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 analysis of the mandibular ramus and its clinical and medicolegal significance

Background: During natural calamities entire skeleton of single person could not be found. In such case, determination of sex with fragments of the bone available required range of data with proven accuracy. Hence this study is aimed at to provide range of data for minimum number of parameters of the ramus of the mandible.Methods: Three hundred dry mandibles of known sexes and bearing all teeth or intact alveolar margin were included in the study. Vertical height; maximum and minimum breadths of the ramus of the mandible were measured. All the data were analyzed for significance of the occurrence in relation to sex and laterality by means of paired t-test.Results: On the basis of all the three parameters together, we got 95% accuracy in determination of sex. Statistically significant differences were found in all parameters between male and female mandibles. The laterality distributions for all the parameters were found to be insignificant.Conclusions: Accurate determination of sex from the available bone fragments such as the ramus of the mandible required wide number of data from the least parameters that could be utilized medicolegally.

Study Of Mandibular Ramus As Predictor Of Sex

Background: Methods based on measurements and morphometry are accurate and can be used in determinationof sex. Even the bony remains like mandibular ramus can be used to predict the sex of the individual which willbe of help for forensic experts. Morphometry of mandibular ramus will also be of importance for anthropologists,anatomists and prosthetists.Materials and Methods: Coronoid height, maximum ramus breadth, minimum ramus breadth and maximumramus height was measured in 200 adult cadavers.Results: The coronoid height varied from 42.02 mm to 68.46 mm in males and it varied from 40.08 mm to 66.76mm in females. The maximum ramus breadth in male mandible varied from 28.84 mm to 42.28 mm and infemales it varied from 27.44 mm to 41.42 mm. The minimum ramus breadth in males varied from 21.92 mm to36.80 mm, in females it varied from 17 mm to 34.26 mm. The maximum ramus height in males varied from 47.76mm to 68.64 mm and in females it varied from 42.56 mm to 69.56 mm.Conclusion: All the parameters measured were higher in males than females. Comparison studies revealed thatthe South Indian parameters were lesser than Thais, Croatians and Africans.

Computed tomography-guided bone block harvesting from the mandibular ramus / Toma de bloque óseo de rama mandibular guiada por tomografía computadorizada

SUMMARY: The aim of this study was to ascertain the distance from the mandibular canal to the lateral, medial and upper zones of the mandibular ramus in order to identify safety margins that reduce the risk of nerve injuries in the process of removing a bone graft. A descriptive study was conducted, analyzing bilaterally 20 CBCT exams from different patients, taking measurements at 4 points in the central, lateral and medial areas of the corresponding mandibular ramus, which was located at a distance of 5 mm between each line, starting at the distal point of the second molar. Forty hemimandibles were included in this study, estimating a vertical distance for the 4 points of analysis, from between 16 and 17 mm, a distance laterally of 5 mm approximately and medially approximately from 3 to 3.9 mm; the lateral zone was significantly larger than the medial zone. It is estimated that the maximum achievement of a bone block from the area posterior to the second molar must be 13 mm deep and 3 mm laterally to minimize the risks of injuries to the inferior alveolar neurovascular bundle.

RESUMEN: El objetivo de esta investigación fue conocer la distancia que existe desde el canal mandibular a la zona lateral, medial y a la zona superior de la rama mandibular a fin de identificar márgenes de seguridad que minimicen el riesgo de lesiones nerviosas en el proceso de retiro de un injerto óseo. Se realizó un estudio descriptivo, analizando bilateralmente 20 exámenes CBCT de pacientes distintos, realizando mediciones en 4 puntos de la zona central, lateral y medial de la rama mandibular correspondiente, los cuales fueron ubicados con distancia de 5 mm entre cada línea, iniciando en el punto distal del segundo molar. Cuarenta hemimandíbulas fueron incluidas en esta investigación, estimando una distancia vertical, para los 4 puntos de análisis, de entre 16 y 17 mm, una distancia hacia lateral de 5 mm aproximadamente y hacia medial aproximadamente de 3 a 3,9 mm; la zona lateral fue significativamente mas grande que la zona medial. Se estima, que la obtención máxima de un bloque óseo desde la zona posterior al segundo molar debe ser con 13 mm de profundidad y 3 mm desde lateral para minimizar los riesgos de lesiones al paquete neurovascular alveolar inferior.

The use of the mandibular ramus for alveolar reconstruction in oral implantology / Uso de rama mandibular para reconstrucción alveolar en implantología oral

Bone grafts are widely used in alveolar ridge augmentations to allow correct implant installations. Intraoral donor sites, such as the maxillary tuberosity, symphysis and mandibular ramus have presented good characteristics and outcomes; however, the mandibular ramus has comparative advantages that promote its increased use. The aim of this work is to describe the current results of the mandibular ramus as a donor site for obtaining bone grafts to be used in alveolar bone augmentations in oral implantology and to determine the survival rate of the implants installed in the grafted sites. A systematic search of the scientific literature between December 2000 and March 2017 was carried out on the MEDLINE, EMBASE, LILACS and SciELO databases, analyzing each article according to the method of diagnosis and planning, bone resorption at the receptor site, presence of postoperative complications and implant survival rate. Eleven works were included in this study with an average of 43 patients; the follow-up times varied between 6 and 120 months, considering in addition an average success rate of 98.7 % in the implants installed in sites reconstructed with mandibular ramus bone; low morbidity in the site mainly linked to temporary neurosensory alterations was identified. It may be concluded that the need for a second surgical site to obtain graft material and the longer time the treatment requires until implant rehabilitation continue to be disadvantages; nevertheless, the mandibular ramus donor site presents low morbidity, high versatility in its use and predictable results for the dental implant installation.

Los injertos óseos son ampliamente utilizados en el aumento de rebordes alveolares atróficos para permitir la correcta instalación de implantes. Sitios donantes intraorales, tales como tuberosidad de la maxila, sínfisis y rama mandibular han presentado buenas caracteristicas y resultados, sin embargo la rama mandibular presenta ventajas comparativas que estimulan el aumento en su uso. El objetivo de éste trabajo es describir los resultados actuales de la rama mandibular como sitio donante en la obtención de injertos óseos para ser utilizados en aumentos oseos alveolares en implantología oral y determinar la tasa de sobrevida de los implantes instalados en los sitios injertados. Se realizó una búsqueda sistemática de la literatura científica entre Diciembre del 2000 y Marzo de 2017 en las bases de datos MEDLINE, EMBASE, LILACS y SciELO, analizando cada articulo según el método de diagnóstico y planificación, la reabsorción ósea en el sitio receptor, presencia de complicaciones postoperatorias y tasa de sobrevida de los implantes dentales instalados. Se incluyeron 11 trabajos en este estudio con un promedio de 43 pacientes; los tiempos de seguimiento de los sujetos fluctuaron entre los 6 y 120 meses, considerando además una tasa de éxito promedio de 98,7 % en los implantes instalados en sitios reconstruidos con hueso de rama mandibular; se identificó una baja morbilidad en el sitio donante vinculada principalmente a alteraciones neurosensoriales transitorias. Se puede concluir que continúa siendo una desventajas la necesidad del segundo sitio operatorio para la obtención de injerto y el mayor tiempo que alcanza el tratamiento hasta la rehabilitación del implante; aun asi, el sitio donante de rama mandibular presenta baja morbilidad, alta versatilidad en su empleo y resultados predecibles para la instalación de implantes dentales.

Surgical treatment of mandibular hypoplasia using inverted-L osteotomy of ramus and iliac creat bone grafting / 口腔疾病防治

Objective@# The present study was designed to evaluate the use of inverted-L osteotomy of ramus combined with iliac bone graft for the treatment of mandibular hypoplasia inadult patients.@*Methods@#Intraoral or extraoralinverted-L osteotomy of ramus and iliac crest bone grafting were used for the treatment of mandibular hypoplasia in 11 adult patients (aged 19 to 29 years) from 2010 to 2016. Data were collected from the patients’ records, photographs andradiographs.@*Results @#The height and width of the mandibular ramus were significantly augmented by inverted-L osteotomy and iliac crest bone grafting with minimal complications in all patients, resulting in remarkable improvements both in facial appearance and occlusion.@*Conclusions @#Our preliminary results showed that the inverted-L osteotomy of ramus and iliac crest bone grafting is safe and effective, and should be considered as a good alternative for the patients with mandibular hypoplasia.

Tumor resection from retromolar trigone, posterolateral maxilla, and anterior mandibular ramus using lower cheek flap approach: a case report and review of literature

A surgical approach involving the retromolar trigone, posterolateral maxilla, and pterygoid region is the most challenging in the field of maxillofacial surgery. The upper cheek flap (Weber-Ferguson incision) with subciliary extension and the maxillary swing approach have been considered as alternatives; however, neither approach provides sufficient exposure of the pterygoid region and the anterior portion of the mandibular ramus. In this report, we describe two cases in which a lower cheek flap approach was used for complete tumor resection in the retromolar trigone and the anterior mandibular ramus. This approach allows full exposure of the posterolateral maxilla and the pterygoid region as well as the retromolar trigone without causing major sensory disturbances to the lower lip. A mental nerve anastomosis after tumor resection was performed in one patient and resulted in approximately 90% sensory recovery in the lower lip. The lower cheek flap approach provides adequate exposure of the posterolateral maxilla, including the pterygoid, retromolar trigone, and mandibular ramus areas. If the mental nerve can be anastomosed during flap approximation, postoperative sensory disturbances to the lower lip can be minimized.

Evaluation of mandibular lingula and foramen location using 3-dimensional mandible models reconstructed by cone-beam computed tomography / 대한악안면성형재건외과학회지

BACKGROUND: The positions of the mandibular lingula and foramen have been set as indexes for inferior alveolar nerve (IAN) block and ramus osteotomies in orthognathic surgery. This study aimed to evaluate the anatomical structures of mandibular ramus, especially the mandibular lingula and foramen, by analyzing the cone-beam computed tomography (CBCT) data of young adults. METHODS: We evaluated 121 sides of hemi-mandibular CBCT model of 106 patients (51 male and 55 female patients; 18 to 36 years old). All the measurements were performed using the 2- and 3-dimensional rulers of OnDemand3D® software. RESULTS: Statistical analysis of the data revealed that there was no significant difference in the mandibular angle between the genders. The mandibular lingula was found to be located at the center of ramus in males, but a little posterior in relation to the center in females. The mandibular lingula was rarely located below the occlusal plane; however, the position of the mandibular foramen was more variable (84.3% below, 12.4% above, and 3.3% at the level of the occlusal plane). CONCLUSIONS: The results of this study provide a valuable guideline for IAN block anesthesia and orthognathic surgery. CBCT can be considered effective and accurate in evaluating the fine structures of the mandible.

Frequency of mandibular asymmetries evaluated by cone beam computed tomography at a radiology diagnostic center in Medellin, Colombia: 2011-2013 / Frecuencia de asimetrias mandibulares evaluadas por tomografia computarizada cone beam de un centro de diagnóstico radiológico de Medellín,Colombia: 2011-2013

Longitudinal differences on the left and right sides of the jaw with respect to the midline in three spatial planes are called mandibular asymmetries. Objective: To determine the frequency of mandibular asymmetries in three spatial planes by means of Cone Beam computed tomography (CBCT) and classify them according to the degree of difference between both sides. Methods: A total of 40 Cone Beam volumetric tomography (New Tom 3G Cone Beam Volumetric tomographic scanner) records were analyzed using simple random sampling of patients between the ages of 18 and 70 from 2011 until 2013. Axial slices were obtained from the lingula in cranio-caudal direction every 5 mm until the gonial angle. Results: From the records, 2.5 percent showed moderate degree of difference in the length of the mandibular body with predominance on the right side. For breadth of the ramus, predominance was found on the left side. In the length of the mandibular ramus, 10 percent presented moderate degree of predominance on the right side. Conclusions: 1) asymmetries are more frequent at the level of the mandibular ramus thickness; (2) moderate and severe degrees of differences are most frequently found in the mandibular ramus thickness. 3) It is not possible to proportionally determine mandibular ramus thickness only with a 2D image...

Se denominan asimetrías mandibulares a las diferencias longitudinales de los lados derecho e izquierdo de la mandíbula con respecto a la línea media en los tres planos espaciales. Objetivo: Determinar la frecuencia de asimetrías mandibulares en los tres planos del espacio por medio de tomografía computarizada Cone Beam (TCCB) y clasificarlas según el grado de diferencia entre ambos lados. Métodos: Se analizaron 40 registros de tomografía volumétrica Cone Beam, (New Tom 3G Cone Beam Volumetric Tomographic Scanner) mediante muestreo aleatorio simple de pacientes entre los 18 y 70 años de edad, entre los años 2011 y 2013. Se obtuvieron cortes axiales a partir de la língula en sentido cráneo-caudal cada 5 mm hasta llegar al ángulo goníaco. Resultados: El 2,5 por ciento de los registros presentaron diferencias moderadas en la longitud del cuerpo mandibular con predominio del lado derecho. En la amplitud de la rama se encontró predominio del lado izquierdo. En la longitud de la rama mandibular el 10 por ciento presentó predominio moderado del lado derecho. Conclusiones: 1) las asimetrías más frecuentes se encuentran a nivel del grosor de las ramas mandibulares. 2) Los grados de diferencias moderados y altos se presentan con mayor frecuencia en el grosor de las ramas mandibulares. 3) No es posible determinar proporcionalmente el grosor de las ramas mandibulares obteniendo solo una imagen 2D...

Endoscopy-assisted open treatment for fractures of the mandibular ramus-condyle unit WANG / 中国医师进修杂志

ObjectiveTo describe the use of endoscopic technique for exposure of the mandibular ramus-condyle unit(RCU) to facilitate reduction and rigid fixation of the fractures.MethodsSixteen patients ( 18 sides) with diagnosis of subcondylar fracture ( 11 sides),condylar neck fracture ( 2 sides ),and mandibular ramus fracture (5 sides ),who underwent endoscopic exposure of the RCU and fixation with miniplates by an extraoral or transoral approach.Six sides were no displacement,10 sides were obvious displacement,and 2 sides were dislocation.ResultsAll patients had successful treatment of fractures of the mandibular RCU,all patients showed quick recovery to preinjury occlusion.Followed up 12-36 months,normal temporomandibular joint function was noted in all patients.No patient had marginal mandibular nerve weakness or other complications.ConclusionsIt demonstrates the feasibility of endoscopic access to the RCU for treatment of the fractures.The procedures can be performed with minimal morbidity and functional impairment.

A Case of Impacted Supernumerary Fourth Molar in the Bilateral Mandibular Ramus / Oral Science International

The occurrence of multiple supernumerary teeth in individuals without any associated syndrome is rare. In this report, a rare case of a 48-year-old woman who had an impacted supernumerary fourth molar in the bilateral mandibular ramus is described. She presented with a swelling in the left cheek region. Radiographic examination revealed an impacted supernumerary tooth in the left mandibular ramus with pericoronal resorption of the bone, suggesting peripheral inflammation. She also had an impacted supernumerary tooth on the right side. After administering an antibiotic and antiinflammatory drug, tooth extraction was performed under general anesthesia.

Clinical usages of ramal autogenous bone grafts in dental implant surgery

Late Vascular Complication after Mandibular Ramus Sagittal Split Osteotomy: A Case Report

PURPOSE: The mandibular ramus sagittal split osteotomy is a common procedure in cosmetic surgery. A late complication of this procedure, pseudoaneurysm rarely happens. The purpose of this case is to present our experience that is rare late vascular complication after mandibular ramus sagittal split osteotomy. METHODS: A 21-year-old male was operated by local plastic surgeon for treatment of mandibular prognathism. After 9 days, the man was transferred to our hospital with persistent bleeding and swelling on the mandibular area. We operated the man three times and failed to control hemorrhage. Therefore, we did angiography and found the pseudoaneurysm on the buccal and pterygoid branches of internal maxillary artery. Then we did selective embolization for removal of the pseudoaneurysm. RESULTS: The man was operated using the therapeutic embolization, and the pseudoaneurysm was removed. The results were successful, and we couldn't find any bleeding and the pseudoaneurysm during the follow-up of 12 months. CONCLUSION: The selective embolization is the good therapeutic method of late vascular complication after mandibular ramus sagittal split osteotomy.

Late Vascular Complication after Mandibular Ramus Sagittal Split Osteotomy: A Case Report

PURPOSE: The mandibular ramus sagittal split osteotomy is a common procedure in cosmetic surgery. A late complication of this procedure, pseudoaneurysm rarely happens. The purpose of this case is to present our experience that is rare late vascular complication after mandibular ramus sagittal split osteotomy. METHODS: A 21-year-old male was operated by local plastic surgeon for treatment of mandibular prognathism. After 9 days, the man was transferred to our hospital with persistent bleeding and swelling on the mandibular area. We operated the man three times and failed to control hemorrhage. Therefore, we did angiography and found the pseudoaneurysm on the buccal and pterygoid branches of internal maxillary artery. Then we did selective embolization for removal of the pseudoaneurysm. RESULTS: The man was operated using the therapeutic embolization, and the pseudoaneurysm was removed. The results were successful, and we couldn't find any bleeding and the pseudoaneurysm during the follow-up of 12 months. CONCLUSION: The selective embolization is the good therapeutic method of late vascular complication after mandibular ramus sagittal split osteotomy.

An anatomical study of the mandibular ramus in Korean patients with dentofacial deformity

Orthognathic surgery of the mandibular prognathism and the retrognathism is tend to be performed on the mandibular ramus to prevent inferor alveolar nerve injuries. The purpose of this study is to find a safe and accurate reference point on mandibular ramus for orthognathic surgery by comparative anatomical study of dentofacial deformity patients. We use 38 Korean Cadavers with normal occlusion(Group 1), 3-dimensional simulation of computerized tomogram of 23 patients with retrognathism (Group 2), 27 patients with mandibular prognathism (Group 3). Following results are obtained : 1. The maximum thickness of the mandibular ramus is 8.78+/-1.15mm for Group 2, 7.61+/-1.26mm for Group 1, 6.95+/-0.82mm for Group3 respectively (P=0001). The minimum thickness is 5.51+/-1.08mm for Group 1 , 5.06+/-0.40mm for Group 2, 4.56+/-0.78mm for Group3, respectively (p=0.0001). But, the thickness at the level of 5mm above the lingular is 0.78+/-0.65mm for Group 2, 5.63 +/-1.28mm for Group 1, 5.32+/-0.91mm for Group 3, respectively. There is no significant difference between these groups(P=0.0510). 2. The horizontal location from the midwaist point to lingular is 0.18+/-1.57mm for Group 1, 0.69+/-1.33mm for Group 2, 0.66+/-1.66mm for Group 3, and there is no significant difference between these groups(p=0.0835). But the vertical location from the midwaist point to lingular is 1.45+/-2.64mm for Group 1, 0.63+/-1.44mm for Group 2, 0.34+/-1.81mm for Group 3, and there is significant difference between these groups(p=0.0030). 3. The horizontal location from the midwaist point to mandibular foramen is 0.29+/-1.75mm for Group 1, 0.63+/-1.44mm for Group 2, 0.34+/-1.81mm for Group 3, and there is no significant difference between these groups(p=0.5403). But the vertical location from the midwaist point to mandibular foramen is -3.33+/-4.43mm for Group1, -4.79+/-2.26mm for Group 2, -6.06+/-2.99mm for Group 3, and there is significant difference between these groups(P=0.0001). 4. The horizontal length from the disto-buccal cusp tip of mandibular second molar to lingula is 30.97+/-4.17mm for Group 3, 28.29+/-2.65mm for Group 1, 25.48+/-0.77mm for Group 2 (p=0.0000), and also vertical length is 7.72+/-3.22mm for Group 3, 6.38+/-1.83mm for Group 1, 5.89+/-2.30mm for Group 2 (P=0.0014). 5. The location of lingular is 0.50 from anterior border of mandibular ramus in all groups, if it assumed the length from anterior border to posterior border is 1. And it is almost 0.33 from the sigmoid notch, if it assumed the length from sigmoid notch to antegonial notch is 1. 6. In Group 1, Antilingular prominence is located on (1.12+/-1.43mm, 4.01+/-2.36mm) from the midwaist point, and there is no correlation between antilingular prominence and lingular, mandibular foramen.

Mandibular anatomy related to sagittal split ramus osteotomy in Koreans

Sagittal split ramus osteotomy (SSRO) is one of the surgical techniques used to correct mandibular deformities. In order to prevent many surgical anatomical problems, we observed the anatomical structures related to SSRO. In dry mandibles of Koreans, lingular tips were located somewhat posteriorly and superiorly on the mandibular ramus. On the coronal sections of mandible, the mean cortical width of facial cortex was increased toward the ramus region while the lingual cortex was thinnest in the ramus region. On the same sections, all the fusion points of the buccal and lingual cortical plate were located above the mandibular lingula and beneath the mandibular notch. So, performing the SSRO on Koreans, medial horizontal osteotomy should be done through the superior aspect of the mandibular lingula. The cut line is extended 5-8 mm posterior to the mandibular lingula to preserve sufficient cortical width to strengthen the involved osseous segments and reduce possible surgical complications.