Mandibular Cortex Research Articles

Automatic segmentation and visualization of cortical and marrow bone in mandibular condyle on CBCT: a preliminary exploration of clinical application.

To develop a deep learning-based automatic segmentation method for cortex and marrow in mandibular condyle on cone-beam computed tomography (CBCT) images and explore its clinical application. 825 condyles of 490 CBCT images from 3 centers of Stomatology hospitalaffliated to Zhejiang University School of Medicinewere collected. A deep learning model was developed for simultaneous segmentation of cortex and marrow in mandibular condyle. It included a region of interest extraction network and a segmentation network based on 3D U-net, with modifications made to improve the segmentation boundaries. To evaluate its clinical potential, the model's segmentation efficiency and accuracy were compared with those of both junior and senior oral and maxillofacial radiologists. Additionally, the model's ability to assist junior radiologists in diagnosis through visualization and quantitative analysis of the generated 3D model was also assessed. The Dice similarity coefficient of the deep learning model was 0.901 (cortex), 0.969 (marrow), and 0.982 (entire condyle). Hausdorff distance was 0.755mm (cortex), 0.826mm (marrow), and 0.760mm (entire condyle). The model outperformed radiologists across all segmentation metrics, completing the task in merely 15.06s. With the assistance of visualization and quantitative analysis generated from the model's segmentation, the diagnostic accuracy of junior radiologists significantly improved. The proposed deep learning-based model achieved accurate and efficient segmentation for mandibular condylar cortex and marrow. It possessed capability to generate precise 3D models, facilitating visual quantitative measurement and aiding in the diagnosis of condylar bony changes. This model holds potential for clinical applications in orthognathic surgery, orthodontic treatment, and other TMJ-related interventions.

A Novel Method of Correcting Lower Facial Asymmetry: Computer-Assisted Surgery with Contralateral Mandibular Outer Cortex Sandwich Grafting.

Lower facial asymmetry often results in an esthetically unpleasing appearance. The purpose of this study was to develop a novel method for correcting lower facial asymmetry using mandibular augmentation with sandwich bone grafts from the contralateral mandibular outer cortex (MOC), and to evaluate the efficacy of this method using computer-assisted techniques. The medical records of 16 patients with lower facial asymmetry who underwent mandibular augmentation with sandwich bone grafts from the contralateral MOC between January 2016 and December 2019 were retrospectively reviewed. Preoperative computer-aided design (CAD) was performed based on CBCT data, MOC grafts were harvested from the donor side using a 3D printed osteotomy guide template and grafted to the recipient side in sandwich manner to augment the contralateral mandible. Effectiveness was evaluated through pre- and postoperative CBCT data and FACE-Q questionnaire scores. Neurosensory recovery of the inferior alveolar nerve was assessed using the functional sensory recovery (FSR) scale. All procedure were successfully completed, and the asymmetry was effectively corrected three-dimensionally with no serious complications. The patients' FACE-Q scores for satisfaction with the lower facial area significantly increased from 52.19±7.51 to 86.69±7.50. No significant differences were observed in the pre- and postoperative lengths of mandibular ramus or body on either side. The donor site volume increased by 559.38±335.12 mm3 at 6 months postoperatively. The recipient site volume increased by 4415.94±1017.21 mm3 on the 7th day postoperatively and decreased by 202.63±300.85 mm3 at 6 months, reflecting a bone resorption rate of 5.67 ± 8.12%. The median FSR time for the chin and lower lip was 90 days. Mandibular augmentation with contralateral MOC sandwich grafts effectively increases mandibular width and volume witha low resorption rate. This method allows for three-dimensional restoration of facial symmetry in cases of mild to moderate lower facial asymmetry, achieving a harmonious and symmetric appearance. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266. www.springer.com/00266.

Screening ability of dental students to detect osteoporosis on dental panoramic radiographs

ObjectivesPostmenopausal women with osteoporosis are frequently underdiagnosed. In Japan, general dental practitioners have begun using the cortical shape of the mandible on dental panoramic radiographs (PRs) to identify and refer women at risk of osteoporosis to medical professionals. It remains unclear whether dental students, after relevant education, possess the ability to identify these at-risk individuals. This study evaluated the ability of dental students to screen for osteoporosis on PRs. MethodsA cohort of 113 fifth-year dental students participated in a lecture on osteoporosis screening using PRs. The students then categorized the mandibular inferior cortex on PRs from 30 postmenopausal women (11 with osteoporosis) as normal, mildly to moderately eroded, or severely eroded. Interobserver agreement between the students and an expert oral radiologist using two cortical groups (normal to moderately eroded and severely eroded) was assessed through kappa statistics. Screening ability for osteoporosis detection by identifying severely eroded cortices was calculated and compared with that of the Osteoporosis Self-assessment Tool for Asians (OSTA). ResultsTwenty-one (18.6%) students demonstrated moderate to substantial agreement with the expert. The mean sensitivity, specificity, and positive and negative predictive values for these students in identifying osteoporosis were 60.2%, 88.0%, 76.3%, and 80.0%, respectively. For the OSTA, sensitivity, specificity, and positive and negative predictive values were 27.3%, 68.4%, 33.3%, and 61.9%, respectively. ConclusionsEven with minimal education, approximately one-fourth of dental students may accurately identify postmenopausal women with osteoporosis on PRs, outperforming questionnaire-based screening tools.

Histological assessment of potential inferior alveolar nerve injury following osteotomy of the mandibular buccal cortex using a piezoelectric saw.

The present study aimed to evaluate the effect of Piezosurgery on histopathologic features of the inferior alveolar nerve (IAN) damage after osteotomy of the buccal cortex of the mandible using piezoelectric devices in Hamdani sheep.A total of ten healthy mature female sheep were included. Each side of the mandible underwent two different experiments: the first experiment operated directly on the mental nerve by touching and activating the piezo tip on the nerve for ten seconds for the left side and thirty seconds for the right side. In the second experiment, the inferior alveolar nerve was touched by an activated piezo tip inside the mandibular canal for ten seconds on the left side and thirty seconds on the right side. All the nerve samples underwent histopathological evaluation, and the scoring system was performed to assess the nerve structures. Mental nerves exposed to piezo tip for 10 seconds showed mild abnormality including disruption of the perineurium with the endoneurium remaining intact. Mental nerves exposed for 30 seconds showed moderate injury with destruction of the perineurium and moderate degeneration of nerve fibers, nevertheless, the endoneurium remained continuous with normal node of Ranvier. Severe damage of the inferior alveolar nerve was seen after exposure to piezo tip for 10 seconds, which showed sloughing of the perineurium and severe vacuolar degeneration of nerve fibers, partial disruption of the endoneurium; however, the axons were still intact. Inferior alveolar nerves exposed for 30 seconds revealed destruction of the perineurium, marked vacuolar degeneration of nerve fibers, focal damage of axon and loss of endoneurium (axonotmesis).Piezosurgery devices have the potential to cause severe nerve damage during surgery and should be used very carefully.

The relationship between radiomorphometric indices and fractal dimension analysis: a cone-beam computed tomography study.

The purpose of this study is to evaluate the relationship between radiomorphometric indices and fractal dimension (FD) analysis in jawbone radiographic density using Cone-Beam Computed Tomography (CBCT). The study included 87 CBCT datasets from dental patients aged 50-79. Four radiomorphometric indices (Computed Tomography Cortical Index (CTCI), Computed Tomography Mental Index (CTMI), Computed Tomography Index-Superior (CTI-S), and Computed Tomography Index-Inferior (CTI-I)) along with age, gender, remaining teeth, and mandibular bone height were evaluated. FD was assessed in trabecular bone near the mental foramen (ROI 1) and on the mandibular cortical bone (ROI 2). Relationships between indices and variables were analyzed using Pearson chi-square, Fisher's exact, one-way ANOVA, Kruskal-Wallis, and Spearman's rho tests. ANOVA showed significant differences in mandibular bone height (p = .004) and FD at ROI 2 (p = .000) across three mandibular cortex types (C1, C2, C3). Spearman's rho indicated significant correlations between FD at ROI 2 and CTMI, CTI-S, CTI-I (p = .000), and between mandibular bone height and CTMI (p = .010). The correlations of FD at ROI 2 ranged from strongest to weakest with CTCI, CTMI, CTI-S, and CTI-I. High-risk osteoporosis radiomorphometric indices are associated with FD analysis of cortical bone.

Evaluation of mandibular bone structure changes in phenylketonuria patients through fractal analysis and radiomorphometric indices

ObjectivesThe aim of this study was to evaluate the effect of phenylketonuria (PKU) on mandibular bone structure by comparing the bone of PKU patients with healthy controls using fractal analysis and the radiomorphometric indices of mandibular cortical width (MCW) and mandibular cortical index (MCI). Study DesignIn total, 32 patients with PKU were analyzed and compared with the control patients. Regions of interest in panoramic radiographs were selected and the fractal dimension (FD) obtained from fractal analysis was calculated. MCW was defined as the cortical thickness of the inferior border of the mandible at the level of the mental foramen. MCI classified the endosteal edge of the mandibular cortex as C1: straight and sharp, C2: the presence lacunar resorption spaces, and C3: distinctly porous and severely eroded. The significance level was P<0.05. ResultsAll FD and MCW values were significantly lower in the PKU patients. The prevalence of C1 was significantly lower and prevalence of C2 was significantly higher in the PKU group. ConclusionThe differences in fractal dimension and radiomorphometric indices between patients with PKU and healthy controls may indicate a potential impact of PKU on mandibular bone structure.

The Value of Mandibular Indices on Cone Beam Computed Tomography in Secondary Causes of Low Bone Mass.

Background: As implant treatment cases increase, many cases of failure/side effects also occur. Generally, dental clinics determine the density of the jawbone using cone beam CT (CBCT). Considering the known potential role of this tool for bone assessment in primary osteoporosis, this study evaluated patients with secondary endocrine causes of low bone mass. Methods: The study included 83 patients with endocrine causes of osteoporosis who were evaluated by dual-energy X-ray absorptiometry (DXA), trabecular bone score (TBS), and mental foramen (MF) region CBCT. The following CBCT indices were measured: anterior (A)-thickness of inferior mandibular cortex 10 mm anterior from MF; molar (M)-thickness of inferior mandibular cortex 10 mm posterior from MF; posterior (P)-thickness of inferior mandibular cortex 25 mm posterior from MF; symphysis (S)-thickness of inferior mandibular cortex equidistant from the centers of right and left MF. Results: The highest correlation coefficient in the secondary causes group was between the A index and the lumbar BMD (r = 0.375, p = 0.001) and the P index and the femoral neck BMD (r = 0.38, p = 0.001). Hypercortisolism seems to be the most predictable cause of secondary osteoporosis using the A, M, and P indices. The A, M, and P indices showed predictive values of the bone micro-architecture that was evaluated using TBS score, and were statistically significant. The symphysis index does not significantly predict osteoporosis or impaired bone micro-architecture. Conclusions: These findings support the potential usefulness of A, M, and P CBCT-derived radiomorphometric mandibular indices in secondary osteoporosis, underlining the well-known effects of these pathologies on bone micro-architecture rather than bone quantity.

Are Radiographic Changes in the Mandibular Canal Associated With Bone Mineral Density?

Osteoporosis, highly prevalent among postmenopausal women, significantly reduces bone density and increases the risk of fractures. Cortical bone, which constitutes the largest calcium deposit in the human skeleton, is primarily affected in various conditions, including osteoporosis. Due to its visibility in panoramic radiography, the cortical area of the mandibular canal could be valuable in assessing decreases in bone mineral density (BMD). The study aimed to characterize and compare changes in the cortices of the mandibular canal between normal, osteopenic, and osteoporotic postmenopausal women. Our cross-sectional study analyzed postmenopausal patients. We included only patients with panoramic radiographs with good quality and who underwent osteoporosis risk assessment by dual-energy x-ray absorptiometry (DXA). BMD was measured by DXA at 3 sites (spine, femur, and forearm) and used to classify the patients into normal, osteopenic, or osteoporotic. This classification remained consistent across all measurement sites. The main outcome variable was BMD of the mandibular canal cortices measured using black pixel intensity. Demographic covariates, including age, weight, height, and BMD, were assessed. One-way analysis of variance between groups considering a P<.05. The relationship between covariates and dependent variables was assessed using the Pearson correlation test. The sample comprised 52 postmenopausal women aged more than 40 years (mean age 61±10years), 26 (50%) normal, 18 (35%) osteopenic, and 8 (15%) osteoporotic. Significant differences were observed in the percentage of black pixels in the mandibular ramus between the groups. In this region, the average percentage of black pixels was 3.19% (± 0.65) for the normal group, 2.78% (±0.65) for the osteopenia group, and 2.35% (± 0.65) for the osteoporosis group (P=.015). No significant differences were found in other mandibular regions. Our findings demonstrate an association between BMD assessed in the mandibular canal cortex and the presence of osteoporosis as determined by DXA. While the observed differences in black pixel percentages in the mandibular ramus are minor, they are statistically significant, suggesting that panoramic radiography may serve as an adjunctive tool for osteoporosis screening.

Radiographical Diagnostic Evaluation of Mandibular Cortical Index Classification and Mandibular Cortical Width in Female Patients Prescribed Antiosteoporosis Medication: A Retrospective Cohort Study.

Osteoporosis is often detected late and becomes severe because of a lack of subjective symptoms. Digital panoramic radiography (DPR) has been reported to be useful for osteoporosis screening based on the morphological classification of the mandibular inferior cortex. The purpose of this study was to evaluate the sensitivity and specificity of the mandibular cortical index (MCI) in the diagnosis of osteoporosis in a group of patients who were and were not using antiosteoporosis medication (AOM). Three hundred and fifty female patients aged 40 years or older who had DPR imaging performed during a 6-year period from December 2015 to February 2022 met the selection criteria. Two examiners recorded mandibular cortical width and MCI from the images. These results were statistically examined together with the patients' demographic data. Forty-nine patients were using AOM (13 nonbisphosphonate/denosumab and 36 bisphosphonate/denosumab). MCI type 3 was the most common in the AOM group. In the MCI classification, DPR imaging among the AOM group was more sensitive (0.95) than that of the control group. This method of estimating osteoporosis based on MCI classification using DPR images has high sensitivity, especially in patients using AOM, suggesting that this method is useful as a screening test.

Strut and radio-morphometric analysis of mandibular trabecular structure in pre-and post-menopausal women to aid in the diagnosis of osteoporosis

PurposeThe purpose of the study is to evaluate the mandibular trabecular pattern in pre- and postmenopausal age women. By analysing the strut, fractal, grey level co-occurrence matrix, and radio-morphometric indices in the panoramic radiograph. MethodPanoramic radiographs from 2019 to 2022 were used to assess pre- and postmenopausal women's bone mineral density. A total of 272 panoramic radiographs, which exhibited clear visibility of the mental foramen on both sides without any blurring, motion artefacts, surgical errors, overlapping hyoid bone, or inferior mandibular cortex, were divided into two groups. Group A (136 premenopausal women) and Group B (136 postmenopausal women). It is a retrospective study that is non-interventional/observational in design. Strut features, fractal dimensions, a grey-level co-occurrence matrix, and radio morphometric indices were used to investigate bone texture in an image processing program. The mean difference between group variables was calculated using an independent sample t-test/unpaired t-test. ResultsPre-menopausal women had a mean age of 38.83 ± 6.01 years, while postmenopausal women had a mean age of 68.26 ± 8.31 In the postmenopausal group Four regions of interest exhibited fractal dimensions with a P value of less than 0.01 and GLCM features including contrast (0.812), correlation (0.230), energy (0.215), and homogeneity (0.322). Strut features of the four regions showed that 15 of 19 characteristics were significantly different. ConclusionOrthopantomogram is useful in screening for osteoporosis. Strut, radio-morphometric indices, and fractal analysis can assess bone texture and quality. Future research incorporating artificial intelligence can revolutionize image analysis and support clinical decision-making.

Role of ortho-pantho-graphic X-ray in the diagnosis of osteoporosis

Background: Osteoporosis affects people, especially old age, as postmenopausal women and remains unnoticeable until the patient presents with a fracture. Osteoporosis in human begins started with the loss of bone mass that increases with age, this is related to the decrease in bone density and an increase in porosity that will cause fractures in this osteoporotic bone. Objective was to assess the usefulness of orthopanthographic (OPG) in the early detection of osteoporosis. Methods: This is an analytic across-sectional test validation study, was done in Hawari Hospital-Benghazi, Libya which considered a referral General Hospital affiliated with University of Benghazi. This study was done during a period from March 2022 to July 2023. Sixty women were selected, divided into osteoporotic and non osteoporotic groups depending on the clinical and laboratory investigations under the supervision of an orthopedic consultant in the outpatient clinic. Panoramic radiographic X-rays were taken for evaluation and estimation of the mandibular cortex on the basis of (Mental index, Klemetti index, and Panoramic mandibular index) as a diagnostic tool to differentiate normal from osteoporotic patient, all three indices correlated significantly with bone mineral density and used as useful indicators for detected the osteopenia and osteoporosis. Results: We calculated values of the three indices (Mental index, Klemetti index, and Panoramic mandibular index) values were low especially in the osteoporotic group, as well the values of mental index and panoramic mandibular index were low compared with low bone mineral density of the patient and klemetti index with: C2, C3 categories (moderate and severe erosion) most common observed in the osteoporotic patient. Conclusions: Orthopanthographic X-rays provide a valuable tool for early detection and assessment of osteoporosis (preclinical stage) especially when characterized by a decrease in bone mineral density.

Relationship between Impacted Mandibular Third Molars and the Mandibular Canal on CBCT Scans.

This study aimed to assess the relationship of impacted mandibular third molars with the mandibular canal on cone beam computed tomography (CBCT) scans. This cross-sectional study was conducted on CBCT scans of 137 patients with 204 impacted mandibular third molars. The relation of age, gender, class of impaction, anatomical position of canal relative to tooth (buccal, lingual, inferior, inter-radicular), tooth angulation (mesioangular, vertical, distoangular, horizontal), relationship of tooth with the mandibular canal (no contact, in contact, relation), relationship of tooth with the mandibular cortex, anatomical site of contact of tooth with the mandibular cortex (buccal, lingual, inferior), and the impression of canal (grooving, no effect) on impacted teeth were evaluated. Data were analyzed using one-way ANOVA, Chi-square test and Fisher's exact test. Class B of impaction (78.9%), inferior position of canal relative to the impacted tooth (53.9%) and mesioangular angulation (53.4%) had the highest frequency, respectively. The relationship of tooth with the mandibular canal was "relation" in most cases (53.4%) followed by no contact (26.9%) and in contact (19.6%). Significant associations were noted between depth of impaction (P < 0.001), tooth angulation (P = 0.024), anatomical position of canal relative to tooth (P < 0.001), relationship of tooth with the mandibular cortex (P = 0.032) and anatomical site of contact of tooth with the mandibular cortex (P = 0.013) with the impacted tooth-mandibular canal relationship. CBCT provides accurate information about the relationship of impacted third molars with the mandibular canal and can decrease the risk of traumatization of inferior alveolar nerve (IAN) during their surgical extraction.

Measurement of the mandibular canal and mandibular incisive canal using cone beam tomography in adults from South Brazil.

To identify and measure the distance from the dental apices to the mandibular (MC) and mandibular incisive (MIC) canals, the diameter of the MC and the distances of the mental foramen (MF). In this retrospective study, cone-beam computed tomography scans of 144 adult patients (males and females) from a dental school in South Brazil were evaluated. Cross-sections were selected on the MC and the MIC paths, perpendicular to the mandibular base, and measurements were taken from the dental apices to the mandibular cortices. The measurement and location of the mandibular and mental foramen on both sides were compared. Paired t-tests compared sides, while Student's t-tests compared sexes (P < 0.05). The distance from the dental apices to the upper wall of the MC was closest in the third molar and farthest in the central incisor region. In both sexes and sides, the path of the MC is in most cases lingually in the molar regions and moves to the buccal region from the second premolar. The MF emerges in the regions between the premolars or near the second premolar. The results of this study highlight the importance of evaluating specific individual characteristics of a given population.

Differences of bone quality in patients type II diabetes mellitus with mandibular cortical index analysis on panoramic radiograph

Objectives: This study aims to determine the quality of the mandibular cortex in Type II diabetes mellitus patients by analyzing the Mandibular Cortical Index on panoramic radiography. Materials and Methods: This type of research is unpaired comparative analytical design research using a cross-sectional stratified random sampling method and the Mann-Whitney statistical test. The subjects in this study were patients who visited and were diagnosed with type 2 DM for ≤ 5 years and &gt; 5 years by doctors at the Endocrine Metabolic Internal Medicine Sub-Specialist Polyclinic, Ulin Hospital, Banjarmasin. Results: Respondents who had suffered ≤ 5 years had the highest mandibular cortical C2 index value of 10 (58.8%). Respondents who suffered &gt; 5 years had the highest mandibular cortical C3 index value of 10 (58.8%). Diabetes mellitus patients with mandibular cortical C3 index value were ranked highest out of a total of 34 samples and were found in patients suffering from diabetes mellitus &gt; 5 years. Conclusion: Patients with diabetes mellitus had poor bone quality, especially patients suffering from diabetes mellitus &gt; 5 years.

Radiographic imagery of aggressive plexiform-type ameloblastoma in the mandible: a case report

Objectives: This case report aims to describe the radiographic characteristics of plexiform ameloblastoma and its impact on surrounding tissues in a middle-aged female patient using panoramic radiography and CBCT, along with case management. Case Report: A 43-year-old female patient presented to the Dental Radiology Unit of RSGMP UNHAS with a panoramic referral letter, diagnosed clinically with anterior mandibular ameloblastoma. Extraoral examination revealed an asymmetrical facial appearance with anterior mandibular enlargement. Intraoral examination showed mucus membrane enlargement in the anterior mandible region (teeth 37-45), soft consistency, absence of crepitus, no palpation tenderness, and mobility in several anterior mandibular teeth. The first panoramic radiograph (March 16, 2022) exhibited a unilocular radiolucent lesion, well-defined, with scalloped margins in the anteroposterior mandibular region. The second panoramic examination (May 23, 2022) indicated a more aggressive lesion expansion, with evidence of root resorption and destruction of the inferior mandibular cortex approaching the mandibular angle. CBCT findings demonstrated a hypodense/radiolucent lesion extending anteroposteriorly, superiorly, and inferiorly, leading to displacement, root resorption, and destruction of the inferior mandibular cortex in the inferior direction. Conclusion: Based on the characteristics and structure of the lesion observed through various radiographic examinations, a unilocular ameloblastoma was suspected. Histopathological examination confirmed the plexiform-type ameloblastoma.

Associations between the 3D position of the mental foramen with sagittal skeletal relationships (classes I, II, and III) and vertical facial growth patterns (normal, long, and short faces) in different ages and sexes: a retrospective cohort study of 360 CBCTs

BackgroundThe 3D position of the mental foramen (MF) is of significant clinical value in dental implantology and mandibular surgeries or in local anesthesia. Despite its importance, it is not clearly known how the position of MF can alter in different individuals, since the literature on the associations between the MF position with vertical growth patterns is non-existent and those on links between the MF position and skeletal malocclusions are scarce. Therefore, we aimed to investigate these, for the first time, on cone-beam computed tomographies (CBCTs).MethodsArchival CBCTs of 9 sub-groups (i.e., 3 skeletal Classes I, II, and III × 3 vertical growth patterns ‘long face, short face, normal face’) were collected by evaluating patients’ SNA, SNB, ANB, facial angle, lower facial height, and FMA (n = 9 × 40 = 360). Included cases were older than 17 years and without any history of orthodontic/orthognathic treatments (243 women, 117 men, mean age: 22.28 ± 2.80 years). Perpendicular distances between the MF and 3 fixed bony structures (the mandibular symphysis [S/width], the mandibular ramus [R/length], and the mandibular lower cortex [C/height]) were measured on different sectional planes on both hemimandibles. Left- and right-side measurements were combined. Data were analyzed using the 3-way ANCOVA, Bonferroni, one-way ANOVA, Tamhane, Pearson, and t-test (α = 0.05).ResultsWidth was the smallest in Class II and greatest in Class III cases (all P values < 0.000001, Bonferroni). It was the shortest in long faces and longest in short faces (all P values ≤ 0.00008). The inferior-superior height was larger in Class III than both Classes I and II (both P values ≤ 0.003); there was no significant difference between Classes I and II in terms of height (P = 0.684). Height was the largest in long faces and smallest in short faces (all P values < 0.000001). The anterior-posterior length was the largest in Class III and smallest in Class II (all P values < 0.000001). Length was larger in short-face people versus normal- or long-face individuals (P ≤ 0.00003); nevertheless, long and normal faces did not differ in terms of length (P = 0.448). Subjects’ age was not correlated with their MF positions (P ≥ 0.579, Pearson coefficient). Sex dimorphism existed only for height (P = 0.009, t-test) but not for length or width.ConclusionsThe MF position may considerably differ in various horizontal or vertical growth patterns and sexes. This should be noted in mandible surgeries.

Evaluation of cortical and trabecular bone structure of the mandible in patients using L-Thyroxine

BackgroundLong-term use of L-Thyroxine (LT4), the synthetic thyroxine hormone used for thyroid hormone replacement therapy, is an important risk factor for osteoporosis. The aim of this study was to investigate the differences between mandibular cortical index (MCI) and trabecular bone fractal dimension (FD) values on panoramic radiographs of patients using LT4 and control subjects.MethodsA total of 142 female patients, 71 cases and 71 controls, were analyzed in the study. Ages were matched in case and control groups and the mean age was 36.6 ± 8.2 (18 to 50) years. MCI consisting of C1 (Normal Mandibular Cortex), C2 (Moderately Resorbed Mandibular Cortex) and, C3 (Severely Resorbed Cortex) scores was determined for case and control groups. Fractal analysis was performed using ImageJ on selected regions of interest from the gonial and interdental regions. The box-count method was used to calculate FD values. Wilcoxon signed-rank test, Mann-Whitney U test, and Spearman correlation analysis were applied to compare the measurements. Statistical significance of differences was established at P < 0.05 level.ResultsFD values did not show statistically significant differences between case and control groups (p > 0.05). The mean FD in the right gonial region was 1.38 ± 0.07 in the case group and 1.38 ± 0.08 in the control group (p = 0.715). The mean FD in the right interdental region was 1.37 ± 0.06 in the cases and 1.36 ± 0.06 in the control group (p = 0.373). The mean FD in the left gonial region was 1.39 ± 0.07 in the cases and 1.39 ± 0.07 in the control group (p = 0.865). The mean FD in the left interdental region is 1.37 ± 0.06 in the cases and 1.38 ± 0.05 in the control group (p = 0.369). The most common MCI score was C1, with 62% in the cases and 83.1% in the control group. MCI scores showed a statistically significant difference between cases and controls (p = 0.016, p < 0.05). While the C2 score was higher in the cases, the C1 score was higher in the controls.ConclusionsLT4 use was not associated with the FD of mandibular trabecular bone, but was associated with MCI values of cortical bone. Further studies on larger samples with different imaging modalities and image processing methods are needed.

Evaluation of cortical and trabecular bone structure of the mandible in patients with ankylosing spondylitis

This study aimed to examine the difference between the fractal dimension (FD) values of the mandibular trabecular bone and the panoramic mandibular index (PMI), mandibular cortical index (MCI) and mandibular cortical thickness (MCW) of patients with ankylosing spondylitis (AS) and healthy control group. A total of 184 individuals (92 cases, 92 controls), were examined in our study. PMI, MCI, and MCW values were calculated on panoramic images of all individuals. For FD values, the region of interest (ROI) was selected with the size of 100 × 100 pixels from the right-left gonial and interdental regions and 50 × 50 pixels from the condylar region. Degenerative changes in the temporomandibular joint (TMJ) region were recorded. PMI, MCI, and MCW values showed statistically significant differences between the groups (p = 0.000, p < 0.001). The radiological signs of mandibular cortical resorption were more severe in the case group than in the control group. PMI and MCW values were found to be lower in the case group than in the control group. It was determined that the number of C3 and C2 values, among the MCI values, was higher in the case group. Only the FD values of the ROI selected from the condyle region were found to be statistically significant and were lower in the case group (p = 0.026, p < 0.05). Degenerative changes in the TMJ region were significantly more frequent in the case groups (p = 0.000, p < 0.001). The fact that the mandibular cortex shows more resorptive features in individuals with AS may require further evaluation in terms of osteoporosis. Because of the low FD values of the condylar regions of these patients and the more frequent degenerative changes, the TMJ region should be followed carefully. Detailed examination of the mandibular cortex and condylar region is beneficial in patients with AS for screening and following osteoporotic changes in these individuals, which is essential for the patient’s life quality.

Relation between maxillary sinus pneumatization and the thickness of the mandibular inferior border in panoramic radiographs

BackgroundMaxillary sinus pneumatization is a physiological process that can adversely affect bone availability for further dental rehabilitation. If a relation between the thickness of the mandibular cortex and maxillary sinus pneumatization is proven, future bone availability can be deducted. Material and methodsIn this cross-sectional study, 85 panoramic radiographs were evaluated. All patients were between 19 and 70, had at least lost a second premolar, first molar, or second molar on one side of the maxilla, and had these teeth on the other side. Four lines were digitally drawn on the radiographs to determine the superior and inferior borders of the sinus on both sides. The amount of inferior sinus border progression was deducted using the digitally-measured lines' ratios. The following tests were done using IBM SPSS ver. 24: Pearson's correlation coefficient test, Tukey's dual comparison posthoc test, One-way ANOVA test, and the independent T-test (p = 0.05). ResultsThere was a negative correlation between the inferior mandibular cortex's thickness and the maxillary sinus's pneumatization (p < 0.001). Also, there was a significant difference between maxilla sinus pneumatization in the second premolar, first, and second molar areas based on the inferior mandibular cortex’s thickness (p = 0.009). ConclusionsBased on the present study, there is a significant relationship between the thickness of the inferior mandibular cortex and maxillary sinus pneumatization, especially for women and patients above 40 years old.

A Panoramic X-ray as a Supportive Diagnostic Tool for the Screening of Osteoporosis in Patients with Hemophilia A and B.

Hemophilia is associated with an increased risk of developing osteoporosis and osteopenia. The aim of the study was to interpret the usefulness of fractal analysis of the trabecular bone of the mandible (FD) and selected radiomorphic indices (the antegonial index (AI) and Klemetti index (KI)) to assess the risk of reduced bone mineral density (BMD) in patients with hemophilia A/B. The study group consisted of 50 patients with type A/B hemophilia. The control group consisted of 25 males without congenital bleeding disorders. The patients had a panoramic radiograph taken with the same X-ray machine (Vistapano S, Durr Dental, Bietigheim-Bissingen, Germany). The AudaXCeph software (Audax d.o.o., Ljubljana, Slovenia) was used to evaluate the AI index, and the ImageJ, software with a specially prepared script, was used to evaluate the FD. The mandibular cortex was assessed distal to the mental foramen using the Klemetti index. There were no statistically significant differences between the AI, KI and FD values between the study group and the control group. This study indicated the lack of usefulness of AI, KI and fractal analysis in identifying patients with hemophilia at risk of reduced bone mass.