Maxillary aperture. Anatomy of the human jaw structure

The upper jaw is a paired bone that is located in the center of the front of the face and connects to the rest of its bones.

Performs a number of important functions: participates in the functioning of the masticatory apparatus, in the formation of cavities for the nose and mouth, and the partitions between them.

The anatomy of the human upper jaw has a complex structure. It consists of a body and 4 processes - alveolar, where the cells of the teeth are located, frontal (directed upward), palatine and zygomatic.

The upper jaw is much thinner, and it is also quite light due to the sinus (cavity), with a volume of approximately 4-6 cm3.

The body of the jaw consists of the anterior, infratemporal, nasal and orbital surfaces. The anterior one includes an opening where thin blood vessels and nerve processes pass.

Blood supply occurs through 4 alveolar openings in the infratemporal area.

The nasal surface forms turbinate, and the flat orbital contains the lacrimal notch.

The upper jaw is motionless due to fusion with the bones of the face, has almost no connection points for the masticatory muscles and is under the influence of pressure rather than traction.

Frontal process

(lat. processus frontalis)

The frontal process of the maxilla is directed upward and connects to the nasal part of the frontal bone. It has a medial and lateral zone. The medial region of the frontal process includes lacrimal ridge. The posterior part borders the lacrimal groove.

Palatine process

(lat. processus palatinus)

The palatine process of the maxilla is part of the system of hard tissues of the palate. It has a connection in the form of a median suture with the process of the opposite side, as well as with the plates of bones. The nasal ridge is formed along this suture. The palatine process has a smooth surface above and rough below.

Alveolar ridge

(lat. processus alveolaris)

The alveolar process of the upper jaw consists of an outer (buccal), inner (lingual) wall, as well as dental alveoli made of spongy substance where the teeth are placed. The complex structure of the alveolar process also includes bone partitions (interdental and interradicular).

Anterior surface of the body

(lat. fades anterior)

The anterior surface of the body borders the infraorbital margin. It has a hole with a diameter of 2-6 mm, under which there is a fang pit. There begins the muscle that is responsible for raising the corner of the mouth. The anterior surface of the body has a slightly curved shape.

Infraorbital foramen

(lat. foramen infraorbitale)

The infraorbital foramen is located on the anterior surface of the body approximately at the level of the 5th or 6th tooth. The thinnest blood vessels, as well as the processes of the trigeminal nerve, pass through it. The diameter of the infraorbital foramen is quite large (can reach 6 mm).

Zygomatic process

(lat. zygomaticus)

The zygomatic process of the maxilla starts from the upper outer corner of the body. It is directed laterally (relates to the side of the surface) and has a rough end. The zygomatic process of the frontal bone connects with the temporal process.

Posterior (infratemporal) surface of the body

(lat. facies infratemporalis)

The posterior surface of the body is separated from the anterior surface with the help of the zygomatic process and has an uneven, often convex shape. Here is the tubercle of the upper jaw, where the alveolar canals open. On the side of the tubercle of the posterior surface of the body there is also a large palatine groove.

Understanding the structure human body is very important in the treatment of various diseases. In particular, the anatomy of the jaw apparatus directly affects the actions of the dentist.

The structure of the skull is very complex. Each part has its own meaning and distinctive characteristics.

Due to the individual shape it changes appearance In humans, the jaws serve as the basis for the formation of sensory organs, thanks to them we have the opportunity to eat and talk.

General information

The jaws are one of the most complex structures of bones and joints in the body. Due to their structure, they can perform certain functions during human life and are able to withstand heavy loads.

The upper is the stationary part of the skull, which serves as the basis for creating the nasal cavity. The lower one has the ability to move, and is attached to the skull using the temporomandibular joint. It is interesting that until the child reaches one year of age, it consists of two separate halves and grows together in the process of growing up.

The jaw apparatus performs a number of important functions. Its lower part experiences a large load and is therefore subject to greater damage. At the same time, oral hygiene is better on it than on the top one. This happens due to poor visibility of the second.

Each person has his own unique differences in the structure of the jaw apparatus, which affect the appearance of the individual. With age, its structure changes, resulting in changes in appearance.

Functions

The complex structure of this part of the body affects not only its appearance, but also allows it to perform a number of functions, without which human existence would be difficult.

Main functions:

1. Biting, chewing food: thanks to the teeth attached to the jaw, we can take food and grind it into small pieces for further digestion. The jaw apparatus can withstand heavy loads, which allows chewing hard and tough foods.
2. Swallowing: help move food into the mouth and swallow it.
3. Spoken speech: the movable jaw part of the skull allows you to produce sounds and communicate with people around you. When damaged or incorrectly structured, diction becomes difficult.
4. Breathing: not directly involved in the breathing process, but with injuries it is much more difficult to inhale or exhale.
5. Fixation of teeth.
6. Formation of cavities for sensory organs.

All functions play an important role for normal life. When certain disturbances occur in their structure, a person experiences difficulties and needs help.

Structure of the upper jaw

It has two paired bones and is the largest part of the skull. Its structure is very different from the lower one. All the bones on the front side of the skull are connected to this part of the jaw apparatus.

It forms the main facial features and cavities for the sense organs:

• walls of the eye sockets;
• oral cavity, nose;
• temporal fossa;
• pterygoid fossa of the palate.

The upper part is relatively large in size, but at the same time light in weight. This is due to the presence of cavities in it. The structure consists of a body and processes.

The blood supply occurs thanks to maxillary artery and its ramifications. It diverges into vessels supplying the teeth and processes of the alveoli, palate and cheeks. Innervation is provided by the trigeminal nerve, namely its maxillary branch.

Structure of the skull. Video:

The main element of the jaws is the body. It contains an air-bearing sinus called the maxillary sinus. It is covered with mucous membrane and is the largest sinus around the nose, shaped like a pyramid.

The sinus has five walls: superior, medial, anterolateral, posterolateral, and inferior. It forms several pockets in which pus can accumulate. This is where the disease sinusitis gets its name.

Four bony processes extend from the body.

They are all directed in a certain direction and carry a certain meaning:

The structure of the body is divided into the following surfaces:

• front or front;
• orbital;
• infratemporal;
• nasal

They all have a characteristic shape and perform specific functions.

The front has a concave shape. The alveolar process originates in its lower part. On top, an infraorbital margin is formed with an opening where the facial nerve endings and blood vessels approach. This is where anesthesia is administered for complex dental operations.

The structure of the right upper part, maxilla (view from the lateral side): 1 - frontal, processus frontalis; 2 - infraorbital margin; 3 - infraorbital foramen, foramen infraorbitale; 4 - nasal notch, incisura nasalis; 5 - canine fossa, fossa canina; 6 - anterior nasal spine, spina nasalis anterior; 7 - alveolar elevations, juga alveolaria; 8 - incisors; 9 - fang; 10 - premolars; 11 - molars; 12 - alveolar process, processus alveolaria; 13 - zygomatic process, processus zygomaticus; 14 - alveolar openings, foramina alveolaria; 15 - tubercle of the maxillary bone, tuber maxillare; 16 - infraorbital groove; 17 - orbital surface of the body of the maxillary bone, facies orbitalis; 18 - tear trough, sulcus lacrimalis

Just below the opening under the eye socket is the canine or canine fossa, where the muscle responsible for raising the corners of the mouth begins. The anterior and orbital surfaces are separated by the infraorbital region. The nasal notch serves as a septum and contributes to the formation of the nasal cavity.

The orbital surface is very smooth and triangular in shape. With its help, the lower wall of the orbit is formed. Anteriorly forms the infraorbital margin. On the outer side it flows into the zygomatic process, and in the middle into the lacrimal crest. The posterior margin provides the basis for the infraorbital groove, which then flows into the corresponding canal and opening in the canine fossa. Participates in the formation of the orbital fissure.

The infratemporal lobe forms elevations, which are also called tuberosities. On the tubercles there are openings where there are channels with branches of nerves and blood vessels to the large molars. It is in this place that anesthesia is given when removing molars.

In the medial direction from the openings there is a pterygopalatine groove, which forms the anterior wall of the canal of the same name. The infratemporal and anterior surfaces are separated using the zygomatic ridge.

The structure of the right upper part, maxilla (view from the medial side): 1 - frontal process of the maxillary bone; 2 - ethmoid ridge, crista ethmoidalis; 3 - lacrimal groove, sulcus lacrimalis; 4 - maxillary sinus, sinus maxillaris; 5 - greater palatine sulcus; 6 - nasal ridge; 7 - palatine grooves; 8 - alveolar; 9 - molars; 10 - palatine, processus palatinus; 11 - premolars; 12 - fang; 13 - incisors; 14 - incisive canal; 15 - anterior nasal spine, spina nasalis anterior; 16 - nasal surface (facies nasalis) of the maxillary bone; 17 - shell crest, crista conchalis

The nasal surface participates in the formation of the lateral wall of the nasal cavity. At the top, in the posterior corner, there is an opening into the maxillary sinus and a lacrimal groove. At the bottom of the front side there is a conchal ridge, where the inferior concha of the nose is fixed.

The bottom of the plane smoothly flows into the process of the nose, which connects the lower passage of the nose and the orbit. Behind the maxillary sinus is the palatine sulcus, which forms the large palatine canal. This is where pus accumulates and the inflammatory process of sinusitis begins.

Teeth

There are from 14 to 16 teeth on each jaw. They all have their own characteristic structure and perform certain functions:

1. The central ones have a slightly flattened and elongated crown shape. On the side of the cutting edge there are three tubercles. The incisors are held in place by one long root. The main function is to bite food.
2. The lateral incisors have a similar structure to the central ones, but are smaller in size. They also participate in the biting process.
3. The canines have a convex cone-shaped crown. The cutting edge is pointed and has one tubercle. Function: biting.
4. include two teeth on the left and right side between the canines and first molars. The first pair has a similar structure with canines, the second pair with molars. They can have from one to three roots. Functions include biting and grinding food.
5. The first ones have a rectangular crown shape with a wide chewing surface. They are attached using three roots - two buccal, one palatal. Main function is grinding food.
6. The second molars have a similar structure to the first, but are smaller. The differences also lie in the location of the fissures.
7. Still others are called wisdom teeth. In some cases, they may not erupt at all. They may have curved roots of varying quantities.

Age-related developmental features

The rudiments are laid at the stage of embryo development. During the process of intrauterine growth and development, bones gradually grow together and teeth form.

In newborn children, the upper jaw is still poorly developed. It consists mainly of a process. Further development occurs unevenly. The main formation occurs during and ends at approximately 16 years of age, when the main bite is formed.

With age, bones increase in size. Both halves are fused with a strong seam, the planes take on their basic shape. The hard palate becomes dome-shaped.

With the onset of aging, changes occur in the jaw apparatus. With the loss of teeth, the processes atrophy and descend, solid sky becomes flat.

Anatomy of the lower

The structure of the lower part of the skull is significantly different from the upper. This part is solid and has a horseshoe shape. Only it in the structure of the skull has the ability to move.

Structure of the skull. Video:

The body structure is divided into the base or lower part and the alveolar part, which contains the teeth.

The body has a curved shape, the outside is convex, and the inside is concave. The connection of the right and left parts of the body occurs at an angle, which determines distinctive features person. This connection is called the basal arch.

The height of the body is not the same throughout the plane. The highest place is in the canine area, the lowest is in the third molar area. The thickness is also uneven. The thickest part is in the area of ​​the molars, and the thinnest is near the premolars.

The number and location of dental roots is determined cross sections. For the front teeth, the sections are triangular shape with the top down, and for radicals, on the contrary, with the top up.

The important parts are two branches (shoots). They diverge upward at an obtuse angle. There are two edges of each branch - front and back, as well as two surfaces - internal and external.

The surfaces of each branch flow into two special processes - the coronoid and condylar. The first is necessary for fixing the temporal muscle, and the second serves as the base of the joint connecting the cheekbones.

The outer side of the branches is curved, in the middle it forms a buccal ridge, where the muscles of the cheeks are attached. This surface also creates a jaw angle where it is attached masseter muscle. The inner surface flows smoothly into the body.

Inside the branches, in the area of ​​the jaw angle, the median pterygoid muscle is attached and there is an opening that is covered by a bony protrusion called the uvula. A little above this hole the jaw ligaments are attached.

The spaces between the branches are different for all people and determine the main facial features.

1 - condylar, 2 - coronoid process, 3 - foramen, 4 - uvula of the lower part, 5 - buccal ridge, 6 - retromolar fossa, 7 - incisors, 8 - alveolar eminence, 9 - mental eminence, 10 - canine, 11 - premolars , 12 - roots of teeth, 13 - canal, 14 - angle, 15 - masticatory tuberosity, 16 - jaw notch, 17 - tongue (external view), 18 - molars.

The structure of the body also includes internal and outer surface. In the center of the outer one is the chin protuberance. He serves distinctive feature today's image of a person and serves as the basis for the formation of the chin. On both sides of the protrusion there are mental tubercles with holes. Nerve fibers and blood vessels run along them.

On the inner surface of the jaw body there is a bony spine called the spine of the chin. This is where the hypoglossal and lingual muscles emerge. Below the spine is the digastric fossa, where the muscle of the same name originates. On the back side of the surface is the mylohyoid line, where the bases of the muscles and recesses for the salivary glands are located.

Teeth position

A person has the same number of teeth below as on top. Their name and functions are the same.

The central incisor is the smallest of all teeth. The lateral incisor and canines are slightly larger, but still smaller than their upper counterparts.

The lower molars and premolars differ from the upper ones by the presence of cusps and roots.

The teeth are located in their individual alveoli, which provide reliable fastening and allow them to withstand heavy loads during the process of chewing food.

In children

The lower jaw in childhood is approximately the same as in adults, but differs in some features. In newborns, it consists of two halves, between which connective tissue is located. Complete fusion of bones occurs only by 1-2 years.

In children, this part of the skull is represented mainly by a process; the jaw body occupies less than half of the total volume. Thanks to this, the body quickly adapts to teething.

The alveolar processes increase only until the age of 3 years. Then only their lengthening occurs. As a person grows, the mandibular body can increase almost 4 times.

The branches are underdeveloped. As the child grows, they expand and change their angle of inclination. The floor of the mouth is shallow, with slightly pronounced folds. The channel is almost straight in shape and runs close to the edge.

The bite is formed in several stages:

1. Temporary or milk bite.
2. Changeable bite – expansion of the distances between teeth before changing them.
3. The permanent one is formed after changing teeth.

Other structural features

A large number of muscles are attached to the jaw. Thanks to them, a person can bite and chew food, talk and breathe through the mouth.

Blood supply is carried out using the maxillary artery and its branches. Blood outflow occurs through the posterior maxillary and facial veins. Lymph nodes are located here - submandibular and submental. Many tumor processes can originate in them.

The trigeminal nerve is responsible for innervation, namely its second and third branches.

1 - mastoid; 2 - posterior belly of the digastric muscle (cut off); 3 - subulate; 4 - pharyngeal-basilar fascia; 5 - superior pharyngeal constrictor; 6 - stylohyoid ligament; 7 - styloglossus muscle; 8 - stylopharyngeal muscle; 9 - stylohyoid muscle; 10 - hypoglossus muscle; 11 - hyoid bone; 12 - intermediate tendon and tendon loop of the digastric muscle; 13 - geniohyoid muscle; 14 - mylohyoid muscle; 15 - genioglossus muscle; 16 - lower longitudinal muscle of the tongue; 17 - palatoglossus muscle; 18 - velopharyngeal muscle

Developmental pathologies

During the process of intrauterine development of the embryo, the foundations of the jaw apparatus are laid; with various disorders, certain deviations from the norm may occur. But even during childbirth and subsequent growing up, there is a risk of developing pathologies as a result of injuries, inflammatory processes and other external influences.

Each anomaly affects a person’s appearance and functional abilities jaws.

Pathologies:

1. arise due to failures embryonic development. The most common clefts in the palate, upper and lower lips. Therapy consists of surgical intervention and suturing clefts.
2. – insufficient formation of the lower part. It can be symmetrical or asymmetrical. In this case, the lower part of the face is reduced and can be shifted in the direction of the lesion or backward. Occurs after illness.
3. or progeny - excessive formation of the lower part. Bottom part The face is massive and protrudes significantly forward. It is mainly a hereditary predisposition.
bracket systems. Therapy can be carried out after the formation of the facial skeleton is completed, after approximately 17 years.

Possible treatment with plastic surgery. Such operations are performed to correct the shape of the bones or soft tissues of the face. Implants may be used.

The jaw apparatus is an important and complex organ human body. Its anatomy affects not only health, but also the aesthetic appearance of the face. He performs important functions in human nutrition and communication.

As a person grows, the jaws undergo certain changes. Developmental pathologies often occur that change a person’s appearance. Any disease requires the help of a doctor and certain treatment.

The two bony structures located near the mouth opening are the human jaw. This is one of the most complex areas of the body, because it is individual, and its structure determines facial features.

Functions

The shape of the jaws determines the oval of the face and visual attractiveness. But this is not the only function of the organ:

1. Chewing. The jaws contain teeth that are involved in the process of chewing and digestion. The bone is able to withstand high chewing loads.
2. Implementation swallowing movements.
3. Talk. Movable bones take part in articulation. If they are injured or incorrectly positioned, diction is impaired.
4. Breath. The organ’s participation in breathing is indirect, but if it is damaged, it is impossible to inhale or exhale.
5. Fixation sense organs.

The jaw is one of the most complex areas of the body.

The organ is designed for high load; its chewing force can reach 70 kilograms.

Structure of the lower jaw

The structure is formed by two fused branches. At birth they form a whole, but later separate. The bone is uneven; it has many roughnesses, depressions, tubercles necessary to ensure fixation of muscles and ligaments.

The strength of the lower bones is less than that of the upper ones. This is necessary so that they bear the brunt of the impact during injuries, since the upper ones protect the brain.

Bones lower jaw less strong than the upper bones.

The frontal region is the location of the mental foramen, through which the blood supply is carried out, and the tubercle for localizing the teeth. If you see a tooth in section, you will find that it is attached to the alveolar foramen; at the bottom there are 14-16 of them (in adults). Another component of the organ is the temporal part, connected to the joint, having ligaments and cartilage that provide movement.

Upper jaw

The upper structure is a paired bone with a large cavity - the maxillary sinus. The bottom of the sinus is located next to some teeth - the second and first molars, the second.

The structure of the tooth suggests the presence of roots, which require treatment in case of pulpitis. Proximity to maxillary sinus complicates the procedure: it happens that due to a doctor’s error, the bottom of the sinus is damaged.

The bone has processes:

• frontal (upward direction);
• palatal (facing the center);
• alveolar;
• zygomatic.

The structure of the jaw is the same in all people; the shape and size are individual parameters.

The alveolar process is the location of the teeth of the upper jaw. They are attached to the alveoli - small depressions. The largest recess is intended for the fang.

The organ has four surfaces:

• anterior with alveolar process;
• nasal;
• orbital, creating the base for the eye socket;
• infratemporal

, ) is located in the upper anterior part of the facial skull. Refers to the number air bones, since it contains a large cavity lined with mucous membrane, - maxillary sinus, sinus maxillaris.

The bone has a body and four processes.

Body of the maxilla corpus maxillae, has four surfaces: orbital, anterior, nasal and infratemporal.

rice. 94. Upper jaw, maxilla, right. (Anterior outer surface.) (Alveolar canals are opened.)

The following bone processes are distinguished: frontal, zygomatic, alveolar and palatine.

orbital surface, facies orbitalis, smooth, triangular in shape, slightly inclined anteriorly, outward and downward, forms the lower wall of the orbit, orbita.

Its medial edge connects in front with the lacrimal bone, forming the lacrimal-maxillary suture, behind the lacrimal bone - with the orbital plate of the ethmoid bone in the ethmoid-maxillary suture, and further posteriorly - with the orbital process of the palatine bone in the palatine-maxillary suture.

The anterior margin of the orbital surface is smooth and forms a free infraorbital margin, margo infraorbitalis, being the lower part of the orbital margin of the orbit, margo orbitalis, (see fig. , ). On the outside it is serrated and passes into the zygomatic process. Medially, the infraorbital margin forms an upward bend, sharpens and passes into the frontal process, along which the longitudinal anterior lacrimal crest stretches, crista lacrimalis anterior. At the place of transition into the frontal process, the inner edge of the orbital surface forms the lacrimal notch (incisura lacrimalis), which, together with the lacrimal hook, limits the lacrimal bone top hole nasolacrimal duct.

The posterior edge of the orbital surface together with the lower edge of the orbital surface of the greater wings running parallel to it sphenoid bone forms the lower orbital fissure, fissura orbitalis inferior. In the middle part of the lower wall of the fissure there is a groove - the infraorbital groove, sulcus infraorbitalis, which, moving anteriorly, becomes deeper and gradually passes into the infraorbital canal, canalis infraorbitalis, (in the groove and to the pala lie the infraorbital nerve, artery and veins). The canal describes an arch and opens on the anterior surface of the body of the upper jaw. In the lower wall of the canal there are many small openings of the dental tubules - the so-called alveolar foramina, foramina alveolaria, (see Fig.), nerves pass through them to the group of anterior teeth of the upper jaw.

infratemporal surface, facies infratemporalis, facing the infratemporal fossa, fossa infratemporalis, and pterygopalatine fossa, fossa pterygopalatina, uneven, often convex, forms a tubercle of the upper jaw, tuber maxillae. There are two or three small alveolar openings leading to the alveolar canals, canales alveolares, (see Fig.), through which the nerves pass to the back teeth of the upper jaw.

Front surface fades anterior, slightly curved. Below the infraorbital margin, a rather large infraorbital foramen opens on it, foramen infraorbitale, below which there is a small depression - the canine fossa, fossa canina, (the levator anguli oris muscle originates here, m. levator anguli oris).

Below, the anterior surface, without a noticeable border, passes into the anterior (buccal) surface of the alveolar process, processus alveolaris, on which there is a series of convexities - alveolar elevations, juga alveolaria.

Inwardly and anteriorly, towards the nose, the anterior surface of the body of the upper jaw passes into the sharp edge of the nasal notch, incisura nasalis. Inferiorly, the notch ends in the anterior nasal spine, spina nasalis anterior. The nasal notches of both maxillary bones limit the piriform aperture (apertura piriformis) leading into the nasal cavity.

nasal surface, facies nasalis, (see Fig.) the upper jaw is more complex. In its upper posterior corner there is an opening - the maxillary cleft, hiatus maxillaris, leading to the maxillary sinus. Posterior to the cleft, the rough nasal surface forms a suture with the perpendicular plate of the palatine bone. Here, a large palatine groove runs vertically along the nasal surface of the upper jaw, sulcus palatinus major. It forms one of the walls of the greater palatine canal, canalis palatinus major. Anterior to the maxillary cleft runs the lacrimal groove, sulcus lacrimalis, limited anteriorly by the posterior edge of the frontal process. Adjacent to the lacrimal groove is the lacrimal bone at the top and the lacrimal process of the inferior concha at the bottom. In this case, the tear trough closes into the nasolacrimal canal, canalis nasolacrimalis. Even more anteriorly on the nasal surface there is a horizontal protrusion - the conchal ridge, crista conchalis, to which the inferior turbinate is attached.

rice. 122. Skeleton of the nasal cavity and orbits; view from above. ( Bottom wall nasal cavity. Horizontal cut through the zygomatic processes of the upper jaws.)

From the upper edge of the nasal surface, at the place of its transition to the anterior one, the frontal process straightens upward, processus frontalis. It has medial (nasal) and lateral (facial) surfaces. The lateral surface of the anterior lacrimal ridge, crista lacrimalis anterior, divides into two sections - front and rear. The posterior portion passes downwards into the lacrimal groove, sulcus lacrimalis. Its border from the inside is the tear edge, margo lacrimalis, to which the lacrimal bone is adjacent, forming with it the lacrimal-maxillary suture, sutura lacrimo-maxillaris. The ethmoidal ridge runs along the medial surface from front to back. crista ethmoidalis. The upper edge of the frontal process is serrated and connects to the nasal part of the frontal bone, forming the frontomaxillary suture, sutura frontomaxillaris. The anterior edge of the frontal process is connected to the nasal bone in the nasomaxillary suture, sutura nasomaxillaris, (see fig.).

Zygomatic process, processus zygomaticus, extends from the outer-superior corner of the body. The rough end of the zygomatic process and the zygomatic bone, os zygomaticum, form the zygomaticomaxillary suture, sutura zygomaticomaxillaris.

rice. 125. Eye socket, orbita, and pterygopalatine fossa, fossa pterygopalatina; right view. (Medial wall of the right orbit. Vertical rapsil, outer wall of the maxillary sinus removed.)

palatine process, processus palatinus, (see Fig. , ), is a horizontally located bone plate that extends internally from the lower edge of the nasal surface of the body of the upper jaw and, together with the horizontal plate of the palatine bone, forms a bony septum between the nasal cavity and the oral cavity. Inner rough edges palatine processes both maxillary bones join to form the median palatine suture, sutura palatina mediana. To the right and left of the suture there is a longitudinal palatine ridge, torus palatinus.

In the median palatal suture, the palatine processes form a sharp marginal projection directed towards the nasal cavity - the so-called nasal ridge, crista nosalis, which is adjacent to the lower edge of the vomer and the cartilaginous septum of the nose. The posterior edge of the palatine process is in contact with the anterior edge of the horizontal part of the palatine bone, forming a transverse palatal suture with it, sutura palatina transversa. The upper surface of the palatine processes is smooth and slightly concave. The lower surface is rough, near its posterior end there are two palatine grooves, sulci palatini, which are separated from one another by small palatine spines, spinae palatinae, (vessels and nerves lie in the grooves). The right and left palatine processes at their anterior edge form an oval incisive fossa, fossa incisiva. At the bottom of the fossa there are incisive holes, foramina incisiva, (there are two of them), with which the incisive canal opens, canalis incisivus, also ending with incisive openings on the nasal surface of the palatine processes (see Fig.). The canal may be located on one of the processes; in this case, the incisive groove is located on the opposite process. The area of ​​the incisive fossa is sometimes separated from the palatine processes by the incisive suture, sutura incisiva), in such cases, the incisive bone is formed, os incisivum.

The alveolar process (processus alveolaris) (see Fig.,), the development of which is associated with the development of teeth, extends down from the lower edge of the body of the upper jaw and describes an arc, convexly directed forward and outward. The lower surface of this area is the alveolar arch, arcus alveolaris. There are holes on it - dental alveoli, alveoli dentales, in which the roots of the teeth are located - 8 on each side. The alveoli are separated from one another by interalveolar septa, septa interalveolaria. Some of the alveoli are in turn divided by interradicular septa, septa interradicularia, into smaller cells according to the number of tooth roots.

The anterior surface of the alveolar process, corresponding to the five anterior alveoli, has longitudinal alveolar elevations, juga alveolaria. The part of the alveolar process with the alveoli of the two anterior incisors represents a separate incisor bone in the embryo, os incisivum, which early merges with the alveolar process of the upper jaw. Both alveolar processes connect and form the intermaxillary suture, sutura intermaxillaris, (see fig.).

This article is aimed at conveying to the reader information about the general structure of the upper and lower jaws of humans, as well as Special attention will be devoted to the alveolar processes, an important component of our masticatory and communication apparatus.

Delving into the upper jaw (HF)

The maxillary part of the human cranial bones is paired. Its location is the central front part. It fuses with other facial bones, and also articulates with the frontal, ethmoid and sphenoid. The upper jaw is involved in the creation of the orbital walls, as well as the oral and nasal cavities, the infratemporal and pterygopalatine fossae.

In the structure of the upper jaw there are 4 multidirectional processes:

• frontal, going upward;
• alveolar, looking down;
• palatal, medially facing;
• zygomatic, laterally directed.

The weight of the human upper jaw is quite small, it does not seem so upon visual inspection, and this is due to the presence of cavities, for example the sinus (sinus maxillaris).

A number of surfaces are also distinguished in the structure of the upper jaw:

• front;
• infratemporal;
• nasal;
• orbital.

The anterior surface originates from the level of the infraorbital margin. Just below there is a hole along which nerve fibers and blood vessels run. Below the opening is the pterygopalatine fossa, in which the beginning of the muscle responsible for raising the oral corners is fixed.

The surfaces of the orbits are covered with lacrimal notches. On their areas remote from the anterior edge there are grooves, one on each, called infraorbital.

Most of the nasal surface is occupied by the maxillary cleft.

Alveolar component

The alveolar process of the maxilla is part of the maxillary body of the bone. It is united by an intermaxillary suture with the outgrowths of the jaw located on the opposite side. Without a visible feature from behind, it changes, turning into a tubercle facing the process of the palate of the upper part of the jaw. At the same time, he looks medially. Its shape is similar to an arc that is curved like a bone ridge, which has a forward-facing convexity.

The outer surface turns into the vestibule of the mouth. It is called vestibular. The inner surface faces the sky. It's called palatal. The alveolar process on its arch has 8 alveoli of different size and shape, intended for molars. The alveoli of the incisors and canines include two main walls, labial and lingual. There are also lingual and buccal walls. But they are located in the premolar and molar alveoli.

Functional purpose

The alveolar processes have interalveolar septa made of bone tissue. Alveoli, which are multi-rooted, contain septa that separate the roots of the teeth. Their size is similar to the shape and size of tooth roots. The first and second alveoli include incisal roots, which look like cones. The third, fourth and fifth alveoli are the location of the roots of the canines and premolars. The first premolar is often divided by a septum into two chambers: buccal and lingual. The last three alveoli contain the roots of the molars. They are separated by an interroot partition into 3 root compartments. Two of them address the vestibular surface, and one - the palatine surface.

The anatomy of the alveolar process of the upper jaw is designed in such a way that it is somewhat compressed on the sides. As a result, its size, like the size of any of these processes, is smaller in the anterior to posterior direction than in the bucco-palatal region. The lingual alveoli have a rounded shape. The variable number and shape of the dental roots of the third molar determine its different shape. Behind the 3rd molar there are plates, external and internal, which, converging, form a tubercle.

Features of the parameters of the upper jaw

The individual shapes of the upper jaw in people vary, as do the shapes of its alveolar processes. However, in the structure of the jaw, two extreme forms can be distinguished:

1. The first is characterized by narrowness and is itself tall.
2. The second is wide and low.

The shapes of the pits of the alveolar processes, accordingly, may also differ slightly depending on the type of jaw structure.

On this jaw there is a maxillary sinus, which is considered the largest of the paranasal sinuses. Its shape is usually determined by the shape of the maxillary body.

General data about the lower jaw (LM)

The bone of the lower jaw takes its development from two arches: the branchial and the first cartilaginous. The size of the lower jaw is significantly smaller than that of human predecessors, which is due to the appearance in humans oral speech. And big sizes the lower jaw would interfere to modern man when chewing food, due to its location when planting the head.

In the lower jaw there are such structural elements as:

• alveolar process - the outermost part of the jaw body in which the dental cells are located;
• mandibular body;
• chin hole;
• mandibular canal;
• mandibular angle;
• branches of the jaw;
• a number of articular and coronoid processes;
• opening of the lower jaw;
• head.

The resulting shoots

The bone in question has the alveolar process of the mandible. The alveolar composite contains eight dental sockets on both sides. These alveoli are separated by septa (septa interalveolaria), and their walls face the lips and cheeks. They are called vestibular. The walls face the tongue. On the surfaces of the alveolar bodies, a raised formation (juga alveolaria) can be clearly seen. In the place between the protrusion of the chin and the alveolar incisors there is a sub-incisal depression.

The depth and shape of the alveolar process can be varied, in accordance with the shape and structure of NP formation. The alveoli belonging to the canines are round in shape, and the deep alveoli belong to the second premolar. Each molar has bony septa between the root attachment sites. The alveolus of the third molar can vary among individuals in appearance and the presence of the number of septa.

In the LF, the alveolar process has a similar structure to the alveoli of the HF. They have two-thirds walls: lower and upper. The upper third is formed by plates of hard and compact substance, and the lower third is lined with spongy-type tissues.

Summing up

Now, having general information about structural components the upper and lower jaws, knowing their location and function, you can characterize them. In addition, the structure of the alveolar processes of these jaws, the presence of special components in them and their functional purpose were examined. We also saw that the alveoli of both jaws are largely similar to each other and can slightly change their shape depending on the type of jaw structure.