Diseases affecting Temporomandibular Joint (1) 口腔病理學 Diseases affecting Temporomandibular Joint (1) 顳 顎 關 節 疾 病 (1) 陳玉昆教授: 高雄醫學大學 口腔病理科 07-3121101~2755 yukkwa@kmu.edu.tw

學 習 目 標 Understanding: 1. Vocabulary 2. Anatomy of temporomandibular joint 3. Normal joint function 4. Function of muscles of mastication

參考資料 References: Oral Pathology for the Dental Hygienist. Olga AC Ibsen, Joan Anderson Phelan, 4th edition, 2004, Chapter 10, p. 356-364 Eric Whaites: Essentials of dental radiography & radiology 3rd edition, Chapter 29, p. 371-388 Peggy Woodward MRI for technologists McGraw-Hill, Chapter 1 pp. 1-12 購網路資源：super_toolcool

Temporomandibular Joint Vocabulary Arthrocentesis(關節穿刺術): Surgical puncture of a joint for withdrawal of fluid. Arthrography(關節造影術): Radiography of a joint after infection of opaque contrast material. Arthroscopy(關節鏡): Method for evaluating & manipulating a joint via the insertion of a camera & instruments. Ref. 1

Temporomandibular Joint Vocabulary Articulation: Joint. Auscultation(聽診): Listening to sounds within the body using a stethoscope(聽筒). Crepitus(捻發音): Dry, cracking sound. Iatrogenic(醫源性): Induced inadvertently by a medical or dental care provider or by medical treatment or a diagnostic procedure. Ref. 1

Temporomandibular Joint Vocabulary Magnetic resonance imaging (MRI): Noninvasive diagnostic technique that uses radio waves to produce computerized images of internal body tissues. Dr. Raymond Damadian built 1st whole body MRI machine - 1977 Dr Raymond Damadian & his associates, Drs Larry Minkoff & Michael Goldssmith, completed the world's 1st whole body MRI scanner. Named Indomitable to capture the spirit of its 7-year construction (now located at Smithsonian Ins, Washington, DC) The first whole body transaxial image took 4 h 45 min to produce. Made on July 3, 1977, it shows the thoracic spine of Larry Minkoff Indomitable Indomitable: 百折不撓 Ref. 3

Temporomandibular Joint Vocabulary Palpation: Physical examination using pressure of hand or fingers. Sign: Objective evidence of disease that can be observed by a health care provider rather than by patient. Symptom: Subjective evidence of disease or a physical disorder that is observed by patient. Trismus(牙關緊閉): Spasm of muscles of mastication. Refs. 1, 4

Anatomy of the Temporomandibular Joint Temporomandibular joint is articulation between condyle of mandible & glenoid fossa of temporal bone. Ref. 1

Anatomy of the Temporomandibular Joint Temporomandibular joint is a highly specialized joint that differs from other joints because of fibrocartilage that covers bony articulating surfaces, its ginglymoarthrodial (rotational & translational) movement. Ref. 1

Anatomy of the Temporomandibular Joint Temporomandibular joint depends on contralateral joint. An articular disk is interposed in the space between temporal bone & mandible. The disk divides the space into an upper (superior joint space) & a lower compartment (inferior joint space). Ref. 1

Anatomy of the Temporomandibular Joint Translational movements occur in upper compartment, whereas lower compartment functions primarily as hinge or rotational component. Ref. 1

Anatomy of the Temporomandibular Joint Superior & inferior spaces contain synovial fluid, which is produced by synovial membrane that lines the joint. Synovial fluid provides nourishment & lubrication of avascular structures. Ref. 1

Anatomy of the Temporomandibular Joint Articular disk is attached to lateral & medial aspects of condyle, to superior belly of lateral pterygoid muscle, & to joint capsule. Ref. 1

Anatomy of the Temporomandibular Joint Disk & bony surfaces are avascular (without blood vessels). Joint is further surrounded & protected by fibrous connective tissue joint capsule. Ref. 1

Anatomy of the Temporomandibular Joint Basic components of TMJ include: Mandibular component: head condyle Disc Temporal component: glenoid fossa & articular eminence Capsule surrounding the joint Condyle head Disc/meniscus Glenoid fossa Lateral pterygoid attachment Upper joint space Lower joint space Ext auditory meatus Ref. 2

Anatomy of the Temporomandibular Joint Lateral Anterior Base Ref. 2

Function of muscles of mastication Understanding location & action of muscles of mastication is important in evaluation of disorders affecting temporomandibular joint. Ref. 1

Function of muscles of mastication Palpation of muscles of mastication during a clinical evaluation is used to determine whether muscle spasm or dysfunctional muscle activity is occurring. Ref. 1

Function of muscles of mastication Muscles of mastication include masseter, temporalis, medial pterygoid, lateral pterygoid, anterior digastric, & mylohyoid (suprahyoids). Ref. 1

Function of muscles of mastication Masseter, medial pterygoid, & temporalis, are elevator muscles that, when activated, close the mandible. Ref. 1

Function of muscles of mastication Opening, or depressor, function is accomplished mainly by lateral pterygoid muscle with some help from anterior digastric muscle. Ref. 1

Function of muscles of mastication Suprior belly of pterygoid muscle seats articular disk on eminence of articulating surface. Inferior belly is attached to mandibular condyle & functions during mouth opening. Ref. 1

Summaries Knowing: Vocabulary related to TMJ Anatomy related to TMJ (glenoid fossa, disk, condyle, capsule, superior belly of lateral pterygoid muscle) 3. Function of muscles of mastication