Anatomy-Lexicon

upper jaw

introduction

The human jaw consists of two parts that differ significantly in size and shape.

The lower jaw (lat. Mandible) is formed from a very large part of the bone and is freely connected to the skull via the temporomandibular joint.
The upper jaw (lat. Maxilla), on the other hand, is made up of a pair of bones and is firmly connected to the skull.

Figure upper jaw

Figure skull from the front and from the left (upper jaw blue)

Upper jaw -
Maxilla
Zygomatic bone -
Os zygomaticum
Nasal bone -
Os nasal
Tear bone -
Lacrimal bone
Frontal bone -
Frontal bone
Lower jaw -
Mandible
Eye socket -
Orbit
Nasal cavity -
Cavitas nasi
Upper jaw, alveolar process -
Alveolar process
Maxillary artery -
Maxillary artery
Under eye cavity hole -
Infraorbital foramen
Ploughshare - Vomer

You can find an overview of all Dr-Gumpert images at: medical illustrations

construction

The body of the upper jaw can be divided into four different areas. At the front edge of the Maxillary body is the so-called face area (lat. Anterior facies), at the rear edge of which the Under sleeping area (lat. Facies infratemporalis) connects. The lower boundary of the eye socket is defined by the eye socket surface (lat. Orbital facies) of the upper jaw. The Nasal surface (lat. Facies nasalis) represents the lateral part of the nasal cavity limitation.

The surface of the upper jaw is not completely even and smooth; various can be seen on its edges Appendages, Indentations and Entry points discover.
The connection structure is the Frontal process (lat. Frontal process) between the nasal bone, lacrimal bone and frontal bone.
The triangular yoke process (lat. Zygomatic process) is located at the bottom of the eye socket surface. The arch-shaped alveolar process (lat. Alveolar process), because it carries the teeth, which play an essential role in the chewing process. In addition, the

Upper jaw has a horizontally lying plate-shaped structure, the Palatal process (lat. Palatine process), which lies between the alveolar process and the surface of the nose and forms the hard palate.

care

For the nervous supply of the upper jaw splits from the fifth Cranial nerve (Trigeminal nerve) a main branch, the Maxillary nerve (lat. Maxillary nerve) from. This nerve cord in turn gives a smaller one annoy, the Infraorbital nerve, which runs through the upper jaw and both the bone as well as the teeth provided.

It enters through a hole in the lower edge of the Eye socket (Infraorbital foramen) from the bony skull.
The blood supply to the upper jaw takes place through the Maxillary artery (lat. Maxillary artery).

These artery is a direct continuation of the outer part of the Carotid artery (lat. External carotid artery). It runs for a long distance behind the neck of Lower jaw bone and then pulls, protected by the Parotid gland, into the so-called wing palate pit (lat. Pterygopalatine fossa). From there it runs between the two heads of an important masticatory muscle (Lateral pterygoid muscle) to their actual coverage area.

Toothed ridge and tooth holding apparatus

The teeth are with the help of the so-called Teeth supporting apparatus relatively firm in the upper jaw anchored. In order to be able to fulfill the various protective functions, the tooth holding apparatus consists of different parts in both the upper and lower jaw.
Small but deep indentations within the Jawbone (lat. Alveoli) contain the root part of every tooth. In addition, the tooth holding apparatus consists of the superficial one Gums (lat. Gingiva propria), the Dental cement (Cementum) and the Root skin (Periodontium or Periodontium). If you take a closer look at the teeth holding apparatus, you can quickly see that the individual teeth are not absolutely firmly in place Jawbone are fixed. In view of the forces that act on the teeth during the chewing process, this would also be counterproductive.

In reality, every single tooth is surrounded by collagen fiber bundles, the so-called Sharpey fibers suspended in the alveolus. As a result, the tooth remains relatively mobile and the forces and pressure loads during the chewing process can be effectively distributed over a larger area. The load that acts on each individual tooth

decreases enormously as a result. In addition, the tension in these collagen fiber bundles during the chewing process prevents the Tooth roots Press too deep into the jawbone under the influence of pressure.

Emergence (embryology)

Historically, a distinction is made between two parts of the skull, the facial and the brain skull. While the brain skull is made up of the bones that form a protective shell around the brain, the facial skull defines the outline of the human face. The upper jaw, in turn, is part of this facial skull.
It comes into contact with various other bony structures and cavities and therefore fulfills a protective function in addition to its chewing function. The upper jaw, for example, forms the floor of the eye socket (lat. Orbit) and thus surrounds the lower part of the eyeball.
Furthermore, the upper jaw forms the lateral wall of the nasal cavity (lat. Cavum nasi) and a large part of the hard palate (lat. Pallatum durum). However, one should not imagine the upper jaw as a compact, dense bone, because it houses one of the largest cavities in the area of the skull, the so-called maxillary sinus (lat. Maxillary sinus).

During the development of an embryo, six so-called gill arches form, which in vertebrates develop from the intestine.
Each of these gill arches has its own gill arch artery, a gill arch vein, a gill arch nerve and various muscle and cartilage systems.
The upper jaw (lat. Maxilla) itself, like the lower jaw (lat. Mandible) from the first of these six gill arches.

The so-called mandibular arch is therefore essential for the formation of the masticatory organ. In addition, all masticatory muscles develop from the first gill arch, the outer part of the carotid artery (External carotid artery), the maxillary artery (Maxillary artery) and the fifth cranial nerve (Trigeminal nerve). Both the lower and the upper jaw are formed from the cartilage part of the first jaw arch.
In addition, the bony palate and two of the three auditory ossicles (hammer and anvil, the stapes arise from the second gill arch) arise from this gill arch.

Diseases of the upper jaw

The most common diseases of the Upper jaw belongs to the Maxillary fracture (lat. Fractura maxillae or Fractura ossis maxillaris), which is a Broken bone of the upper jaw.

The maxillary fracture usually shows typical courses (Fault lines) that correspond to the weak points of the bone architecture. In most cases, fractures of the upper jaw result from blunt force, typical causes include:

traffic accidents
physical Arguments
Falls and
Sports accidents

The fracture of the upper jaw accounts for a high proportion of facial fractures with a percentage of around 15%. Another typical disease in the area of the upper jaw is Maxillary sinus infection. The Maxillary sinus (lat. maxillary sinus) becomes the Sinuses counted and located within the bony upper jaw.
The inflammation of the maxillary sinus is in most cases caused by the harmful effects of bacteria and Viruses Induced change in the mucous membrane in the area of the paranasal sinuses. In medicine, a distinction is made between an acute and a chronic form of maxillary sinus inflammation.

The acute form of the maxillary sinus inflammation usually goes with high fever, a headache, Feeling of pressure in the Head area and severe discomfort. In the majority of cases, the nasal mucous membrane serves as the entry point for the pathogens; it is a typical droplet infection.
The chronic maxillary sinusitis usually emerges directly from an acute illness; this can happen if an acute inflammation does not heal or heals insufficiently. Just at Tooth removals Particular caution is required in the area of the lateral upper jaw.

Since the long roots of the Molars in many people reaching into the maxillary sinus, the dentist has to check whether there is an opening in the maxillary sinus after pulling a tooth. Such an opening must imperatively be closed and the patient with one antibiotic because the artificial junction between the oral and maxillary sinuses can otherwise serve as a gateway for pathogens and provoke an maxillary sinus inflammation.