Cone-beam Computed Tomography Assessment Research Articles

Key insights into antiresorptive drug use and osteonecrosis in osteoporotic patients undergoing tooth extractions: A clinical and CBCT assessment.

To describe the effects of antiresorptive drugs (ARD) in the maxilla and mandible and risk factors for medication-related osteonecrosis of the jaws (MRONJ) in osteoporotic patients undergoing tooth extractions using clinical data and cone beam computed tomography (CBCT). This retrospective cohort study collected clinical and CBCT data from 176 patients. The study group (n = 78; 224 extractions) received ARD treatment, underwent tooth extraction, and had a pre-operative CBCT. Additionally, age-, sex-, and tooth-matched controls were selected (n = 98; 227 extractions). Radiographic examinations were performed independently by three calibrated examiners. Statistical analysis included Chi-square, Fisher's exact, Mann-Whitney U, and t-tests to contrast clinical and radiographic data between study and control, MRONJ + and MRONJ - , and bisphosphonate and denosumab patients/sites. Significance was set at p ≤ 0.05. From the study group, 4 patients (5%) and 5 sites (2%) developed MRONJ after tooth extraction. ARD-treated patients exhibited significantly more thickening of the lamina dura and a longer average mucosal healing time (4.4weeks) than controls (2.6weeks). In the study group, MRONJ risk significantly increased with corticosteroid intake and in multi-rooted teeth. No significant differences between bisphosphonates and denosumab use were seen in the tomographic features (p > 0.05). Lastly, bone sequestrum was exclusively observed in osteoporotic patients, who exhibited post-operative exposed bone or histological evidence of osteonecrosis. Osteoporotic patients under ARD may exhibit thickening of the lamina dura and prolonged post-operative healing. Among these patients, multi-rooted teeth are at higher risk for MRONJ than single-rooted teeth. Sequester formation is a radiographic indicator of osteonecrosis.

Cone beam computed tomography assessment of maxillary anterior teeth cervix dimensions in healthy adults for optimal anatomic healing abutments.

The abutments produced with circular symmetry failed to accurately replicate the natural teeth's cervical shapes. The purpose of this study was to measure cervical cross-sections of maxillary anterior teeth using cone beam computed tomography (CBCT) images to design anatomic healing abutments. CBCT data of 61 patients were analyzed using Ez3D Plus software. Measurements were taken at the cemento-enamel junction (CEJ) and 1 mm coronal to CEJ for maxillary central incisors, lateral incisors, and canines. Various parameters, including area, perimeter, and eight line segments in the distal (a), disto-palatal (b), palatal (c), mesio-palatal (d), mesial (e), mesio-labial (f), labial (g), and disto-labial (h) directions, were used to describe dental neck contours. The ratios (f/b and h/d) were analyzed, and differences based on sex and dental arch morphology were explored. Significant differences were found in area and perimeter between males and females, but not in f/b and h/d ratios. Differences in the f/b ratio were observed among dental arch morphologies for maxillary central incisors, lateral incisors, and canines. CBCT measurements of cervical cross-sections provide more accurate data for designing anatomic healing abutments. The fabrication of anatomical healing abutments needs to consider the influence of gender on cervical size and to explore the potential effect of arch shape on cervical morphology. The novel method provides detailed measurements for the description of dental cervical contours for patients with bilateral homonymous teeth missing. The measurements of this study could be utilized to design more accurate anatomic healing abutments to create desired morphology of peri-implant soft tissue.

A CBCT Assessment of Orthodontic Mini-Implant Placement

ABSTRACT Objectives: This study compares the precision of cone beam computed tomography (CBCT) and two-dimensional radiography for mini-implant implantation. Materials and Method: For 30 sites (in 15 patients between the ages of 13 and 26 years), the buccal interradicular region among the 2nd premolar and 1st molar was found to be the best location for mini-implants. Next, two groups of the mini-implant implantation process were created. Mini-implants were positioned at the CBCT data-identified sites in the CBCT group. Mini-implants were inserted in the RVG group by using two-dimensional digital radiography and a specially constructed guide. To assess the precision of the mini-implant implantation, post-placement CBCT images were acquired. The obtained data were statistically analyzed. Result: The two groups showed a statistically considerable variation in the mini-implant placement’s departure from the optimal height. Due to the smaller interradicular space and decreased convenience in the posterior mandibular area, two out of 15 mini-implants in the RVG group demonstrated root contact in the mandibular jaw Conclusion: The two-dimensional intraoral radiograph of the interradicular area provides sufficient information for mini-implant placement even though CBCT accurately visualizes the interradicular space in three dimensions.

Presurgical Cone-beam Computed Tomography Assessment of Maxillary Sinus Septa for Posterior Maxillary Implant Placement

Presurgical Cone-beam Computed Tomography Assessment of Maxillary Sinus Septa for Posterior Maxillary Implant Placement

Radiographic Assessment of Cleft Alveolar Bone Defects: A Preliminary Comparison of Periapical and Cone Beam Computed Tomography Images

Background & Purpose Accurate radiographic assessment of secondary alveolar bone grafting (SABG) is critical in evaluating SABG outcomes in patients with cleft lip and palate. This study compared Periapical (PA) and Cone beam computed tomography (CBCT) grading of SABG outcomes and conducted an analysis of agreement rate between the two imaging modalities. Methods A retrospective chart review was performed of patients who underwent secondary alveolar bone grafting at a single institution. Bone quality of the alveolar cleft site was assessed at three root levels of the adjacent teeth on PA and CBCT images. Results 48 patients had pre- or post-operative images with both CBCT and PA that were appropriate for comparison. A total of 174 alveolar bone sections (three root levels of adjacent teeth in 58 pairs) were graded on CBCT and PA images. Agreement of CBCT grading with PA grading was 41.3% (72/174) overall. CBCT assessments rated bone quality lower than PA grading in 51.2% (89/174) of sections. CBCT had higher grading than PA image grading in 7.5% (13/174) of sections. The weighted Cohen Kappa value for comparison of CBCT and PA readings was 0.17, indicating a low rate of agreement. Wilcoxon signed rank test demonstrated that the difference between grading on CBCT and PA assessments was statistically significant ( P < .001). Conclusions CBCT and PA readings demonstrated an overall low rate of agreement in the assessment of cleft alveolar bone. This investigation suggests that PA radiographs have lower sensitivity in detecting poor bone grafting outcomes.

Cone-Beam Computed Tomography Assessment of Prevalence of Procedural Errors in Maxillary Posterior Teeth.

A range of procedural errors can occur when performing endodontic treatment on posterior teeth. These errors may decrease the success rate in endodontic practice. This study assessed the prevalence of procedural errors and the quality of endodontic treatments in maxillary molars and premolars using cone-beam computed tomography (CBCT). CBCT scans from two private radiology centers were assessed retrospectively to ensure the same calculated sample size of 327 teeth for each of the four maxillary posterior tooth types (a total of 1,308 endodontically treated teeth). Image sets were evaluated for procedural errors categorized as follows: obturation length (overfilling or underfilling by >2 mm short of the root apex), missed canals, perforations, strip perforations (with extrusion of material into the furcation area), separated instruments in the root canal space, and root fracture. Data were analyzed with SPSS version 20 (SPSS Inc., Chicago, IL, USA), and frequency data was assessed using the Monte Carlo test at the 0.05 level of significance. The procedural errors most commonly reported in the present study were from most frequent to least frequent: underfilled canals (50.0%), missed canals (27.5%), overfilled canals (12.5%), apical perforations (5.0%), separated instruments (3.1%), and root fractures (1.9%). No strip perforations (with extrusion of material into the furcation area) were seen in the study (0%). Underfilled and missed root canals were the most frequent procedural errors identified in the present study. These findings underline the importance of more consideration of critical working length management during all stages of root canal treatment, greater awareness of root canal anatomy, and the use of imaging and diagnostic devices that enhance the ability to identify and treat root canals both safely and effectively.

Reliability and reproducibility of CBCT assessment of mandibular changes before and after treatment for Class III growing patients - an easy and quick way for evaluation.

The objective of this study was to evaluate intraobserver reliability and inter-observer reproducibility of a 3-dimensional (3D) assessment method for mandibular changes of growing patients after orthodontic treatment for Class III malocclusion.Methods Cone-beam computed tomography (CBCT) scans were performed before and after orthodontic treatment for 27 patients. During the scan, the patient was positioned such that his/her mandibular plane was parallel to floor. Three observers independently worked on the DICOM data, reconstructed the pre- and post-treatment 3D models in software, selected the stable anatomical structures (basal bone area from the lingual surface of the symphysis to the distal aspect of the first molars) to guide the automated superimposition process. Then, each observer registered 14 anatomical landmarks on the virtual models, for three times after suitable interval, to generate 3 sets of coordinates; the mean was taken as the coordinates for that particular landmark. The intraobserver reliability and inter-observer reproducibility of the method were analyzed.Results The ICCs was > 0.90 for 25 (92.6%) of the intraobserver assessments. The precision of the measurement method was < 0.3mm in 24 (88.9%) cases. The interobserver reproducibility errors were < 0.3mm in 21 of the 27 cases.Conclusions The intraobserver reliability and inter-observer reproducibility of 3D assessment of mandibular changes using the virtual models were excellent.

What is the Success Rate of Repeat Alveolar Bone Graft?

Success rates for alveolar bone grafting range from 30 to 96%. There is limited information regarding the success of repeat grafts. The purpose of this study was to determine the radiographic success rate of repeat alveolar bone grafts. The study designs was a retrospective cohort study of patients who underwent repeat grafting by 1 surgeon over 15years. To be included, subjects had to have: cleft lip and alveolus and a cone-beam computed tomography (CBCT) scan obtained >6months after repeat graft. Patients were excluded if CBCT was inadequate. Predictor variables were sex, age at repeat graft, cleft type, presence of an erupted canine, premaxillary osteotomy at time of repeat graft, presence of a visible oronasal fistula, size of bony defect, presence of a bony palatal bridge, and whether the surgeon who performed the repeat graft also performed the initial graft. The outcome variable was graft success determined using CBCT assessment and defined as a score of >3 out of 4 in each domain: vertical bone level, labiopalatal thickness, and piriform symmetry. The covariates were time from bone graft to CBCT (months) and age at time of CBCT (years). Frequency distributions, relative risk with 95% confidence intervals, medians, and interquartile ranges were calculated. Pearson c2 and Fisher exact tests were performed to determine predictors of outcome. A P<.05 was considered statistically significant. Fifty subjects (54% male) who had repeat bone grafting to 59 cleft sites were included. Median follow-up time from repeat graft to CBCT was 7.0months (interquartile range: 5.9months). The radiographic success rate was 81.4%:91.7% if the same surgeon performed both initial and repeat grafts, but 78.7% if initial graft was completed by another surgeon (P=.43). Despite being a multifactorial issue, extensive and bilateral clefts, the presence of an erupted tooth in the cleft area, a visible oronasal fistula, and concomitant osteotomy of the premaxilla are warning signs of the possibility of failure. Performing repeat alveolar bone grafting by an experienced surgeon appears to increase the chance of success.

Prevalence and Morphology of C-Shaped Canals in Mandibular First and Second Molars of an Iranian Population: A Cone-Beam Computed Tomography Assessment.

The complex anatomy of C-shaped canals poses challenges for clinicians compared to teeth with normal root canal anatomy. This study is aimed at evaluating the frequency and morphology of C-shaped canals in the mandibular first and second molars among an Iranian population using cone-beam computed tomography (CBCT). This cross-sectional study evaluated 369 CBCT scans from the archives of a radiology clinic in Ardabil, Iran. The sample included 248 mandibular first molars and 478 mandibular second molars. The presence of C-shaped canals and their classification, according to Fan et al., were evaluated at four levels: orifice, coronal, middle, and apical. Prevalence based on gender and tooth type was also assessed. A total of 199 (53.9%) males and 170 (46.1%) females were evaluated. C-shaped canals were found in 11 (8 males/3 females) out of 248 (4.4%) first molars and in 20 (11 males/9 females) out of 478 (3.7%) second molars. The C2 configuration was most prevalent in the orifice, coronal, and middle levels of both molar types, while C3 and C4 morphologies were most commonly found apically in the second and first molars, respectively. A significant difference in configuration was found only at the coronal level between molar types. A significant association between gender and configuration was observed only at the orifice level of the second molars. No other significant differences were found (P > 0.05). C-shaped canal configurations should be expected in 4.4% of mandibular first molars and 3.7% of the second molars in this Iranian population, with a predominance of the C2 configuration in the orifice, coronal, and middle levels.

Cone-beam computed tomography assessment of the root canal morphology of primary molars

BackgroundThis study aimed to assess the root canal morphology of primary molars using cone-beam computed tomography (CBCT).MethodsThis cross-sectional study evaluated 60 maxillary and mandibular primary first and second molars on CBCT scans of patients retrieved from the archives of Hamadan School of Dentistry between 2018–2020. The teeth were evaluated regarding the number of roots and canals, canal type according to the Vertucci’s classification, and root surface concavities. Data were analyzed descriptively and by independent t-test.ResultsThe most frequent number of canals and roots in the maxillary right and left first molars was 3 canals (60%) and 3 roots (80%). These values were 4 canals (80%) and 5 canals (50%) with 3 roots in the maxillary right and left second molars, respectively, 4 canals (100%) and 2 roots (50%), and 3 canals (60%) and 2 roots (50%) in mandibular right and left first molars, respectively, and 4 canals (92.3%) and 3 roots (61.5%) in mandibular right and left second molars. Vertucci’s type IV was the most common canal type in mesial and distal canals, type I was the most common in mesiobuccal, mesiolingual, distobuccal, and distolingual, and types I and II were the most common in the palatal canal. The maximum and minimum concavities were noted in the buccal (26.7%) and mesial (8.3%) surfaces, respectively.ConclusionsA wide variation exists in the number of roots and canals of maxillary and mandibular primary molars, which calls for further attention in treatment of such teeth.

Cone-Beam Computed Tomography Assessment of Morphologic and Anatomic Changes of the Nasopalatine Canal: Cross-Sectional Study

Objective: To reveal the morphological and anatomical structure of the nasopalatine canal (NPC) and analyze its measurements via cone-beam computed tomography (CBCT). Methods: A total of 246 CBCT images were included in the study.) NPC diameter, length, angle, distance from the IF to buccal bone (M1), distance from the NF to buccal bone (M2), and the distance from the middle of the NPC to buccal bone (M3) were measured. Statistical significance was assumed at p &lt; 0.05. Results: There was a significant difference between gender and NPC length, M1 and M3 (p = 0.008, p = 0.019 and p &lt; 0.001, respectively), and between the presence of teeth in the anterior maxilla and M1 (p &lt; 0.001). There was a significant difference between the shape of NPC in the coronal plane and NPC angle (p = 0.012) and between the shape of NPC in the sagittal plane and NF diameter, IF diameter, M1 and the M3 (p &lt; 0.001, p = 0.006, p = 0.031 and p &lt; 0.001, respectively). Conclusion: NPC variations, gender, and the presence of teeth in the anterior maxilla could affect NPC measurements. Physicians planning surgery in the anterior maxilla should pay attention to this situation.

The effects of miniscrew-assisted rapid palatal expansion on the upper airway of adults with midpalatal suture in the last two degrees of ossification.

Transverse deficiencies of the maxillary basal bone have been treated in adult patients using miniscrew-assisted rapid palatal expansion (MARPE) therapy. However, the midpalatal suture's degree of ossification may affect the upper airway dimensions. This study compared the volumetric changes of the total upper, retropalatal, retroglossal airways, and the minimal transverse airway constriction after MARPE therapy in patients with midpalatal suture in the last stages of ossification. This controlled clinical trial included a total of 20 adult patients (mean age 24.5 ± 6.2 years) with maxillary atresia treated with MARPE. Preoperative (T0) cone-beam computed tomography scans were used to determine the degree of midpalatal suture ossification. Two groups were formed considering the last two stages of sutural ossification "D" or "E" (n=10 per group). After 120 days of the therapy (T1), cone-beam computed tomography assessments were performed to compare the pre and post-treatment outcomes. The total upper, retropalatal, and retroglossal airways and the minimal transverse airway constriction were evaluated. The three-dimensional reconstruction was performed with OsiriX MD software. The comparisons were carried out using mixed models for repeated measures at fixed time points (α=0.05). Groups D and E showed no significant difference for any of the analyzed parameters (P > 0.05). Both groups showed a statistically significant increasefor all airway segments after the treatment with MARPE (P < 0.05). The total upper airway increased (11.6% and 16.1%) for groups D and E, respectively (P=0.3356). MARPE therapy resulted in dimensional gains of the upper airway for adult patients, irrespective of the intermaxillary sutural degree of ossification.

Cone-Beam Computed Tomography Assessment of Bifid and Trifid Mandibular Canals: A Cross-Sectional Study

The exact knowledge of the mandibular canal position is fundamental in oral surgery and implantology. Clinicians have to be extremely cautious when operating in close proximity to this structure in order to avoid damaging the neurovascular bundle. Several anatomical variations of the mandibular canal have been described in the literature, such as bifid or trifid structures. The use of cone-beam computed tomography (CBCT) offers a detailed representation of the inferior alveolar nerve path, albeit with some difficulties of identification when dental implants or metal prosthesis are present. The aim of this study is to retrospectively evaluate the prevalence and location of bifid/trifid mandibular canals (BMC/TMC) by CBCT in Italian patients. The screening phase involved 584 patients, only 238 enrolled (97 men; 141 women), with an average age of 51 ± 17.20. A total of 36 patients (15.25%) showed at least one bifid mandibular canal; only 2 patients (0.84%) showed a trifid mandibular canal. Overall, 12 patients (5.04%) presented this variation bilaterally. There was no association with the sex of the enrolled sample. In conclusion, the presence of BMCs and TMCs may be considered as a risk factor for the onset of neurovascular complications. Being aware of changes in the mandibular canal helps clinicians to prevent inferior alveolar nerve impairments that may occur during oral surgery and implantology.

TMJ degenerative joint disease: relationships between CBCT findings, clinical symptoms, and signs

Objectives The relationships between cone-beam computed tomography (CBCT) findings, Temporomandibular disorder (TMD) symptoms, and signs were investigated in patients with TMJ degenerative joint disease (DJD). Material and Methods Adult patients with Diagnostic Criteria for TMDs (DC/TMD)-defined intra-articular conditions were enrolled and subjected to CBCT assessment. The participants were organized into three groups, namely no (NT), early (ET), and late (LT) TMJ DJD based on radiographic findings. TMD symptoms/signs were appraised using the DC/TMD methodology. Statistical analyses were performed using Chi-square/non-parametric tests and Kappa statistics (α = 0.05). Results The mean age of the participants (n = 877) was 30.60 ± 11.50 years (86.6% women). NT, ET, and LT were observed in 39.7%, 17.0%, and 43.3% of the study sample. Significant differences in the prevalence of TMD symptoms (TMD pain, TMJ sounds, opening, and closing difficulty) and signs (TMD/TMJ pain, TMJ clicking/crepitus, and opening limitation) were discerned among the three groups (p ≤ .001). TMD/TMJ pain and opening difficulty/limitation were more prevalent in early rather than late degenerative changes. While moderate agreements between symptoms and signs were observed for TMD pain/opening limitation, the concurrence for TMJ sounds was fair. Conclusions Young adults with TMJ sounds and pain should be examined with CBCT to establish the extent/progress of osseous changes.

Cone-Beam Computed Tomography Assessment of Quality of Endodontic Treatment and Prevalence of Procedural Errors in Mandibular Molars.

This study assessed the quality of endodontic treatment and the prevalence of procedural errors in permanent mandibular molars using cone-beam computed tomography (CBCT). This cross-sectional study was conducted on 328 CBCT scans (182 females and 146 males) of endodontically treated mandibular molars retrieved from the archives of two radiology centers in Ardabil city, Iran, in 2019. Mandibular molars were evaluated on sagittal, coronal, and axial sections regarding obturation length, obturation density (voids), missed canals, broken instruments, apical perforation, strip perforation, ledge formation, transportation, root fracture, root resorption, and periapical lesions by a senior dental student under the supervision of an oral and maxillofacial radiologist and an endodontist. Differences between the frequency of procedural errors and tooth type and gender were analyzed by the chi-square test. The frequency of underfilling, missed canals, overfilling, voids, apical perforation, transportation, ledge formation, broken instruments, root fracture, strip perforation, root resorption, and periapical lesions was 34.8%, 17.4%, 16.8%, 14.3%, 7.3%, 6.1%, 4.3%, 3%, 1.2%, 0.6%, 5.5%, and 46%, respectively. The frequency of root fracture was significantly higher in females than in males (P < 0.05). The prevalence of underfilling was the highest in right second molars (47.2%), followed by right first molars, left second molars, and left first molars (P < 0.005). The frequency of transportation was maximum in right first molars (10%), followed by right second molars, left first molars, and left second molars (P < 0.04). Underfilling, missed canals, and overfilling were the most prevalent procedural errors in mandibular molars in our study population.

CBCT Assessment of Gubernacular Canals on Permanent Tooth Eruption in Down's Syndrome.

The gubernacular canal (GC) is an important dental structure that enables the alveolar bone ridge cohesion of permanent teeth, although GC absence may indicate a dental eruption that might be associated with certain syndromes such as Down's syndrome. This study aims to correlate the eruptive delay of permanent teeth in individuals with Down's syndrome (Ds) and the gubernacular canal (GC) through cone-beam computed tomography (CBCT). This cross-sectional study was conducted between January and July 2022 with a total of 31 individuals (G1 = 16 nonsyndromic and G2 = 15 Down's syndrome) who went through imaging evaluation using CBCT with the following acquisition parameters: tube voltage of 95 kVp, tube current of 7 mA, exposure time of 5.9 s and voxel sizes and field of view 0.15 mm and 0.30 mm, respectively. The imaging evaluation was to assess whether all teeth analyzed had the presence of GC and/or teeth eruption disturbance, with a descriptive statistical analysis of relative frequencies and quantitative variables as well as the p-value (p < 0.005) by G Test. A total of 618 teeth among 31 individuals were analyzed, 475 (76.8%) GC were detected by CBCT in 23/31 patients and of these, 6 belonged to G2. G2 had a decreased GC detection rate (n = 180-37.9%) and the most common tooth with GC detected was the mandibular 1st molar (21 GC/25 teeth-84%) and the absence of GC was most frequently observed in impacted and delayed/unerupted teeth of Ds individuals. We concluded that GC absence was higher among Ds individuals, explaining the increased rates of unerupted or impacted teeth in Ds individuals.

Intraoperative Cone-Beam Computed Tomography Assessment of Spinal Pedicle Screws Placement Precision Is in Full Agreement with Postoperative Computed Tomography Assessment

To assess agreement between pedicle screw placement evaluated on post-operative computed tomography (CT) and on intra-operative cone beam computed tomography (CBCT) and compare procedure characteristics when using 1st and 2nd generation robotic C-arm systems in the hybrid operation room. All patients who received pedicle screws for spinal fusion at our institution between June 2009 and September 2019 and underwent intra-operative CBCT and post-operative CT were included. The CBCT and CT images were reviewed by two surgeons to assess the screw placement using the Gertzbein-Robbins and the Heary classifications. Inter-method agreement of screw placement classifications -as well as inter-rater agreement were assessed using Brennan-Prediger and Gwet's agreement coefficients. Procedure characteristics using 1st and a 2nd generation robotic C-arm systems were compared. Fifty-seven patients were treated with 315 pedicle screws at thoracic, lumbar and sacral levels. No screw had to be repositioned. On CBCT, accurate placement was found for 309 (98.1%) screws using the Gertzbein-Robbins classification and 289 (91.7%) using the Heary classification and on CT these were 307 (97.4%) and 293 (93.0%) respectively. Inter-method between CBCT and CT, and inter-rater agreements between the two raters were almost perfect (>0.90) for all assessment. There were no significant differences in mean radiation dose (p=0.83) and fluoroscopy time (p=0.82), but length of surgery using the 2nd generation system was estimated 107.7 min (95% CI: 31.9 to 183.5min, p=0.006) shorter. Intra-operative CBCT provides accurate assessment of pedicle screw placement and enables intra- operative repositioning of misplaced screws.

Clinical and Radiographic Evaluation of Third-Generation Pericardium Membrane for the Treatment of Grade II Furcation Defect in Stage III Periodontitis Patients.

Background and Objectives: Guided tissue regeneration, with or without a bone graft, is a modality for the treatment of furcation involvement. Because the direct application of a bone graft into the periodontal defect has drawbacks, such as the risk of microbial contamination and/or graft containment, a new modality of directly loading bone graft particles over the barrier membrane is now used. This study aimed to evaluate clinically and radiographically the effects of a two-layered membrane consisting of a layer of nanohydroxyapatite particles on a pericardium membrane in the treatment of stage III periodontitis, compared with direct application of a nanohydroxyapatite bone graft. Materials and Methods: Forty individuals with grade II furcation involvement were divided into two groups. Group I was treated with a two-layered membrane consisting of a pericardium membrane with nanohydroxy particles loaded onto its surface; group II was treated with direct application of a nano bone graft covered with pericardium membrane. Clinical and cone beam computed tomography (CBCT) radiographic assessments of the two groups were carried out after a 6-month follow-up period. Results: Clinically, the results showed a significant reduction in furcation involvement (F). The CBCT assessment also revealed reductions in depth (D), height (H), width (W), and 3D radiographic volume of furcation involvement in all study groups at baseline and at 6 months postoperative (p < 0.05) with no significant differences between groups. Conclusions: According to the results of the current study, a two-layer membrane formed by direct loading of bone graft particles onto a pericardium membrane can be used as an effective, reliable, and easy-to-use substitute for direct bone graft application into periodontal defects.

CBCT Assessment of the Anatomical Characteristics of Gubernacular Canal in Impacted Teeth.

Gubernacular canal (GC) is a canal that extends from the follicle of unerupted permanent teeth to the alveolar bone crest filled with remnants of the dental lamina. This canal is thought to guide tooth eruption and be related to some pathologic conditions. This study aimed to determine the presence of GC and its anatomical characteristics in teeth, which failed to erupt normally on cone beam computed tomography (CBCT) images. This cross-sectional study evaluated CBCT images of 77 impacted permanent and supernumerary teeth obtained from 29 females and 21 males. The frequency of GC detection, its location in relation to the crown and root, the anatomical surface of the tooth from which the canal has originated, and the adjacent cortical table to which the canal opens, along with the length of the GC were studied. GC was observed in 53.2% of teeth. The anatomical tooth aspect of origin was occlusal/ incisal in 41.5% and crown in 82.9% of teeth. Moreover, 51.2% of GCs opened in palatal/lingual cortex and 63.4% of canals were not located along the tooth long axis. Finally, GC was detected in 85.7% of teeth undergoing the crown formation stage. Although GC was introduced as an eruption pathway, this canal is also present in impacted teeth. This means that presence of this canal does not promise the normal eruption of tooth and the anatomical characteristics of GC may influence the eruption process.

Does Head and Neck Posture Affect Cone-Beam Computed Tomography Assessment of the Upper Airway?

Radiographic analysis is often used as a screening tool to assess for risk of sleep-related breathing disorders. This study aimed to address 2 questions: (1) Does head posture significantly affect the minimum cross-sectional area (MCA)? and (2) Is the NBC3 (nasion-basion-C3) angle a reliable measurement to control for alteration of head position in cone-beam computed tomography (CBCT) scans? Study design: prospective cohort study. Private practices affiliated with a research institution. convenience sample of adult volunteers. CBCT scans were taken in 2 conditions: baseline (natural head position, NHP) and 1 of 5 experimental conditions (head tilted up, head tilted down, sitting vs standing, use of chin-rest, and swallow variation). For the primary aim of our study, the primary predictor variable was head posture and the main outcome variable was percentage change in MCA. For the secondary aim, the primary predictor variable was head posture and the main outcome variable was degree change in NBC3 angle. Ninety subjects were included (age 40.7±13.7years, 70% female). Mean NBC3 at baseline was 112.4±8.3°. Head tilted down significantly decreased (-41.4±18.5mm2, P=.03∗) and head tilted up significantly increased MCA (+147.4±43.3mm2, P=.0018∗). Head tilted down significantly reduced the NBC3 angle measurement (-10.5±6.8°, P=.006) and head tilted up significantly increased the NBC3 angle measurement (+14.4±5.8°, P=.0004). A quadratic regression model was fitted with moderately strong correlation (R2=0.54) showing an exponential effect of small changes in the NBC3 angle on MCA, P<.0001. The model predicts that increasing NBC3 by+5 and+10° resulted in MCA changes of+25% and+88%, whereas a decrease in NBC3 by -5 and -10° results in MCA changes of -21% and -23%, respectively. Alterations in head posture significantly affect the MCA of the upper airway on CBCT. The NBC3 angle can be used to reliably assess changes in cranio-cervical extension and validate comparisons of MCA between CBCT scans for the same patient. A standardized protocol for CBCT acquisition is proposed.