cone-beam CT with different voxel resolutions and a digital intraoral sensor.

OBJECTIVES: This study assessed in vitro the diagnostic ability of intraoral digital CCD sensor images and CBCT images at different voxel resolutions in the detection of occlusal caries. STUDY DESIGN: The study sample consisted of 130 mandibular molars (61 sound and 69 diseased). Digital intraoral images and CBCT images were obtained at 0.1-mm, 0.2-mm, and 0.3-mm voxel sizes. All images were evaluated separately by 4 observers, and evaluations were repeated after a 4-week interval. Weighted kappa coefficients were calculated to assess intra- and interobserver agreement for each image set, and scores were compared with the histological gold. For the estimation of nonparametric imaging modality effects and tests of hypotheses, SAS 9.0 and SAS macros were used for F1_LD_F1 factorial design. An a priori level of significance of P equals .05 was used. RESULTS: High intra- and interobserver agreements were obtained (Kappa value range: 0.825 to 0.948 for intraobserver agreement and 0.700 to 0.903 for interobserver agreement). Estimated relative treatment effects (RTE) ranged from 0.26 to 0.85, which varied with caries level and imaging modality. Differences between RTE values obtained with ultra-resolution and high- and low-resolution images were not statistically significant for all caries levels. Comparing 3D and intraoral imaging modalities among caries levels showed that imaging modality performance was different for deep enamel, superficial dentine, and deep dentine; however, imaging modality performance was not statistically different for healthy and superficial enamel caries groups. CONCLUSION: At all voxel sizes, CBCT images can be considered a tool for use in the diagnosis of occlusal caries.

Interpretation of chemically created periapical lesions using 2 different dental cone-beam computerized tomography units, an intraoral digital sensor, and conventional film.

OBJECTIVE: To assess the diagnostic potential of 2 different cone-beam computerized tomography (CT) units and compare this with intraoral digital and conventional film in the detection of chemically created periapical lesions. STUDY DESIGN: Periapical lesions were created chemically in 27 intact roots of 23 teeth (6 incisors, 4 canines, 6 premolars, and 7 molars). Cone-beam CT and digital and film images of the teeth were obtained before and after the lesions were created. Three observers separately used a 5-point scale to rate the images for the presence or absence of periapical pathology. Images were scored twice by each observer, with an interval of 4 weeks. Kappa values were calculated to assess intra- and interobserver agreement. Data were analyzed using repeated-measures analysis of variance for nested designs. R(2) values were used to assess the models for each observer for each method. Differences between observers and methods were tested for statistical significance with the paired t test. RESULTS: Kappa coefficients for intraobserver agreement ranged from 0.196 to 0.542 for the 2-dimensional (2D) images and from 0.533 to 0.699 for the cone-beam CT images, whereas kappa coefficients for interobserver agreement ranged from 0.223 to 0.302 for the 2D images and from 0.417 to 0.461 for the cone-beam CT images. The R(2) values for each observer showed that cone-beam CT images were superior to 2D intraoral images. There was no difference between the 2 cone-beam CT units tested (P > .05), and no difference was found between the 2 intraoral radiographic techniques tested (P > .05). CONCLUSION: The 2 cone-beam CT units tested performed similarly, and both performed better than intraoral digital and film radiography in detecting chemically created periapical lesions.