The mandibular notch, also known as the sigmoid notch, is a groove in the
ramus of the mandible
In anatomy, the mandible, lower jaw or jawbone is the largest, strongest and lowest bone in the human facial skeleton. It forms the lower jaw and holds the lower teeth in place. The mandible sits beneath the maxilla. It is the only movable bone ...
. It is the gap between the
coronoid process anteriorly and the
condyloid process
The condyloid process or condylar process is the process on the human and other mammalian species' mandibles that ends in a condyle, the mandibular condyle. It is thicker than the coronoid process of the mandible and consists of two portions: the ...
posteriorly.
Structure
The mandibular notch is a concave groove at the top of the
ramus of the mandible
In anatomy, the mandible, lower jaw or jawbone is the largest, strongest and lowest bone in the human facial skeleton. It forms the lower jaw and holds the lower teeth in place. The mandible sits beneath the maxilla. It is the only movable bone ...
. It is the gap between the
coronoid process anteriorly and the
condyloid process
The condyloid process or condylar process is the process on the human and other mammalian species' mandibles that ends in a condyle, the mandibular condyle. It is thicker than the coronoid process of the mandible and consists of two portions: the ...
posteriorly.
Function
The mandibular notch allows for the passage of the
masseteric nerve (a branch of the
mandibular nerve (V3) division of the
trigeminal nerve
In neuroanatomy, the trigeminal nerve ( lit. ''triplet'' nerve), also known as the fifth cranial nerve, cranial nerve V, or simply CN V, is a cranial nerve responsible for sensation in the face and motor functions such as biting and chew ...
), the
masseteric artery, and the
masseteric vein.
Clinical significance
The mandibular notch may be palpated to locate the
parotid duct,
the
facial artery,
the
facial vein,
and the
medial pterygoid muscle.
Other animals
The mandibular notch can be found in other mammals, such as
dogs and
cats.
There can be significant variation in its shape even within the same species. Archaeological evidence shows that the mandibular notch is different in other
hominidae, such as
neanderthals, and may be
asymmetrical
Asymmetry is the absence of, or a violation of, symmetry (the property of an object being invariant to a transformation, such as reflection). Symmetry is an important property of both physical and abstract systems and it may be displayed in pre ...
.
Additional images
References
External links
*
Diagram at unc.edu
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Bones of the head and neck