Ministry of Health of Ukraine Ukrainian Medical Dental Academy Methodical instructions for independent work for students during training to practical (seminar) classes and in class Academic discipline Surgical dentistry Module № 5 Lesson topic № 1 Anatomy of the temporomandibular joint (TMJ). Modern methods of diagnosing TMJ diseases. Arthroscopy, its possibilities in the diagnosis and treatment of TMJ diseases. Dislocations of the mandible: etiology, clinic, diagnosis, treatment. Curation of the patient in the clinic of maxillofacial surgery. Writing an academic medical history. Course V Faculty Stomatological Poltava 2020 1. Relevance of the topic. Knowledge of the anatomical structure of the temporomandibular joint (TMJ) and the characteristics of modern diagnostic methods for assessing their pathologies. The etiology, clinical diagnosis and treatment of mandibular dislocations allows you to choose a timely and effective way to treat this pathology, avoid mistakes and complications, allows the dentist to diagnose TMJ and prescribe optimal treatment. Academic history in which the student is able to use knowledge , obtained in the study of basic and applied sciences, obtained demonstrate practical skills. 2. Specific target: 2 .1.Analyze to know statistics, diseases TMJ.; 2.2. Explain the methods of diagnosing diseases TMJ; 2.3. To offer to examine patients with diseases of TMJ; 2.4. Classify diseases TMJ; 2.5. Interpret theoretical and clinical studies of diseases TMJ; 2.6. Draw diagrams, graphs 2.7. Analyze the treatment plan for patients with diseases TMJ; 2.8. Make a plan for the treatment of patients with diseases TMJ; 3. Basic knowledge, skills, abilities necessary for studying the topic (interdisciplinary integration). Names of previous Acquired skills disciplines Anatomy To study the anatomical and topographic structure of the temporomandibular joint. 2. Physiology Know the spatial ratio of the components of the temporomandibular joint. 3. Biophysics Determine the functional load on the joint. 4. Surgical dentistry To make methods of treatment of patients with TMJ. 4. Tasks for independent work in preparation for class and in class. 4.1 The list of the basic terms, parameters, characteristics which the student should master at preparation for employment: Term Definition TMJ temporomandibular joint Congruence Correspondence of an articular surface to each other Incongruence Mismatch of the articular surface to each other 4.2. Theoretical questions for the lesson: 1. Classification of the temporomandibular joint by type of structure. 2. Classification of the temporomandibular joint by periods of postnatal development of the TMJ. 3. Features of the structure of the TMJ in the age aspect. 4. The effect of masticatory muscle contractions on movements in the joint. 5. Innervation and blood supply of the TMJ. 6. Biomechanics of the TMJ depending on the type of bite. 4.3. Practical work (tasks) performed in class: 1. By demonstrating stands with different types of joints in animals: predators, rodents, primates with an explanation of the prevalence of certain movements of the mandible in students formed an idea of the structure and movements of the TMJ. 2. Students on the human skull indicate the ratio of the articular head to the articular fossa, the location of the articular tubercle and other bone formations that are part of the TMJ. Topic content: The temporomandibular joint is one of the most active human joints. The movements of the lower jaw occur almost constantly - during the function of chewing, speech, etc. The formation of TMJ in phylogeny is inextricably linked with human activities, the nature of nutrition, ie depends on the characteristics of the movements of the mandible. Predators in the TMJ have only vertical movements that allow them to tear off food, so it has a hinged structure. The heads of the mandible are located deep in the pits and completely fill them. The joint of primates has an intra-articular disk, the head of the mandible does not completely occupy the fossa, due to which the movements in the joint are complicated and perform a combined action. Human TMJ is more perfect, has a variety of movements, but it is less durable. Its structure is attributed to diarthritic or synovial joints, it consists of a complex of formations that provide movements of the lower jaw. This complex includes bone and cartilaginous structures of the articular surfaces, ligaments and muscles. Bone structures include: the head of the mandible, the articular fossa and the articular tubercle of the temporal bone. The articular fossa of the temporal bone has the shape of an ellipse and is convex in the anterior part (articular tubercle) and concave - in the distal part. The articular tubercle is a dense bone formation that provides the perception of masticatory load. In the posterior (concave) part is the head of the articular sprout at rest. It occupies the same place when the teeth are in the central occlusion. The articular process of the mandible ends with an elliptical head. By structure, it has mainly a spongy fabric, bordered by a thin layer of compact substance. On its anterior surface there is a pterygoid fossa - the place of attachment of the lower bundle of the lateral pterygoid muscle. The dimensions of the articular fossa and the head of the articular process differ from each other, their incongruence and the possibility of different positions of the head in the fossa - depending on the condition of other components of the tissue complex that provide movement in the joint. The articular surfaces of the articular head and the articular cavity have a fibro-cartilaginous coating, which is generally represented by collagen fibers. During embryonic development, connective tissue structures are formed from the mesenchyme, which form a disc, capsule and wedge-mandibular ligament. In the same period 2 floors of a joint cavity are formed. Between the head of the articular process and the articular fossa is an articular disc of biconcave oval shape. The lower part repeats the shape of the head, the upper - the articular fossa. The presence of the disc avoids incongruence of bone formations of the joint, as well as its lower surface forms a hole for the rotation of the articular head. The disc consists of dense fibrous connective tissue with inclusions of cartilage cells. Its posterior part extends into the connective tissue bilaminar zone, which connects the posterior part of the fossa and the posterior part of the articular plane of the head. The joint is divided by a disk into two floors. The volume of the upper floor is 1.2 ml, the lower - 0.9 ml. All these structures are surrounded by a joint capsule, which is a connective tissue shell. The top of the capsule is attached to the temporal bone, below - to the neck of the articular process. The connection of the capsule with the disc is strengthened by intra-articular ligaments, which are attached to the disc and the bone structures of the articular fossa and the head of the articular process. The capsule and posterior disc compartments form parallel axes that macroscopically merge with the disc. These are the so-called inspiratory protrusions, which consist of two parts: the posterior - between the disc and the capsule and the anterior, which protrudes from the capsule and is intertwined with ligaments and muscles. The fibers of these protrusions form folds, and their bone attachments allow you to control the movements of the disk. The anterior disc edge of the anterior disc layer is the site of attachment of the capsular disc head to the masticatory muscle. A layer of this muscle (20-30 mm long and 10 mm thick) goes up and back and attaches to this protrusion. The connecting part of the specified beam is attached in the center of a mandibular fossa on the outside. The capsule of the joint, which descends from the posterior third of the temporalis muscle, is attached to the middle and anterior parts of the protrusion. The fibers of the temporalis muscle go down, back and obliquely from the scales of the temporal bone, and the capsular disc part of the lateral pterygoid muscle passes into the tendon part of the anterior head of this muscle. So not only the lateral pterygoid muscle, but also the actual masticatory and temporal muscles are related to the movements of the disc. From the upper surface of the disc to the articular fossa are elastic bundles of ligaments, and from the bottom - a thick fibrous connective tissue. The upper elastic ligaments rotate the disc back when moving it forward, and the lower, rough, help keep it from moving forward. The disk is suspended from the sides to the poles of the head and separated from the capsule. The structure of the joint capsule is represented by two layers: outer (fibrous) and inner (epithelial). In the posterior part of the joint between the capsule and the posterior pole of the disc is a loose connective tissue called the "dyspnea cushion", or bilaminar area. The inner layer of the capsule and the bilaminar area are the site of production of synovial fluid, which reduces surface friction during movement and is an immunobiological environment that protects the joint from infection. The joint capsule is strengthened by extra-articular ligaments that counteract its stretching. These connections include: temporomandibular, maxillary and maxillary-maxillary. The ligaments are formed by inelastic connective tissue, so in the case of overstretching, they do not restore the original size. The blood supply to the TMJ comes from the external carotid artery basin through the superficial temporal, deep auricular, anterior tympanic, middle arteries, dura mater, and pterygoid artery. Anastomoses between arteries are weakly expressed. The most pronounced vascular network on the periphery of the disc, in the bilaminar zone and the capsule of the joint, from where the vessels penetrate to the periosteum of the head.