ATM y Músculos de la Masticación - Anatomía

Summary

In this video, Javier A. Maizares explains the structure and function of the temporomandibular joint (TMJ) and the muscles responsible for mastication. He covers the anatomy of the TMJ, including its synovial nature, ligaments, and relationships with surrounding structures. Javier also delves into the muscles involved in chewing, focusing on both superficial and deep muscles like the temporal, masseter, and pterygoid muscles, describing their functions and insertions. The video offers a comprehensive overview of how these elements work together during mastication, providing a detailed understanding for viewers.

Takeaways

• 😀 The temporomandibular joint (TMJ) is a synovial hinge joint formed by the condylar process of the mandible and the temporal bone, both covered with cartilage.
• 😀 The articular capsule of the TMJ attaches superiorly to the temporal bone and laterally to the zygomatic arch, reinforced by ligaments.
• 😀 The most developed ligament around the TMJ is the lateral ligament, which plays a key role in stabilizing the joint.
• 😀 The sphenomandibular ligament connects the spine of the sphenoid bone to the mandible and interacts with important structures like the auriculotemporal nerve and maxillary vessels.
• 😀 Another important ligament is the stylomandibular ligament, connecting the styloid process to the posterior edge of the mandible.
• 😀 The TMJ cavity is divided into two compartments by a dense fibrocartilage disc: the infradiscal and supradiscal compartments.
• 😀 During mouth opening, the initial movement is a rotational motion of the condylar head relative to the disc, followed by a translational movement as the jaw opens further.
• 😀 Closing the mouth follows the reverse process, with the condylar head returning to its original position relative to the disc.
• 😀 The TMJ is located near important structures, including the parotid gland, the ear (middle and external), and crucial nerves and blood vessels such as the auriculotemporal nerve and maxillary artery.
• 😀 The primary muscles involved in chewing are the masseter, temporalis, and pterygoid muscles, all innervated by the mandibular branch of the trigeminal nerve.

Q & A

What is the temporomandibular joint (ATM) and what does it connect?

The temporomandibular joint (ATM) is a synovial joint formed by the condylar process of the mandible and the temporal bone, particularly the mandibular fossa. It allows for the movement of the jaw.

What is the role of the cartilage in the ATM?

Both the mandibular condyle and the temporal bone's fossa are covered with cartilage, which facilitates smooth movement in the joint.

How is the articular capsule of the ATM reinforced?

The articular capsule is reinforced by ligaments, with the most developed being the lateral ligament. These ligaments help stabilize the joint.

What is the significance of the lateral ligament in the ATM?

The lateral ligament is crucial for the stabilization of the ATM and helps maintain the joint's structural integrity during movement.

How does the stylomandibular ligament function in the ATM?

The stylomandibular ligament connects the styloid process of the temporal bone to the posterior edge of the mandible's ramus. It plays a role in limiting excessive jaw movement.

What happens during jaw opening at the ATM?

During jaw opening, the first movement is the rotation of the condylar head relative to the disc, followed by a translation of the condyle and disc together as the jaw opens wider.

What are the compartments formed by the articular disc in the ATM?

The articular disc divides the joint cavity into two compartments: the infradiscal and supradiscal compartments, each playing a role in jaw movement.

How does the position of the temporomandibular joint relate to surrounding structures?

The ATM is located laterally under the parotid gland, posteriorly adjacent to the middle and external ear through the tympanic bone, and medially it is near several important nerves and blood vessels.

What muscles are involved in the process of mastication?

The primary muscles involved in mastication are the temporalis, masseter, and other muscles of mastication. These muscles work together to move the jaw during chewing.

How are the muscles of mastication categorized?

The muscles of mastication are categorized into superficial muscles (temporalis and masseter) and deep muscles (medial pterygoid and lateral pterygoid). Each muscle plays a specific role in the movement of the jaw.