The Mandible
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Let's take a unique bone found in the head: the jaw bone. Its anatomical name is the mandible, derived from the Latin word for “jaw.”
We only have one mandible, making it an unpaired bone. Most bones in the body come in left and right pairs (called paired bones), and paired bones outnumber unpaired bones by roughly five to one.
The mandible has three distinct sections: a horizontal base and two vertical “arms.” When viewed from the front, it resembles a capital “U.” From the side, it looks like a short capital “L.”
The top of each vertical arm (the top of the “L”) ends in a semi-spherical surface called a condyle. Each condyle—one left and one right—fits into a hollow in the skull located about 1 cm in front of the ear canal. Where two bones meet, we have a joint. In this case, the joint is called the TMJ.
Functions of the Mandible:The mandible plays several important roles:
Movement and TMJ Function:Multiple movements occur at the TMJ, allowing us to bite, grind, and chew food. These include:
Four primary muscles act directly on the TMJ to open and close the mouth, two of which are located inside the mouth. Three additional “assistant” muscles also contribute and attach to a bone just above the Adam’s apple. If any of these muscles are tighter on one side than the other, they can contribute to uneven jaw movement and TMJ pain.
Our Treatment Goal:As massage therapists, our goal is to ensure that the muscles affecting the TMJ are symmetrically soft, loose, and relaxed, helping to support smooth, pain-free jaw movement.
We only have one mandible, making it an unpaired bone. Most bones in the body come in left and right pairs (called paired bones), and paired bones outnumber unpaired bones by roughly five to one.
The mandible has three distinct sections: a horizontal base and two vertical “arms.” When viewed from the front, it resembles a capital “U.” From the side, it looks like a short capital “L.”
The top of each vertical arm (the top of the “L”) ends in a semi-spherical surface called a condyle. Each condyle—one left and one right—fits into a hollow in the skull located about 1 cm in front of the ear canal. Where two bones meet, we have a joint. In this case, the joint is called the TMJ.
- T = Temporo (referring to the temporal bone of the skull)
- M = Mandibular (referring to the mandible)
- J = Joint
Functions of the Mandible:The mandible plays several important roles:
- It forms the lower half of the mouth (no mandible = no mouth!)
- It houses the lower teeth
- It serves as the framework from which the oral diaphragm is suspended—a group of muscles that form the floor of the mouth, including the tongue
- It helps determine the shape of the lower face, including the jawline
Movement and TMJ Function:Multiple movements occur at the TMJ, allowing us to bite, grind, and chew food. These include:
- Opening and closing the mouth
- Side-to-side jaw movement
- Forward and backward jaw movement
Four primary muscles act directly on the TMJ to open and close the mouth, two of which are located inside the mouth. Three additional “assistant” muscles also contribute and attach to a bone just above the Adam’s apple. If any of these muscles are tighter on one side than the other, they can contribute to uneven jaw movement and TMJ pain.
Our Treatment Goal:As massage therapists, our goal is to ensure that the muscles affecting the TMJ are symmetrically soft, loose, and relaxed, helping to support smooth, pain-free jaw movement.