Posterior Border Of Mandibular Ramus Research Articles

Gender-based Morphometric Analysis of Mandibular Foramen in Dry Adult Human Mandibles in the Tertiary Care Centre, Dehradun: A Cross-sectional Cadaveric Study

Introduction: The knowledge of the location of the Mandibular Foramen (MF) is important for effective local anaesthesia in dental surgeries and mandibular implants. The location of the foramen can vary in different populations, but very few studies have explored the differences between males and females. Aim: To estimate the morphometric parameters of the MF in male and female dry adult mandibles. Materials and Methods: A cross-sectional cadaveric study was conducted in the Department of Anatomy at Shri Guru Ram Rai Institute of Medical and Health Sciences, Dehradun (Uttarakhand) India, from October 2019 to December 2022. The location of MF in 75 dry adult male mandibles and 50 dry adult female mandibles was measured. All the anatomical parameters (MF to Anterior Border of mandibular ramus (MF-AB), MF to Posterior Border of mandibular ramus (MF-PB), MF to Mandibular Notch (MF-MN), MF to Angle of Mandible (MF-AG), MF to Inferior Border of mandibular ramus (MF-IB), MF to Mandibular Condyle (MF-MC), MF to apex of Retromolar Trigone (MF-RT), and AB of mandibular ramus to PB of mandibular ramus (AB-PB)) were measured using a sliding digital vernier caliper in both genders, based on the right and left mandibular foramina from different bony landmarks. Continuous data obtained was expressed as mean±Standard Deviation (SD). Analysis was done by applying an independent t-test via Statistical Package for Social Sciences (SPSS) version 23.0. Results: MF-IB was 26.09 mm±3.52 mm (RT) and 25.31 mm±3.24 mm (LT) in males, while it was 24.29 mm±3.27 mm (RT) and 24.12 mm±3.21 mm (LT) in females. The difference was found to be statistically significant (p<0.05), implying that the distance is larger in males as compared to females. MF-MC was 35.59 mm±4.44 mm (RT) and 34.89 mm±4.91 mm (LT) in males and 32.39 mm±4.11 mm (RT) and 32.52 mm±4 mm (LT) in females. The difference between the two was found to be statistically significant (p<0.05). MF-RT in males was 11.41 mm±2.19 mm (RT) and 11.87 mm±2.57 mm (LT), while in females, it was 11.40 mm±2.05 mm (RT) and 11.30 mm±2.09 mm (LT). The difference between these two was statistically significant (p<0.001) on the left-side. AB-PB was longer on the right-side in males (32.31 mm±3.05 mm) than in females (21.66 mm±3.0 mm), and the difference was statistically significant (p<0.001). Therefore, the results imply that the MF is located lower and slightly more anteriorly in males as compared to females. Conclusion: The results indicate significant differences in the location of the male and female MF. The present study provides useful information for successful inferior alveolar nerve blocks during dental surgeries and maxillofacial surgeries.

Metode Pengukuran Sudut Gonial antar Pola Vertikal Skeletal pada Sefalometri Lateral

Background: Gonial angle is one of the angles measured in vertical skeletal analysis using lateral cephalograms. Gonial angle is made of tangent line to the posterior border of mandibular ramus with mandibular plane. Definition of gonial angle depends on mandibular plane which generally consists of various methods according to Downs, Tweed, and Steiner. Purpose: To investigate the difference of gonial angles measurement methods among vertical skeletal patterns on lateral cephalograms. Methods: Observational analytic research was conducted on 21 lateral cephalograms of orthodontic patients who had come to one of orthodontic clinic in Solo in 2016-2021. The cephalograms were taken by the same operator using Vatech PaX-i3D™, then they were categorized into 3 vertical skeletal pattern groups. Reference points and tracings were submitted to supervising orthodontist via ZOOM twice daily in the morning and in the afternoon. The measured data was recorded in table and was analyzed with Statistical for Social Science (SPSS) program. Results: In each vertical skeletal pattern groups, there was no significant difference found among Downs’s, Tweed’s, and Steiner’s gonial angles. There was significant difference among gonial angles of hypodivergent, normodivergent, and hyperdivergent samples. Conclusion: There was no significant difference of three gonial angle measurement methods among three vertical skeletal patterns on lateral cephalograms.

METODE PENGUKURAN SUDUT GONIAL ANTAR POLA VERTIKAL SKELETAL PADA SEFALOMETRI LATERAL

Background: Gonial angle is one of the angles measured in vertical skeletal analysis using lateral cephalograms. Gonial angle is made of tangent line to the posterior border of mandibular ramus with mandibular plane. Definition of gonial angle depends on mandibular plane which generally consists of various methods according to Downs, Tweed, and Steiner. Purpose: To investigate the difference of gonial angles measurement methods among vertical skeletal patterns on lateral cephalograms. Methods: Observational analytic research was conducted on 21 lateral cephalograms of orthodontic patients who had come to one of orthodontic clinic in Solo in 2016-2021. The cephalograms were taken by the same operator using Vatech PaX-i3D™, then they were categorized into 3 vertical skeletal pattern groups. Reference points and tracings were submitted to supervising orthodontist via ZOOM twice daily in the morning and in the afternoon. The measured data was recorded in table and was analyzed with Statistical for Social Science (SPSS) program. Results: In each vertical skeletal pattern groups, there was no significant difference found among Downs’s, Tweed’s, and Steiner’s gonial angles. There was significant difference among gonial angles of hypodivergent, normodivergent, and hyperdivergent samples. Conclusion: There was no significant difference of three gonial angle measurement methods among three vertical skeletal patterns on lateral cephalograms.

Positional relationship between branches of the facial nerve and the plane of angulus oris: an anatomical study

Objective: To investigate the relationship between the inferior buccal branch and mandibular marginal branch of the facial nerve in the plane of angulus oris. Methods: Twenty unilateral adults cadaveric heads were dissected. In the vicinity of the posterior border of mandibular ramus, the positional relationship between mandibular marginal branch and the plane of angulus oris, the inferior buccal branch and the plane of angulus oris was recoded and analyzed. Results: In 18 of the 20 samples, the plane of angulus oris was between the inferior buccal branch and mandibular marginal branch in the vicinity of the posterior border of mandibular ramus. In one sample, the plane of angulus oris was below the inferior buccal branch and mandibular marginal branch in the vicinity of the posterior border of mandibular ramus. Another sample was excluded because the starting points of the inferior buccal branch and mandibular marginal branch were in front of the posterior border of mandibular ramus. The distance from the intersection of the posterior border of mandibular ramus and the plane of angulus oris to the intersection of inferior buccal branch and the plane of angulus oris was (14.96±8.55) mm. Conclusions: In most cases studied, the plane of angulus oris is between the inferior buccal branch and mandibular marginal branch in the vicinity of the posterior border of mandibular ramus. Along the plane of angulus oris, within 1.0 cm anterior to the posterior border of mandibular ramus, it is a relatively safe place for surgical approach.

Morphological evaluation of the mandibular lingula using cone-beam computed tomography.

Lingula is a tongue-like flap of bone that overlaps the mandibular foramen antero-medially and location is clinically significant in oral and maxillofacial surgeries. The aim of this study was to assess the shape and precise location of lingula using cone-beam computed tomography (CBCT). In this study, 3-dimensional images provided by CBCT of 63 patients (28 females, 35 males, age range 25-70 years) were retrospectively evaluated. All CBCT images were performed due to implant planning. From both sides of 63 mandibles were classified in the following shapes: triangular, truncated, nodular and assimilated. The location was determined by 5 distances from the lingula: the anterior and the posterior borders of the mandibular ramus, man-dibular notch and lover border of mandible. Height of the lingula was measured from the lingular tip to the mandibular foramen. Nodular shape of lingula was the most commonly found (32.5%). The mean distance of lingula from anterior and posterior borders of mandibular ramus was 18.5 ± 2.3 and 16.9 ± 3.5 mm, respectively. The lingula was located at 18.1 ± 3.6 mm from the mandibular notch and 38.3 mm from the lover border of mandible. The mean height of lingula was 7.8 ± 2.4 mm. The present study provides the morphological variation and localization of the lingula. The lingula is an important clinical landmark for mandibular osteotomy, and for determining the distance to mandibular foramen entrance.

Evaluation of localisation of mandibular foramen in patients with mandibular third molar teeth using cone-beam computed tomography.

It is important to know the correct anatomical location of the mandibular foramen to obtain successful anaesthesia of inferior alveolar nerve and to prevent injury to the mandibular vessels and nerve, during a variety of oral and maxillofacial surgical procedures. The aim of this study is to evaluate localisation of the mandibular foramen in patients with the third molars using cone-beam computed tomography (CBCT). Cone-beam computed tomography was used to determine the location of the mandibular foramen in 67 patients (totally 99 sides) with unilateral or bilateral impacted mandibular third molars. The distance from the posterior border of the mandibular ramus to mandibular foramen did not differ significantly among the other angulations. But the difference between vertical and horizontal angulation of the impacted mandibular third molars according to 'fd' values (the shortest distance between mandibular foramen and the posterior border of mandibular ramus) was found to be statistically significant (p < 0.05). The present study provides new information to the literature concerning relationship between the location of the mandibular foramen and the mandibular third molars.

Ramus Condyle Unit Reconstruction Using Vertical Ramus Osteotomy in Temporomandibular Joint Ankylosis.

Treatment of bony Temporomandibular Joint (TMJ) Ankylosis includes release of the ankylosis and creation of a gap with or without insertion of interposing material and complete reconstruction of the joint using e.g. costochondral, autogenous coronoid/ankylosed mass, sternoclavicular, clavicular bone grafts etc. As these are non-pedicled grafts, there is eventual resorption with subsequent decrease in height of the ramus, facial asymmetry, deviated mouth opening and reankylosis. The authors have applied the method of vertical ramus osteotomy (VRO) on the posterior border of the mandibular ramus for reconstruction of the ramus condyle unit (RCU) as a pedicled graft along with Myofascial Temporalis Interposition for the correction of TMJ Ankylosis. Ten patients of TMJ Ankylosis were included in this study. All ten patients were treated using VRO for the RCU reconstruction with posterior border of mandibular ramus after Gap Arthroplasty. Temporalis myofascial flap was used as an interpositional material in all patients. Patients were followed from 20 to 30months (mean 24months). As a result of successful procedure the post-operative maximal mouth opening of 32-45mm (mean 37mm) was achieved. No patient experienced pain and infection at surgical site. None of the patients had graft rejection and reankylosis at follow-up. The results showed that VRO on the posterior border of the mandibular ramus seems to be an alternative and promising method for RCU reconstruction in patients with TMJ Ankylosis.

Advances in temporomandibular joint reconstruction in TMJ ankylosis : Our experiences and literature review

The treatment of temporomandibular joint ankylosis poses a significant challenge because of the high incidence of recurrence .The only treatment option for TMJ ankylosis is surgical with or without condylar reconstruction. Various grafts are available for condylar reconstruction after removing the ankylotic mass such as costochondral, sternoclavicular, posterior border of mandibular ramus, fibular, coronoid process, and metatarsophalangeal, alloplastic graft like hydroxyappatite collagen and recently condylar distraction osteogenesis. To date, there is no ideal autogenous graft for condylar reconstruction that satisfies the complex anatomy and the myriad of functions of a missing condyle. This study was conducted to determine the efficacy of using the various autogeneous and alloplastic graft and condylar distraction osteogenesis for reconstruction of mandibular condyle.

Cone-beam computed tomography analysis of the shape, height, and location of the mandibular lingula

The precise anatomic location of the lingula is clinically significant because it is subject to injury during a variety of oral and maxillofacial surgical procedures. This is the first study to identify and classify the different morphological shapes of the mandibular lingula using cone-beam computed tomography. A retrospective study was performed to evaluate the shape, height, and location of the lingula in relation to surrounding structures using cone-beam computed tomographic images. The shape of the lingula was classified into triangular, truncated, nodular, and assimilated types. The location was determined by five distances from the lingular tip to: the anterior and the posterior borders of the mandibular ramus, the mandibular notch, the distal surface of the mandibular second molar, and the occlusal plane. Nodular shape of the lingula was most commonly found [51.2% (422)] followed by truncated [32% (264)]. The mean height of the lingula was 7.97 ± 1.84 mm. The mean distance of lingula from the anterior and posterior borders of mandibular ramus was 16.7 ± 2.7 and 13.0 ± 2.3 mm, respectively. The lingula was located at 15.3 ± 2.4 mm from the mandibular notch and 29.4 ± 3.9 mm from the distal side of alveolar socket of mandibular second molar tooth. The present study provides new information to the literature concerning the shape, height, and location of the lingula in the Turkish population. This finding may assist surgeons to localize the lingula and avoid intraoperative complications.

Anatomic study to determine a safe surgical reference point for mandibular ramus osteotomy

ObjectiveThe purpose of this study was to identify a surgical reference point on the mandibular ramus that can be used during ramus osteotomy to prevent injury to the inferior alveolar nerve. Materials and methodsA total of 125 subjects' mandibles were analyzed and compared on a three-dimensional (3D) model constructed from computed tomography (CT). 25 volunteer subjects with normal class I occlusion (group I, control), 50 consecutive subjects (25 females and 25 males) diagnosed with mandibular retrognathism (group II), and 50 consecutive subjects (25 females and 25 males) with prognathism (group III) were included. This study created a landmark (the midwaist point) at the halfway point on a horizontal plane between the most concave points on the anterior and posterior borders of mandibular ramus, with the vertical plane bisecting the horizontal plane. The midwaist point was compared to other anatomic landmarks including antilingula, lingula, and mandibular foramen for correlation. ResultsThe distance from the midwaist point to lingula and mandibular foramen along the horizontal plane was not significantly different among three groups. Lingula and mandibular foramen were mostly located within 2 mm posterior of the midwaist point, whereas the locations of lingula and mandibular foramen along the vertical plane to the midwaist point were highly variable. ConclusionThe midwaist point is an excellent intraoperative reference point that can help surgeons to identify the position of the lingual and the mandibular foramen, thus preventing inferior alveolar nerve injury.

Cone Beam Computed Tomographic Analysis of the Shape, Height, and Location of the Mandibular Lingula in a Population of Children

Objectives. This is the first study to identify and classify the different morphological shapes of the mandibular lingula (ML) in children using cone-beam computed tomography (CBCT). Material and Methods. A retrospective study was performed to evaluate the shape, height, and location of the ML in relation to the surrounding structures using CBCT images of mandibles obtained from 269 children. The shape of the ML was classified into triangular, truncated, nodular, or assimilated types. The location was determined by five distances. The height of the lingula was also measured from the lingular tip to the mandibular foramen. Results. A nodular shape of the ML was most commonly found (48.3%, n = 260) followed by truncated (23.4%, n = 126), assimilated (14.4%, n = 78), and triangular (13.7%, n = 74). The mean distance of ML from the anterior and posterior borders of mandibular ramus was 13.3 ± 2.3 mm and 10.2 ± 1.6 mm, respectively. In the majority of the mandibles studied, the ML was located above the occlusal plane. Conclusion. The present study provides new information to the literature concerning the shape, height, and location of the lingula in a Turkish pediatric population. This finding may assist clinicians to localize the lingula and avoid intraoperative complications.

Morphological analysis of the lingula in dry adult human mandibles of north Indian population

Context: Lingula is a sharp tongue-shaped bony projection located on the medial aspect of mandibular ramus and knowledge regarding its shape, size, and location is clinically significant in oral and maxillofacial surgeries. Aim: The present study aims to study shape, height, and precise location of lingula in dry adult human mandibles. Materials and Methods: The material for this study comprised of sixty (120 sides) dry adult human mandibles of North Indian origin to determine the morphological features and location of lingula. Student's t -test was used for statistical analysis. Results: Triangular (61.6%) shape of lingula was most commonly found followed by truncated (46.6%), nodular (31.6%), and assimilated (11.6%) types. Each type of lingula was more often unilateral than bilateral. The mean height of the lingula was 5.5 ± 2.02 mm. The mean distance of lingula from the anterior and posterior borders of mandibular ramus was 20.0 ± 2.4 mm and 15.0 ± 2.7 mm, respectively. The lingula was located at 15.4 ± 2.7 mm from the mandibular notch and 30.4 ± 3.5 mm from the distal side of alveolar socket of mandibular second molar tooth. The mean lingula ratio was 0.567 ± 0.005. Conclusion: The information regarding shape, height, and precise location of lingula in relation to various mandibular ramal landmarks could be of immense help in performing surgical procedures such as bilateral sagittal split ramus osteotomy (BSSRO), intraoral ventral ramus osteotomy (IVRO), and inferior alveolar nerve block.