3D Cone Beam Research Articles

Three-dimensional comparison of bone-borne and tooth-bone-borne maxillary expansion in young adults with maxillary skeletal deficiency.

To compare the transverse dental and skeletal changes in patients treated with bone-anchored palatal expander (bone-borne, BB) compared to patients treated with tooth and bone-anchored palatal expanders (tooth-bone-borne, TBB) using cone-beam computer tomography (CBCT) and 3D image analysis. The sample comprised 30 patients with transverse maxillary discrepancy treated with two different types of appliances: bone-borne (Group BB) and tooth-bone-borne (Group TBB) expanders. CBCT scans were acquired before (T1) and after completion of maxillary expansion (T2); the interval was 5.4 ± 3.4 and 6.2 ± 2.1months between the T1 and the T2 scans of Group TBB (tooth-bone-borne) and Group BB (bone-borne), respectively. Transverse, anteroposterior and vertical linear and angular three-dimensional dentoskeletal changes were assessed after cranial base superimposition. Both groups displayed marked transverse skeletal expansion with a greater ratio of skeletal to dental changes. Greater changes at the nasal cavity, zygoma and orbital levels were found in Group BB. A relatively parallel sutural opening in an anterior-posterior direction was observed in Group TBB; however, the Group BB presented a somewhat triangular (V-shaped) opening of the suture that was wider anteriorly. Small downward-forward displacements were observed in both groups. Asymmetric expansion occurred in approximately 50% of the patients in both groups. Greater skeletal vs dental expansion ratio and expansion of the circummaxillary regions were found in Group BB, the group in which a bone-borne expander was used. Both groups presented skeletal and dental changes, with a similar amount of posterior palate expansion. Asymmetric expansion was observed in both groups.

Cone Beam Computerized Tomographic Analysis of Collum Angle of the Maxillary Central Incisors in Different Types of Malocclusion: Comparative Assessment in Saudi, Jordan and Egypt Subpopulation.

Background: The collum angle (CA) is an extremely significant for patients who are undergoing orthodontic, dental implant restoration, prosthodontic and periodontic treatments. Aim and Objectives: To determine and compare the mean CA for maxillary central incisor in different types of malocclusion utilizing 3D Cone Beam Computerized Tomography (CBCT) images. The additional objectives were to determine and compare the mean CA for maxillary central incisor based upon the demographic characteristics among Saudi, Jordan and Egypt subpopulation and to test for significant differences in the CA of maxillary central incisor with different molar malocclusions. Methodology: A total of 400 CBCT images were included from the radiology archive at the College of Dentistry, Jouf University (Sakaka, Saudi Arabia). The CBCT images were divided into four groups based upon molar classifications. The selected records were used for the measurement of CA of maxillary central incisor using the measurement tool built into 3D:OnDemand software. Statistical analysis was done using independent t test and ANOVA to examine the differences between gender and races. Results: The mean CA for Class II div 2 exhibited significantly higher crown-root variation as compared other groups (p < 0.0001). Males sample showed greater value of CA for each group as compared to the females and this difference was statistically significant for all the groups other than for Class I (p < 0.05). The post hoc pairwise comparisons between the races showed statistically insignificant findings (p > 0.05). Significant difference was found on pairwise comparisons among different malocclusion groups other than for group Class I/Class II div 1 (p < 0.05). Conclusion: The CA of Class II div 2 group was the greatest as compared to other malocclusion groups. Males sample showed greater value of CA for each group as compared to the females and this difference was statistically significant for all the groups other than for Class I. Statistically insignificant difference was noted for the mean CA among different races whereas significant difference was found on pairwise comparisons among different malocclusion groups other than for group Class I/Class II div 1.

Comparison of cephalometric measurements with conventional lateral cephalic 2D and reconstructed lateral cephalic of CBCT

Lateral cephalic radiography is mainly used to describe the morphology and growth of the craniofacial skeleton. It is considered a valuable diagnostic aid in orthodontics to plan treatment and evaluate the results. (1)(2) Cephalometric analyses requires identifying specific reference points and calculating various angular and linear dimensions. (3) Because cephalometry has been one of the most important diagnostic tools available to orthodontists for more than seven decades, different cephalometric norms have been published by leading physicians and researchers and it is used for: diagnosis, treatment progress, post-treatment evaluation, and research. (4) According to the orthodontic literature, other reconstructions such as lateral cephalic are known from more recent 3D cone beam computed tomography images. The attempt to develop 3D analysis and diagnosis is more interesting today. (4) (15) (23) Lateral cephalic radiographs are two-dimensional (2D) images that are used to represent three-dimensional (3D) structures. (5) Due to the different disadvantages of a 2D lateral cephalic X-ray: geometric distortion and the superposition of anatomical structures, 3D imaging has overcome the hurdle of 2D imaging by allowing orthodontists to visualize craniofacial structures without overlap or distortion.(6)(7)

Can the Density of Mineralized Dental Tissues (Dentin and Enamel) Be Measured and Compared with 3D Cone Beam Computed Tomography in Cases of Ectodermal Dysplasia?

BackgroundSince 3-dimensional cone beam computed tomography (CBCT) started to be used in dentistry, mineral density can now be examined with computer software from the data on the images obtained. Detailed and clear images at different slice intervals can be obtained with CBCT, and mineral density can be measured from the image data on a computer with a Hounsfield unit (HU) scale. In addition to the broad opportunities presented by CBCT, this feature has presented a wider perspective to researchers.Material/MethodsIn this study, the CBCT images obtained from patients with the genetic disorder of ectodermal dysplasia were compared with the images of a control group to determine differences in mineralization of the teeth and to show that these could be compared by measuring the mineral density of dentin and enamel tissues using the HU scale on data from CBCT images. This opens new opportunities for cognitive and implementation research.ResultsIn the study, CBCT images of 14 ectodermal dysplasia and 14 control group cases previously obtained for various reasons were used. Mineral density measurements were made from 4 different regions of the teeth of the ectodermal dysplasia and control groups (incisor edge of the crown, the center buccal, cervicale line, and apex of the teeth), and the groups were compared.ConclusionsThe aim of this study was to provide a new overview of the feasibility and suitability of mineralization measurement of dentin and enamel dental tissues with CBCT in ectodermal dysplasia and control groups.

Stress distribution in restorations with glass fiber and polyetheretherketone intraradicular posts: An in silico analysis.

This study evaluated stresses generated at maxillary central incisor (21) root restored with lithium disilicate crown (LDC), and glass fiber (GFP) or polyetheretherketone (PEEK) post. 3D models created by computed tomographic image (i-CAT Cone Beam 3D Dental Imaging System) reproduced maxillary central incisor. Each model had prosthetic LDCs (2.0 mm thick) cemented to GFP or PEEK posts with dual resin cement. Different loads were applied to each model (cervical, incisal, axial, middle). At maximum principal stress, PEEK showed higher stress than GFP in all loads, but with qualitative similarity. At minimum principal stress, PEEK and GFP showed qualitative and quantitative similarities, except axial load. Maxillary central incisor restored with GFP or PEEK and LDC presented, in general, similar stress intensity and distribution for main occlusal loads. Only two of sixteen occlusal loads tested (cervical for maximum principal; axial for minimum principal) showed significant quantitative difference.

Evaluation of amniotic membrane in the healing of apicomarginal defects using 2D and 3D imaging modalities: a randomized controlled trial.

The study aimed to evaluate healing in apicomarginal defects with amniotic membrane (AM) using 2D periapical radiography and 3D cone beam computed tomography imaging. Thirty-four patients with symptomatic apical periodontitis and apicomarginal communication were allocated to either the AM or control group. Clinical and radiographic assessment was performed at baseline and at 12 months using Molven criteria, modified Penn 3D criteria, and RAC and B indices at resected plane, apical area, cortical plate, and combined apicocortical area, respectively. There was no significant difference in the healing outcome in 2D imaging (93.3% control and 86.7% AM) and 3D imaging (80.0% control and 53.3% AM) between the groups. With RAC scoring, a greater percentage of unhealed cases was observed in cortical plate. Radiographic buccal bone formation in the 3D imaging was evident only in six cases. However, both the groups depicted significantly greater percentage reduction in the size of the lesion in 2D than the 3D analysis (AM group 91.69 ± 15.99 2D, 76.06 ± 47.62 3D, P = .020) and (control group 92.06 ± 14.36 2D, 85.12 ± 18.55 3D, P = .005). No significant difference in healing was observed between the AM and the control groups with the use of both periapical radiography and CBCT imaging. Despite good clinical healing and radiographic apical bone fill, buccal bone formation was not evident in 3D imaging in most of the cases.

Assessment of sexual dimorphism using 3D CBCT image data among Indians.

It is of interest to investigate the use of frontal sinus morphology, bizygomatic and intermaxillary distance for the determination of gender using Cone-Beam Computer Tomography (CBCT). The study population consisted of 75 subjects (35 females and 40 males) with a mean age of 39.25 years (range: 20-70 years), of ethnic group of south-Indian based population. The data was categorized into three age groups of 20-35, 36-50 and ≥ 50 years. All the features and measurements are recorded for each case using CBCT images that were acquired with a CBCT scanner (Planmeca Mid Proface Cone Beam 3D, Helsinki Finland). The data were subjected to a discriminant functional analysis, compared and statistically analyzed. No two persons had the same measurements. Statistically significant differences were found in the frequency of overall metric parameters between the two genders (P < 0.05) except intermaxillary distance (P = -0.034) respectively. These data provide a valuable tool in differentiating gender. It should be noted that bizygomatic distance can significantly improve the gender determination using discriminant analysis. Cone beam computed tomography is a safe procedure with minimal radiation exposure proved to be highly accurate in sinus imaging and provide irreplaceable and precise information about frontal sinus and the whole skull. Measurements showed significant difference except intermaxillary distance and intersinus width among the three age groups. The discriminant analysis showed that the ability of frontal sinus parameters and bizygomatic distance to identify gender with high accuracy.

Dental age estimation of Malaysian children: a comparison of two-dimensional versus three-dimensional imaging analyses of the developing root apices

Aim This study compared the effectiveness of the three-dimensional (3D) cone beam computed tomography (CBCT) method of age estimation developed by Asif et al. with two-dimensional Cameriere’s method. Subjects and methods CBCT images belonging to 129 Malaysian Chinese and Malay ethnic groups aged 7–14 years were investigated and analysed. Results The results indicated a strong correlation between chronological age and the predictor variables for both Cameriere’s (r = 0.984) and Asif’s (r = 0.988) methods of age estimation. Fisher Z test analysis indicated no statistically significant difference in the correlation values between the two methods. Mean absolute error (MAE) value of 0.613 was observed for Cameriere’s and 0.290 was observed for Asif’s method. Conclusions The results indicated that the methods of age estimation from both Asif et al. and Cameriere et al. are applicable on Malaysian children. However, Asif et al.’s 3D CBCT method of age estimation resulted in greater accuracy and reliability in estimating chronological age.

Head and neck cancer patient positioning using synthetic CT data in MRI-only radiation therapy.

PurposeThe accuracy and precision of patient positioning is crucial in radiotherapy; however, there are no publications available using synthetic computed tomography (sCT) that evaluate rotations in head and neck (H&N) patients positioning or the effect of translation and rotation combined. The aim of this work was to evaluate the differences between using sCT with the CT for 2D‐ and 3D‐patient positioning in a magnetic resonance imaging (MRI)‐only workflow.MethodsThis study included 14 H&N cancer patients, with generated sCT data (MRI Planner v2.2) and the CT deformably registered to the MRI. Patient positioning was evaluated by comparing sCT against CT data: 3D cone beam CT (CBCT) was registered to the deformed CT (dCT) and sCT in six degrees of freedom (DoF) with a rigid auto‐registration algorithm and bone threshold, and 2D deformed digital reconstructed radiographs (dDRR) and synthetic DRRs (sDRR) were manually registered to orthogonal projections in five DoF by six blinded observers. The difference in displacement in all DoF were calculated for dCT and sCT, as well as for dDRR and sDRR. The interobserver variation was evaluated by separate application of the paired dDRR and sDRR registration matrices to the original coordinates of the planning target volume (PTV) structures and calculation of the Euclidean distance between the corresponding points. The Dice similarity coefficient (DSC) was calculated between dDRR/sDRR‐registered PTVs.ResultsThe mean difference in patient positioning using CBCT was <0.7 mm and <0.3° and using orthogonal projections <0.4 mm and <0.2° in all directions. The maximum Euclidean distance was 5.1 mm, the corresponding mean (1SD) Euclidean distance and mean DSC were 3.5 ± 0.7 mm and 0.93, respectively.ConclusionsThis study shows that the sCT‐based patient positioning gives a comparable result with that based on CT images, allowing sCT to replace CT as reference for patient treatment positioning.

Knowledge and Perception of Senior Dental Students Regarding Digital Dentistry and Its Use in Prosthodontics

Technology is becoming an ongoing expense as dentists across the globe expect Digital Radiology, Computer-Aided Design and computer-aided manufacturing (CAD/CAM), and 3D Cone Beam technology to be utilized in every practice in the future. To keep up with the rapidly increasing demand for digital technology in dentistry and meet new dental Accreditation Council (CODA) standards, dental education is making a solid transition to actively integrate technology into the curriculum. This is a cross-sec

Reduction Malarplasty Using Customized Surgical Stent Based on 3D Virtual Surgery, CAD/CAM, and 3D Printing Technology: Case Series.

The zygomatic bone is a structure that protrudes symmetrically on both sides of the midface and plays an important role in the overall aesthetic appearance of the face. Unlike Caucasians, the mesocephalic facial shape is predominant in Asians, and therefore, many people have a relatively laterally developed zygomatic bone. In Asians, when the zygomatic bone is excessively developed, it gives a strong and stubborn image, and aesthetically, many people want to reduce the zygomatic bone because they prefer an oval and slim face.To reduce the excessive zygomatic bone, a reduction malar- plasty through an intraoral and preauricular approach has been performed. Although reducing the zygomatic bone is not a big problem in most cases of symmetric reduction malarplasty, it is not easy to produce surgical results as intended by the surgeon in asymmetric malar patients or patients requiring a three-dimensional (3D) change of zygoma. In addition, because of the mobility of the zygoma segment, it may be difficult to drill holes and fix plate after osteotomy. Moreover, these factors can increase the possibility of malunion or nonunion.In this study, cutting guides made with the aid of 3D virtual surgery, 3D printing, and customized titanium plates manufactured with the computer-aided design/computer-aided manufacturing technology are used for 8 patients to maximize the recovery of 3D symmetry and minimize complications through accurate fixation after surgery. During the surgical procedures, screw hole drilling and osteotomy were performed using a cutting guide, and then, the malar segment was fixed by matching the premade customized plates with the predrilled holes. As a result of checking the accuracy of the surgery by superimposing the postoperative 3D cone beam computed tomography image and virtual surgery data based on the skull base, the 2 images almost overlapped and no significant differences were observed, so it was confirmed that the operation was performed exactly as planned.When using the 3D technology, it is possible to perform a more accurate surgery in patients with asymmetry due to congenital anomalies or trauma as well as simple asymmetry, so it can be concluded that using the 3D technology can overcome the limitations and disadvantages of the conventional method as in the cases in this study. The accurate prediction of soft tissue is still insufficient, and further research is needed to overcome this limitation.

Effect of Different Voxel Sizes on Accuracy of 2D and 3D Mandibular Linear Measurements Using CRANEX® 3D Cone Beam Computed Tomography Machine: Preclinical Study

Aim To assess the accuracy of linear measurement obtained from CBCT images in 3D volumetric rendering and multiplanar slices with different voxel sizes. Methodology: 9 mandibles with twelve radioopaque markers fixed on each one were imaged using CRANEX® 3D CBCT machine. Each mandible was imaged twice with voxel sizes 250 μm and 350 μm. 2D and 3D linear measurements from CBCT images were compared to the real physical measurements taken by a digital caliper. Software measurements were recorded twice by the principal investigator and once by the supervising professor. Intra- and inter-observer agreements were assessed using Intra-Class Correlation Coefficient (ICC). SPSS®IBM Version 24 and MedCalc® version 12.1 for Windows were used for statistical analysis. Results: CBCT 2D measurements with voxel sizes of 250μ and 350μ showed a mean difference= 0 mm both with 95% of difference being -0.6 mm above or 0.7mm below and-0.5 mm above or 0.6 mm below the Gold Standard respectively. CBCT 3D measurements with voxel sizes of 250μ and 350μ showed a mean difference= 0 mm both with 95% of difference being -0.5 mm below or 0.5 mm above and -0.6 mm above or 0.7 mm below the Gold Standard. Intra-observer and inter-observer reliability regarding all measurements showed excellent agreement. Conclusions: 2D and 3D measurements driven from CBCT images with voxel size of 350 μ are accurate as measurements driven from CBCT images with voxel size of 250 μ with less radiation delivered to the patient. 2D and 3D CBCT measurements driven from CBCT are reliable.

Graft Materials and Canine Vertical Position Associated with Alveolar Bone Graft Outcomes Assessed by 3D Cone Beam CT

The introduction of Cone Beam Computed Tomography (CBCT) into the alveolar bone grafting protocol now allows surgeons to look at pre- and postoperative bony structures to determine surgical success. Until recently, pre- and postoperative assessment have been determined by 2-dimensional (2D) periapical and panoramic radiographs. CBCTs can now be used to volumetrically assess defects. Yet to date, no scale has been standardized to classify alveolar bone grafting levels postoperatively to determine the success of the procedure. This study aims to analyze pre- and postoperative cone bean CBCT scans to determine if variables such as cleft size, canine position, and bone grafting material can help predict surgical outcomes. A total of 79 patients (average 10.4 years) with non-syndromic complete unilateral cleft lip and palate had been treated with ABG and bone morphogenetic protein-2 with demineralized bone matrix (BMP2/DBM) versus iliac crest bone (ICB) were compared. Preoperative CBCT scans (n = 27) were available to determine the cleft width. The postoperative CBCT was analyzed by the Bergland scale score. A novel method for categorizing canine eruption separated post-graft patients into 5 groups. The cleft width might be correlated with bone graft outcomes, but limited to the sample size, with no statistical significance (n = 27, R2 = 0.378, P > .05). In total, 21 (26.6%) patients have supernumerary or impacted teeth in the cleft, but not related to bone graft outcomes. There is no statistical difference between the 4 surgeons’ cleft repair. The 2D modalities traditionally used to interpret SABG results possess inherent limitations of structure overlapping and distortion of the relationship of anatomy. Since the advent of the CBCT, 3D volumetric analysis has largely accounted for these errors. Yet to date, no scale standardized to the CBCT has been developed to assess SABG results.The authors' results suggest that graft outcomes correlate with pre-graft canine positions. An unerupted, high permanent canine vertical position will yield poor results, likely due to previously documented growth-inhibiting scarring of soft tissue, and the ideal timing of SABG may be when two-thirds of the canine crown is located below the palatal plane with the adjacent premolars not fully erupted. This may be due to the optimal timing for the canine to complete its eruption into the grafting site to influence the maintenance of the graft and periodontal support of the adjacent teeth. In a patient with complete unilateral cleft lip and palate, iliac crest bone graft tended to have better graft outcomes than BMP2/DBM in this sample. This may be attributed to BMP2/DBM's osteoconductive properties vs. ICB's osteogenic, osteoinductive, and osteoconductive properties. There was no evidence that cleft width correlates with the grafting outcome. However, results were limited to sample size.

Deep Learning-Based Three-Dimensional Oral Conical Beam Computed Tomography for Diagnosis.

In order to deeply study oral three-dimensional cone beam computed tomography (CBCT), the diagnosis of oral and facial surgical diseases based on deep learning was studied. The utility model related to a deep learning-based classification algorithm for oral neck and facial surgery diseases (deep diagnosis of oral and maxillofacial diseases, referred to as DDOM) is brought out; in this method, the DDOM algorithm proposed for patient classification, lesion segmentation, and tooth segmentation, respectively, can effectively process the three-dimensional oral CBCT data of patients and carry out patient-level classification. The segmentation results show that the proposed segmentation method can effectively segment the independent teeth in CBCT images, and the vertical magnification error of tooth CBCT images is clear. The average magnification rate was 7.4%. By correcting the equation of R value and CBCT image vertical magnification rate, the magnification error of tooth image length could be reduced from 7.4. According to the CBCT image length of teeth, the distance R from tooth center to FOV center, and the vertical magnification of CBCT image, the data closer to the real tooth size can be obtained, in which the magnification error is reduced to 1.0%. Therefore, it is proved that the 3D oral cone beam electronic computer based on deep learning can effectively assist doctors in three aspects: patient diagnosis, lesion localization, and surgical planning.

Occupational and patients effective radiation doses in dental imaging

Ionizing radiation exposure from medical applications is increasing annually worldwide. It was estimated that 325 million dental procedures were performed in the United States. Radiation exposure from dental radiography consists of intraoral, panoramic, and 3D imaging cone-beam computed tomography (CBCT) imaging. Recent studies reported an association between dental imaging procedures and increased cancer probability of brain and thyroid. Previous studies showed that some dental imaging practices exposed patients and staff to unnecessary radiation doses due to incorrect image acquisition and insufficient radiation protection measures. This study aims to (i) measure the occupational and patients doses during dental procedures and (ii) assess the current imaging techniques and radiation protection practices. Two hundred fourteen patients were evaluated for periapical, bitewing, cephalometric, occlusal, and panoramic procedures. Organ equivalent doses were quantified for the breast, eye lens, and thyroid gland during CBCT procedure. Occupational and ambient dose assessment were assessed using calibrated thermoluminescent dosimeters (TLD-100(LiF: Mg. Ti). Ambient doses were measure at different locations at the department using TLDs. Patients' radiation doses were quantified using kerma area product (PKA (mGy.cm) and the entrance surface air kerma (ESAK (mGy). Fixed tube voltage (65kVp) and tube current-time product (7mAs) were used. The overall mean, sd, and range of patients dose values during intraoral (mGy), panoramic and CBCT examinations were 4.6±0.7 (1.4-7.1), 135±45 (75.2-168.5), and 215±165 (186-2115), respectively. The mean and range of the annual occupational doses (mSv) were 1.4 (0.6-3.7), which below the annual dose limits for radiation workers (20mSv/y). The study showed that inadequate radiation protection for patients existed in terms of the use of the thyroid shield, the technologist's presence inside the room during radiation exposure. Patients' radiation doses were comparable with the international diagnostic reference level (DRL). Staff education and training in radiation protection aspects are highly recommended.

Accuracy of 3-dimensional soft tissue prediction for orthognathic surgery in a Chinese population

ObjectivesThis study aims to determine the validity of a 3D planning software in predicting the soft tissue outcome of Chinese patients undergoing orthognathic surgery for correction of Skeletal III dentofacial deformity. MethodsPre- and post-operative 3D facial stereophotogrammetric scans and cone beam computed tomography were taken for 10 Chinese patients who had underwent orthognathic surgery. The pre-operative 3D facial scan was integrated with the pre-operative CBCT using the ProPlan CMF software. The simulated soft tissue 3D face was then compared with the actual 3D facial scan obtained at least 6 months postoperatively. Two outcome measures were computed as follows (i) mean absolute difference between meshes (ii) percentage of points where the distance between the two meshes is 2mm or less. ResultsThe mean absolute difference between the predicted and actual soft tissue surface meshes for the full face and the 6 anatomic regions ranged from 0.72mm to 1.42 mm. The mean absolute distance between the meshes for all the anatomic regions were within 2 mm (p<0.05). The percentage of mesh points with less than 2mm error ranged from 72.5% to 92.5%. The accuracy of soft tissue prediction, assessed using mean absolute distance for the full face, was significantly correlated to the amount of sagittal surgical movement (r=0.707, p=0.022). The lower lip was also found to be the least accurate. ConclusionsUsing ProPlan CMF, the accuracy of 3D soft tissue predictions for bimaxillary orthognathic surgery in Chinese Skeletal III patients were clinically satisfactory.

Optimization of X-ray Investigations in Dentistry Using Optical Coherence Tomography

The most common imaging technique for dental diagnoses and treatment monitoring is X-ray imaging, which evolved from the first intraoral radiographs to high-quality three-dimensional (3D) Cone Beam Computed Tomography (CBCT). Other imaging techniques have shown potential, such as Optical Coherence Tomography (OCT). We have recently reported on the boundaries of these two types of techniques, regarding. the dental fields where each one is more appropriate or where they should be both used. The aim of the present study is to explore the unique capabilities of the OCT technique to optimize X-ray units imaging (i.e., in terms of image resolution, radiation dose, or contrast). Two types of commercially available and widely used X-ray units are considered. To adjust their parameters, a protocol is developed to employ OCT images of dental conditions that are documented on high (i.e., less than 10 μm) resolution OCT images (both B-scans/cross sections and 3D reconstructions) but are hardly identified on the 200 to 75 μm resolution panoramic or CBCT radiographs. The optimized calibration of the X-ray unit includes choosing appropriate values for the anode voltage and current intensity of the X-ray tube, as well as the patient’s positioning, in order to reach the highest possible X-rays resolution at a radiation dose that is safe for the patient. The optimization protocol is developed in vitro on OCT images of extracted teeth and is further applied in vivo for each type of dental investigation. Optimized radiographic results are compared with un-optimized previously performed radiographs. Also, we show that OCT can permit a rigorous comparison between two (types of) X-ray units. In conclusion, high-quality dental images are possible using low radiation doses if an optimized protocol, developed using OCT, is applied for each type of dental investigation. Also, there are situations when the X-ray technology has drawbacks for dental diagnosis or treatment assessment. In such situations, OCT proves capable to provide qualitative images.

Comparison of rotary NiTi reciprocating file systems using Cone Beam CT in root canal transportation

Aim: T assess the root canal transportation caused by these rotary NiTi reciprocating file systems using 3D cone beam computed tomography Method: This experimental study was conducted on 60 samples of rotary NiTi reciprocating file systems using CBCT. The extent of canal transportation and the centering ratio was analyzed using independent sample t test. The significance level was set at 95%. Results: Mean apical canal transportation was lower in wave one Gold groups as compare to Reciproc (0.8724±0.04SD vs 0.9463±0.02SD, p=0.000). Mean apical canal transportation at 5 mm was lower in wave one gold group as compare to reciproc blue group (0.5610±0.02SD vs 0.7253±0.06SD, p=0.000). Mean apical canal transportation at 8mm was lower in wave one group as compare to reciproc blue (0.358±0.03SD vs 0.5766±0.10SD, p=0.000). Conclusion: Wave one Gold had high centering ability and lower canal transportation as compare to Reciproc Blue single file system. CBCT is an efficient method of understanding Canal transportation Keywords: CBCT, NiTi wire, Root canal transportation, Reciproc blue

VALIDATION OF KPG INDEX “CLASSIFICATION METHOD TO PREDICT ORTHODONTIC TREATMENT DIFFICULTY LEVEL OF IMPACTED CANINES”

Objective: To determine the position of impacted canine in 3 dimensions and estimate the difficulty of treatment using 3D “KPG index”, a new classification method.&#x0D; Study Design: Cross sectional analytical study.&#x0D; Place and Duration of Study: Orthodontic Department, Rehman College of Dentistry, Peshawar, from Aug to Oct 2020.&#x0D; Methodology: 3D cone beam computed tomography (CBCT) scans of 43 subjects with 47 impacted canines were obtained. Using KPG index, 6 measurements were taken for each impacted tooth in three planes. The scores were later summed up. Based on the cumulative scores, each impaction was classified into the difficulty categories of Easy (0–7), Moderate (8–14), Difficult (15–19), and Extremely Difficult (20+). Comparison of Gender and position of impacted canine with the KPG treatment difficulty index was also performed.&#x0D; Results: Impacted canines were found to be on the left and palatal side with a female predilection. Canines scored with KPG index were mostly in the moderate category. Highest percentage of the impacted canines were in Sector II, followed by sector III and IV. Comparing KPG treatment difficulty index of impacted maxillary canines found on the right and left sides (p=0.087), buccal or palatal (p=0.545), males and females (p=0.279), in-statistically significant difference was found.&#x0D; Conclusion: 3D imaging has allowed us to precisely locate the impacted canine in 3 sagittal, coronal and axial planes. Hence, KPG index dictated our anticipated difficulty of treatment.

Comparison of two established 2D staging techniques to their appliance in 3D cone beam computer-tomography for dental age estimation

For medicolegal purposes, orthodontic or orthognathic treatment various stomatological staging technique for age estimation with appliance of conventional radiographic images have been published. It remains uninvestigated if cone beam computer-tomography delivers comparable staging results to the conventional radiographic stages of third molar analysis. We conducted a retrospective cross-sectional study of 312 patients aged 13–21 years. Dental age estimation staging technique, introduced by Nolla and Demirjian, were applied on the left lower third molar imaged by conventional panoramic radiographs and cone beam computer-tomography. It was investigated if 2D and 3D imaging presented different staging results for dental age estimation. In 21% the Demirjian’s staging differed by a single stage between 2 and 3D images. The greatest congruence (87%) between 2 and 3D images was revealed for stage 7 (G). In contrary, stage 5 (E) presented the lowest level of congruence with 47.4%. The categorization of Nolla revealed divergences in staging for than two categorical variables in Nolla’s stages 3, 4, 5 and 6. In general, the analysis of the data displayed the divergence for Nolla’s stages 4–8. The staging results for 2D and 3D imaging in accordance to the rules of Nolla and Demirjian showed significant differences. Individuals of 18 years may present immature third molars, thus merely an immature third molar cannot reject legal majority. Nolla’s and Demirjian’s 2D and 3D imaging present significantly different staging results.