Bigonial Width Research Articles

Sex estimation in a Chilean population by mandibular analysis in cone beam computed tomography images

BackgroundSex estimation is the first stage in the identification of an individual in the forensic context, and can be carried out from bone structures like the mandible. The aim of this study was to estimate sex from metric analysis of the mandible in cone beam computed tomography images (CBCT) of adult Chilean individuals.MethodsSix mandibular measurements were analysed, five linear and one angular, in CBCT of adult Chilean individuals of both sexes. ROC Curve analysis was performed, with cut-off points, and of the overall model quality. Univariate discriminant function analysis was used to determine the accuracy of each measurement for sex estimation. Multivariate discriminant function analysis, both directly and by steps, was used to obtain the predictive value of the mandible including all the measurements.ResultsThe data included were 155 CBCT, 105 of females and 50 of males. The mandible presented great sexual dimorphism, with the mandibular ramus presenting greater predictive power than the mandibular body. When each mandibular measurement was analysed separately, the maximum height of the mandibular ramus presented the greatest predictive power (76.5%), while the mandibular angle was the least accurate parameter for sex estimation (58.1%). Direct method analysis presented 87.1% accuracy for sex identification of adult Chilean individuals, and joint analysis of maximum mandibular ramus height (MRH), corono-condylar distance and bigonial breadth presented 86.5% accuracy. In ROC Curve analysis the MRH was the variable with the greatest discriminating capacity (AUC = 0.833), MA was the only variable which presented no discriminating capacity (AUC = 0.386) and also presented low quality in model quality analysis.ConclusionMetric analysis of the mandible in CBCT images presents an acceptable accuracy for sex estimation in Chilean individuals, and its use for that purpose in forensic practice is recommended.

Mandibular morphology in schizophrenia patients compared with non-psychiatric controls using digital panoramic radiography: a retrospective cross-sectional study from Istanbul, Türkiye

BackgroundSchizophrenia is a chronic severe mental disorder characterized by impairment in cognition, emotion, perception, and other aspects of behavior. In light of the association of craniofacial dysmorphology with schizophrenia, mandibular morphology may provide clues about the role of neurodevelopment in the pathophysiology of schizophrenia. This retrospective cross-sectional study aimed to compare the mandibular morphology of patients with schizophrenia with controls using digital panoramic radiography (DPR).Methods302 recorded diagnostic panoramic images obtained from 143 schizophrenia patients (98 males, 45 females), and 159 controls (73 males, 86 females), aged 18–45 years, were evaluated. Seven mandibular measurements consisting of ramus height, condylar height, gonial angle, antegonial angle, antegonial notch depth, ramal notch depth and bigonial width were measured from the DPRs in a double-blinded manner. Bivariate comparisons were carried out using the Independent t-test and Mann–Whitney U test. Logistic regression analysis was used for multivariate comparisons.ResultsLinear measurements were higher while angular measurements were lower in schizophrenia patients. Regression analyses indicated that female patients had greater ramus height (OR = 1.243; P = 0.001), condylar height (OR = 1.463; P = 0.048) and bigonial width (OR = 1.082; P < 0.001); male patients had greater ramus heights (OR = 1.216; P = 0.001) and bigonial width (OR = 1.076; P < 0.001) as well as lower antegonial angle (OR = 0.908; P = 0.012) compared to their respective controls.ConclusionQuantitative differences in mandibular morphology in schizophrenia patients versus controls deserve attention and corroborate with the concept of abnormal neurodevelopment in schizophrenia.

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

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.

Mandibular Gender Dimorphism: The Utility of Artificial Intelligence and Statistical Shape Modeling in Skeletal Facial Analysis.

In gender-affirming surgery, facial skeletal dimorphism is an important topic for every craniofacial surgeon. Few cephalometric studies have assessed this topic; however, they fall short to provide skeletal contour insights that direct surgical planning. Herein, we propose statistical shape modeling (SSM) as a novel tool for investigating mandibular dimorphism for young white individuals. A single-center, retrospective study was performed using computed tomography (CT) scans of white individuals, aged 20 to 39 years old. AI-assisted, three-dimensional (3D) mandibles were reconstructed in Materialise Mimics v25.0. We used SSM to generate average 3D models for both genders. Relevant manual anthropometric measurements were taken for the SSMs and individual mandibles. Contour disparities were then represented using 3D overlays and heatmaps. Statistical analyses were performed using unpaired student t testing or Wilcoxon signed rank testing with 95% confidence interval as deemed appropriate by population-level normality assessment. Ninety-eight patients (53 females, 45 males) were included. Male mandibles showed greater bigonial width, intercondylar width, ramus height, and body length [p<0.005]. There was no statistically significant difference in the gonial angle measurements [p=0.62]. All relevant manual individual measurements demonstrated excellent concordance to their SSM counterparts. The 3D overlays of SSMs revealed squarer male chins with more lateral but less anterior projection than their female counterparts. Also, the female mandibles showed smoother transition at the gonial angle. SSM provides a novel tool to objectively evaluate volumetric and contour dimorphisms between genders. Moreover, this method can be automated, allowing for expedited comparisons between populations of interest compared to manual assessment. 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 . Bullet points about the importance of this work: Advancing Anthropometric Assessment: Statistical shape modeling (SSM) offers a cutting-edge approach to visualizing gender-specific skeletal anatomic differences for aesthetic and gender-affirming facial surgery. Expediting Comparative Analysis: The workflow established in this paper streamlines the evaluative process, enabling rapid morphologic comparisons between populations. Patient-Centered Care: This study establishes a foundation for the development of SSMs in individualized operative planning.

Sex estimation from mandibular morphometry using discriminant analysis–CT scan based retrospective study

Sex estimation from mandibular morphometry using discriminant analysis–CT scan based retrospective study

Quantifying Sexual Dimorphism by Analyzing Ramus Flexure and Bigonial Width in Orthopantomography.

Introduction The mandible constitutes one of the skull's largest and strongest bones. Growth spurts can influence it, and it has a variety of dimorphic traits that can be used to identify sex. In addition to observing, comparing, and evaluating the potential for mandibular ramus flexure and bigonial breadth to discriminate between sexes using digital orthopantomograms (OPG), a retrospective study was conducted to examine the validity of this method for sex estimation in the Indian population. Aim and objective This study aims to quantify sexual dimorphism by analyzing two mandibular parameters, the ramus flexure and the bigonial width, using orthopantomography (OPG). The objective is to determine the accuracy of sex determination using the ramus flexure and bigonial width. Materials and methods A total of 500 OPG images (250 males and 250 females) were analyzed using the Planmeca software (Helsinki, Finland). The ramus flexure was measured as the angle formed between the tangent to the inferior border of the mandible and the tangent to the posterior border of the ramus. The bigonial width was measured as the distance between the left and right gonion points. A statistical analysis was performed to assess sexual dimorphism and determine the accuracy of sex determination using these parameters. The study employed descriptive statistics, such as means and standard deviations, and an independent t-test to determine the significance of the characteristics in relation to males and females. Results The mean bigonial width for females was 193.3068 mm (SD = 13.51669 mm) and for males was 217.6308 mm (SD = 10.87453 mm), with a statistically significant difference (p = 0.000). The 95% confidence interval for the difference in the bigonial width between males and females was between -49.97173 mm and -43.93787 mm. For the ramus flexure, the mean was 0.0000 for both males and females (SD = 0.00000), with a significant difference between males and females (p = 0.003). The 95% confidence interval for the difference in the ramus flexure between males and females was between -0.59543 and -0.12457. Conclusion The results indicated significant sexual dimorphism in both the ramus flexure and bigonial width. This study demonstrated that the ramus flexure and bigonial width, measured using orthopantomography (OPG), exhibited significant sexual dimorphism. The analysis of these mandibular parameters provided valuable information for sex determination in forensic and anthropological contexts.

Forensic evaluation of craniometric characteristics of the Kazakhstan population

The human skull is the part of the skeleton most frequently used in population studies, as it was more exposed to genetic factors and less exposed to environmental factors. The skull is an important component in human forensic identification. The craniometric characteristics of 186 male and 114 female skulls found on the territory of Kazakhstan were studied. Dimensions were measured using standard anthropometric methods and instruments. The results of measurements of 25 craniometric parameters are presented. Methods of descriptive and parametric statistics were used. Statistical analysis showed significant regional dimorphism, confirming theindividuality of the Kazakhstan population. Statistically significant deviations werefound in 6 male craniometric characteristics and 4 female craniometric characteristics(p<0.05). The most dimorphous variables for regional identification in Kazakhstanmales were the higher skull base and frontal chord width , full face height , condylarand bigonial width , and low mandibular body reference values (p<0.05). For females,significant statistical discrepancies were seen in the transverse diameter and skullbase width, mastoid and occipital aperture width (p<0.05). The recorded variations and changes in the morphology of the humanskull of the population of Kazakhstan indicate the need to develop and updateosteometric standards used in practice for specific populations. All this will significantlyimprove the accuracy of forensic identification and more fully study the biologicalpatterns of population formation, as well as evaluate the comparative effectiveness ofindividual features in the reconstruction of the population history of various populationgroups.

Are computed tomography images of the mandible useful in age and sex determination? A forensic science meta-analysis.

This meta-analysis addresses the use of mandibular computed tomography (CT) scans for age and/or sex determination in forensic science. Six databases were searched until June 2023, using the keyword "mandible" combined with keywords related to "multislice computed tomography" (MCT) or "cone-beam computed tomography" (CBCT) and keywords related to "skeletal age determination" or "sex determination analysis." Among the 23 studies included, 11 used MCT and 12 used CBCT to perform forensic assessments. Age determination was the aim of a single study, sex and agedeterminations were the objective of five studies, and the other studies investigated the determination of sex only. Metaanalysis could be performed only for sex determination. Mandible measurements are useful in sex determination, as the bicondylar and bigonial breadth are larger in males than in females. For the mandible angle, the meta-analysis results confirm sex dimorphism in CBCT scans but not in MCT scans. For age estimation, further studies are needed to prove that the mandible hole is a reliable parameter for age estimation. PROSPERO registration number: CRD42021260967.

Analyzing Mandibular Characteristics for Age and Gender Variation Through Digital Radiographic Techniques: A Retrospective Study.

Background Forensic odontology has emerged as a crucial method for identifying skeletal or dental remains. Due to the restricted accuracy of current techniques for estimating age at death, researchers have endeavored to illustrate age-related alterations in dental hard tissues. Bone remodeling constitutes an ongoing and intricate process throughout our lifespan. It is believed that morphological changes in the mandible during an individual's lifetime are influenced by both dental condition and the individual's age. Objectives This study aims to evaluate the efficacy of mandibular parameters such as projective ramus height (PRH), maximum ramus breadth (MaRB), bigonial width (BGW), antegonial depth (Ant.D), and antegonial angle (Ant.A), as a gender-determining tool and compare and analyze the mandibular parameter measurements using digital orthopantomography. Methodology In this study, the total number of samples used was 500 out of which 250 were males and 250 were females. Planmeca software (Version 6.0, Planmeca Romexis, Charlotte, NC) was used and the accuracy test, analysis of variance (ANOVA), multiple regression, and discriminant analysis for gender were performed using SPSS for Windows, Version 16.0(SPSS Inc., Chicago, IL). Results For age estimation, the least standard error of 0.008 was observed for BGW. A maximum standard error of 0.230 was observed for Ant.D. For sex determination, the coefficient function was positive for PRH, BGW, and Ant.A, with values of 0.202, 0.805, and 0.052, respectively. Ant.D and MaRB both exhibited negative values of -0.204 and -0.379, respectively. Conclusions Out of all the parameters assessed, BGW is the most preferred parameter for age estimation and Ant.A can be preferred for sex estimation. Age and gender can be estimated using the two parameters in the Indian population.

Analysis of Sexual Dimorphic Features of the Jawline and Chin in White Celebrity Faces.

The jawline greatly influences facial shape and contributes to facial dimorphism. Analysis of lower facial shape and sexual dimorphic differences in contemporary attractive white faces can advance the goals of lower facial aesthetics and facial gender-affirming surgery (FGAS). Full-face, front-view photos of 47 white female and 21 white male celebrities were included from a list generated using GQ magazine's Highest Paid Models issue, People Magazine's Beautiful issue (1991-2022), and celebrities featured on lifestyle websites. Facial landmarks were detected through a facial analysis program using Vision framework and MATLAB. After converting pixel distances to absolute distances, lower face measurements were compared between males and females. The mean lower facial height was 6.08cm in females and 7.00cm in males ( P value<0.001). The mean bigonial width was 11.21cm in females and 12.30cm in males ( P value<0.001). The ratio of facial height to lower facial height was 2.98 in females and 2.76 in males ( P value<0.001), signifying that symmetry in facial thirds is more prevalent in attractive female faces, while a longer lower face is more common in attractive male faces. The greatest differences in female and male facial contours were at gonial angles and chin. Analysis of contemporary white celebrity faces demonstrated significantly wider and longer lower facial measurements in males. The overall contour of the female lower face was more tapered at the gonial angles and chin compared to males. These results are important when planning lower facial rejuvenation or FGAS, as lower face size and proportions influence perceived gender and attractiveness.

Facial Anthropometric Analysis of Gender-Related Characteristics in Computed Tomography.

In recent years, facial feminization surgery (FFS) has gained increasing popularity because of increases in transgender individuals and the acceptance of diversity in gender identity. However, there is still a scarcity of anthropometric research to guide evidence-based practices for FFS in Taiwan. The purpose of this study was to provide a reference for surgeons to achieve optimal outcomes for patients undergoing FFS. The anthropometric analysis could help surgeons meet patients' specific requirements and improve patients' alignment with their gender identity. The study group consisted of 100 patients (50 males and 50 females) who had undergone cranial computed tomography at Chang Gung Memorial Hospital in Taiwan because of the indication of blunt injuries to the head and face with suspected skull and facial fractures. The computed tomography images were imported into the OsiriX image software to conduct an anthropometric evaluation. The parameters used in the measurements included 2 aspects: bone and soft tissue anthropometric analysis. Anthropometric data were obtained from 50 males (age 32.6 ± 11.4 years) and 50 females (age 33.7 ± 10.3 years). The results for bone measurements showed that both the forehead bossing length and nasal bone width in the male group were significantly greater. The frontal angle in both bone and soft tissue in the male group was significantly smaller. The chin height and bigonial width in both bone and soft tissue in the male group were significantly greater. Although the average gonial angle was greater in the female group, the difference was not significant. For the measurements of lip projection, the results showed that there was no significant difference. Although this group of Asian males had more acute nasolabial angles, the difference was not statistically significant. However, the average nasofrontal angle among females was significantly more obtuse than among males. The results revealed that Asian males tend to have more prominent superior orbital rims, wider nasal bones, and wider and taller mandibles compared with Asian females. Despite showing some trends, the gonial angle and lip projections did not reveal any significant differences, which is likely because of a large amount of variation.

Estimation of Stature from Bigonial Breadth in Population of Western Maharashtra

Estimation of Stature from Bigonial Breadth in Population of Western Maharashtra

Ramus &amp; gonial angel measurement in sexual dimorphism - A digital panoramic study

Age and sex must be determined for forensic practise and medico-legal objectives. The mandible, which is the most heterogeneous bone in the skull and is frequently found intact, may be a key component in sex assessment. In this regard, the availability of a large number of antemortem orthopantomograms may be very beneficial in researching and creating standards that are population-specific for precise sex and age determination. Determining the value of different mandibular ramus linear and gonial angle measures as sex and age markers on digital panoramic pictures was the goal of the current investigation. This retrospective study was conducted on 600 orthopantomogram of patients of both gender with age group of 18 to 50 years. The selected JPEG images of the digital OPG’s were converted to PDF format and exported to Adobe Acrobat Reader software on an HP Laptop for assessment of linear and angular measurements. The parameters employed in the current study were projective ramus height (PRH), condylar ramus height (CNNRH), coronoid ramus height (CRRH), upper ramus breadth (URB), lower ramus breadth (LRB), bigonial width (BW) and gonial angle (GA). The right PRH, CRRH, CNRH, URB, LRB and bigonial width were higher in males as compared to females similarly left PRH, CNRH, CRRH, URB were higher in males as compared to females with a statistically significant P value (0.001) It was concluded from the current study that various parameters, including the projective ramus height, minimum ramus breath, and coronoid ramus height, could be very helpful in determining gender.

The effect of N95 designs on respirator fit and its associations with gender and facial dimensions.

This study examined the association of various brands of NIOSH-certified N95 filtering face-piece respirators (FFR) fit with facial dimensions and gender. One hundred and thirty-five participants (77 females and 58 males) were recruited from the previous facial anthropometry study among Malaysians in 2020. Quantitative respirator fit testing of six FFR were performed using the TSI Portacount Pro+ 8038 which comprised of four exercises (bending over, talking, up-down head movement, and side to side head movement). An overall fit factor (FF) of ≥ 100 was considered a pass for each FFR. Analysis was done using T-test, Pearson's correlations, and generalised linear regression. The passing rates for the six FFR were 36.3% (Cup B), 50.4% (Trifold A), 54.1% (Duckbill A), 57.0% (Cup A), 74.1% (Trifold B), and 83.7% (Duckbill B). Both Duckbill B and Trifold B had the highest passing rates for both genders. However, certain FFR models (Cup B, Trifold A, Trifold B, and Duckbill A) fit better for participants with large facial size who were mostly males, while others (Cup A and Duckbill B) specifically fit better for those with small facial size, who were mostly females. This study showed significant positive effect of nose protrusion, nasal root and subnasale-sellion and the negative effect of menton-sellion, bigonial breadth and nose breadth on fit factors of various FFR. The results of this study emphasized the importance of choosing and designing FFR based on local anthropometry data, with careful consideration on the dimensions that affect the respirator fit. Since N95 are commonly used in the healthcare settings to prevent airborne transmission, the practice of respirator fit testing and selecting N95 with high passing rates for healthcare workers need to be emphasized.

Morphometric measurements of mandible to determine stature and sex: A postmortem study

Identification of humans has medicolegal relevance in civil issues involving property inheritance, marriage, contested sex, admission to educational institutions, and the disappearance of individuals. To determine the sex of human remains, forensic anthropologists usually use morphologic and metric approaches. This study was conducted to determine stature and sex according to mandibular dimensions in postmortem autopsy samples. A total of 150 mandibles from people 18-65 years of age were studied. Stature and sex were noted, and six mandibular measurements were taken with Vernier calipers, flexible measuring tape, a protractor, and a graduated autopsy table. Statistical analysis of the measured parameters was conducted in SPSS software. Statistical parameters, such as mean, standard deviation, Spearman's correlation coefficient, multiple linear regression, stepwise regression, and Mann-Whitney U test were analyzed. Bicondylar width was the stature estimation predictor with the strongest correlation (r=0.439). The other parameters significantly associated with stature were bigonial width (p=0.000), mandibular angle (p=0.004), and mandibular arch length (p=0.000), according to Spearman's correlation coefficient. The mandibular angle had the greatest dimorphic statistical significance (p=0.004) according to the Mann-Whitney U test. Bicondylar width may serve as a valuable tool for estimating stature, and mandibular angle can be used to identify sex. Our findings may help forensic anthropologists estimate stature and identify human remains.

Morphometric Analysis of Mandible for Gender determination in adult patients: A Cone Beam Computed Tomography Study

Context: Gender determination is an important component of personal identification. Aims: Assessment of gender using mandible with Cone Beam Computed Tomography (CBCT). Settings and Design: This cross-sectional prospective study was conducted on dental outpatients in the department of Oral Medicine and Radiology. Methods and Material: 148 dental outpatients were selected and subjected to CBCT. Mandibular landmarks such as gonial angle, alveolar ridge to mental foramen distance, mental foramen to the inferior border of mandible distance, mandibular canal to the most anterior tangent point of buccal and lingual mandibular plate distance, mandibular canal border to the lowest tangent point on the inferior border of the mandible, coronoid height, bigonial breadth, minimal ramus breadth and ramus length were assessed on CBCT scan. Statistical Analysis Used: Data was represented as mean and Standard Deviation (SD). Parameters were compared between males and females using Kruskal-Wallis and Student’s independent T-test. A value below 0.05 represented significant results. Results: All parameters except gonial were significantly higher in males as compared to females angle (P&lt; 0.05). The distance from the lowest point of the mandibular canal to the most posterior tangent point of the Mandibular Lingual Plate (MCLM) and bigonial breadth was higher in males than females but the difference was non-significant (P&gt;0.05). The accuracy of CBCT was found to be 89.7% in males and 88.5% in females. Conclusions: Gender determination by morphometric analysis of the mandible using cone beam computed tomography is an effective method and provides higher accuracy as compared to two-dimensional conventional radiographs.

Relationship of bizygomatic and bigonial breadth with the suitability of surgical masks

Use of masks is mandatory to prevent the transmission of COVID-19. Appropriate masks that match the face size is very important to avoid leakage. This study aimed to evaluate the relationship between bizygomatic and bigonial breadth with the suitability of surgical masks. It was an analytic observational study with a cross-sectional design conducted at the Occupational Medicine Laboratory, Faculty of Medicine, Universitas Trisakti, Jakarta during March to April 2021. A total 132 employees of Faculty of Medicine, Universitas Trisakti aged from 20 to 64 y.o. who meet the inclusion and exclusion criteria participated in this study. No significantly difference in age (p=0.248) and body mass index (BMI) (p=0.226) was observed. However, there was a significantly difference in bizygomatic width (p=0.000) and bigonial width (p=0.001) between men and women. The use of appropriate surgical masks was observed in 89 respondents, but not suitable for 43 respondents. There was no significantly difference between BMI, bizygomatic width and bigonial width with the suitability of surgical masks. However, old age was significantly more appropriate for using surgical masks than young people. In conclusion, BMI, bizygomatic width, and bigonial width are not substantially different with the suitability of surgical masks. However, older age is more suitable for employing surgical masks than younger age.

Transverse Skeletal Effects of Hyrax-Type Rapid Maxillary Expansion with or without Laser Biostimulation

Purpose: The aim of this study is to assess the effect of Laser biostimulation on the transverse changes of maxilla and mandible after rapid maxillary expansion in growing patients. Subject and Methods: Twenty growing patients with posterior teeth in crossbite were included in this study. Patients were randomly divided into two groups. Rapid maxillary expansion had been carried out for all patients. In laser group Laser was applies on mid palatal suture during active expansion and during retention. The control group had no laser with their expansion procedures. Pre-treatment and post-treatment Cone beam computed tomographies were used to compare the changes in skeletal maxillary and mandibular widths. Results: The two groups showed insignificant increase in both interjugale distance and bigonial distance. No significant difference was found between the laser group and the control group regarding the amount of change of both bigonial and inter widths. P ≤ 0.05. Conclusions: In both Laser and non-Laser groups, Rapid maxillary expansion in growing patients with crossbite produces insignificant increase in maxillary transverse inter jugale and bigonial widths. Laser application during maxillary expansion has statistically insignificant effect on changes in maxillary interjugale width and mandibular bigonial width.

Transverse Skeletal Effects of Hyrax-Type Rapid Maxillary Expansion with or without Laser Biostimulation

Purpose: The aim of this study is to assess the effect of Laser biostimulation on the transverse changes of maxilla and mandible after rapid maxillary expansion in growing patients. Subject and Methods: Twenty growing patients with posterior teeth in crossbite were included in this study. Patients were randomly divided into two groups. Rapid maxillary expansion had been carried out for all patients. In laser group Laser was applies on mid palatal suture during active expansion and during retention. The control group had no laser with their expansion procedures. Pre-treatment and post-treatment Cone beam computed tomographies were used to compare the changes in skeletal maxillary and mandibular widths. Results: The two groups showed insignificant increase in both interjugale distance and bigonial distance. No significant difference was found between the laser group and the control group regarding the amount of change of both bigonial and inter widths. P ≤ 0.05. Conclusions: In both Laser and non-Laser groups, Rapid maxillary expansion in growing patients with crossbite produces insignificant increase in maxillary transverse inter jugale and bigonial widths. Laser application during maxillary expansion has statistically insignificant effect on changes in maxillary interjugale width and mandibular bigonial width.

A review on bigonial width reduction by botulinum toxin injections in masseter.

It is of interest to study the efficacy of botulinum toxin injection in masseter reducing bigonial width of the face. Online databases such as PubMed, Cochrane Library, Google Scholar, Science Direct database and ResearchGate were searched from initiation until October 2022 using keywords such as "masseter muscle injections", "botulinum toxin," "bigonial width reduction," "masseter muscle hypertrophy," and "lower face contouring" All available retrospective as well as prospective studies, were included with specific weightage to the efficiency of Botulinum Toxin (BT) injection in masseter muscle and the technique, unfavorable events, and the extent of its effects. A total of 20 publications were acknowledged. All prospective studies were included. Relevant data on patient selection, injection methods, efficiency, dose, rate of recurrence, and significant side effects of BT injections in masseters were collected. All excluding one were prospective studies. Bilateral injections were used in all the studies. Follow up period was 3-48 months. This systematic review focuses on the effectiveness of Botulinum toxin injection in lowering the bigonial width by decreasing the volume of the masseter. Repeat treatment at regular intervals is advisable to maintain desired results. The procedure was carried out in an office environment and was completed within 15 mins. There are no permanent adverse events related to the procedure. Further studies involving randomized control trials with larger sample sizes are warranted to optimize the dose and frequency of BT injection.