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

Role of Mandibular Parameters in Gender Determination: A Systematic Review and Meta-Analysis

Forensic anthropology and forensic medicine both have been fascinating fields that deal with mandibular characteristics and sex determination. Researchers may determine an individual's biological sex with amazing precision by examining the size, shape, and proportions of the mandible. This information is useful for anthropological studies and criminal investigations. This systematic review aims to evaluate the consistency and validity of using mandibles as a method for gender determination across different populations. A systematic search was conducted in PubMed, Web of Science, and Scopus databases. Further, a manual search was carried out to find additional studies. Mandibular parameters and other relevant data about research were extracted from the included studies. Random effects meta-analysis was carried out for four parameters. A total of nine studies were included in the systematic review out of 76 initial search results. All studies were in vitro. Nine studies were included in the qualitative analysis, whereas only seven studies were included in the meta-analysis. A total of 2385 individuals (1193 male and 1192 female) were evaluated in the included studies. The parameters assessed were as follows: minimum ramus breadth (MiRB), maximum ramus breadth (MaRB), projective ramus height (PRH), bigonial width (BGW), gonial angle (GA), and antegonial angle (AGA). Meta-analysis was conducted for four parameters out of six. For the two parameters, meta-analysis was not conducted as only one study was evaluated. Meta-analyses of PRH obtained a high degree of heterogeneity (99%), mean difference (MD) of 4.06 mm, and p-value of p=0.09. Meta-analysis of BGW obtained 93% heterogeneity, MD of 9.03 mm, and p=0.0007. Meta-analysis of GA showed 99% heterogeneity, MD of 3.44 mm, and p=0.66. Meta-analysis of AGA obtained a low heterogeneity of 30%, MD of -0.77 mm, and p=0.23. The parameter, BGW, can be considered a useful tool in identifying sex. The parameters, PRH, GA, and AGA, cannot be preferred as a reliable tool in identifying the sex of an individual in forensic contexts.

Radiologic Evaluation of Odontometric and Osteologic Traits for Gender Determination in Adult Ethnic Tamil Population

Background: Odontometric and osteologic trait have always served as an excellent resource in anthropological, genetic, odontologic, and forensic investigations. Traits: The aim of this study was to find the most reliable method for gender determination by correlating both the odontometric and osteologic variables. Materials and Methods: A retrospective study was conducted using digital panoramic radiographs of 400 individuals (200 males and 200 females) with age ranging from 20 to 50 years. Standardized digital panoramic radiographs of patients taken as part of pretreatment planning for implants, extractions of third molars, and for periodontal diseases were selected from the archives. Measurements were done using IMAGE Pro software. Results: Mesiodistal width of 17–47 exhibited significant gender variation. Osteologic parameters such as ramus dimension and the gonial angle also showed significant gender variation and the mandibular asymmetry was significant in both the genders. Conclusion: Correlation of the two group of traits showed strong positive predictive values attributable for gender determination.

The influence of the mandibular gonial angle on the occurrence of mandibular angle fracture

BACKGROUND/AIMS

Angle fractures represent the largest percentage of mandibular fractures. They pose as a unique entity because of their codependent morphological dynamic factors, rendering the understanding of the mechanism, and treatment challenging. The aim of this study was to analyze the association between the mandibular gonial angle and the risk of mandibular angle fracture while highlighting its clinical relevance.

MATERIALS AND METHODS

A retrospective analysis of radiographs of patients treated for mandibular fractures was done. The factors studied were as follows: the presence of a high gonial angle and an impacted third molar. The outcome was mandibular angle fracture. The gonial angle was measured using Planmeca Digital Software 3.7.0.R. Status of the third molar was also noted. Data obtained were analyzed using SPSS 22 (IBM Corp, Armonk, NY).

RESULTS

The sample comprised 70 mandibular fractures (32 angle fractures and 38 non-angle fractures). The mean gonial angle in the angle fracture group was 128.5 ± 5.4º which was 10.2° larger than in the non-angle group (mean 118.5 ± 4.4º; P = 0.0001). Patients with a high gonial angle were 8.7 times more likely to sustain an angle fracture than those with normal or low gonial angles. A statistically significant relationship between the presence of impacted third molar and patients sustaining mandibular angle fractures was noted (P = 0.0001).

CONCLUSION

Subjects with a high gonial angle and an impacted third molar are at an increased risk for mandibular angle fracture due to direct and indirect morphological factors.

Imaging study on relationship between the location of lingula and the Gonial angle in a Chinese population

PURPOSE

The purpose of this study was to investigate the Gonial angle in relation to the position of the lingula using computerized image analysis to guide the oral surgeons to prevent injury to the inferior alveolar nerve and peripheral blood vessels during surgery.

METHODS

We measured Gonial angle sizes of bilateral rami and the distances from the lingula tip to the mandibular notch (LN), the anterior (LA) and posterior (LP) margin of the mandibular ramus, the mandibular base (LB) and the occlusive plane (h) in 407 Chinese adults with CBCT.

RESULTS

In males, the mean distance of LN was 17.64 mm in the low Gonial angle group while 16.76 mm in the high Gonial angle group, which was significantly different between two groups (P < 0.001). The distance of LA in LGA group was obviously longer than that in HGA group (P < 0.001). The mean distance LP of men was 17.94 mm in LGA group while 16.9 mm in HGA group (P < 0.001). In females, the mean distance of LB in LGA group was 33.32 mm and 32.37 mm in HGA group (P < 0.01).

CONCLUSION

We discovered that the segment of the mandibular branch, between the mandibular lingula and the mandibular angle, was obviously smaller in the HGA group than that in the LGA group.

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.