Cone beam computed tomographic assessment of mandibular condyle in Kennedy class I patients

OBJECTIVES

The aim of this study was to assess the dimensional and volumetric changes in the mandibular condyle in Kennedy class I patients versus completely dentate patients by cone beam computed tomography (CBCT) to estimate the effect of loss of posterior teeth on the mandibular condyle.

PATIENTS AND METHODS

This study was performed on one hundred patients requesting CBCT scans: fifty Kennedy class I patients and fifty fully dentate controls. Condyle dimensions mesio-distal, cranio-caudal and antero-posterior as well as condyle volume were measured in both the groups.

RESULTS

Kennedy class I patients showed statistically significant higher mean condyle width but lower mean condyle height than the control group. No statistically significant difference was found between the study group and the control group regarding condyle AP dimension. There was no statistically significant difference between condyle volumes in the two groups.

CONCLUSION

Loss of posterior teeth is accompanied by significant decrease in condyle height and increase in condyle width with no change in the total condyle volume or antero-posterior dimensions.

Correlation of panoramic high-risk markers with the cone beam CT findings in the preoperative assessment of the mandibular third molars

Background/purpose

Preoperative radiographic examination of mandibular third molars (MTM) is essential to prevent inferior alveolar nerve (IAN) injury. The aim of this study was to assess the panoramic radiography (PAN) signs considered as indicators of increased risk of IAN injury and to correlate them with the cone beam CT (CBCT) findings.

Materials and methods

58 patients who had MTMs extraction between January 2012 and January 2018. OPG were evaluated for the following signs: interruption of the roof of the canal, root darkening, roots deflection and narrowing, canal deviation, superimposition between the MTM roots and mandibular canal. Loss of canal cortication, root grooving, thinning and perforation of lingual cortex were assessed in CBCT images. Chi-square test and multivariate logistic regression tests were used to test the relationship between PAN signs and CBCT findings.

Results

A total of 79 MTMs were examined. Loss of canal cortication in CBCT was seen in 22 (27.8%) of the cases. Root darkening in PAN images was the most frequent radiographic sign. Canal deviation and interruption of white line in PAN demonstrated a statistically significant correlation with the loss of canal cortication between the MTM and the mandibular canal on CBCT images (p = 0.004 and p = 0.012, respectively). No statistically significant association was observed for the other PAN signs and CBCT findings.

Conclusion

Canal deviation and interruption of white lines were associated with loss of canal cortication on CBCT, indicating a direct contact between the roots and the mandibular canal which required a further assessment prior to the extraction.

Cone Beam Computed Tomography Analysis of Root and Root Canal Morphology of First Permanent Lower Molars in a Middle East Subpopulation

Aim:

The aim of this study was to investigate variations in the number of roots and root canals in first permanent lower molars (FPLMs) using cone beam computed tomography (CBCT).

Materials and Methods:

A total of 640 CBCT images were analyzed using SIDEXIS XG software version 2.62 (Sirona Dental Systems, Bensheim, Germany). The entire root anatomy of FPLMs was investigated in three dimensions and the number of roots, root canals, and the number of canals per root were recorded. Statistical analysis was performed using the Statistical Package for the Social Sciences (SPSS) software, version 24, (IBM Corporation, USA) to determine the relationship between root anatomy and gender, age, or tooth location (right or left side).

Results:

The majority of FPLMs had two roots (96%), whereas the remaining 32 FPLMs (4%) had three roots. Almost two-thirds of the sample (62.7%) had three root canals, whereas only three cases (0.4%) of the FPLMs had six canals. When comparing bilateral differences in the distribution of root canals, it was determined that a quarter of FPLMs (24.1%) had an unequal number of canals. Moreover, there were differences in the number of additional canals between the mesial and distal roots with 17.5% of the former having three canals as compared with only 0.5% of the distal root. Interestingly, not more than one canal was observed in all additional root cases. No significant differences were observed in the number of canals between males and females or between right and left sides of the examined FPLMs (P > 0.05).

Conclusion:

Dental clinicians should be aware of the presence of an additional root in 4% of FPLMs, and about a quarter of the cases (27%) had an extra middle mesial canal in the mesial root, which was found to be more prevalent in middle age groups.

Canalis sinuosus: anatomical variation or structure?

PURPOSE

The main goal of the present study was to verify the presence, spatial location, the end of the canalis sinuosus (CS) trajectory and size of CS using cone beam computed tomography (CBCT) to characterise it as either a structure or an anatomical variation.

METHODS

A trained examiner specialist in dental radiology and imagenology selected 200 CBCT images of the maxilla from 107 (53.5%) female and 93 (46.5%) male individuals aged between 18 and 85 years.

RESULTS

A total of 133 (66.5%) patients had CS, being 61 (45.86%) unilateral and 72 (54.14%) bilateral. A higher frequency of CS was observed in males (P < 0.05) and no relationship was found between its presence and age. The end of the CS trajectory was more frequent in the regions of central incisor (n = 91; 44.39%), followed by lateral incisor (n = 45; 21.95%) and canine (n = 29; 14.15%). In our sample, the majority of these canals had a diameter of up to 1 mm (n = 198/205; 96.6%). No statistically significant relationship between diameter and the end of the CS trajectory, with location (i.e. bilateral or unilateral) was found. Gender and age had no influence on diameter, spatial location and the end of the CS trajectory (P > 0.05%).

CONCLUSION

As CS was frequently found in our sample, it can be considered an anatomical structure, and as such, it is fundamental that the dentist requests a CBCT examination before performing any invasive procedure in the maxillary region to preserve this important structure.

Comparison between Glenoid Fossa Roof Thickness in TMD and non-TMD Patients, a CBCT Study

Statement of the Problem

Various pathologic conditions can affect the thickness of the roof of glenoid fossa (RGF). The relationship between the RGF thickness and temporomandibular joint disorder (TMD) is not explicitly investigated. Considering the changes in RGF thickness, as a radiographic sign for TMD diagnosis, the phenomenon may necessitate specific treatment and may influence the treatment course and results.

Purpose

This research was designed to examine the relationship between TMD and RGF thickness changes compared to non-TMD group.

Materials and Method

In this cross sectional analytic research CBCT images of 70 TMD patients (140 joints) and 70 non-TMD individuals (140 joints) as control group were evaluated for thickness of RGF and presence of discontinuity in RGF. The distance between superior and inferior cortex of glenoid fossa was measured as RGF thickness. Inability to follow the course of cortex in any given image was considered as discontinuity. T-test, Chi-square and odds ratio (OR) were used for statistical analysis. In this study, p< 0.05 was considered meaningful.

Results

The mean thickness of RGF in our non-TMD samples was 1.12 mm. RGF thickness was significantly increased in TMD patients compared non-TMD group (p= 0.00). This value was also greater in males. On the other hand, TMD patient showed a higher incidence of discontinuity in RGF, in comparison with non-TMD patients (p= 0.006).

Conclusion

The increased thickness of RGF can be considered as a sign of TMD, which may help in diagnosis of TMD. It seems that there is a direct relationship between TMD and discontinuity of RGF.

Quantifying Subresolution 3D Morphology of Bone with Clinical Computed Tomography

The aim of this study was to quantify sub-resolution trabecular bone morphometrics, which are also related to osteoarthritis (OA), from clinical resolution cone beam computed tomography (CBCT). Samples (n = 53) were harvested from human tibiae (N = 4) and femora (N = 7). Grey-level co-occurrence matrix (GLCM) texture and histogram-based parameters were calculated from CBCT imaged trabecular bone data, and compared with the morphometric parameters quantified from micro-computed tomography. As a reference for OA severity, histological sections were subjected to OARSI histopathological grading. GLCM and histogram parameters were correlated to bone morphometrics and OARSI individually. Furthermore, a statistical model of combined GLCM/histogram parameters was generated to estimate the bone morphometrics. Several individual histogram and GLCM parameters had strong associations with various bone morphometrics (|r| > 0.7). The most prominent correlation was observed between the histogram mean and bone volume fraction (r = 0.907). The statistical model combining GLCM and histogram-parameters resulted in even better association with bone volume fraction determined from CBCT data (adjusted R² change = 0.047). Histopathology showed mainly moderate associations with bone morphometrics (|r| > 0.4). In conclusion, we demonstrated that GLCM- and histogram-based parameters from CBCT imaged trabecular bone (ex vivo) are associated with sub-resolution morphometrics. Our results suggest that sub-resolution morphometrics can be estimated from clinical CBCT images, associations becoming even stronger when combining histogram and GLCM-based parameters.

Evaluation of maxillary sinus volume and surface area in children with β-thalassaemia using cone beam computed tomography

OBJECTIVES

Among children with β-thalassaemia, skeletal changes and abnormalities, such as decreased volume or obliteration of the sinus, result primarily from hypertrophy and expansion of the erythroid marrow due to ineffective erythropoiesis. This study evaluated the volumes and surface areas of the maxillary sinuses of children with β-thalassaemia using cone beam computed tomography (CBCT), and compared these findings with corresponding measurements in age- and sex-matched control children.

METHODS

CBCT images were retrospectively evaluated for 16 children with β-thalassaemia, 19 children with a class I skeletal pattern (class I group), and 18 children with a class II skeletal pattern (class II group). After three-dimensional analyses and segmentation of each maxillary sinus, the volumes and surface areas were calculated.

RESULTS

The volumes and surface areas of the right (p > 0.05 and p > 0.05) and left maxillary sinuses (p > 0.05 and p > 0.05) and SNA angles (p > 0.05) were not significantly different among the groups. The ANB (p < 0.05) and SNGoMe (p < 0.05) angles were significantly greater and the SNB (p < 0.05) angle was significantly smaller in the class II and thalassaemia groups than in the class I group.

CONCLUSION

Children with thalassaemia tended to have lower maxillary sinus volumes and surface areas on both right and left sides, compared to those of children with class I and class II skeletal patterns; however, these differences were not statistically significant. In children with thalassaemia, a large intermaxillary discrepancy (ANB) indicated a tendency toward the class II skeletal pattern.

Evaluation of pneumatic cavities surrounding temporomandibular joint by cone beam computed tomography

OBJECTIVE

The purpose of this study was to detect the prevalence and characteristics of pneumatization in the roof of the glenoid fossa (PRGF) and articular eminence (PAT) by using cone beam computed tomography (CBCT) images.

MATERIAL AND METHOD

CBCT images of 378 patients (756 TMJ) were analyzed to determine the PRGF and PAT. Twenty-eight patients were excluded due to some reasons such as trauma, degeneration, previous surgical operation of temporomandibular joint (TMJ). Pneumatization was detected in 297 of 350 patients, but not pneumatization in 53 patients. Age, gender, laterality (unilateral, bilateral) and lacunarity (unilacunar, multilacunar) were recorded. Unilateral types were also noted as right and left localization. Chi-square test was used to evaluate relationship between pneumatization and gender, lacunarity and laterality.

RESULTS

PRGF and/or PAT were diagnosed in 491 (70%) TMJ components whom 178 (51%) were male and 172 (49%) were female with mean age of 40.38±18.34 years. In total, 103 (35%) of the patients had unilateral and 194 (65%) patients had bilateral pneumatization.

CONCLUSION

CBCT provides reliable and precise images to detect pneumatization surrounding TMJ structure in comparison to 2D images. Evaluation of TMJ components accurately before surgical intervention is crucial to prevent complication or increase the success of therapy.

Morphometric analysis of occipital condyles using alternative imaging technique

PURPOSE

The occipital condyles (OCs) are crucial anatomical structures in the cranial base. To our knowledge, there is no cone beam computed tomography (CBCT)-based study on the morphometric analysis of OCs. The aim of this study was to evaluate the morphometric analysis of OCs using CBCT.

METHODS

CBCT images of 200 OCs from 100 patients of which 39 males and 61 females in the age group of 18-67 years were included in the study population. Linear and angular measurements of OCs were performed.

RESULTS

The average OC width, length, height, sagittal angle, and effective height were 10.3 ± 1.3 mm, 19.6 ± 2.0 mm, 9.1 ± 1.4 mm, 7.4 ± 1.7 mm, and 35.3 ± 5.2 mm. Condylar width and sagittal angle measurements were found significantly different between the right and left sides; and were not found significant difference between the right and left sides in the measurements of condylar height, length, and effective height. Also the average intercondylar anterior distance (ICAD), intercondylar posterior distance (ICPD), distance between the basion and the anterior apex of the occipital condyle (B-AAOC), distance between the basion and posterior apex of the occipital condyle (B-PAOC), distance between the opisthion and anterior apex of occipital condyle (O-AAOC), and distance between the opisthion and posterior apex of occipital condyle (O-PAOC) were 20.9 ± 1.5 mm, 44.0 ± 2.0 mm, 12.3 ± 1.9 mm, 34.5 ± 4.2 mm, 29.8 ± 1.7 mm, and 27.0 ± 2.1 mm. There was not significant difference in the morphometric measurements among age groups. All morphometric measurements showed a significant difference depending on gender.

CONCLUSIONS

The morphometric evaluation of OCs may be effectively examined using CBCT. Linear and angular measurements data of OCs in the present study may be used as a reference database for future morphometric and surgical investigations.

Cone beam computed tomographic evaluation of styloid process: A retrospective study of 1000 patients

Objective:

The styloid process (SP) is a bony projection, located just anterior to the stylomastoid foramen, the normal length of which is approximately 20–30 mm. The length of SP when exceeds 30 mm it is said to “elongated.” The purpose of this retrospective study was to assess the prevalence of elongated SP (ESP) by cone beam computed tomography (CBCT) examination in Turkish subpopulation and its relation to gender and age.

Materials and Methods:

This study analyzed CBCT of 1000 patients who were randomly selected to participate and were aged from 14 to 78 years. Any radiograph with questionable SP was excluded from the study. The apparent length and thickness of the SP were measured by two dental and maxillofacial radiologists. The ESP was classified with radiographic appearance-based morphology of elongation. The data were analyzed with the IBM SPSS Statistics 20.0.

Results:

The mean age of patients was 42.49 ± 14.83 years. The length of SP was measured over 30 mm in 151 patients (15.1%). A total of 151 CBCT showed ESP, of which 87 (57.6%) were noticed in males and 64 (42.4%) in female patients. The length of right-sided SP ranged from 30.05 to 85.49 mm and left-sided SP from 30.14 to 83.72 mm.

Conclusion:

CBCT is a valuable diagnostic imaging tool which makes accurate length measurements. It is important for the clinicians to be aware of natural variations of the SP whose clinical importance is not well understood.

Risks of angled implant placement on posterior mandible buccal/lingual plated perforation: A virtual immediate implant placement study using CBCT

Background/purpose

Immediate implant placement has been considered to be a successful treatment procedure. The bone plate perforation (BPP) may be one of severe complication and potentially life-threatening situation. The aim of this virtual study is to evaluate the influences of angled implant insertion on BPP during immediate implant installation in the posterior mandible.

Materials and methods

Cone beam computed tomography images of 488 posterior teeth from 61 patients were selected. Virtual immediate implant placement (VIIP) was performed at each posterior tooth following the appropriate axis with the prosthetic-driven planning and different deviation angles of 3-, 6-, or 9-degree. BPP was then examined from cross-sectional images obtained. Furthermore, the relation of lingual bony morphology and BPP were also determined.

Results

The incidence of buccal and lingual BPP increased as the deviation angle increased in posterior mandible area. Incidence of lingual BPP was significantly influenced by angular deviation and type of lingual bony morphology after adjusting for age, gender, tooth type, and right/left side. An increase in incidence odds of over 6-fold (OR = 6.583) was noted for placements angled by 9° compared with placements made without angulation, and an increase in incidence odds of over 3-fold (OR = 3.622) was noted for teeth with the undercut-type lingual morphology compared with the other types.

Conclusion

The present Results indicate that accurate selection of the implant insertion angle and full awareness of the bony anatomy at the implant recipient site are essential to prevent BPP in the posterior mandible.

Comparative determination of skeletal maturity by hand-wrist radiograph, cephalometric radiograph and cone beam computed tomography

OBJECTIVES

The purpose of this study is to assess the stages of skeletal maturity in cone beam computed tomography (CBCT), hand-wrist radiography (HWR) and cephalometric radiography (CR) techniques of orthodontic patients, and associate skeletal maturity stages with chronological age, in a Turkish subpopulation.

METHODS

Hand-wrist radiographs, cephalometric radiographs and CBCT of 105 patients were evaluated. For evaluation of HWR, the "Hand Bone Age A Digital Atlas of Skeletal Maturity" of Vicente Gilsanz and Osman Ratib (2005) was used. Skeletal maturation in the cephalometric radiographs and sagittal sections of cervical vertebrae obtained by CBCT were evaluated with Hassel and Farman's method (1995). All results were re-evaluated 3 weeks later to assess intra-observer reliability.

RESULTS

Intra-observer reliability coefficients of the skeletal maturity stages in HWR, CR, and CBCT were 0.912, 0.595, 0.756 respectively (p < 0.05). Spearman's correlation coefficient value between skeletal developmental stages in in HWR, CR, and CBCT was found to be 0.785, 0.875, and 0.791, respectively (p < 0.05).

CONCLUSION

Results of this study reveal that the determination of the skeletal development status with analysis of cervical vertebrae using cephalometric radiographs and CBCT is as reliable method as the evaluation of the hand-wrist radiographs and is compatible with chronological age in a subgroup of the Turkish population. When assessing the skeletal development stages of patients, both CBCT and CR can be used validly, so no extra hand-wrist radiography is required. This information is important for the prevention of increased radiation doses in patients.

Evaluation of upper airway volume and craniofacial volumetric structures in obstructive sleep apnoea adults: A descriptive CBCT study

OBJECTIVE

The aim of this investigation was to assess, with a descriptive three-dimensional evaluation, the volume of upper airway (UAWV) and the volume of craniofacial structures in adult patients suffering from obstructive sleep apnoea (OSA) and compare them to the corresponding findings in adults with no sleep disorders.

MATERIALS AND METHODS

The sample consisted of 54 adult males, 27 suffering from OSA diagnosed by means of the Apnoea Hypopnea Index and 27 with no history of sleep disorders. All subjects had a cone beam computerized tomography scan performed with the same head position. UAWV was assessed with the Amira® software, and craniofacial volumes by means of a specially developed data-processing program, which allowed the construction of tetrahedrons using anatomical landmarks. Assessed volumes were naso-maxillary, cranium upper anterior, oral cavity, post-oral cavity, hyoid to mandible, and post-hyoid. SPSS (version 19.0) was used for the statistical analysis. The Levene's test for Equality of Variance, the t-test for Equality of Means and the Mann-Whitney test were used to evaluate the variables. The level of significance was set at P ≤ 0.05.

RESULTS

The mean value of UAWV was smaller in the OSA group. The post-hyoid volume, the calculated posterior volume, and the ratio of posterior to total volume showed differences between the groups.

CONCLUSIONS

Craniofacial structures did not show significant differences between the groups, but in the OSA group the posterior space released for upper airway was significantly bigger and UAWV was significantly smaller.

Comparison of Accuracy and Reliability of Working Length Determination Using Cone Beam Computed Tomography and Electronic Apex Locator: A Systematic Review

AIM

To compare the accuracy and reliability of cone beam computed tomography (CBCT) and electronic apex locator (EAL) in determining the working length (WL).

BACKGROUND

A comprehensive literature search was conducted across several databases and gray literature. A total of 1,358 potentially relevant journal articles were identified with publication dates ranging from 1996 to 2017. After screening and applying the inclusion and exclusion criteria, five studies were identified as eligible for review. Data extraction was completed in two blinded pairs, cross-referenced and subsequently merged. Discrepancies were resolved through collaborator mediation. Meta-analysis was not undertaken due to heterogeneity between included studies.

REVIEW RESULTS

In all five studies, no statistically significant difference was found between CBCT and EAL measurements of WL. The reliability of CBCT compared with EAL was not determined.

CONCLUSION

Due to significant heterogeneity between the included studies, the accuracy of CBCT compared to EAL couldn't be determined. Based on limited evidence, CBCT appeared to be as accurate as EAL. There was weak evidence suggesting that CBCT was reliable. Also the superiority of one method over the other could not be determined. These results should be interpreted judiciously. Further research is required to conclusively evaluate the accuracy and reliability of CBCT compared with EAL.

CLINICAL SIGNIFICANCE

Preexisting CBCT scans may be appropriate for WL determination but acquiring a new CBCT for endodontic treatment is inadvisable due to cost and the as low as reasonably achievable (ALARA) principle.

Age estimation using canine pulp volumes in adults: a CBCT image analysis

Secondary dentine deposition is responsible for the decrease in the volume of the pulp cavity with age. Therefore, the volume of the pulp cavity can be considered as a predictor for estimating age. The aims of this study were to investigate the relationship strength between canine pulp volumes and chronological age from homogenous (approximately equal numbers of individuals in each age range) age distribution and to assess the effect of sex as predictor in age estimation. This study was performed on 719 subjects of Pakistani origin. Cone beam computed tomography images of 521 left maxillary and 681 left mandibular canines were collected from 368 females and 349 males aged from 15 to 65 years. Planmeca Romexis® software was used to trace the outline of the pulp cavity and to calculate pulp volumes. Regression analysis was performed to assess the correlation between pulp volumes considering with and without sex as a predictor with chronological age. The obtained results showed that mandibular canine pulp volume and sex have the highest predictive power (R² = 0.33). The relationship between mandibular canine pulp volume and sex with chronological age demonstrates an odd S-shaped non-linear relationship. A statistically significant difference in volumes of pulp was found (p = 0.000) between males and females. The conclusion was that predictions using the pulp volume of the mandibular canine and sex produced the best estimates of chronological age.

Frequency, location, and morphology of accessory maxillary sinus ostia: a retrospective study using cone beam computed tomography (CBCT)

PURPOSE

To evaluate the reliability of cone beam computed tomography (CBCT) imagining in the assessment of the frequency, location, and morphological characteristics of accessory maxillary ostia (AMOs), and to analyze a potential association with sinus and dentoalveolar pathologies.

METHODS

CBCT scans with bilateral maxillary sinuses that were acquired from September 2016 to September 2018 were initially screened. A total of 160 CBCT scans (320 sinuses) that fulfilled the inclusion criteria were included for further analysis. The presence, location, and morphological characteristics of the AMOs were evaluated in axial, coronal, and sagittal CBCT views. The findings were correlated with age, gender, sinus, and dentoalveolar pathology to assess for potential influencing factors on AMOs.

RESULTS

An AMO was present in 151 (47.2%) of the 320 sinuses. Most of the AMOs were located within the region of the nasal fontanelle or hiatus semilunaris (81.1%) presenting with an ovaloid (48.4%) or a round shape (39.0%). The average length of the AMOs was 2.33 ± 1.42 mm, occupying an area of 3.43 ± 4.51 mm², respectively. Morphological changes of the maxillary sinus mucosa were positively associated with length and area of AMOs. Furthermore, the status of the dentition in the posterior maxilla seemed to be an influencing factor on AMO shape.

CONCLUSIONS

Nearly half of the maxillary sinuses assessed in the present study population had an AMO. Pathologies of the maxillary sinus seem to have an impact on AMOs, which is demonstrated here by morphological changes of the sinus mucosa being associated with an increase in length and area of accessory ostia.

Cone-beam computed tomography of the head in standing equids

Background

Computed tomography in standing horses has revolutionized diagnostic imaging. The O-arm®, a cone beam computed tomography (CBCT) scanner with a gantry opening of 96.5 cm is routinely used for image-guided spine and neurosurgery in humans. The aim of this study is to describe the set-up and first experiences using the O-arm® to achieve CBCT imaging of the head in standing horses.

CT imaging of the predefined region of interest (ROI) was tested on 2 cadaveric heads, concentrating on centering issues within the gantry, as well as determining the number of scans needed per ROI. All horses presented with head-related diseases and subjected to a CBCT examination between February 2015 and November 2016 for CBCT were included. Per scan, a limited field of view, i.e. a cylindrical volume of 21 cm in diameter and 16 cm in height was acquired within 13 s. Depending on the dimensions of the ROI, the minimum number of scans could range from one to six, if the entire equine head is to be examined in an adult horse.

Results

Sixty-eight horses were included, five of which had a follow-up CBCT exam, and two of which were presented twice for two different indications (75 clinical cases). A total number of 449 acquired three-dimensional (3D) scans were recorded for these 75 cases. Two-hundred and forty-two 3D scans (54%) were considered as diagnostic quality. The imaging procedure was generally well tolerated by the sedated, standing equid, and diagnostic studies were performed in 73 out of 75 cases (97.3%). Motion artefacts and inadequate centering of the ROI were the most common reasons for non-diagnostic quality images and repeat scans of the same ROI.

Conclusions

CBCT is a valuable imaging modality for the equine head. Advantages of the O-arm® compared to a conventional multi-slice helical CT for imaging of the head in standing equids include the rapid image acquisition, the gantry’s mobility in all dimensions, and the free movability of the entire imaging unit. Disadvantages include the considerable sensitivity to motion artefact, increased scatter, low soft tissue contrast and the limited dimensions of the field of view.

Investigation using cone beam computed tomography analysis, of radicular grooves and canal configurations of mandibular premolars in a Turkish subpopulation

OBJECTIVE

To conduct an in vivo evaluation of prevalence of root canal configurations, lengths of C-shaped canals, prevalence and depths of radicular grooves (RGs), in mandibular first and second premolars in a Turkish subpopulation using cone beam computed tomography (CBCT).

MATERIALS AND METHODS

CBCT images of 327 first and 264 second premolars were included. Canal configurations, locations, lengths, and types of C-shaped canals, and RGs were evaluated on CBCT images. Data were statistically analyzed (P < 0.05).

RESULTS

First and second premolars were classified as follows: type I, (83.8%, 97.72%); type V, (12.22%, 0.76%); type III, (3.06%, 0.76%); and other types. RGs were exhibited by 14.68% of first and 2.27% of second premolars (P < 0.05). Incidence of complex canals (types III, V and other types, 89.8%) in first premolars with RGs was significantly higher versuswithout RGs (P < 0.05). C-shaped configuration was exhibited by 4.58% of first (80% semilunar-type), and 1.13% of second premolars (P < 0.05). All first premolars with C-shaped canals showed RGs and complex canals.

CONCLUSIONS

Complex canals and RGs frequently co-exist in mandibular premolars. C-shaped canals are not common in mandibular premolars, and mostly located in middle thirds. Type V is the most prevalent complex canal configuration in first premolars, and frequently associated with a C-shaped semilunar-type anatomy.

Three-dimensional evaluation of mandibular volume in patients with cleft lip and palate during the deciduous dentition period

OBJECTIVES

To examine the relationship between mandibular volume and craniofacial morphology in patients with cleft lip and palate using cone beam computed tomography (CBCT) and to compare these findings with control (noncleft) patients undergoing CBCT for other purposes during the deciduous dentition period.

MATERIALS AND METHODS

Eighty-four patients were categorized into the unilateral cleft lip and alveolus (UCLA) group (n = 25; mean age, 4.60 ± 0.40 years), unilateral cleft lip and palate (UCLP) group (n = 23; mean age, 4.52 ± 0.39 years), bilateral cleft lip and palate (BCLP) group (n = 22; mean age, 4.54 ± 0.37 years), and control group without cleft (n = 14; mean age, 5.19 ± 0.52 years). Mandibular volume and craniofacial cephalometric measurements were obtained using CBCT. All measurements were assessed by analysis of covariance (ANCOVA) using Bonferroni post hoc pairwise comparison tests.

RESULTS

ANCOVA revealed no statistically significant differences in mandibular volume among the groups. SNA° and ANB° were significantly larger in the UCLA and BCLP groups than in the control group. SN-MP° was smallest in the UCLA group. Co-A in the UCLP group was shorter than in the UCLA and BCLP groups. Go-Gn was shortest in the UCLP and BCLP groups compared with the control group.

CONCLUSIONS

Three-dimensional evaluation of craniofacial morphology using CBCT can provide valuable information on malocclusion and other dentoskeletal problems among patients with CLP.

Genial tubercles: Morphological study of the controversial anatomical landmark using cone beam computed tomography

BACKGROUND

Identification of the morphology of the genial tubercles (GTs) is valuable for different dental applications. The morphological pattern of the GTs is still controversial, and therefore, the study of its morphology using cone beam computed tomography (CBCT) plays a valuable role in resolving the controversy.

AIM

To assess the morphological pattern, dimensions and position of the GTs using CBCT among a selected Saudi population.

METHODS

CBCT records of 155 Saudi subjects (49 female and 106 male) were used to assess the pattern and size of the GTs and to determine the distance from the apices of the lower central incisors to the superior border of the GTs (I-SGT) and the distance from the inferior border of the GTs to the menton (IGT-M).

RESULTS

The results of this study showed that the most common morphological pattern was of two superior GTs and a rough impression below them (36.8%), followed by two superior GTs and a median ridge representing fused inferior GTs below them (22.6%) and a single median eminence or projection (20%). The classically described pattern, of two superior and two inferior GTs placed one above the other, was found in only 14.2% of cases, while 6.4% of the studied cases had no GTs. The mean width and height were 6.23 ± 1.93 mm and 6.67 ± 3.04 mm, respectively, while the mean I-SGT and IGT-M measurements were 8.26 ± 2.7 mm and 8.13 ± 3.07 mm, respectively.

CONCLUSION

The GTs are a controversial anatomical landmark with wide variation in their morphological pattern. The most common pattern among the studied Saudi sample was of two superior GTs and a rough impression below them, and there were no significant differences between males and females.

Relationship between condyle cortication, sphenooccipital synchondrosis, and chronological age

OBJECTIVE

To assess the relationship between chronologic age, mandibular condyle cortication, and sphenooccipital synchondrosis (SOS) fusion.

METHODS

Cone Beam Computed Tomography data of 253 patients were retrospectively evaluated. Mandibular condyle cortication was divided into three classes as Types I, II, and III. SOS fusion grade was categorized using a four-stage system (0-3). These variables were evaluated in relation to age and sex.

RESULTS

There were significant positive relationships between age and condyle cortication, and between age and SOS fusion stage and between cortication type and SOS fusion stage.

CONCLUSION

Due to the positive correlation between the degree of SOS fusion stage, the condyle cortication type, and the chronological age, these indicators can be used for age estimation.

Assessment of prevalence and volumetric estimation of possible Stafne bone concavities on cone beam computed tomography images

OBJECTIVES

Our study aimed to determine the prevalence and volumetric estimates of Stafne bone cavities (SBC) on cone beam computed tomography (CBCT) images.

METHODS

This retrospective study, which involved the CBCT images of 1141 men and 1260 women with an age range of 10-90 years, aimed to determine the prevalence of SBCs and to calculate their volumes using the semi-automatic segmentation method.

RESULTS

A total of 15 SBCs were diagnosed in 14 patients. Among the detected SBCs, 7.14% were found in a female patient and 92.86% were found in 13 male patients. Of the total number of SBCs, 6.67% were anteriorly located and 93.33% were posteriorly located. Bilateral SBCs had a prevalence of 0.04%; unilateral posterior SBCs 0.54% and anterior SBCs 0.04%. The mean SBC volume was calculated as 338.05 mm³.

CONCLUSIONS

The results of our study showed that SBC is a rare anomaly. In contrast to two-dimensional imaging techniques, CBCT allows a precise determination of SBCs' pattern of impact on adjacent bony structures, relationship with the mandibular canal and dimensions.

Anatomical analyses for maxillary sinus floor augmentation with a lateral approach: A cone beam computed tomography study

BACKGROUND

Various anatomical references and structures should be analyzed prior approaching a surgery in the maxillary sinus. The objective of the present study was to evaluate the anatomical structures and references involved in sinus floor elevation with a lateral approach.

MATERIALS AND METHODS

Seventy-five patients planned for sinus floor elevation were included in the study. Eighty-eight maxillary sinuses were evaluated using cone beam computed tomographies (CBCTs). The nasal floor was used as main reference (X) and sinus mucosa width, bone crest height, palatal-nasal recess angle (PNR), sinus width at the level of the nasal floor, distance from the nasal floor to the base of the sinus (X-F), position of the posterior superior alveolar artery (PSAA height) and diameter (PSAA diameter), lateral bone wall width at 3mm (LW 3mm) and 9mm (LW 9mm) from the base of the sinus (F), patency of the ostium (OP), and presence and position of septa have been evaluated.

RESULTS

The mean dimensions and standard deviations were the following: mucosa thickness was 2.0±1.4mm, bone crest height 2.8±1.4mm, distance X-F 8.3±1.9mm, PNR angle 135.5±23.1, sinus width 12.6±4.2mm, X-F 8.3±1.9mm, PSAA height 14.4±2.9mm, PSAA diameter 1.1±0.4mm, LW 3mm 1.5±1.2, LW 9mm 1.3±0.6mm, OP 1.9±0.4mm. Septa were present in 19.3% of the sinuses evaluated and were located mostly in the molar region.

CONCLUSIONS

In conclusion, the analysis of the CBCT before sinus floor elevation allows the identification of anatomical structures and references that might be used for the planning of the surgical approach, aiming to improve the outcome of the treatment and to avoid possible complications.

Computed Tomography Versus Dacryocystography for the Evaluation of the Nasolacrimal Duct-A Study With 72 Patients

Objectives

In patients with epiphora, imaging of the nasolacrimal duct is essential not only for differential diagnosis, but also for preoperative planning. Advances in imaging technology and introduction of cone beam computed tomography (CB‐CT) enable the combination of contrast agent‐based imaging with a three dimensional tomography with low radiation exposure. However, the value of CT/CB‐CT as an alternative to conventional dynamic dacryocystography (DCG) has not been evaluated yet.

Study Design

Retrospective study.

Methods

Conventional DCG was performed preoperatively in 72 consecutive patients treated for epiphora between 01/2013 and 04/2015 in our department. CB‐CT or conventional CT was performed afterward with the contrast media still in place. Three separate experts (two radiologists and one otorhinolaryngologist) analyzed the radiographic images without any information about the respective clinical or surgical findings. The presence of further findings in the CT/CB‐CT (eg, septal deviation, sinusitis) that were not detected in DCG and the overall visibility of the lacrimal duct system in both modalities were evaluated.

Results

Good delineations of bone, soft tissue, and contrast agent in the lacrimal system were achieved with both methods. No side effects were noted. Beside the pathology of the lacrimal duct, CT/CB‐CT scans enabled the additional diagnosis of pathologies in the nose and the sinus system in 65.7% of the patients. Accordance in the identified level of obstruction between the two modalities was achieved in 71.4% of the patients.

Conclusion

Thus, CT/CB‐CT should be used in conjunction with contrast agent to reliably identify the level of obstruction as preoperative standard and can be used as diagnostic tool in addition to or even instead of conventional DCG.

Level of Evidence

4

Comparing dental identifier charting in cone beam computed tomography scans and panoramic radiographs using INTERPOL coding for human identification

According to INTERPOL, the comparison of antemortem and postmortem dental identifiers is a scientifically reliable approach for human identification. This study aimed to quantify the prevalence of corresponding INTERPOL coded dental identifiers in cone beam computed tomography (CBCT) scans and panoramic radiographs (PR). The sample consisted of 100 CBCT scans and 100 PR taken the same day from the same patients (35 males and 65 females). Randomly and independently, forty-one INTERPOL coded dental identifiers were searched in each image. Wilcoxon test compared the prevalence of codes in CBCT scans and PR, Chi-square tested the dependence between codes and teeth; and multiple correspondence analyses (MCA) explored the association between codes and teeth in color maps for CBCT scans and PR. No statistically significant differences between the prevalence of identifiers in CBCT scans and PR were detected (p=0.693). In CBCT scans and PR, dependence between teeth and codes was detected (p<0.05). In the study sample, the strongest associations were found between the codes unerupted (UNE), partially erupted (ERU) and impacted (IMV) and third molars, both in CBCT scans and PR. INTERPOL coded dental identifiers registered on CBCT scans and PR can be exchanged during human identification.