Study of Mandibular Foramen in Adult Human Mandible Bones: An Osteological Study

Introduction: The mandibular foramen is located on the medial surface of the ramus of mandible through which inferior alveolar nerve and vessels pass and supply the lower jaw. For dentists inferior alveolar nerve block is important to anesthetize the lower jaw for conducting various surgical procedures. Aims: To determine the accurate position of mandibular foramen through which inferior alveolar nerve and vessels were passing and supply the lower jaw and its clinical importance. Methods: This study was conducted on 35 dry mandible bones consisting of 70 mandibular foramens of unknown sex. All the important parameters were studied using vernier caliper. Results: The mean distance of mandibular foramen from mandibular notch was 21.00 mm on right side and 20.29 mm on left side, from posterior border was 12.63 mm on right side and 12.37 mm on left side, from angle of mandible was 20.60 mm on right side and 20.46 mm on left side, from base of the mandible was 23.57 mm on right side and 23.6 mm on left side, from anterior border was 16.74 mm on right side and 16.89 mm on left side. Conclusion: The accurate position of mandibular foramen varies. The knowledge of the average distance of mandibular foramen from various landmarks is useful for dental anesthesia and also helps to avoid complications.

A novel intramandibular joint facilitates feeding versatility in the sixbar distichodus

The intramandibular joint (IMJ) is a secondary point of movement between the two major bones of the lower jaw. It has independently evolved in several groups of teleost fishes, each time representing a departure from related species in which the mandible functions as a single structure rotating only at the quadratomandibular joint (QMJ). In this study, we examine kinematic consequences of the IMJ novelty in a freshwater characiform fish, the herbivorous Distichodus sexfasciatus. We combine traditional kinematic approaches with trajectory-based analysis of motion shapes to compare patterns of prey capture movements during substrate biting, the fish's native feeding mode, and suction of prey from the water column. We find that the IMJ enables complex jaw motions and contributes to feeding versatility by allowing the fish to modulate its kinematics in response to different prey and to various scenarios of jaw-substrate interaction. Implications of the IMJ include context-dependent movements of lower versus upper jaws, enhanced lower jaw protrusion, and the ability to maintain contact between the teeth and substrate throughout the jaw closing or biting phase of the motion. The IMJ in D. sexfasciatus appears to be an adaptation for removing attached benthic prey, consistent with its function in other groups that have evolved the joint. This study builds on our understanding of the role of the IMJ during prey capture and provides insights into broader implications of the innovative trait.

Intraoral and dental panoramic imaging: A diagnostic reference level study comparing radiation dose using two dosimeters in Saudi Arabia

The purpose of this study was to determine local diagnostic reference levels (DRLs) for patients undergoing intraoral and panoramic dental examinations at the intraoral radiology units of the public hospitals in Najran, Saudi Arabia. DRLs were determined based on measurements of dose area product (DAP) at intraoral and dental panoramic radiology units. This study has covered over 47% of the public hospitals in Najran with the intention to establish the local DRLs for all the possible intraoral and panoramic X-ray examinations for children and adults. For intraoral, the values for the estimated DAP ranged from 6 to 70 mGy.cm2 (average: 27.6, 29.8, 39.9 and 39.6 mGy.cm2 for incisive, both premolar and canine, molar upper and lower jaw, respectively). For panoramic, the mean value of DAP is 61.5 and 89.8 mGy.cm2 for paediatric and adult patients, respectively. DRLs were established at the 3rd quartile for incisive, both premolar and canine, molar upper and lower jaw protocols are 29.2, 37.1, 50.2 and 50.1 mGy.cm2, respectively. Furthermore, DRLs for panoramic radiography for paediatric and adult patients are 72.7 and 92.3 mGy.cm2, respectively. The proposed DRLs were comparable to those previously reported in other countries, such as UK and India.

Crown root fracture imaging on Cone Beam Computed Tomography

Objectives: This case report is aimed to describe the features of CBCT in assessing tooth fracture. Case Report: A 50-year-old man came with complaints of discomfort in the right lower jaw area, especially when used for chewing. The results of the percussion test were positive. CBCT examination showed that there was a radiolucent image of the enamel in the middle of the crown root to the 1/3 apical of the mesial and distal roots of tooth 47 which resembled a fracture line. The fracture line also appears to have reached the pulp. In addition, there is a well-defined radiolucent appearance with an irregular shape along the root from the buccal to lingual alveolar crest and accompanied by a decrease in the alveolar crest. The fracture that occurred in this case was from the enamel to the apical and involved the pulp, thus the radiodiagnosis on tooth 47 was a complicated crown root fracture with lateral periodontal cyst. Conclusion: CBCT can be used to help identify tooth fractures by obtaining a more accurate and useful value in differentiating conditions associated with fractures. CBCT provides data on the size and length of the fracture line and the size of the lesion.

The result of instrumental analysis of the amount of motion in patients with different occlusive and skeletal classes according to the condylography

The temporomandibular joint is paired, a complex formation of an ellipsoid shape, which is formed by the articular head of the lower jaw, the mandibular fossa and the articular tubercle of the temporal bone, covered with fibrous cartilage. There are two types of movements in the temporomandibular joint: translation and rotation, which implement protrusion-retrusion, right and left mediotrusion, and opening-closing. Computerized axiography is used for assessment of the mandibular movements and the patient’s skeletal parameters. This type of examination allows you to adjust the articulator for an individual function and to study the qualitative and quantitative characteristics of the temporomandibular joint.

Assessment of the quality of life of patients with total jaw defects

Cancer of the lower jaw is one of the most common causes of the development of total defects. There are many indices and indicators to assess the quality of life of patients with this pathology, but they do not fully describe the features of their postoperative rehabilitation. The question of developing an evaluation criterion for the introduction of a special device in patients with subtotal defects of the lower jaw remains open.Material and methods. In the period from 2010 to 2021, 100 patients with subtotal defects of the lower jaw, aged 30 to 65 years old, who are being treated in the Department of Maxillofacial Surgery at the Department of Maxillofacial Surgery of the GBUZ SKKKB, were interviewed. All patients were divided into 2 groups of 50 people each. In the main rehabilitation was carried out using a special device to optimize the biomechanics of the lower jaw, in the control group, rehabilitation was carried out without one. The article presents the results of assessing the quality of life, which were carried out using a special questionnaire.Conclusions. This questionnaire makes it possible to assess the standard of living of patients using a special device at the stages of rehabilitation.

The Macromicroscopic Anatomy and Microtopography of the Lower Jaw in Fetuses of 14–18 Weeks

In the article the features of anatomical structure and microtopography of the lower jaw of fetus at the age of 14–18 weeks were discussed. The relevance of the research is due to the prevalence of congenital pathology of the maxillofacial region, the possibilities of its early prenatal diagnosis and correction in connection with the development of fetal surgery.The aim of the research is to get new data of the macromicroscopic anatomy and microtopography of the lower jaw in fetuses of 14–18 weeks.Material and methods. The object of the research was the lower jaw of 40 male and female fetuses at the age of 14–18 weeks. The research was carried out using morphological methods and the method of ultrasound scanning. The qualitative and quantitative characteristics of the lower jaw were studied.Results. The lower jaw of the fetus at the age of 14–18 weeks is already formed and has basic anatomical structures. The body, angle, ramus, condylar and coronoid processes, teeth anlages, which can be described on morphological preparations and studied using the method of ultrasound scanning, are defined in the lower jaw. In front of the lower jaw, soft tissues are located, their thickness varies from 2.1 to 3.9 mm. Behind the lower jaw, there is a slit space with a width of 0.3 to 1.5 mm, behind it the tongue and the oral part of the pharynx are situated. The latter has an irregular shape. In a fetus of 14-18 weeks, major salivary glands (parotid, sublingual and submandibular) are already formed and determined on different cuts. The length of the alveolar arch is 29.1±6.2 mm, the width of the lower jaw is 19.5±4.2 mm. At this time, the lower jaw can be presented by two anlages and a symphysis located along the median line. The symphysis on horizontal cut has a fusiform shape, it narrows to the outer and inner surfaces of the lower jaw. In the narrow part, its size varies from 0.1 to 0.4 mm, the extension in the central part is from 0.5 to 0.9 mm. In the lower jaw, the anlages of decidual teeth of an irregular shape are determined. The size of anlages varies from 1.3 to 2.3 mm, depending on the type of tooth. On some cuts under the anlage of primary tooth, it is possible to determine the anlage of permanent one. The significant bilateral and sex differences of human fetuses at the age of 14–18 weeks of intrauterine development were not revealed.Conclusion. The lower jaw of fetuses at the age of 14–18 weeks has all elements of the anatomical structure, with certain fetal features (incomplete accretion of the mandibular processes, anlages of decidual and permanent teeth, microtopographic relationships with adjacent anatomical structures). At this stage of development, there are no significant bilateral and sex differences. The use of various methodological approaches to the research of the qualitative and quantitative anatomy of the lower jaw makes it possible to detail and supplement the substantiation of approaches for fetal surgery.

Functional interaction of chewing muscles in children with dentoalveolar system anomalies

Relevance. The focus of modern dental treatment not only on the elimination of aesthetic, but also functional disorders requires an understanding of the functional conjugation of the chewing muscles, the possibility of interprognosis of parameters. Objective. Assess the functional relationship between the tone of the chewing muscles proper and the bioelectric activity of the temporal and sublingual muscle groups in children with anomalies of the dentoalveolar system. Materials and Methods. The study involved 36 patients of Childrens Clinical Dental Clinic No. 2 of Voronezh, aged 6 to 12 years, who had not previously received orthodontic treatment and had distal occlusion anomalies. Evaluation of the bioelectric activity of temporal and sublingual muscles was carried out using surface electromyography on the Electromyograph Dental apparatus (Taganrog, Russia), the Chewing General sample. Evaluation of the tone of the chewing muscles proper was carried out using the Mioton-3C device in a state of physiological rest of the lower jaw. Statistical processing was carried out using Microsoft Excel, version 7.0 and the statistical programs SPSS Statistics 21 and STATISTICA 7. Results and Discussion. Correlation analysis revealed the presence of 4 weak positive, 2 weak negative, 14 moderate positive, 3 moderate negative, and 1 noticeable positive correlation between the tone of the right chewing muscle proper and the parameters of the bioelectric activity of the right and left temporal and sublingual muscles. Correlation analysis revealed the presence of 5 weak positive, 7 weak negative, 9 moderate negative correlations between the tone of the left chewing muscle proper and the parameters of bioelectric activity of the right and left temporal and sublingual muscles. Conclusion. A greater effect of the tone of the right chewing muscle on the bioelectric activity of temporal and sublingual muscles was found compared to the tone of the left chewing muscle itself. 27 equations have been derived that can be used as predictive models for calculating the tone of right and left chewing muscles proper depending on the indicators of bioelectric activity of temporal and sublingual muscles.

Lower jaw reconstruction using a vascularized bone graft is the main stage of complex rehabilitation of a child with lower jaw osteoblastoclastoma

BACKGROUND: Jaw bone benign tumors and dysplasia in childhood often have an aggressive growth pattern, which requires early radical operations. Uneven growth and changing morphological characteristics of the childs dentofacial apparatus imply stage-by-stage bone and plastic surgery in the maxillofacial region. CLINICAL CASE: The paper presents a clinical observation of the medical rehabilitation of a patient from 5 to 24 years old with lower jaw osteoblastoclastoma following our proposed algorithm. DISCUSSION: The presented clinical observation demonstrates all the main stages of medical rehabilitation of a child with a benign lower jaw neoplasm. Along with timely and fully operative neoplasm removal, rational dental prosthetics, and dispensary observation with X-ray diagnostics play an important role in the childs growth period. All these measures were important to prevent a possible neoplasm recurrence, partially maintain the masticatory function for the growth period, and avoid secondary postoperative dental apparatus deformities. The age of repeated surgery to replace the titanium structure with autosteal tissue depends on the individual characteristics of patients. The operation can be performed, in some cases, starting from age 1617 years. CONCLUSIONS: Successful treatment of children with benign neoplasms of the lower jaw after post-resection defects is a complex multi-stage process of medical rehabilitation, of which the completion, most often, passes into the adult period.

Case Report: Necrotizing Stomatitis as a Manifestation of COVID-19-Associated Vasculopathy

Necrotizing stomatitis is a rare, acute-onset disease that is usually associated with severely malnourished children or diminished systemic resistance. We describe a 1-year-old girl who developed necrotizing stomatitis, vasculitic rash, skin desquamation on the fingers and toes, and persistent hypertension after serologically confirmed SARS-CoV-2 infection. Her laboratory investigations revealed positive IgG anticardiolipin and IgG anti-β2 glycoprotein antibodies, and biopsy of the mucosa of the lower jaw showed necrosis and endothelial damage with mural thrombi. Swollen endothelial cells of small veins in the upper dermis were confirmed also by electron microscopy. As illustrated by our case, necrotizing stomatitis may develop as a rare complication associated with SARS-CoV-2 infection and can be considered as a part of the clinical spectrum of COVID-19 vasculopathy. The pathogenic mechanism could involve a consequence of inflammatory events with vasculopathy, hypercoagulability, and damage of endothelial cells as a response to SARS-CoV-2 infection.