Lecture 8 Oral Musculature and TMJ Anatomy PDF

 Oral Musculature and Temporomandibular Joint Anatomy 1602305 Dental Occlusion and Temporomandibular Joint disorders 1/12/2024 Fall Semester 2024/2025 Assistant Professor...

 Oral Musculature and Temporomandibular Joint Anatomy 1602305 Dental Occlusion and Temporomandibular Joint disorders 1/12/2024 Fall Semester 2024/2025 Assistant Professor Week 8 Mostafa Mahmoud Youssef  “Nothing Is More Fundamental To Treating Patients Than Knowing The Anatomy.” Today our lecture covers the following Overview of the Masticatory System Skeletal Components of the Masticatory System Temporomandibular Joint (TMJ) Anatomy Muscles of Mastication  Overview of the Masticatory System Overview of the Masticatory System A comprehensive understanding of the masticatory system's anatomy is essential for clinical applications. Overview of the Masticatory System The masticatory system is responsible for chewing, speaking, and swallowing. It also plays a significant role in tasting and breathing. Overview of the Masticatory System It includes bones, joints, ligaments, teeth, & muscles, & regulated by a complex neurologic system. Skeletal Components of the Masticatory System Stationary part of masticatory system Temporal bone Temporal Bone Temporomandibular Joint (TMJ) Anatomy  Temporomandibular Joint (TMJ) Anatomy The area where the mandible articulates with the temporal bone of the cranium is called the temporomandibular joint (TMJ). The TMJ is certainly one of the most complex joints in the body.  Ginglymoarthrodial Joint Ginglymoid Joint Arthrodial Joint provides for provides for gliding hinging movement movements Compound Joint Allowing for complex movements and acting as a non-ossified bone. The articular disc is composed of dense fibrous connective tissue and is divided into three regions based on thickness. It adapts to the movements of the condyle and fossa, maintaining joint stability and function. The precise shape of the disc is determined by the morphology of the condyle and mandibular fossa. Trigeminal Nerve (CNV) Mandibular division (V3) ○ Auriculotemporal nerve – Sensory nerve with autonomic nerve contribution – Innervates medial, posterior, and lateral walls of Capsule, Also innervates lateral half of anterior wall of capsule. Masseteric nerve Afferent branches supply anterior region of joint (anteromedial TMJ capsule)  Motor or efferent branches innervate masseter muscle  Deep temporal nerve Posterior deep temporal nerve, along with masseteric nerve, innervates anterior region of joint Branches follow course of masseteric nerve Innervation to temporalis muscle External Carotid Artery  Superficial temporal artery ○ Supplies lateral and ventral articular regions External Carotid Artery  Maxillary artery  ○ Branches  – Deep temporal artery (anterior to condyle)  □ Supplies anterior articular region  – Tympanic artery (posterior to condyle)  □ Supplies medial articular region (with middle meningeal artery)  □ Sends branch to retrodiscal tissue  – Middle meningeal artery (medial to condyle)  □ Arises anterior and medial of joint  □ Supplies medial articular region (with tympanic artery)  □ Sends branch to retrodiscal tissue  – Inferior alveolar artery  □ Feeds marrow spaces of condyle  – Deep auricular Venous Drainage  Superficial temporal vein  Maxillary plexus  Pterygoid plexus (1) The Collateral Ligaments. (2) The Capsular Ligament. (3) The Temporomandibular Ligament. There Are Also Two Accessory Ligaments: (4) The Sphenomandibular (5) The Stylomandibular. (1) The Collateral Ligaments. (2) The Capsular Ligament. (3) The Temporomandibular Ligament. There Are Also Two Accessory Ligaments: (4) The Sphenomandibular. (5) The Stylomandibular. (1) The Collateral Ligaments. (2) The Capsular Ligament. (3) The Temporomandibular Ligament. There Are Also Two Accessory Ligaments: (4) The Sphenomandibular. (5) The Stylomandibular. (1) The Collateral Ligaments. (2) The Capsular Ligament. (3) The Temporomandibular Ligament. There Are Also Two Accessory Ligaments: (4) The Sphenomandibular. (5) The Stylomandibular. (1) The Collateral Ligaments. (2) The Capsular Ligament. (3) The Temporomandibular Ligament. There Are Also Two Accessory Ligaments: (4) The Sphenomandibular. (5) The Stylomandibular. (1) The Collateral Ligaments. (2) The Capsular Ligament. (3) The Temporomandibular Ligament. There Are Also Two Accessory Ligaments: (4) The Sphenomandibular. (5) The Stylomandibular. Muscles of Mastication (1) The Masseter (2) The Temporalis (3) The Medial Pterygoid (4) The Lateral Pterygoid (5) The Digastric Origin The zygomatic process of the maxilla and the anterior two thirds of the lower border of the zygomatic arch Insertion The angle and lower half of the lateral surface of the ramus of the mandible Function Elevates the mandible, contributes to protrusion Innervation Masseteric branch of the mandibular nerve of the trigeminal nerve Blood Supply Masseteric artery  Origin The zygomatic process of the maxilla and the anterior two thirds of the lower border of the zygomatic arch  Insertion The angle and lower half of the lateral surface of the ramus of the mandible  Function Elevates the mandible, contributes to protrusion  Innervation Masseteric branch of the mandibular nerve of the trigeminal nerve  Blood Supply Masseteric artery Origin The lateral aspect of the skull to the full extent of the superior temporal line. Insertion The anterior border of the coronoid process and the anterior border of the ramus of the mandible as far forward as the last molar tooth. Function Elevates the mandible, Contributes to retrusion. Innervation Deep temporal nerve from the mandibular branch of the trigeminal nerve. Blood Supply Anterior, posterior, and superficial temporal arteries  Origin The lateral aspect of the skull to the full extent of the superior temporal line.  Insertion The anterior border of the coronoid process and the anterior border of the ramus of the mandible as far forward as the last molar tooth.  Function Elevates the mandible, Contributes to retrusion.  Innervation Deep temporal nerve from the mandibular branch of the trigeminal nerve.  Blood Supply Anterior, posterior, and superficial temporal arteries Origin The medial surface of the lateral pterygoid plate and the grooved surface of the pyramidal process of the palatine bone. Insertion The inferior and posterior portion of the medial surface of the ramus and angle of the mandible, as high as the mandibular foramen. Function Elevates the mandible, Contributes to protrusion. Innervation Mandibular branch of the trigeminal nerve. Blood Supply Pterygoid branch of maxillary artery  Origin The medial surface of the lateral pterygoid plate and the grooved surface of the pyramidal process of the palatine bone.  Insertion The inferior and posterior portion of the medial surface of the ramus and angle of the mandible, as high as the mandibular foramen.  Function Elevates the mandible, Contributes to protrusion.  Innervation Mandibular branch of the trigeminal nerve.  Blood Supply Pterygoid branch of maxillary artery Origin The lateral surface of the lateral pterygoid plate. Insertion The neck of the mandibular condyle. Function Protrudes the mandible, contributes to lateral movements and mouth opening. Innervation Pterygoid branch of the trigeminal nerve. Blood Supply Pterygoid branch of the maxillary artery Origin The lower part of the lateral surface of the great wing of the sphenoid and from the infratemporal crest. Insertion The neck of the mandibular condyle and into the front margin of the articular disc. Function Stabilizes the condyle and disc during mandible loading (i.e., unilateral chewing). Innervation Mandibular branch of the trigeminal nerve. Blood Supply Pterygoid branch of maxillary artery Origin A depression on the inner side of the lower border of the mandible, close to the symphysis. Insertion A tendon which passes through a tendinous pulley attached to the hyoid bone. The anterior digastric attaches to the tendon of the posterior digastric muscle. Function Stabilizes the condyle and disc during mandible loading (i.e., unilateral chewing). Innervation Mandibular branch of the trigeminal nerve. Blood Supply The submental artery Origin The inferior surface of the skull, from the mastoid notch on the medial surface of the mastoid process of the temporal bone and a deep groove between the mastoid process and the styloid process. Insertion A tendon that passes through a tendinous pulley attached to the hyoid bone. The posterior digastric attaches to the tendon of the anterior digastric muscle. Function Depresses the mandible and elevates the hyoid bone. Innervation Digastric branch of facial nerve. Blood Supply Lingual artery and facial artery  “Nothing Is More Fundamental To Treating Patients Than Knowing The Anatomy.”