Question

Unilateral action of medial pterygoid results in

Answer 1

Deviation of the mandible to the contralateral side.

Explanation

The medial pterygoid muscle plays a crucial role in mandibular movement. When it contracts unilaterally, it causes the mandible to move towards the opposite side. This action results in the deviation of the mandible to the contralateral side from the muscle that contracts.

This muscle's unilateral action is vital in various activities involving chewing and speaking. For instance, during mastication, if the left medial pterygoid contracts, it pulls the mandible to the right, aiding in grinding food on that side. This action is essential for efficient chewing and ensures that both sides of the jaw work in coordination.

However, any imbalance in the function or strength between the left and right medial pterygoid muscles can lead to issues such as jaw deviation during opening or closing, causing discomfort or difficulty in performing everyday activities like eating or speaking. It highlights the significance of balanced muscle function for proper jaw movement and function. Therefore, understanding the actions of the medial pterygoid muscle is crucial in diagnosing and treating various conditions related to jaw movement and alignment.

Answer 2

Unilateral action of the medial pterygoid results in lateral excursion of the mandible, which refers to the side-to-side movement necessary for effective chewing.

Step-by-step explanation:

The unilateral action of the medial pterygoid muscle results in lateral excursion of the mandible, which is a side-to-side movement toward the opposite side of the activated muscle. When the medial pterygoid muscle on one side contracts, it pulls the mandible toward the opposite side, allowing chewing movements necessary for breaking down food. This action complements the work of the masseter and temporalis muscles, which are primarily responsible for elevating and closing the jaw.