Mandibular bone remodelling in adults: evaluation of panoramic radiographs

Determination of Mandibular Morphology in a Turkish Population With Bipolar I Disorder Using Panoramic Radiography

ABSTRACT

The presence of specific craniofacial deviations may be evidence of abnormal early brain development in bipolar disorder (BD). This study aimed to compare mandibular morphology in patients with BD versus nonpsychiatric controls using panoramic radiography. A total of 215 recorded images, 70 patients with BD and 145 controls, were evaluated. Seven mandibular parameters of the ramus height (RH), condylar height (CH), gonial angle (GA), antegonial angle (AGA), antegonial notch depth (AND), ramal notch depth (RND), and bigonial width (BGW) were measured in a blinded manner. Group analysis was conducted separately for males and females. The univariate comparisons showed increased values in RH, CH, AND, RND, and BGW and decreased values in GA in males with BD compared with male controls. In addition, females with BD had higher RH, CH, RND, and BGW values in comparison to female controls. The differences were statistically significant. Data from multivariate analyses revealed that increases in RH and BGW values in both sexes were significant predictive variables that distinguished patients with BD from controls. Moreover, deeper AND was the most prominent predictor that distinguished male patients with BD from male controls. The identification of subtle changes in mandibular measurements is consistent with the notion of impaired neurodevelopment in BD.

Can Different Impression Techniques Affect the Chewing Efficiency of Mandibular Implant-Retained Overdentures?

Several impression techniques and theories have been developed for implant-retained overdentures, each with its own set of advantages and limitations. This study aimed to assess the chewing efficiency of mandibular implant-retained overdentures fabricated using three distinct impression techniques (mucofunctional, selective, and minimal pressure impression techniques). Twenty-six patients with complete edentulism free from any oral or systemic disease were selected to participate in the study. Three complete mandibular implant-retained overdentures were constructed for each patient, and grouped into three groups according to the impression technique employed in overdenture construction; Group A: Patients were treated by mandibular implant-retained overdenture fabricated using mucofunctional impression technique; Group B: Patients were treated by mandibular implant-retained overdenture fabricated using selective pressure impression technique; Group C: Patients were treated by mandibular implant-retained overdenture fabricated using minimal pressure impression technique. Chewing efficiency was evaluated for each patient with the implant-retained mandibular overdenture after three months of prosthesis insertion as an adaptation period. The data were collected, tabulated, and statistically analyzed. Results indicated that mandibular implant-retained overdentures made using the mucofunctional impression technique showed higher mean values of chewing efficiency parameters than mandibular overdentures made using selective and minimal pressure impression techniques. Within the limitations of this study, it can be concluded that the mucofunctional impression technique may be effective in improving the chewing efficiency of mandibular implant-retained overdentures more than minimal or selective pressure impression techniques.

Automatic and robust estimation of sex and chronological age from panoramic radiographs using a multi-task deep learning network: a study on a South Korean population

Sex and chronological age estimation are crucial in forensic investigations and research on individual identification. Although manual methods for sex and age estimation have been proposed, these processes are labor-intensive, time-consuming, and error-prone. The purpose of this study was to estimate sex and chronological age from panoramic radiographs automatically and robustly using a multi-task deep learning network (ForensicNet). ForensicNet consists of a backbone and both sex and age attention branches to learn anatomical context features of sex and chronological age from panoramic radiographs and enables the multi-task estimation of sex and chronological age in an end-to-end manner. To mitigate bias in the data distribution, our dataset was built using 13,200 images with 100 images for each sex and age range of 15-80 years. The ForensicNet with EfficientNet-B3 exhibited superior estimation performance with mean absolute errors of 2.93 ± 2.61 years and a coefficient of determination of 0.957 for chronological age, and achieved accuracy, specificity, and sensitivity values of 0.992, 0.993, and 0.990, respectively, for sex prediction. The network demonstrated that the proposed sex and age attention branches with a convolutional block attention module significantly improved the estimation performance for both sex and chronological age from panoramic radiographs of elderly patients. Consequently, we expect that ForensicNet will contribute to the automatic and accurate estimation of both sex and chronological age from panoramic radiographs.

Morphological evaluation of gonial and antegonial regions in bruxers on panoramic radiographic images

BACKGROUND

This is the first study to report both cortical and trabecular bone evaluation of mandibles in bruxers, within the knowledge of the authors. The purpose of this study was to evaluate the effects of bruxism on both the cortical and the trabecular bone in antegonial and gonial regions of the mandible, which is the attachment of the masticatory muscles, by using panoramic radiographic images.

METHODS

In this study, the data of 65 bruxer (31 female, 34 male) and 71 non-bruxer (37 female, 34 male) young adult patients (20-30 years) were evaluated. Antegonial Notch Depth (AND), Antegonial-Index (AI), Gonial-Index, Fractal Dimension (FD) and Bone Peaks (BP) were evaluated on panoramic radiographic images. The effects of the bruxism, gender and side factors were investigated according to these findings. The statistical significance level was set atP ≤ 0.05.

RESULTS

The mean AND of bruxers (2.03 ± 0.91) was significantly higher than non-bruxers (1.57 ± 0.71; P < 0.001). The mean AND of males was significantly higher than females on both sides (P < 0.05). The mean AI of bruxers (2.95 ± 0.50) was significantly higher than non-bruxers (2.77 ± 0.43; P = 0.019). The mean FD on each side was significantly lower in bruxers than in non-bruxers (P < 0.05). The mean FD of males (1.39 ± 0.06) was significantly higher than females (1.37 ± 0.06; P = 0.049). BP were observed in 72.5% of bruxers and 27.5% of non-bruxers. The probability of existing BP, in bruxers was approximately 3.4 times higher than in non-bruxers (P = 0.003), in males was approximately 5.5 times higher than in females (P < 0.001).

CONCLUSION

According to the findings of this study, the morphological differences seen in cortical and trabecular bone in the antegonial and gonial regions of the mandible in bruxers can be emphasized as deeper AND, higher AI, increased of existing BPs, and lower FD, respectively. The appearance of these morphological changes on radiographs may be useful for indication and follow-up of bruxism. Gender is an effective factor on AND, existing BP and FD.

Fractal dimension analysis of different mandibular regions in familial Mediterranean fever patients: A cross-sectional retrospective study

Familial Mediterranean fever (FMF) is a genetic condition that may cause loss of bone mineral density (BMD) due to chronic inflammation. Previously, fractal dimension (FD) analysis values of mandibular cortical bone were shown to be lower in osteoporosis. Therefore, FD might be considered as an auxiliary tool to refer patients for dual-energy x-ray absorptiometry (DXA), which is the gold standard for BMD measurement. The purpose of this cross-sectional retrospective study was to evaluate trabecular and cortical microarchitecture of the mandible with FD analysis on panoramic radiographs in a subpopulation of FMF. Also, the effect of colchicine use was investigated. Forty-three FMF patients, aged between 10.8 and 71.2 years, and age- and gender-matched control group consisting of patients, who had no systemic diseases, were included. Demographic information such as age and gender, and colchicine use were recorded. In terms of age, the patients were classified as <30 and 30< years. On each panoramic radiographs five regions of interest were selected on the mandible as: 1- premolar, 2- molar, 3- angular, 4- condylar, and 5- basal cortical bone regions on right (R) and left (L) sides. Statistical significance was accepted at p<0.05 level. Intra- and inter-observer agreements demonstrated good to excellent consistency. In FMF patients, L3 and L4 values were higher, whereas L5 values were lower (p<0.05) than the control group. In terms of age, the difference between groups was insignificant in FMF patients (p>0.05), whereas in control group R3 and L4 values were higher in the 30< age group (p<0.05). Regarding gender and colchicine use, the difference between groups was insignificant (p>0.05). FMF disease might be a candidate for referral to DXA examination based on decreased bone density in the mandibular cortex detected by FD measurements on routine panoramic radiographs. Further studies are warranted to ascertain this relationship.

Tridimensional assessment of the mandibular angle in patients with different skeletal patterns by cone-beam computed tomography scans: a retrospective study

BACKGROUND

Since the muscles of chewing are involved in the region of the mandibular angle, important structures in surgical and orthodontic procedures, to study its morphological aspects and the possible influence of different patterns of skeletal development would be of interest. Thus, this study aimed to assess the influence of patient characteristics - such as sex, skeletal malocclusion (Class I, Class II, and Class III) and facial type (brachycephalic, mesocephalic, and dolichocephalic) - on the width, height, thickness, and volume of the mandibular angle, using cone-beam computed tomography (CBCT) scans.

METHODS

CBCT scans were assessed - 144 men and 154 women, total of 298 - and classified according to skeletal patterns (skeletal malocclusions and facial types). Width, height, and thickness of the mandibular angle were measured using OnDemand 3D software. The volumetric measures of the mandibular angle were obtained using the ITK-SNAP software. Analysis of Variance (multiway ANOVA) with Tukey's post-hoc test compared the data, with a 5% significance level.

RESULTS

Among the factors studied, sex significantly influenced all the analyzed variables (height, width, thickness, and volume of the mandibular angle) (p < 0.05); in general, male individuals presented higher values than females. In some cases, the skeletal malocclusion and facial type factors influenced only the width and height variables (p < 0.05); in general, the Class III and dolichocephalic individuals presented higher values in relation to the other types of skeletal malocclusions and facial types.

CONCLUSIONS

Variations in the craniofacial growth pattern, considering the different skeletal malocclusions and facial types, had some influence in the width and height dimensions of the mandibular angle. Furthermore, sex influenced all the studied variables.

Forensic Gender Determination by Using Mandibular Morphometric Indices an Iranian Population: A Panoramic Radiographic Cross-Sectional Study

Gender determination is the first step in forensic identification, followed by age and height determination, which are both affected by gender. This study assessed the accuracy of gender estimation using mandibular morphometric indices on panoramic radiographs of an Iranian population. This retrospective study evaluated 290 panoramic radiographs (145 males and 145 females). The maximum and minimum ramus width, coronoid height, condylar height, antegonial angle, antegonial depth, gonial angle, and the superior border of mental foramen were bilaterally measured as well as bicondylar and bigonial breadths using Scanora Lite. Correlation of parameters with gender was analyzed by univariate, multiple, and best models. All indices except for gonial angle were significantly different between males and females and can be used for gender determination according to univariate model. Condylar height, coronoid height, and superior border of mental foramen and ramus were still significantly greater in males than in females after controlling for the effect of confounders (p < 0.05). Based on the best model, a formula including five indices of bicondylar breadth, condylar height, coronoid height, minimum ramus width, and superior border of mental foramen was used for gender determination. Values higher than 56% indicate male gender, while lower values indicate female gender, with 81.38% specificity for correct detection of females and 88.97% sensitivity for correct detection of males. Despite the satisfactory results, future research should focus on larger populations to verify the accuracy of the present findings.

Psychometric and Perceptometric Comparisons of the Perspectives of Orthodontists, Oral and Maxillofacial Surgeons, and Laypeople of Different Ages and Sexes towards Beauty of Female Jaw Angles (Intergonial Widths and Gonial Heights) on Frontal and Three-Quarter Views

Objectives

The jaw angle plays an important role in facial beauty. Therefore, this study is aimed at comparatively determining the range of most attractive female intergonial widths and gonial heights on Perceptometric frontal-view and three-quarter-view images, from the perspective of orthodontists, oral maxillofacial (OMF) surgeons, and laypeople of different ages and sexes.

Methods

This prospective multivariate Perceptometric study was performed on 4191 esthetic scores given by 127 individuals to 33 Perceptometric face images. Frontal view and three-quarter-view photographs of a normal young woman were modified by image editing software to create two Perceptometric sets, one for the 24 gradual changes of intergonial width on the frontal view, and the other for the 9 vertical changes of the jaw angle on the three-quarter view. An online questionnaire was designed including 24 frontal and 9 oblique view photographs. The questionnaires' internal consistencies were almost perfect. Enrolled were 127 raters, including 33 orthodontists, 32 OMF surgeons, and 62 laypeople. The esthetics of different images were compared across different professions, across different ages, and between the sexes using 2-way MANCOVA, ANCOVA, and Bonferroni; the zones of esthetic jaw angles and also the sensitivity of judges to Perceptometric anatomical changes were assessed using 2-way RM-ANCOVA and Bonferroni (α = 0.05, α = 0.0056, α = 0.0021, and β = 0.05).

Results

Orthodontists and surgeons gave the highest attractiveness scores to intergonial: interzygomatic ratio of 72.53%, while the best ratio was 74.45% for the laypeople. The range of beautiful intergonial is as follows: interzygomatic ratio was 72.53% to 86.03%. OMF surgeons and orthodontists gave the highest score to a gonial height of 4.5 mm above the mouth corner, while the laypeople gave the highest score to the gonial height of 4.5 mm below the mouth corner. The range of beautiful gonial height was from 4.5 mm above the mouth corner to 9 mm below the mouth corner. The education of observers may affect their perception of beauty; orthodontists tended differ from laypeople, overall and also specifically in the case of the highly attractive frontal images concerning the intergonial width changes. However, no such differences were detected between surgeons with orthodontists or laypeople. Although age did not affect the overall esthetic scores, it did affect the sensitivity of the judges to the anatomic changes. So did expertise, i.e., the expertise of judges affected their sensitivity to anatomical changes; orthodontists showed steeper slopes of esthetic preference alterations to anatomical changes, while laypeople had the gentlest slope of preference changes. Judges' sex did not affect either their overall esthetic preferences or their sensitivity to anatomic changes.

Conclusion

Narrower female jaw angles and jaw angles that are vertically close to the level of the mouth corner may be unanimously more desirable. Thus, treatments aiming at widening the jaw angle of a woman or lowering it should be discouraged, at least in Persians. Orthodontists, but not surgeons, are more sensitive than laypeople to anatomic changes of the jaw angle. The judges' age can affect this perceptive sensitivity, but their sex cannot.

Panoramic Indices: An Aid to Early Detection of Patients with Low Bone Mineral Density

Objective An early identification of patients who are at an obvious increased risk of osteoporosis and subsequent high risk of pathological bone fractures is important to prevent morbidity and its subsequent impact on the quality of life of the affected patients. Dental professionals have a chance of identifying such cases in their very initial stages through routinely prescribed dental radiographs. The aim of this study was to assess the influence of gender and age on different parameters of alveolar bone loss using orthopantomograph (OPG) as an aid to identify patients with low bone mineral density (BMD).

Materials and Methods This study included eighty subjects in whom after taking OPGs, mandibular cortical index (MCI), mandibular cortical width (MCW), and panoramic mandibular index were assessed, while the results obtained were subjected to statistical analysis. One-way analysis of variance followed by Tukey's test was used to compare the means, while p-value less than 0.05 was considered statistically significant.

Results The findings of this study revealed a significant association between MCI and age for females, with C2 and C3 categories being more common with advancing age. Also, a significant difference could be seen in relation to gender (p-value = 0.0315) for MCW with a concomitant decrease in the values of MCW in females over 60 years of age.

Conclusion Panoramic radiographic measurements could provide valuable information and help in screening patients with low BMD.

Comparison of the Gonial Angle With Age and Gender Using Cone-Beam Computed Tomography Images

Introduction

The mandible is one of the most important bones used in gender determination in forensic medicine and anthropology. In literature, there are many studies examining the relationship between the gonial angle on the mandible and gender. However, these studies reported different results. This study aimed to measure the gonial angle with cone-beam computed tomography (CBCT) images and investigate the relation of this angle with age and gender.

Materials and methods

CBCT images of 235 dentate individuals (111 males and 124 females) aged between seven and 77 years were evaluated. The individuals examined were categorized into four age groups: 7-19 years (group I), 20-39 years (group II), 40-59 years (group III), and 60-77 years (group IV). The gonial angle was measured bilaterally in all individuals.

Results

The mean age of the males was 41.70 ± 19.14, and the mean age of the females was 39.47 ± 17.90 years. There was no statistically significant difference between the ages based on gender (p = 0.356). It was observed that there was a statistical difference between the gonial angle and gender in groups II and III. There was no correlation between age and gonial angle in all groups.

Conclusion

The results obtained in this study and the comparison of these results with the literature clearly show that it is currently not possible to clearly express the relationship between the gonial angle and both age and gender. For this reason, we believe that conducting further studies evaluating both the gonial angle and the relationship between the gonial angle and other anatomical structures on a larger sample can yield more meaningful results.

Radiographic features of cleidocranial dysplasia on panoramic radiographs

Purpose

This study aimed to investigate the panoramic imaging features of cleidocranial dysplasia (CCD) with a relatively large sample.

Materials and Methods

The panoramic radiographs of 40 CCD patients who visited Seoul National University Dental Hospital between 2004 and 2018 were analyzed. Imaging features were recorded based on the consensus of 2 radiologists according to the following criteria: the number of supernumerary teeth and impacted teeth; the shape of the ascending ramus, condyle, coronoid process, sigmoid notch, antegonial notch, and hard palate; the mandibular midline suture; and the gonial angle.

Results

The mean number of supernumerary teeth and impacted teeth were 6.1 and 8.3, respectively, and the supernumerary teeth and impacted teeth were concentrated in the anterior and premolar regions. Ramus parallelism was dominant (32 patients, 80.0%) and 5 patients (12.5%) showed a mandibular midline suture. The majority of mandibular condyles showed a rounded shape (61.2%), and most coronoid processes were triangular (43.8%) or round (37.5%). The mean gonial angle measured on panoramic radiographs was 122.6°.

Conclusion

Panoramic radiographs were valuable for identifying the features of CCD and confirming the diagnosis. The presence of numerous supernumerary teeth and impacted teeth, especially in the anterior and premolar regions, and the characteristic shapes of the ramus, condyle, and coronoid process on panoramic radiographs may help to diagnose CCD.

Is There Any Difference Between Gonial Angle Values Measured on Digital Lateral Cephalograms and Orthopantomograms?

Objective

To determine whether there is a difference between the gonial angle (GoAng) values measured on digital lateral cephalograms (Lat Cephs) and orthopantomograms (OPGs) using a software.

Methods

This study was conducted by examining the digital Lat Cephs and OPGs of 51 patients (9 males, 42 females) who received orthodontic treatment. The mean age of the patients was 19.51±4.92 years. All digital radiographs were acquired with the same machine. The GoAng measurements were performed digitally using TotalCeph software. In order to evaluate the difference between the GoAngs measured on the digital Lat Cephs and OPGs, a paired t-test was used. To compare the two techniques (digital Lat Ceph and OPG) in terms of GoAng measurement, Bland-Altman analysis was used. The differences between the right and left GoAngs measured on the digital OPGs were evaluated using a paired t-test. The intraobserver reliability was assessed with the intraclass correlation coefficient (ICC) for repeated measurements.

Results

The intraobserver reliability was 0.99 for repeated measurements. There were no statistically significant differences between the GoAngs measured on digital Lat Cephs and OPGs (p=0.1). Bland-Altman analysis showed high levels of agreement between digital Lat Cephs and OPGs with a bias value of -0.4° for GoAng measurement. Moreover, the differences between the right and left GoAngs measured on the digital OPGs were not statistically significant (p=0.73).

Conclusion

The results of this study demonstrated that the digital OPGs were as reliable as the digital Lat Cephs for measuring Go angles using a software.

Mandibular Gonial Angle Measurement as a Predictor of Gender-A Digital Panoramic Study

Objective:

The present study is intended for properly assessing, comparing, and evaluating the contemporary measurements of gonial angle using digital panoramic radiography. In addition, this research evaluates the importance of mandibular gonial angle in gender determination.

Materials and Methods:

Technically, this is a retrospective cross-sectional study, where the study sample was composed of 590 (295 males and 295 females) patients undergoing digital panoramic radiography in the College of Dentistry in University of Science & Technology of Fujairah, Fujairah, UAE . These patients had been prescribed panoramic radiographs based on different factors. As a generally adopted procedure, bilateral gonial angle measurements were carried out, results were recorded, and their predictability as a determinant of gender was assessed. ANOVA and t-test procedures were utilized for statistical analysis of the collected data.

Results:

The analysis of the present study confirmed a statistically significant difference between the right and left sides of the gonial angle in both genders. Further, the mean comparison exposed a variation between males and females, based on gonial angle values; females have a statistically significant higher mean angle values than males. Based on the analysis, the present study concludes that this difference between males and females from both sides suggests that the gonial angle helps in sex identification.

Conclusion:

It has been concluded that gender significantly influences the gonial region and has great potential to be used as a forensic tool in gender determination. Digital panoramic radiography is a good study tool and it can be used to determine the morphology of the mandible.

Radiographic evaluation of remodeling of mandible in adult South Indian population: Implications in forensic science

INTRODUCTION

Panoramic X-ray is an imagiological examination produced by a technique that exhibits images of the facial structure present in the upper and lower dental arches, as well as the support structures in the diagnosis of problems that require a broad view of the oral-maxillofacial complex, such as the assessment of traumatisms, extensive lesions, dental development, tooth retention, and growth anomalies. Many morphological and anatomical changes are exhibited by the mandible with the advancement of age and changes in gender, as well as dentoalveolar condition of the patient, and it can be assessed with the help of such radiograph, thus playing an important role in personal identification in forensic dentistry.

AIMS

This study aimed to evaluate the changes in gonial angle (GA), antegonial angle (AGA), and antegonial depth (AGD) in adult mandible with regard to age, gender, and dental status using panoramic radiographs.

SETTINGS AND DESIGN

This cross-sectional retrospective study was done using hospital records.

SUBJECTS AND METHODS

A total of 100 panoramic radiographs were evaluated. The images were grouped into three age groups (40-70) of 10 years each. GA, AGA, and AGD were digitally measured from the radiographs.

STATISTICAL ANALYSIS USED

Descriptive statistics of the variables were expressed in percentage, frequencies, mean, and standard deviations. Statistical differences between the variables were explored using independent sample t-test and one-way ANOVA. The significant level was set as 0.05.

RESULTS

There were no significant changes in GA, AGA, and AGD with age and dental status of the patients. Males had significantly smaller GA and AGA than females. Understandably, AGD was significantly greater in males than females.

CONCLUSIONS

Remodeling changes of the mandible with respect to the age groups and dental status studied were minimal. However, gender-related differences in ante AGA, depth, and GA were significant, which can be used as a tool in forensic identification.

Panoramic radiograph as a forensic aid in age and gender estimation: Preliminary retrospective study

BACKGROUND

The temporomandibular joint is a hinge joint which is formed by the mandible with articulation of the jaw with the cranium. The morphology of the mandible is evaluated by measuring the gonial angle ramus height and bigonial width.

AIM

The aim of this study to investigate the impact of age and gender on ramus height, gonial angle and bigonial width in the dentulous odisha population using digital panaromic radiographs.

MATERIALS AND METHODS

A total of 50 dentulous participants (25 males and 25 females) aged between 10 and 80 years were included in this study. The data were collected after comprehensive examination by 1 principal and two coinvestigators.

STATISTICAL ANALYSIS

The mean difference between gender and different age groups was calculated using SPSS version 20.0. Unpaired t-test and one-way ANOVA were used for comparison studied parameters according to gender, side and different age groups followed by Tukey's post hoc test.

RESULTS

A statistically significant gender difference was seen for gonial angle, ramus height and bigonial width. All the parameters increased with increase in age. This difference was statistically significant on the right side for gonial angle and ramus height.

CONCLUSION

This study is useful as for age and sex determination using mandible as primary object in forensic odontology.

Morphological alterations in the position of the mandibular foramen in dentate and edentate mandibles

The technique of inferior alveolar nerve (IAN) block must be based on precise anatomical knowledge regarding the correct position of the mandibular foramen (MF). The aim of the investigation reported here was to determine the anatomic and topographic localization of the MF according to mandibular ramus anatomic landmarks and to identify morphological alterations in the position of the MF and size and shape of the ramus in terms of the impact of tooth socket loss in the molar and premolar region. Seventy-three dry human adult mandibles were divided into two groups according to dental status. These were measured to determine the distances from the anterior and posterior ramus border (AB, PB) to the midpoint of the MF fossa, and from the mandibular notch (MN) and inferior ramus border (IB) to the MF entering point. A number of relevant ramus anatomic features were analyzed, such as ramus width (RW), height (RH), and thickness (RT). The MF was closer to the PB and IB in edentate mandibles (right/left mean PB-MF 10.66 ± 1.84/11.06 ± 2.05 mm; right/left mean IB-MF 21.77 ± 3.23/21.8 ± 2.27 mm) compared to dentate mandibles (right/left mean PB-MF 11.87 ± 2.08/12.04 ± 1.94 mm; right/left mean IB-MF 22.94 ± 3.09/22.74 ± 3.74 mm). Edentate mandibles demonstrated reduced RW (right/left mean RW 26.03 ± 3.53/26.49 ± 3.90 mm), significantly reduced (p = 0.03) right RH (right/left mean RH 43.56 ± 4.74/45.43 ± 4.86 mm), and significantly reduced (p < 0.05) RT in the area of the MF fossa depression (right/left mean RT 5.52 ± 1.21/5.21 ± 0.91 mm) compared to dentate mandibles (right/left mean RW 27.34 ± 3.84/27.48 ± 3.80 mm; right/left mean RH 46.33 ± 4.52/47.40 ± 4.20 mm; right/left mean RT 7.86 ± 1.98/8.10 ± 1.92 mm). Alterations in MF position and mandibular ramus anatomic features in edentate mandibles increase the potential risk of complications and failure of IAN block.

Dilemma of gonial angle measurement: Panoramic radiograph or lateral cephalogram

Purpose

The purpose of this study was to evaluate the accuracy of panoramic imaging in measuring the right and left gonial angles by comparing the measured angles with the angles determined using a lateral cephalogram of adult patients with class I malocclusion.

Materials and Methods

The gonial angles of 50 class I malocclusion patients (25 males and 25 females; mean age: 23 years) were measured using both a lateral cephalogram and a panoramic radiograph. In the lateral cephalograms, the gonial angle was measured at the point of intersection of the ramus plane and the mandibular plane. In the panoramic radiographs, the gonial angle was measured by drawing a line tangent to the lower border of the mandible and another line tangent to the distal border of the ascending ramus and the condyle on both sides. The data obtained from both radiographs were statistically compared.

Results

No statistically significant difference was observed between the gonial angle measured using the lateral cephalograms and that determined using the panoramic radiographs. Further, there was no statistically significant difference in the measured gonial angle with respect to gender. The results also showed a statistically insignificant difference in the mean of the right and the left gonial angles measured using the panoramic radiographs.

Conclusion

As the gonial angle measurements using panoramic radiographs and lateral cephalograms showed no statistically significant difference, panoramic radiography can be considered in orthodontics for measuring the gonial angle without any interference due to superimposed images.

Age and gender correlation of gonial angle, ramus height and bigonial width in dentate subjects in a dental school in Far North Queensland

Background

This study aimed to determine if mandibular parameters (gonial angle, bigonial width and ramus height) measured from panoramic radiographs, can be used to determine a correlation with an individual’s age and gender in dentate subjects in Far North Queensland.

Material and Methods

The study utilised 2699 randomly selected panoramic radiographs of patients between the ages of 19-69 years, from which 220 fulfilled the inclusion criteria. Each panoramic radiograph was analysed and the above three parameters recorded and measured. These values were collated into appropriate age and gender groups and subjected to statistical analysis.

Results

The mean age of the participants was 44.1±14.41, with males being shown to have a statistically significant larger ramus height and bigonial width than females (P<0.0001 for both). Females, on the other hand, were shown to have a significantly larger gonial angle than males (P<0.0002). General trends revealed gonial angle to increase with age, whilst bigonial width and ramus height were shown to decrease with age.

Conclusions

The assessment of mandibular morphology through radiographic measurements may be useful in estimating an individual’s age and gender when comparing to a known population standard.

Key words:Bigonial width, gonial angle, panoramic radiograph, ramus height.

Importance of teeth in maintaining the morphology of the adult mandible in humans

Edentulism can negatively affect both masticatory performance and dietary intake by altering the patterns of biomechanical stress and strain, which in turn modifies the morphology of the different regions of the mandible. The morphological changes in the mandible caused by these stressors are unknown when comparing mandibles across varying dentition states. This study investigated differences in the morphology of human mandibles across various states of the dentition. In total, 498 mandibles of individuals between 20 and 80 yr of age at death were sourced from the Raymond A. Dart Collection of Human Skeletons. These included fully dentate (n = 95), partially edentulous (n = 333), and fully edentulous (n = 70) mandibles. Twelve linear anthropometric measurements of the mandible were derived from digitized landmarks located on its external surface. Data analysis included geometric morphometrics and multivariate analyses. Compared with dentate and partially edentulous mandibles, fully edentulous mandibles showed a shorter alveolar height (-0.4 mm), a shorter mandibular body length (-4 mm), a larger gonial angle (+4°), a more obtuse mental angle (+4.7°), a broader bicondylar width (+3.8 mm), and a taller ramus height (+1.6 mm). Thus, edentulous states are associated with an altered mandibular morphology, which may result from a reduction in jaw function.

The evaluation of MCI, MI, PMI and GT on both genders with different age and dental status

OBJECTIVES

The aim of this study was to measure the mandibular cortical index (MCI), mental index (MI), panoramic mandibular index (PMI) and cortical bone thickness in the zone of the gonial angle (GT) in panoramic radiographies from a large sample of males and females and to determine how they relate to patients' age, gender and dental status.

METHODS

910 panoramic radiographs were obtained and grouped into age, dental status and gender. The MCI, MI, PMI and GT were analysed.

RESULTS

Remarkable differences were observed for MCI and GT regarding gender, age groups and dental status on both sides (p < 0.05). While age and dental status had an effect on the MI and PMI in females, dental status had an effect on the MI and PMI in males (p < 0.05). Also, gender had an effect on the MI and PMI (p < 0.05).

CONCLUSIONS

The effects of age and tooth loss are different in females and males. In females, the harmful effects of tooth loss and age are more prominent according to the PMI and MI measurements. The effects of age and tooth loss in the GT and MCI measurements are similar, and these indices can be accepted as more reliable in studies including both genders.

Identifying dental panoramic radiograph features for the screening of low bone mass in postmenopausal women

A retrospective cohort study was performed to evaluate the use of panoramic radiographs as a screening tool for low bone mass in postmenopausal women. Female subjects aged ≥50 years were included. The predictor variables were gonial angle, antegonial angle, mandibular cortical bone integrity, periodontal disease status, and number of remaining teeth. The primary outcome variable was bone mineral density status. Descriptive and logistic regression statistics were computed; P<0.05 was considered significant. The sample was composed of 273 subjects, aged 50-89 years. Visual assessment of mandibular cortical bone integrity demonstrated a statistically significant correlation with low bone mass diagnosis on univariate logistic regression (P=0.019), but lost significance on multivariate analysis with age, body mass index, and number of remaining teeth (P=0.6). A visual estimation of the mandibular cortical bone integrity from panoramic radiographs may be useful for identifying postmenopausal women at high risk for osteoporosis.

Radiographic evaluation of mandible to predict the gender and age

PURPOSE

This study is been conducted using digital panoramic radiographs for predicting age in various age groups and the accuracy of the parameters were accessed as age advances.

MATERIALS AND METHODS

The selected 300 panoramic images were divided into 3 age group of Group A (25-34 years), Group B (35-44 years), and Group C (45 -54 years). Each group comprised of 100 subjects in which 50 were males & 50 females. The age changes were evaluated using five parameters collectively, which were: Gonial angle, Antegonial angle, Mental foramen, Mandibular canal, Mandibular foramen. These parameters were evaluated on panoramic radiographs for age prediction and changes in their position as age advances.

RESULTS

Among all the parameters changes in Mandibular canal and mandibular foramen was found to be highly significant (p value ≤0.05) as age advances.

CONCLUSION

These parameters can be used to predict the age of the individual as there were significant changes in Mandibular canal and Mandibular foramen as age advances. For Further studies large sample size, and recent modalities in radiography like CBCT or CT scan are required.

Cephalometric: evaluation of influence of edentulousness on mandibular morphology: a comparative study

Mandible undergoes several dimensional changes due to aging accompanied with gradual loss of teeth. There is marked alterations in shape and dimensions of the parts of the mandible associated with complete or nearly complete loss of dentition. The purpose of this study was to analyze the effect of loss of dentition on the dimensions of mandible using lateral cephalogram. The study group comprised of 35 dentulous subjects (age range 25-30 years) and 35 edentulous subjects (age range 45-65 years), with a period of edentulousness of 1-5 years. Subjects were selected based on certain selection criteria and lateral cephalograms were taken. Lateral cephalograms were traced and the values obtained were statistically analyzed using T test. On statistical analysis it was found that the thickness of condylar process and corpus were reduced in edentulous subjects. Length of mandible, ramus and corpus were reduced in edentulous subjects when compared to dentulous subjects. Gonial angle was more obtuse in edentulous subjects. Reduction in thickness of condylar length and length of mandible were negatively correlated to duration of edentulousness. It can be concluded that mandible undergoes significant dimensional changes as a result of loss of teeth.

Association of mandible anatomy with age, gender, and dental status: a radiographic study

Introduction. Gonial angle and antegonial region are important landmarks in mandible which is influenced by gender, age, and dental status. The objective of this study was to evaluate the gonial angle, antegonial angle, and antegonial depth and to investigate their relationship to gender, age group, and dental status. Materials and Methods. A total of 1060 panoramic radiographs were evaluated: the dentulous group, 854 subjects and the edentulous group, 206 subjects. The patients were grouped into six age groups of 10-years each. Gonial angle, antegonial angle, and antegonial depth were measured from panoramic radiographs. Results and Discussion. Corelation of age with gonial angle, antegonial angle and antegonial depth was not significant. Significant difference in mandibular angle was found between males and females. Males had significantly smaller antegonial angle and greater antegonial depth than females. Significant difference was found for gonial angle, antegonial angle, and antegonial depth between right and left sides of mandible. Conclusion. Gonial angle, antegonial angle, and antegonial depth can be implicated as a forensic tool for gender determination but not suitable for age determination.

Evaluation of the morphological changes in the mandible for dentate and totally edentate elderly population using cone-beam computed tomography

PURPOSE

The loss of teeth considerably modifies the mandibular shape. The aim of this study was to compare the morphological changes in the mandible for dentate and totally edentate elderly subjects using cone-beam computed tomography.

METHODS

In total, 50 cone-beam computed tomography patients (25 dentate, 25 edentate) without any maxilla-mandibular dysmorphosis were analyzed retrospectively. Panoramic representations of the mandible with superimposed axial slices and cross-sectional slices were developed with the cone-beam computed tomography scans. Values of the mandibular cortical index, bone quality index, gonial angle, antegonial angle, antegonial depth and condyle angle in the left and right side were measured.

RESULTS

There was a significant difference in the mandibular cortical index between the total edentate group and the dentate group in the left side of the mandible (p < 0.001). There was a significant difference in the bone quality index between the total edentate group and the dentate group in the right side and the left side (p < 0.001). There was a significant difference in the bone quality index between the right side and the left side (p < 0.005). When comparing gender, there was only a difference in the right side (p < 0.05).

CONCLUSIONS

Our study concluded that the mandibular basal bone morphology changes as a consequence of tooth loss. Cone-beam computed tomography is shown to be a good tool in investigating and achieving these results.

Loss of molar occlusion and mandibular morphology in adults in an ancient human population consuming a coarse diet

The purpose of the study is to investigate the link between number of molar teeth retained in occlusion and mandibular morphology in adults in an ancient, high dental wear human population. The study material comprises skeletons from Mediaeval Wharram Percy, England (N = 50 female, 69 male adults). It was hypothesized that adults retaining fewer occluding molars would show reduction in mandibular dimensions, particularly in the ascending ramus and gonial regions where the main muscles of mastication have their insertions. Molar occlusal status is assessed using the concept of functional units. Mandibular morphology is assessed using a suite of ten linear measurements plus the mandibular angle. Results show no evidence for any association between number of molars retained in occlusion and mandibular angle. There was an association between mandibular size and number of molars retained in occlusion, with smaller mandibular dimensions in those retaining fewer occluding molars. Some measurements were affected more than others so that there was also some shape alteration. Alteration of mandibular dimensions was more clearly demonstrable in females than in males. Only in females could significant reduction in the ascending ramus and gonial regions be demonstrated. Reasons for the apparent difference in response to loss of molar occlusion between male and female mandibles are unclear, but sex differences in bony metabolism mediated by hormonal factors may be implicated. Results suggest that care should be exercised when including mandibles from individuals showing loss of molar occlusion in morphological studies.

Association of gonial angle with morphology and bone mineral content of the body of the adult human mandible with complete permanent dentition

We investigated the differences between 2 gonial angle (GA) size groups with respect to the morphometry and quantitative bone mineral content (QBMC) of mandibles with all teeth erupted and normal occlusion. We used 19 dried mandibles that were obtained from an Indian population and stored in our department. These mandibles were at Hellman's developmental dental stage VA and were divided into low gonial angle (LGA) (GA ≤ 120°; 8 specimens; 16 sides) and high gonial angle (HGA) (GA ≥ 125°; 11 specimens; 22 sides) groups. After lateral radiography of the mandibles using a titanium step wedge, linear measurements and the QBMC were determined, on hard copies and digital images, respectively. The age and sex of the cadavers to which the specimens belonged were unknown. The mandibular cortical width (MCW) and the antegonial notch depth of the LGA group were significantly larger than those of the HGA group. No significant difference was found in the distribution of the 3 categories of mandibular cortical index (MCI) or in cortical and trabecular bone mineral contents (CBMC and TBMC). The GA size was negatively and moderately associated with the MCW and the mandibular cortical width on the point AG (MCWAG), but was not significantly associated with either variable for CBMC and TBMC. These results suggested that the GA size of these stage-VA mandibles influenced changes in the width of inferior cortex and morphology of antegonial notch. The GA size did not influence QBMC under the mental foramen of the mandible and had negative associations with the MCW and MCWAG.

Evaluation of bone alterations in the jaws of HIV-infected menopausal women

The advent of highly active antiretroviral therapy (HAART) has caused a reduction in mortality, thus contributing to an increase in the number of women with HIVࢧAIDS who reach the climacteric period, experience decline in ovarian function, and develop complications of viral infection and HAART, which can accelerate bone loss. The aim of this study was to detect possible alterations in the jaws of HIV-infected women by panoramic radiography. The study comprised a total of 120 women above 40 years of age who were divided into the following two groups: women who are HIV positive (Group I) and women with no known HIV infection (Group II). Measurement of the following three radiomorphometric indexes was performed by panoramic radiography: Mental Index (MI), Panoramic Mandibular Index (PMI) and Antegonial Depth (AD). A total of 70% of women in the control group and 50% of women in the HIV group were in the postmenopausal period, and the average values of both MI (p = 0.0054) and AD (p < 0.0001) for this period were lower in the HIV group than in the control group. For patients who were in the premenopausal period, the average AD was lower in the HIV group than in the control group (p = 0.0003). Despite the difference in the average age between groups, greater bone resorption in the mandible was found in the group of HIV-positive women.

Panoramic radiographic evaluation of the mandibular morphological changes in elderly dentate and edentulous subjects

OBJECTIVE

The aim of the present study was to analyze the changes in the gonial angle, ramus height, condyle height and cortical bone thickness in relation to gender and dental status in elderly patients.

MATERIALS AND METHODS

The study population comprised 240 patients (age ranged from 60-69 years) who had digital panoramic radiographs taken for various purposes. One group consisted of 120 patients, 60 men and 60 women, who had all natural teeth present except for third molars. The second group consisted of the remaining 120 patients (60 men and 60 women) who were in a completely edentulous state (maxilla and mandible). The gonial angle, ramus height, condylar height and cortical bone thickness of the mandible were measured by computer software on their panoramic radiographs.

RESULTS

Women showed larger gonial angles than men, while men had greater cortical bone thickness and ramus height (p < 0.05). However, no significant difference in condylar height was found between both genders (p > 0.05). Edentulous subjects had a larger gonial angle than dentate subjects, while dentate subjects had greater cortical bone thickness on both sides and left side of condylar height (p < 0.05). The gonial angle had statistically negative correlations with cortical bone thickness and ramus height, regardless of gender.

CONCLUSIONS

The outcomes of the present study indicate that the edentulous women undergo morphological changes of the mandible influenced by the dental status more than men.

Does the panoramic radiography have the power to identify the gonial angle in orthodontics?

PURPOSE

The objective of this study was to assess gonial angle under the angle classification by comparing panoramic radiograph and lateral cephalometric radiograph.

MATERIALS AND METHODS

49 patients (25 males, 24 females) with an age range of 12-29 years participated in the present study. Subjects were retrospectively selected among those categorised as skeletal and dental Class I, II, and III malocclusion group. Using lateral cephalometric radiograph, mandibular and ramal planes were drawn and based on these planes. Gonial angle was determined from two tangents which were drawn from the inferior border of the mandible and posterior borders of the condyle and ramus of both sides in the panoramic radiographs. Multiple comparison tests (ANOVA) were used to determine differences between the three angle groups.

RESULTS

There were no significant differences between Class I, II, and III malocclusion group values of gonial angles determined by lateral cephalometric radiograph and panoramic radiographs (P > 0.05).

CONCLUSION

Panoramic radiograph results were shown to be as reliable as lateral cephalometric radiograph in all angle classifications. Panoramic radiography can be used as an alternative radiographic technique to detect gonial angle in orthodontic patients.

Quantitative estimation of vertical heights of maxillary and mandibular jawbones in elderly dentate and edentulous subjects

The residual alveolar ridge resorption is inevitable with aging. The purpose of the study was to determine and compare differences in the vertical measurements of jaw bones in elderly dentate and edentulous subjects. The study sample included 51 elderly dentate subjects and 59 edentulous subjects. The panoramic radiographs were used to quantify the reduction in the alveolar ridges at 5 sites in each jaw. There were significant differences between elderly dentate and edentulous subjects in maxilla and mandible. The percentage reduction in the vertical height of edentulous subjects as compared to dentate subjects ranges from 29% to 39%. The reduction in the heights was greater in mandible than in maxilla in both the study groups. The vertical measurements were significantly greater in men than in women in maxilla and the mandible. Vertical heights of maxillary and mandibular jaw bones are important factors in planning complete denture and the implant supported prosthesis. Further studies would be necessary to determine the region specific resorption of jaw bones and its association with the duration of denture wear in edentulous subjects.

Analysis of gonial angle in relation to age, gender, and dentition status by radiological and anthropometric methods

Background:

With development and function, the mandibular angle has shown changes in size and shape. A variation in mandibular angle with age, gender, and even the dental status has been observed, which is supported by radiographic and anthropometric studies.

Aims:

The aim of this study were to evaluate relationship between complete loss of teeth and changes in the gonial angle; the study further intends to evaluate any variation in gonial angle with age and gender. The study intends to assess the reliability and accuracy of age and gender determination using gonial angle as a parameter.

Materials and Methods:

A total of 185 subjects (91 males; 89 females) were included in the study and were divided into five groups on the basis of the chronological age. Physico-forensic anthropometry and lateral cephalometric methods were used to record the gonial angle.

Results:

The present study shows a definite decrease in the gonial angle with advancing age, but the intergroup analysis does not follow a significant pattern. The study showed no correlation of gonial angle with gender. However, the study observed a 6° increase in gonial angle for edentulous subjects.

Conclusion:

Gonial angle has been used as an adjuvant forensic parameter, but its reliability is questionable, as the mandible does not follow one characteristic pattern. Gonial angle does show changes with dentition status, which may be attributed to physiologic function of the mandible. However, when evidence is scanty, it can be used to direct the investigation.

Differences in 5 anatomic parameters of mandibular body morphology by gonial angle size in dentulous Japanese subjects

This study aimed to determine the differences in 5 anatomical parameters of the mandibular body on dental panoramic radiographs (DPRs) of 234 dentulous Japanese subjects (21-78years; mean, 25.76; median, 27 teeth) according to gender and gonial angle (GA) size, and to analyse the correlations between GA size and each variable by gender. The subjects were divided into low (LGA≤120°) and high gonial angle (HGA≥125°) groups. Linear, angular, and morphological measurements were obtained using the DPRs. Statically significant differences were determined using the Mann-Whitney U and χ(2) tests and simple regression analysis. Mandibular cortical width - MCW, antegonial notch depth - AD and angle - AA, and panoramic mandibular index - PMI in the LGA group were significantly larger than those of the HGA group. In men, a significant difference was observed in the distribution of the 3 mandibular cortical index categories between both GAs. Sexual dimorphism for MCW and AD was significantly greater in men than in women. There were significantly negative low correlations between the GA and variables of the MCW, AD, and PMI. These results suggest that the MCW and AD can show significantly different morphology according to gender and GA size.

Relationships between the gonial angle and mandibular ramus morphology in dentate subjects: a panoramic radiophotometric study

Analysis of dental panoramic radiographs (DPRs) is an indispensable diagnostic tool for dental implants both pre and post operation. Many studies on linear and angular morphometry of the mandibular body have been conducted, but those on the mandibular ramus have not yet been reported. The purpose of this study was to investigate the differences in the morphometric parameters of the mandibular ramus between high and low gonial angles (GAs) on DPRs as well as between genders, and to determine the relationships between GA and variables of the mandibular ramus morphometry. The DPRs of 156 dentate subjects (78 for each gender) with more than 15 teeth present, a mean age of 49.54 years, and a mean number of teeth of 26.20 were examined. The films were divided into the following 2 groups of GA: less than 120° (low gonial angle, LGA) and more than 125° (high gonial angle, HGA) in both the right and left sides. The parameters for Ar'-Go, MaF-Go, RW, and RD in the LGA group were significantly larger than those in the HGA group in both men and women, but that for the ramus angle (RA) was significantly smaller in the LGA group than in the HGA group. Significant gender differences in the 2 GA groups were recognized with respect to the Ar'-Go, MaF-Go, RW, and RD parameters. Significant negative low and moderate correlations were found between GA and the Ar'-Go, MaF-Go, RW, and RD variables, whereas significant positive low correlation was found between GA and the RA variable. Within the limits of this study, the analysis of the mandibular ramus morphometry on DPRs in terms of GA size and gender was found to be useful for devising a highly predictive and strategic plan for implant-supported oral rehabilitation.

Immunohistochemical and CBCT-based examination of differences between deformed and normal human condylar processes

The condylar process is the most common site of mandibular fracture; however, the biomechanics of this site are not well understood. Vascular endothelial growth factor (VEGF) is a marker for vasculogenesis and the formation of bone. Alkaline phosphatase (ALP) is also a biochemical marker of bone formation. To better understand the biomechanics of the condylar process, we examined the structure of the heads and necks of human mandibles from 35 male cadavers aged 25 to 90 years (mean, 61.5 years) using cone-beam computed tomography (CBCT). In addition, we used immunohistochemistry to assess the expression of the vascular markers VEGF and CD31 as well as the bone formation marker ALP. Significant differences were observed in the thickness of the posterolateral region of the cortical bone in the head of the mandible (p < 0.05) as well as in the medial (p < 0.001) and posterior (p < 0.01) regions of the neck of the mandible. VEGF accumulated more in deformed heads than in heads with oval-shaped structures. ALP was found in numerous small cavities of cortical bone in oval-shaped heads. These differences may be related to dislocation caused by muscle tension or the occlusion of temporomandibular joint movement.

Influence of edentulousness on gonial angle, ramus and condylar height

It has been shown that the shape of the mandible correlates with occlusal condition and the function of the masticatory muscles. Edentulous subjects have a wider gonial angle than dentate subjects, and a gender difference has also been shown. However, some studies have reported differing results. Less is known about the effect of dental status and gender on the ramus and condylar height. The aim of this study was to evaluate the association of tooth loss on the shape of mandible (i.e., gonial angle, ramus height and condylar height) in subjects aged 60 years and older. A total of 1036 subjects (667 dentate, 389 edentulous; 554 women and 482 men) were included in the study. Interviews and clinical and panoramic radiographic examinations were carried out. The gonial angle of the mandible and the mandibular and condylar height were measured using panoramic radiographs. In edentulous subjects, the gonial angle was significantly larger, while the ramus and condylar height was significantly smaller on both sides compared with dentate subjects. Women had a significantly larger gonial angle and smaller ramus and condylar height on both sides compared with men. In conclusion, the morphology of the mandible changes as a consequence of tooth loss, which can be expressed as a widening of the gonial angle and shortening of the ramus and condylar height. These findings highlight the importance of rehabilitation of the masticatory system to maintain good functioning of the masticatory muscles for as long as possible.

Mandibular morphological changes in low bone mass edentulous females: evaluation of panoramic radiographs

OBJECTIVE

The objective of this study was to evaluate morphological changes of the mandible in osteopenic and osteoporotic edentulous females.

STUDY DESIGN

Fifty-two female edentulous patients underwent panoramic radiography and dual-energy x-ray absorptiometry of the lumbar spine and femoral neck. Measurements of the gonial angle, antegonial angle, antegonial depth, antegonial index (AI), and mental index (MI) were performed. Patients were classified as normal (T-score > -1.0), osteopenic (T-score of -1.0 to 0 -2.5), or osteoporotic (T-score < -2.5).

RESULTS

The gonial angle did not show differences among the three categories of skeletal bone status (P > .05). The antegonial angle was significantly smaller in individuals with low bone mass (P < .05). The antegonial depth was significantly greater in osteoporotic (P < .05) and osteopenic individuals (P < .05). The AI and MI were significantly smaller in individuals with low bone mass (P < .05); however, after age adjustment there were no differences among the groups (P > .05).

CONCLUSIONS

Edentulous females with low bone mass have a deeper antegonial region. The thickness of the cortical mandibular bone is highly influenced by age.