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 c ...

posteriorly.

Structure

The mandibular notch is a concave groove at the top of the

. It is the gap between the coronoid process anteriorly and the

posteriorly.

Function

The mandibular notch allows for the passage of the

masseteric nerve The masseteric nerve is a nerve of the face. It is a branch of the mandibular nerve (V3). It crosses the mandibular notch to reach masseter muscle. It supplies the masseter muscle, and gives sensation to the temporomandibular joint. It may be us ...

(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 chewin ...

), the

masseteric artery The masseteric artery is small and passes laterally through the mandibular notch to the deep surface of the masseter muscle, which it supplies. It anastomoses with the masseteric branches of the external maxillary artery and with the transverse ...

, and the masseteric vein.

Clinical significance

The mandibular notch may be palpated to locate the

parotid duct The parotid duct, or Stensen duct, is a salivary duct. It is the route that saliva takes from the major salivary gland, the parotid gland, into the mouth. Structure The parotid duct is formed when several interlobular ducts, the largest ducts insi ...

, the

facial artery The facial artery (external maxillary artery in older texts) is a branch of the external carotid artery that supplies structures of the superficial face. Structure The facial artery arises in the carotid triangle from the external carotid arte ...

, the

facial vein The facial vein (or anterior facial vein) is a relatively large vein in the human face. It commences at the side of the root of the nose and is a direct continuation of the angular vein where it also receives a small nasal branch. It lies behind t ...

, and the

medial pterygoid muscle The medial pterygoid muscle (or internal pterygoid muscle), is a thick, quadrilateral muscle of the face. It is supplied by the mandibular branch of the trigeminal nerve (V). It is important in mastication (chewing). Structure The medial ptery ...

Other animals

The mandibular notch can be found in other mammals, such as

dogs The dog (''Canis familiaris'' or ''Canis lupus familiaris'') is a domesticated descendant of the wolf. Also called the domestic dog, it is derived from the extinct Pleistocene wolf, and the modern wolf is the dog's nearest living relative. Do ...

and

cats The cat (''Felis catus'') is a domestic species of small carnivorous mammal. It is the only domesticated species in the family Felidae and is commonly referred to as the domestic cat or house cat to distinguish it from the wild members of t ...

. 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 The Hominidae (), whose members are known as the great apes or hominids (), are a taxonomic family of primates that includes eight extant species in four genera: '' Pongo'' (the Bornean, Sumatran and Tapanuli orangutan); ''Gorilla'' (the ea ...

, such as

neanderthals Neanderthals (, also ''Homo neanderthalensis'' and erroneously ''Homo sapiens neanderthalensis''), also written as Neandertals, are an Extinction, extinct species or subspecies of archaic humans who lived in Eurasia until about 40,000 years ag ...

, 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
{{Authority control Bones of the head and neck