Upper jaw

Introduction

The human jaw consists of two parts, which differ clearly from each other in size and shape. The lower jaw (lat. Mandibula) is formed by a very large proportion of bone and is freely connected to the skull via the mandibular joint. The upper jaw (lat. Maxilla) on the other hand is formed by a pair of bones and is firmly connected to the skull.

Structure

The body of the upper jaw can be divided into four different areas. At the front edge of the upper body is the so-called facial surface (lat. Facies anterior), at the rear edge of which is the lower temporal surface (lat.

Facies infratemporalis). The lower border of the orbit is formed by the orbital surface of the upper jaw (lat. Facies orbitalis).

The nasal surface (lat. Facies nasalis) represents the lateral part of the nasal cavity boundary. The surface of the upper jaw is not completely flat and smooth, and various extensions, depressions, and points of emergence can be seen at its edges.

As a connecting structure, the frontal process (lat. Processus frontalis) lies between the nasal bone, lacrimal bone and frontal bone. The triangular zygomatic process (lat.

Processus zygomaticus) is located at the lower edge of the orbital surface. Probably the most important functional task is performed by the arch-shaped alveolar process (lat. Processus alveolaris), because it carries the teeth that play an essential role in the chewing process. In addition, the upper jaw has a horizontal, plate-like structure, the palatal process (lat. Processus palatinus), which lies between the alveolar process and the nose and forms the hard palate.

Supply

For the nervous supply of the upper jaw, a main branch, the maxillary nerve, splits off from the fifth cranial nerve (trigeminal nerve). This nerve cord in turn gives off a smaller nerve, the nervus infraorbitalis, which runs through the upper jaw and supplies both the bone and the teeth. It emerges from the bony skull through a hole at the lower edge of the orbit (infraorbital foramen).

The blood supply to the upper jaw is through the maxillary artery (lat. Arteria maxillaris). This artery is a direct continuation of the outer part of the carotid artery (lat.

Arteria carotis externa). It runs for a long distance behind the neck of the lower jaw bone and then, protected by the parotid gland, moves into the so-called wing palate pit (lat. Fossa pterygopalatina). From there it runs between the two heads of an important masticatory muscle (Musculus pterygoideus lateralis) to its actual supply area.