Lecture 10. TMD Diagnosis and Classification PDF

Temporomandibular Joint Disorders: Diagnosis and Classification Occlusion 15-18/12/2024 First Semester 2024 Dr Ibrahim Khatib DDS MClinDent MPros Outline The TMJ Complex Biomechanics of the TMJ Etiology Clinical Feat...

Temporomandibular Joint Disorders: Diagnosis and Classification Occlusion 15-18/12/2024 First Semester 2024 Dr Ibrahim Khatib DDS MClinDent MPros Outline The TMJ Complex Biomechanics of the TMJ Etiology Clinical Features Examination Diagnosis and Classification The temporomandibular joint is an atypical synovial joint that permits a hinging movement and a gliding motion of the surfaces. The TMJ shares some commonalities with other synovial joints such as a disc, fibrous capsule, fluid, synovial membrane and ligaments. However, the features that make the TMJ unique are its articular surface covered by fibrocartilage rather than hyaline cartilage. Temporomandibular Joint Complex The joint The ligament The muscles  The joint: The articulating surfaces (condylar head and glenoid fossa) don't come into contact with each other.  The joint: The articular disc is a biconcave fibrocartilaginous structure that functions to accommodate the hinging and gliding actions of the condyle. The disk has anterior and posterior bands. The posterior band attaches to the fossa and is known as the retrodiscal tissue (highly innervated and vascular). The anterior band attaches to the superior head of the lateral pterygoid. The articular disc is composed of dense fibrous connective tissue for the most part devoid of any blood vessels or nerve fiber. The central area is the thinnest and is called the intermediate zone. The disc becomes considerably thicker both anterior and posterior to the intermediate zone. In the normal joint the articular surface of the condyle is located on the intermediate zone of the disc, bordered by the thicker anterior and posterior regions. The articular disc is attached posteriorly to a region of loose connective tissue that is highly vascularized and innervated (Retrodiscal tissue). Synovial fluid provides lubrication and metabolic requirements. The ligaments: Ligaments provide stability and proprioception to the TMJ. The main three are the temporomandibular ligament, the sphenomandibular ligament and the stylomandibular ligament. Temporomandibular ligament functions: Limits extent of mouth opening Prevents excessive rotation of condyle, forcing it to glide Limits posterior movement of disk and condyle The muscles: Four pairs of muscles make up a group called the muscles of mastication: the masseter, temporalis, medial pterygoid, and lateral pterygoid. Although not considered muscles of mastication, the digastrics also play an important role in mandibular function.  Biomechanics of the TMJ Since the disc is tightly bound to the condyle by the lateral and medial discal ligaments, the only physiologic movement that can occur between these surfaces is rotation of the disc on the articular surface of the condyle. The disc and its attachment to the condyle are called the condyle–disc complex; this is the joint system responsible for rotational movement in the TMJ.  Biomechanics of the TMJ The second system is made up of the condyle– disc complex functioning against the surface of the mandibular fossa. Since the disc is not tightly attached to the articular fossa, free sliding movement is possible between these surfaces in the superior cavity. This movement occurs when the mandible is moved forward (referred to as translation) Translation occurs in the superior joint cavity between the superior surface of the articular disc and the mandibular fossa. According to the Glossary of Prosthodontic Terms, temporomandibular disorders (TMD) are defined as conditions producing abnormal, incomplete, or impaired function of the temporomandibular joints. The reported prevalence of TMD is between 5–50% as the majority of patients do not report or seek help for their symptoms. Epidemiological studies reveal that the most TMD symptoms are reported by people in the 20- to 40-year age group. Females seek medical assistance more than males (4:1) Etiology Multifactorial, with different biological and psychosocial factors. Depression, lack of sleep and stress-related disorders may underlie or contribute to the development of chronic TMD. Furthermore, patients with TMD have been shown to have lower pain thresholds at the site of pain and at other sites. The relationship between TMD and parafunctional habits (bruxism and clenching) has historically been reported as a significant cause and effect relationship. However, the association between them is highly inconsistent. The literature is unable to demonstrate a dose–response between bruxism and TMD because most bruxists do not report intense levels of TMD pain. Similarly, occlusal interferences, malocclusions and orthodontics seem to be of minor importance in the etiology of TMD. Trauma, in the form of macro-trauma to the head and neck (e.g. head injury), or micro-trauma (e.g. dental treatment) may contribute to the development of TMD in predisposed patients. Trauma seems to have a greater impact on intracapsular disorders than on muscular disorders. Increased levels of emotional stress experienced not only increases the tonicity of the head and neck muscles but it can also increase levels of nonfunctional muscle activity, such as bruxism or tooth clenching. Clinical features: Presenting symptoms Pain in one or more of the muscles of mastication (localized or generalized) Pain in TMJ on palpation or movement Clicking, popping, or crepitus with or without locking Decreased mouth opening Headache in the temporal region Otalgia in the absence of aural disease For most patients, the examination process includes a detailed clinical interview and a comprehensive physical inspection. Temporomandibular joint (TMJ) imaging and additional tests are necessary only for very few specific cases. It has been stated that approximately 70% of the diagnostic process is based on the history review Physical examination must include investigation of the mandibular active range of motion (AROM), standardized TMJ and masticatory and cervical muscle palpation, as well as inspection of articular joint sounds. The clinical interview of the TMD patient should be well documented and must contain questions regarding the onset of the problem, previous diagnosis and performed treatment. The following information should be part of a comprehensive history: chief complaints, history of present illness, past medical and dental history, review of the systems and psychosocial history. Onset: This information is useful to determine whether the patient has an acute or chronic condition, which is crucial for the establishment of a proper therapy Location: The intra-capsular pain is well pointed by the patient, but muscle pain is diffuse and difficult to be localized. The detection of the pain source is decisive for the success of the treatment. It is important to note that the site of pain can be different from the source of pain (ectopic pain), as in the myofascial pain syndromes Intensity: Intensity of pain is a difficult parameter to quantify. The visual analogue scale (VAS) is a simple and reliable method that is extensively used in clinical practice and research to measure pain intensity. Frequency: When pain is of musculoskeletal origin and manifests only during activities such as chewing and speaking, the treatment normally assumes a non-invasive approach. Quality: TMD pain is normally described as deep, dull and sometimes aching (throbbing), like in the inflammatory acute processes of the joints. Burning or shock-like pain is probably from neuropathic origin. Headache reports are associated with migraine or other primary headache disorders History of the chief complaints: it is valuable to detect possible aggravating factors to the pain and to obtain more information about the patient’s chief complaints. Musculoskeletal pain is aggravated when using masticatory system structures and also by emotional stress. Avoiding these activities or using anti-inflammatory or analgesic medications may alleviate patient symptoms. Vascular or neurogenic pain is usually not affected by masticatory function Dental history: many patients associate the onset of the painful sensation with a procedure performed by a dentist. Patients very often report the onset of pain after long dental treatment appointments, such as root canal therapy and third molar extractions. Presence of parafunctional habits: The patient should be asked about the presence of any parafunctional activity. The habits most frequently found in TMD patients are clenching and grinding. Nail biting and poor posture due to occupational activities should also be recorded Physical Examination A comprehensive physical examination will help to determine the source of pain as well as the severity of the dysfunction. This part of assessment includes TMJ evaluation (joint range of motion, inspection of joint sounds and pain on palpation), and muscle palpation. TMJ evaluation TMJ range of motion: The patient is requested to fully open the mouth and the sum of inter-incisal distance and overbite, measured with a millimeter rule is documented The mandibular opening and closing movements may be accomplished in a straight line, to assess deviation or deflection. Range and path of movement tests: Normal range is 10-14 mm in protrusive. About 10 mm toward right and left. Minimum opening is around 30mm or 3 finger width. Maximum opening without discomfort is about 40-60 mm. Detection of joint sounds: The presence of joint sounds during mouth opening and mandibular excursion can be useful in the diagnosis of disc-condyle incoordination. Using a stethoscope is very reliable in the detection of articular sounds Clicking and crepitation are the most common sounds in TMD patients TMJ palpation: Tenderness to palpation is considered one of the most important signs in the detection of intracapsular pathologies The joint should be palpated bilaterally and any pain should be noted ‫ ﻳﻌﺘﺒﺮ‬.‫أﻣﺮا ﺣﻴﻮﻳً ﺎ ﻟﻠﻜﺸﻒ ﻋﻦ اﻻﺿﻄﺮاﺑﺎت داﺧﻞ اﻟﻜﺒﺴﻮﻟﺔ‬ ً ‫ﻳﻌﺪ اﻟﻀﻐﻂ ﻋﻠﻰ اﻟﻤﻔﺼﻞ أﺛﻨﺎء اﻟﻔﺤﺺ‬ ‫اﻷﻟﻢ ﻋﻨﺪ اﻟﻠﻤﺲ ﻋﻼﻣﺔ ﻫﺎﻣﺔ ﻟﺘﺤﺪﻳﺪ وﺟﻮد ﻣﺸﺎﻛﻞ ﻓﻲ اﻟﻤﻔﺼﻞ اﻟﺼﺪﻏﻲ اﻟﻔﻜﻲ‬ Any muscle tenderness should be noted. The three portions of the temporalis (posterior, medial and anterior), superficial and deep masseter, as well as the insertion of the medial pterygoid muscle should be examined The temporalis and masseter should be manually palpated and the lateral pterygoid should be assessed by the resisted movement test. The occlusion should be assessed including any evidence of tooth wear or fractured restorations. The soft tissues should be assessed for tongue scalloping and frictional keratosis/linea alba of the buccal mucosa. Imaging Mostly adjunctive and usually not required. Radiographs (DPT) can be used to assess suspected bony pathology/fracture. Magnetic resonance imaging (MRI) is the optimal modality for comprehensive joint assessment, allowing detailed examination of the soft tissues (disk). Diagnosis and Classification Muscle disorders: Local myalgia Myofascial pain (most common symptom) Myofascial pain with referral Local Myalgia Dull localized muscular pain Pain intensity increases with function Pain on palpation ROM may be limited Generally self limiting Myofascial pain Deep diffuse persistent pain Local trigger points cause pain in the muscle and adjacent areas Pain beyond the boundary of the muscle being palpated Most common type of muscular TMD Myofascial pain with referral Pain is referred to areas that are not anatomically connected Trigger point palpation causes pain in distant areas Disc displacement: With reduction (reproducible click) - common Without reduction, with limited mouth opening Without reduction, without limited mouth opening Disc displacement with reduction Disc displacement with reduction The articular disc is displaced from its normal position but returns to the correct alignment during mandibular movements Produces clicking or popping sounds If clicking occurs on opening and on closing - reciprocal click Range of motion is usually normal Onset can be gradual or sudden Disc displacement without reduction Disc displacement without reduction occurs when the articular disc of the temporomandibular joint (TMJ) is displaced from its normal position and fails to reduce during mandibular movements. This condition often results in limited jaw movement, joint pain, and possible locking of the jaw. (a) Disc displaced anteriorly or medially or both when in ICP. On opening, the disc does not go back into place but blocks condylar movement. (No click!) (b) Maximum opening is often restricted, especially during the acute phase. The trapped disc may also cause mandibular deviation to the affected side. Disc displacement without reduction In the chronic phase, adaptive changes may occur and allow for improved jaw function Other disorders: Arthralgia (painful TMJ, no crepitus) Osteoarthritis (crepitus and pain) Osteoarthrosis (crepitus without pain) Crepitus, sometimes called crepitation, describes any grinding, creaking, cracking, grating, crunching, or popping that occurs when moving a joint. Acute vs Chronic Acute TMD often has an identifiable cause, such as a stressful life event or mechanical trauma (e.g. localized myofascial pain with limited opening following a difficult lower third molar extraction). It is often of short duration and self-limiting, and normally resolves following rest, a soft diet and simple analgesia. Chronic TMD relates to pain that normally exceeds 3–months duration. The pain may become biopsychosocially destructive, result in depression, or the development of chronic pain behaviors and disability. Thank you