TMJ MORPHOLOGICAL FEATURES OF DIFFERENT TYPES OF MALOCCLUSION CAUSING PATHOLOGICAL LOWER JAW POSITION ASYMMETRY

According to Russian researchers, the prevalence of temporomandibular joint dysfunction ranks third in the structure of dental morbidity among adults. In recent decades, the attention of clinicians to the problem of TMD has been growing rapidly due to the difficulties in the diagnosis and treatment of patients with malocclusion, complicated by joint pathology. The purpose of this article is to search for new knowledge that will improve quality of diagnosis of dysfunctional changes in the TMJ of patients with various malocclusion pathologies by identifying correlations between anatomical and morphological features of the joint and dentoalveolar anomalies. Understanding the trends in the development of characteristic morphofunctional disorders will make it easier for doctors to plan treatment for orthodontic patients and increase its effectiveness. Such patients require special attention from orthodontists. When writing this article, we have studied a lot of modern literature, as well as studies of foreign and Russian scientists who is involved in the treatment of dysfunction. However, we have not found the information that would show a direct relationship between anatomical and morphological features and malocclusion pathology, which was the purpose of our work. The article describes in detail the morphological and functional changes that occur at different stages TMD, the relationship between the shape of the glenoid fossa morphology process, included classification of the forms condyloid process described features of the development of bone structures of the TMJ depending on the type of pathological occlusion. Revealed statistics demonstrate the dependence of the frequency of dysfunction on the shape of the articular head and fossa. The analysis of computer tomograms of patients of the Department of Pediatric Dentistry and Orthodontics of the First Sechenov Moscow State Medical University allows us to conclude that the oval shape of the TMJ head and the rounded shape of the articular surface of the temporal bone can become a prerequisite for the development of dysfunctional changes. The results of our study will help orthodontists improve the quality of diagnostic measures and the effectiveness of treatment of patients with suspected TMD.

Embryonic Development and Comparative Anatomy of the Mandible

Objective: This study was designed to determine the ossification time and pattern of the mandible. Methodology: Three hundred and fifty (350) wasted fetuses consisting of 70 Balami, 140 each of Uda and Yankasa breeds whose crown vertebral rump length ranged from 3.0-15 cm were used. The fetuses were processed using the Alizarin technique and the mandible was dissected from the head for stereography. Result: The result revealed that the first part of the mandible to develop was the body and mental foramina at the 42nd–44th days of gestation while the coronoid process, rami, and condyloid process develop later at different time points. In addition, the mandibular foramina remained undeveloped in all age groups. Interestingly, the mandibular canal began ossification earlier in the Yankasa breed compared to other breeds. It was shown to arise from a cartilaginous tissue at the medial and lateral surfaces of the body and dorsally remained opened and undifferentiated from the teeth alveoli of the lower jaws in the 7 age groups. Conclusion: It was therefore concluded that the mandible arises from three ossification centres at the body, rami, and coronoid process. These segments develop at different time intervals in the three breeds of sheep with Yankasa mandible ossifying and progressing faster than in Balami and Uda. Doi: 10.28991/SciMedJ-2021-0301-3 Full Text: PDF

STUDY OF THE SIZE OF THE CORONOID PROCESS OF MANDIBULE

The mandible serves as an important structure in relation to mastication as all the muscles of mastication are attached to it. The Coronoid process is the anterior bony projected part of ramus of mandible giving attachment to two important muscles of mastication. The aim of our study was to observe the variation in the size of coronoid process in relation to its side (laterality), shape, age and sex. The material for this study comprised of 80 (160 sides) dry human mandibles. The age and sex differentiating criteria were detailed in materials and methods. The size of coronoid process was found to be approximately 1.5 mm longer on the right side than on the left side; 0.01 mm longer in males than females and 0.01 mm longer in dentulous than in edentulous. Triangular coronoid process was found to be the longest followed by round and then hook shaped. Male hormonal impact on muscle growth, bone remodeling and psychology probably lead to enhanced functional stress on mandible due to mastication as compared to that in females. Pterygoid muscles are involved mainly in side to side movement and Masseter-Temporalis (M-T) component in the robust vertical thrust during mastication for crushing. The condyloid process is for pterygoid and M-T-Coronoid Lever complex engenders the proportionate sexual dimorphism as observed in this study. Poor crushing activity in the edentulous is also corroborated in our observation.This comparative study is a pioneer study which will be beneficial for the Anthropologists, Forensic scientists and Reconstructive surgeons.

ANALYSIS OF MORPHOLOGICAL PARAMETERS OF DENTAL SYSTEM WITH GNATHIC FORM OF MALOCCLUSION CLASS III USING SIMPLYCEPH SOFTWARE (RUSSIA)

Mesiocclusion associated with asymmetric mandibular development is a gnathic form of mesiocclusion characterized by asymmetric deformation of the facial skeleton, requiring detailed examination to perform differential diagnostics. We need to analyze lateral teleroentgenogram of the head using «SimplyCeph» software, frontal teleroentgenogram of the head, multidetector computed tomography. According to scientific data, asymmetric mandibular development is much rarer in clinical practice. Etiology of this abnormality is not determined to date. It is believed that growth zones are activated in condyloid process and mandibular angle for unknown reasons. Aim - to determine the morphological condition of stomatognathic system on the stages of rehabilitation after complex treatment of patients with asymmetric growth of mandible. Materials and methods. We examined 40 patients with malocclusion class III aged from 16 to 40. The examined group included patients with malocclusion class III that corresponded to the certain degree of severity of the abnormality: Grade I - joining of the first permanent molars and canines for Class II Angle, displacement value does not exceed 1/2 of the first permanent molar cusp. Sagittal overjet is absent; the value of anterior crossbite is minimal, moderate or deep. Results. During the stages of rehabilitation of patients with malocclusion class III and asymmetry of the mandible it is necessary to conduct a comprehensive study of facial and gnathic areas of dental system, analyze the results of radiodiagnosis of sagittal, transversal and vertical skull parameters. Conclusion. Method of subcondylar vertical osteotomy helps to normalize the morphological state of dental system. Keywords: malocclusion class III, computer program «SimplyCeph», analysis of lateral teleroentgenogram.

Morphological and morph metric study of the mandible in the local Rabbits (Oryctolagus Cunicuius)

Eleven adult local rabbits (6 female and 5male) were used for this study. The mandible were prepared to study the gross anatomical features. The main gross characteristics feature of the local rabbits mandible the ramus forms a broad, thin and flat plate, the surface of the ramus is greatly increased in its posteroventral portion to form the angle or angular process. The articular surface is elongated and carry on its caudodorsal end a slightly oblique condyloid process, this process in rabbit is raised much above the planes of the molar table and has a prolonged aspect in a longitudinal plan. In front of the shallow mandibular notch, the coronoid process is short and blunt process situated in front of mandibular notch. In the rabbit mandible the alveoli for the canine teeth were absent resulting in a large diastema Mandibular foramen situated on the medial surface immediately behind the last molar. There is a large retroalveolr foramen. The female local rabbit showed significant greater measurement than the male.

Diversity Of Mandibular Morphology In Some Carnivorans

Comparison of mandibular morphology of some aquatic (seals, walruses, and sea otters) and terrestrial (hyenas and pandas) carnivorans demonstrates a rather general pattern correlating size of condyloid angle, size of gape, and diet. Structural differences of carnivoran jaws reveal morphological and ecological adaptations that are directly correlated with availability of prey, diving depth, feeding competition and specialized feeding methods. Specifically, the inclination of the condyloid process relative to the axis of the alveolar row (= condyloid angle) can be used to determine dietary preferences, including size of prey. Generally, carnivorans with a large condyloid angle feed on larger prey, while a low condyloid angle suggests feeding on small prey or can be an advantageous feeding mechanism. Mirounga angustirostris (Northern elephant seal) displays sex-specific characters in cranial and postcranial elements. Likewise, significant sexually dimorphic differences in the size of condyloid angle imply that deeper-diving male Northern elephant seals have a feeding niche dissimilar to that of females. Morphological assessment of male M. angustirostris suggests they are bottom-feeding seals that utilize a suction-feeding mechanism to capture small prey and crush shells with their teeth, which become weaker as they age.

Remarks on Correlations and Implications of the Mandibular Structure and Diet in Some Seals (Mammalia, Phocidae)

Remarks on Correlations and Implications of the Mandibular Structure and Diet in Some Seals (Mammalia, Phocidae). Koretsky, I. A., Rahmat, S. J., Peters, N. — The diverse representatives of Recent seals within the three extant subfamilies (Cystophorinae, Phocinae, Monachinae) of the family Phocidae exhibit dietary variations among species, feeding on invertebrates and a diversity of prey depending on the season and availability. To explain this variability, an introductory morphological examination of the mandibular structure of Recent seals from each subfamily was performed, focusing on: heights of the mandibular ramus and condyloid process; measurements of the masseteric fossa; and attachments of muscles of mastication. After measuring the condyloid angles (the inclination of the condyloid process in relation to the axis of the alveolar row) among the examined species, a correlation between the size ofthe angle, function, and diet was recognized. Seals with a tall mandibular ramus and greater condyloid angle (Cystophorinae) feed on larger-sized prey, while seals with a shorter ramus and lesser condyloid angle feed on small (Monachinae) to medium-sized (Phocinae) prey, regardless of the overall size of the seal. This study focused on the mandibular morphology of some living and fossil representatives of Phocidae, providing an association between functional and ecological interpretations of modern seals in general and extrapolating this knowledge for fossil dietary preference.

Temporomandibular joint ankylosis and salivary mucocele in a cat: case report

An approximately 1.5-year-old, not neutered mixed breed cat was referred for evaluation of inability to open its mouth, and soft tissue swelling around the intermandibular region. Both signs were present since the cat was adopted, 1 year before presentation. The cause of the signs was not determined prior to referral. Based on the physical and radiographic examinations, left temporomandibular joint ankylosis and salivary mucocele were diagnosed. The lateral aspect of the condyloid process of the left mandible was removed and the salivary mucocele was treated by right mandibular and sublingual gland resection and drainage of the mucocele. After surgery, the cat showed good functional use of the mandible without discomfort.