Sex estimation by metric analysis of the angle of mandible and the mandibular ramus: a systematic review / Estimación sexual mediante análisis métrico del ángulo de la mandíbula y de la rama mandibular: revisión sistemática

SUMMARY: Sex estimation is the first step in human identification. The mandibular ramus and the condyle have been widely used as indicators for sexual diagnosis because they are regions that undergo important morphological changes which increase sexual dimorphism. The object of the present study was to carry out a systematic review to determine the metric parameters of the mandibular ramus that present the greatest sexual dimorphism, and to sex estimation from the angle of mandible (MA). We included documents in English, Spanish and Portuguese which analysed sex estimation or sex diagnosis by metric analysis of the mandibular ramus in humans. The search was conducted in PubMed/MEDLINE, EMBASE, LILACS, up to December 2020. The risks of bias were analysed using the AQUA tool. The search identified 538 studies. After exclusion of duplicates and irrelevant articles, 39 studies were included for qualitative analysis. Of these, 18 studies were carried out on dry mandibles and 21 by imaging techniques, totalling 7270 participants of 14 different nationalities. We found 14 sex-estimation parameters in the mandibular ramus, plus the MA. Sex estimation by the MA is variable; it is a good predictor only for some populations. The height of the mandibular ramus, the angle of mandible, the bicondylar angle and the height of the coronoid process were the estimation parameters cited in the greatest number of studies. The mandibular ramus presents great sexual dimorphism and can be used as a sex predictor in different populations. Although some parameters of the mandibular ramus can present accuracy of almost 80 % when analysed in isolation, more accurate sex estimation is achieved when the parameters are analysed in conjunction.

RESUMEN: La estimación sexual es el primer paso en la identificación humana. La rama mandibular y el cóndilo se han utilizado ampliamente como indicadores para el diagnóstico sexual debido a que son regiones que sufren cambios morfológicos importantes, aumentando el dimorfismo sexual. El objetivo del presente estudio fue realizar una revisión sistemática a fin de determinar los parámetros métricos de la rama mandibular que presentan mayor dimorfismo sexual, bien estimar el sexo a través del ángulo de la mandíbula (AM). Se incluyeron artículos en Inglés, Español y Portugués que analizaron la predicción sexual o el diagnóstico sexual mediante análisis métrico de la rama mandibular en humanos. La búsqueda fue realizada a través de PubMed/MEDLINE, EMBASE, LILACS, con límite hasta Diciembre 2020. El análisis de los riesgos de sesgos se realizó con la herramienta AQUA. Fueron identificados 538 estudios. Tras la exclusión de duplicados y estudios fuera del tema fueron incluidos 39 estudios para análisis cualitativa. De estos, 18 estudios fueron realizados en mandíbulas secas y 21 en exámenes de imagen, totalizando 7270 participantes de 14 nacionalidades distintas. Fueron encontrados 14 parámetros predictores del sexo en la rama mandibular más el AM. La predicción sexual a través del AM es variable, siendo un buen predictor solamente para algunas poblaciones. La altura de la rama mandibular, ángulo bigoníaco, ángulo bicondilar y la altura del proceso coronoides fueron los parámetros predictivos citados en mayor número de estudios. La rama mandibular presenta gran dimorfismo sexual y puede ser utilizada como predictor del sexo en diferentes poblaciones. A pesar que algunos parámetros de la rama mandibular pueden presentar una precisión de casi 80 % cuando analizadas de forma aislada, una mayor predicción sexual es alcanzada cuando los parámetros son analizados en conjunto.

Morphometric Study of Dry Adult Human Mandible Using Minimum Ramus Breadth and Mandibular Angle in Mahakaushal Region

Proper analysis of human skeletal remains is very essential for medico legal and anthropological work. The mandible is the largest and the strongest bone of face. Mandible retains its shape better than other bones, so, it plays an important role for forensic osteology and anthropological works, hence, aim of present study to measure and compare the measurement of mandibular ramus and to assess the utility of mandibular ramus as aid in gender determination. 52 dry and adult human mandibles of known sex (29 male and 23 female) were used in this study. Measurement of the ramus and angle of the mandible were measured by sliding Vernier caliper and with the help of protector and the result was statistically analyzed using IBM SPSS software. In results it is found that angle of mandible in 29 male & 23 female mandibles of right side, mean & SD is 122.24 ± 6.71 & 124.61 ± 5.33 respectively and "P" value is 0.1734. Similarly in case of left side mean & SD is 121.59 ± 6.65 & 124.17 ± 5.87 respectively and "P" value is 0.1489. While measuring minimus ramus breadth it is noticed that mean & SD for right side in male and female are 31.44 ± 2.68 & 29.22 ± 3.040 respectively and the "P" value is 0.0073, on the other that, mean & SD for left side in male and female are 31.56 ± 2.47 & 29.31 ± 3.53 respectively and the "P" value is 0.0095Measurement of mandibular ramus may be used to differentiate between male and female bones and to determine the position of mandibular foramen and canal by maxillofacial and plastic surgeons to preserve the neurovascular bundles of mandible during surgeries.

The morphometry of the angle of mandible and its correlation with age and sex in the Ethekwini Metropolitan Region: a panoramic study / Morfometría del angulo de la mandíbula y su correlación con edad y sexo en la región metropolitana Ethekwini: un estudio panorámico

The angle of mandible is formed by the tangent line joining the posterior margin of the ramus and the base of the mandible. The angle of mandible has population-specific characteristics therefore; it is imperative to the field of forensic anthropology for age and sex determination. Literary reports regarding the use of the angle of mandible for age and sex determination vary, as some studies support it, while other studies have documented inefficiencies. Therefore, the aim of this investigation was to document the morphometry of the angle of mandible and to determine if a correlation between the angle of mandible, age and sex exists. Sixty four digital panoramic radiographs (n=128) of individuals between 16-30 years were morphometrically analysed using the Dicom Digital Imaging Software. The data was captured and analysed using the Statistical Package for Social Science (SPSS version 23.0). Despite females having a greater angle of mandible than males, no statistically significant correlation was found between the size of the angle of mandible and sex (p=0.088). The angle of mandible was observed to decrease with advancement of age, however only the 16-19 year age cohort displayed a statistically significant correlation with the size of the angle of mandible (p=0.006). Therefore, this study concluded that the angle of mandible may not be a useful indicator of sex, but may be a reliable indicator of age for individuals between 16-19 years in the eThekwini Metropolitan region.

El ángulo de la mandíbula está formado por la línea tangente que une el margen posterior de la rama y la base de la mandíbula. El ángulo de la mandíbula tiene características específicas según la población; es imperativo en el área de la antropología forense para la determinación de la edad y género. Los informes literarios sobre el uso del ángulo de la mandíbula para la determinación de edad y género varían, según algunos estudios que lo apoyan, mientras que otros estudios han documentado ineficiencias. El objetivo de esta investigación fue documentar la morfometría del ángulo de la mandíbula y determinar si existe una correlación entre el ángulo de la mandíbula, la edad y el sexo. Se analizaron 64 radiografías panorámicas digitales (n = 128) de individuos entre 16-30 años morfométricamente utilizando el software Dicom Digital Imaging. Los datos fueron capturados y analizados utilizando el Paquete Estadístico para Ciencias Sociales (SPSS versión 23.0). A pesar de que las mujeres tenían un ángulo de la mandíbula mayor que los hombres, no se encontró una correlación estadísticamente significativa entre el tamaño del ángulo de la mandíbula y el sexo (p = 0,088). Se observó que el ángulo de la mandíbula disminuyó con el avance de la edad, y solamente la cohorte de edades de 16-19 años mostró una correlación estadísticamente significativa con el tamaño del ángulo de la mandíbula (p = 0,006). Por lo tanto, este estudio concluyó que el ángulo de la mandíbula puede no ser un indicador útil de sexo, pero puede ser un indicador confiable de edad para individuos entre 16-19 años en la región metropolitana de eThekwini.

Location of Mandibular Foramen in Correlation with the Gonial Angle in Indian Population: A Morphometric Study for Surgical Practices.

Background: The mandibular foramen, is the emerging point of the neurovascular bundle which makes it fundamental for performing anaesthetic techniques for desensitization of the mandible in oral surgery interventions. The knowledge of position of mandibular foramen is neccessary while anaesthetizing palate during periodontal procedures, tooth extractions and maxillofacial surgeries. Objective: The present study was carried out to identify the position and location of mandibular foramen in relation to the angle of mandible (gonial angle) in adult human mandibles of Indian origin . Materials and Methods: The study was conducted on 300 adult human dry skulls of Indian Population. Angle of mandible, Distance of mandibular foramen from angle of mandible and Angle of mandibular foramen with the base of mandible were measured. Measurements were done with Steel measuring tape and Mylometer. The data was Statistically analysed. Results and Conclusion: The Mean value of the angle of mandible (Gonial Angle) was 121.870 ± 6.220. The Mean value of the distance of mandibular foramen from angle of mandible was 22.78± 4.05 mm. The angle of mandibular foramen was Mean ± standard deviation of 82.240± 6.870. The morphometric correlation of the parameters analyzed in the mandibles showed a statistically significant Pearson correlation. Regression line was also derived.

Tooth in the line of fracture: Its prognosis and its effects on healing.

Aims and Objective: The aim of this prospective study was to compare the postoperative results of mandibular angle fracture cases treated by open reduction and internal fixation wherein the third molar in the line of fracture was preserved in one group while it was extracted in the second group. Materials and Methods: Group I consisted of 30 patients in which the mandibular third molar in the line of fracture was preserved and group II consisted of 24 patients in which it was extracted following specific criteria. Various parameters like postoperative healing, infection, occlusion, tooth vitality, and mobility were graded numerically. Statistical analysis using a t-test was done. Data were expressed as mean±SD and a probability (P) value of <0.05 was considered significant. Results: The presence of infection with pain and tenderness was higher in group I. Osteogenesis was higher in group I till the end of the third week but the difference was not significant later. Discrepancy in occlusion was more in group II. Mobility of tooth decreased and status of periodontal tissue improved significantly with time. In the tooth involved, the return of vitality and decrease in pain/tenderness was significant after 1 week and continued till 24 weeks to normalcy. Two teeth showed mild root resorbtion and none showed ankylosis. Conclusion: Postoperative occlusal discrepancy is less but infection is higher when the tooth in the line of fracture is preserved as compared to when it is removed. More than half of the teeth in the fracture line show complete recovery within a period of 6 months to 1 year. Despite the risk of an increase in the rate of complications, the tooth in the line of fracture should be preserved for its merits.