The frontal process of the maxilla is a strong plate, which projects upward, medialward, and backward from the

maxilla In vertebrates, the maxilla (: maxillae ) is the upper fixed (not fixed in Neopterygii) bone of the jaw formed from the fusion of two maxillary bones. In humans, the upper jaw includes the hard palate in the front of the mouth. The two maxil ...

, forming part of the lateral boundary of the

nose A nose is a sensory organ and respiratory structure in vertebrates. It consists of a nasal cavity inside the head, and an external nose on the face. The external nose houses the nostrils, or nares, a pair of tubes providing airflow through the ...

. Its ''lateral surface'' is smooth, continuous with the anterior surface of the body, and gives attachment to the quadratus labii superioris, the orbicularis oculi, and the medial palpebral ligament. Its ''medial surface'' forms part of the lateral wall of the

nasal cavity The nasal cavity is a large, air-filled space above and behind the nose in the middle of the face. The nasal septum divides the cavity into two cavities, also known as fossae. Each cavity is the continuation of one of the two nostrils. The nas ...

; at its upper part is a rough, uneven area, which articulates with the ethmoid, closing in the

anterior ethmoidal cells The ethmoid sinuses or ethmoid air cells of the ethmoid bone are one of the four paired paranasal sinuses. Unlike the other three pairs of paranasal sinuses which consist of one or two large cavities, the ethmoidal sinuses entail a number of smal ...

; below this is an oblique ridge, the ethmoidal crest, the posterior end of which articulates with the

middle nasal concha The medial surface of the labyrinth of ethmoid consists of a thin lamella, which descends from the under surface of the cribriform plate, and ends below in a free, convoluted margin, the middle nasal concha (middle nasal turbinate). It is rough, ...

, while the anterior part is termed the agger nasi; the crest forms the upper limit of the atrium of the middle meatus. The ''upper border'' articulates with the

frontal bone In the human skull, the frontal bone or sincipital bone is an unpaired bone which consists of two portions.'' Gray's Anatomy'' (1918) These are the vertically oriented squamous part, and the horizontally oriented orbital part, making up the bo ...

and the ''anterior'' with the nasal; the ''posterior border'' is thick, and hollowed into a groove, which is continuous below with the lacrimal groove on the nasal surface of the body: by the articulation of the medial margin of the groove with the anterior border of the lacrimal a corresponding groove on the lacrimal is brought into continuity, and together they form the lacrimal fossa for the lodgement of the

lacrimal sac The lacrimal sac or lachrymal sac is the upper dilated end of the nasolacrimal duct, and is lodged in a deep groove formed by the lacrimal bone and frontal process of the maxilla. It connects the lacrimal canaliculi, which drain tears from th ...

. The lateral margin of the groove is named the anterior lacrimal crest, and is continuous below with the orbital margin; at its junction with the orbital surface is a small tubercle, the lacrimal tubercle, which serves as a guide to the position of the lacrimal sac.

Additional images

File:Frontal process of maxilla - animation01.gif, Frontal process shown in red. Animation. File:Frontal process of maxilla - animation02.gif, Left and right frontal process of maxilla, and upper teeth. Animation. File:Gray167.png, Articulation of left palatine bone with maxilla. File:Gray190.png, The skull from the front. File:Gray194.png, Sagittal section of skull. File:Gray196.png, Roof, floor, and lateral wall of left nasal cavity. File:Slide8hhhh.JPG, Frontal process of maxilla File:Slide11hhhh.JPG, Frontal process of maxilla

External links

* - "Osteology of the Skull: The Maxilla" * {{Authority control Bones of the head and neck