Alveolar bone. Alveolar process of the jaw Bone alveolus

Alveolar processes are the parts of the face to which teeth are naturally attached. Such formations are located on both the upper and lower jaws.

Structure

The maxillary part of the human skull bones is a pair, located in the central part of the face. In its structure, there are 4 types of processes: frontal (runs upward), alveolar (looks down), palatine and zygomatic. The total weight of the upper jaw is small (although visually it seems that it is heavy), this is due to the presence of many cavities (sinuses) in it.

The alveolar process of the maxilla (shown in the photo above) consists of two wall coverings - the outer (includes the labial wall) and the inner (lingual cavity). Each of the presented areas is an arch, a sinus in the direction of the jaw endings. AO is a special recess designed for attaching a tooth.

In its upper part, the walls of the alveolar process of the lower jaw begin to touch from the second large molar, and in the lower part they transform into a jaw branch with an opening of several millimeters. In the cavity between the outer and inner coverings there are sinuses, holes, cells (holes). The teeth are located in the alveoli.

Atrophy is caused by a bay of the upper or lower jaw. The alveoli are separated from each other by dental bony septa. In the area of ​​holes with a large number of roots, there are interroot partitions.

Thus, several parts of the joint-stock company are anatomically distinguished:

• external - that is facing the cheeks, lips, towards the vestibule of the oral cavity;
• internal - located closer to the tongue and palate;
• the segment on which all the alveolar openings (sockets), as well as the dental units themselves, are directly located.

The upper part of the joint is called the alveolar ridge; it becomes clearly visible after teeth have been lost and the alveolar sockets have become overgrown. In the absence of functional loads on the ridge, its height gradually decreases.

Atrophy (destruction) of the joint is understood as pathological changes in the structure of a given anatomical unit, which can subsequently lead to a wide range of dental problems

The alveolar process has other anatomical features. The bone tissues of the upper and lower jaw are subject to constant changes throughout human life. This is explained by the physical and work loads that occur on the teeth.

Such transformations provoke a fracture of the alveolar process of the upper jaw, as a result of which the patient may need correction (plasty) of this anatomical unit. As teeth age, they wear down the active surface area. In this case, the parties facing each other suffer. Corresponding changes occur in the alveolar covering, which can lead to damage.

Possible injuries

Natural aging, physical stress, fracture and alveolar bone cancer are all abnormal processes that can affect the upper and lower jaws. Each of them can develop not even as a result of an intense blow or mechanical trauma, but on its own, with a not very strong bite (the duration of pathological changes can be very diverse).

With age, the risk of damage to the alveolar process naturally increases, especially the cleft of this formation (the most fragile part) suffers. To prevent such problems, it is necessary to regularly visit the dentist and resort to appropriate treatment and preventive measures.

AO restoration methods

Jaw fractures and other injuries require subsequent correction of both the alveolar processes and the teeth themselves; this is necessary to preserve the “healthy” functioning of a person.

The list of restoration measures is as follows:

• group of surgical methods - filling, after removal - prosthetic processes;
• the use of special preparations that strengthen the enamel, hard tissues of teeth, sinuses;
• the use of compounds to additionally protect the integrity of teeth - this is necessary for people engaged in active physical labor and athletes.

Surgical intervention is the only therapeutic measure for AO injuries

Correcting the condition of teeth in this case is much more problematic than any other type of prosthetics. Restoration can involve both the root part and the sinuses, other fragments, or even the entire jaw and oral mucosa.

Important! Small height (that is, essentially, a lack of bone tissue volume) is a limitation for dental implantation. To subsequently secure the prosthesis, the patient first undergoes bone grafting.

As you can see, the alveolar processes are important anatomical structural units of the upper and lower jaw, which, in fact, are the basis for the attachment of teeth. AO injuries are a direct indication for bone grafting and dental prosthetics.

The alveolar process appears only after teeth erupt and almost completely disappears with their loss.

Dental alveoli, or sockets - separate cells of the alveolar process in which the teeth are located. The dental alveoli are separated from each other by bony interdental septa. Inside the alveoli of multi-rooted teeth there are also internal interradicular septa that extend from the bottom of the alveoli. The depth of the dental alveoli is slightly less than the length of the tooth root.

The dontal space is penetrated by blood and lymphatic vessels and nerves."

2) The supporting alveolar bone includes:

a) compact bone that forms the outer (buccal or labial) and inner (lingual or oral) walls of the alveolar process, also called cortical plates of the alveolar process;

b) spongy bone, filling the spaces between the walls of the alveolar process and the alveolar bone itself.

The cortical plates of the alveolar process continue into the corresponding plates of the body of the upper and lower jaw. They are much thinner in the alveolar process of the upper jaw than in the lower jaw; They reach their greatest thickness in the area of ​​the lower premolars and molars, especially on the buccal surface. Corti-

the cal plates of the alveolar process are formed by longitudinal plates and osteons; in the lower jaw, the surrounding plates from the body of the jaw penetrate into the cortical plates.

Spongy bone is formed by anastomosing trabeculae, the distribution of which usually corresponds to the direction of forces acting on the alveolus during chewing movements. Trabeculae distribute the forces acting on the alveolar bone itself to the cortical plates. In the area of ​​the lateral walls of the alveoli they are located predominantly horizontally; at their bottom they have a more vertical course. Their number varies in different parts of the alveolar process and decreases with age and in the absence of tooth function. Spongy bone forms both interradicular and interdental septa, which contain vertical feeding canals, bearing nerves, blood and lymphatic vessels. Between the bone trabeculae there are bone marrow spaces, filled in childhood with red bone marrow, and in adults - with yellow bone marrow. Sometimes certain areas of red bone marrow can persist throughout life.

RESTRUCTURING THE ALVEOLAR PROCESS

The bone tissue of the alveolar process, like any other bone tissue, has high plasticity and is in a state of constant restructuring. The latter includes balanced processes of bone resorption by osteoclasts and its new formation by osteoblasts. Processes of continuous restructuring ensure the adaptation of bone tissue to changing functional loads and occur both in the walls of the dental alveolus and in the supporting bone of the alveolar process. They are especially clearly manifested during physiological and orthodontic movement of teeth.

Under physiological conditions, after teeth erupt, two types of movement occur: associated with abrasion of approximal (facing each other) surfaces and compensating occlusal abrasion. When the approximal (contacting) surfaces of the teeth are worn away, they become less convex, but the contact between them is not disrupted, since at the same time the interdental septa become thinner (Fig. 9-8). This compensatory process is known as approximal, or medial, displacement of teeth. It is assumed that its driving factors are occlusal forces (in particular, their component directed anteriorly), as well as the influence of transseptal periodontal fibers that bring the teeth together. The main mechanism providing medial displacement is the restructuring of the alveolar wall. At

Rice. 9-8. Abrasion of proximal (contacting) surfaces of teeth

And age-related periodontal changes.

A - appearance of the periodontium of molars shortly after eruption; b - age-related changes in teeth and periodontium: abrasion of the occlusal and proximal surfaces of the teeth, a decrease in the volume of the tooth cavity, narrowing of the root canals, thinning of the interdental bone septum, cement deposition, vertical displacement of the teeth and an increase in the clinical crown (according to G. H. Schumacher et al., 1990 ).

In this case, on its medial side (in the direction of tooth movement), a narrowing of the periodontal space and subsequent resorption of bone tissue occur. On the lateral side, the periodontal space expands, and on the alveolar wall, coarse fibrous bone tissue is deposited, which is later replaced by lamellar tissue.

The abrasion of the tooth is compensated by its gradual advancement from the bone alveolus. An important mechanism of this process is the deposition of cement in the region of the root apex (see above). In this case, however, the walls of the alveoli are also reconstructed, at the bottom of which and in the area of ​​the interradicular septa, bone tissue is deposited. This process reaches particular intensity with the loss of tooth function due to the loss of the antagonist.

During orthodontic displacement of teeth, thanks to the use of special devices, it is possible to provide effects on the alveolar wall (mediated, obviously, by the periodontium), which lead to resorption of bone tissue in the area of ​​pressure and its new formation in the area of ​​tension (Fig. 9-9). Excessively large forces acting on a tooth for a long time during orthodontic reshaping143

Rice. 9-9. Restructuring of the alveolar process during orthodontic horizontal movement of teeth.

a - normal position of the tooth in the alveolus; b - inclined position of the tooth after exposure to force; c - oblique-rotational movement of the tooth. Arrows indicate the direction of force and movement of the tooth. In pressure zones, resorption of the alveolar bone wall occurs, and in traction zones, bone deposition occurs. ZD - pressure zones; ZT - traction zones (according to D. A. Kalvelis, 1961, from L. I. Falin, 1963, with modifications).

placement, can cause a number of unfavorable phenomena: compression of the periodontium with damage to its fibers, disruption of its vascularization and damage to the vessels supplying the tooth pulp, focal root resorption.

The cancellous bone surrounding the alveolar bone itself also undergoes constant restructuring in accordance with the load acting on it. So, around the alveolus of a non-functioning tooth (after the loss of its antagonist), it undergoes atrophy -

bone trabeculae become thin and their number decreases.

The bone tissue of the alveolar process has a high potential for regeneration not only under physiological conditions and under orthodontic influences, but also after damage. A typical example of its reparative regeneration is the restoration of bone tissue and the reconstruction of a section of the dental alveolus after tooth extraction. Immediately after tooth extraction, the alveolar defect is filled with a blood clot. The free gum, mobile and not connected to the alveolar bone, bends towards the cavity, thereby not only reducing the size of the defect, but also helping to protect the blood clot.

As a result of active proliferation and migration of the epithelium, which begins after 24 hours, the integrity of its cover is restored within 10-14 days. Inflammatory infiltration in the area of ​​the clot is replaced by migration of fibroblasts into the alveoli and the development of fibrous connective tissue in it. Osteogenic precursor cells also migrate into the alveolus, differentiate into osteoblasts and, starting from the 10th day, actively form bone tissue that gradually fills the alveolus; At the same time, partial resorption of its walls occurs. As a result of the described changes, after 10-12 weeks the first, reparative phase of tissue changes after tooth extraction is completed. The second phase of changes (reorganization phase) lasts for many months and includes the restructuring of all tissues involved in reparative processes (epithelium, fibrous connective tissue, bone tissue) in accordance with the changed conditions of their functioning.

DENTAL JOINT

The dentogingival junction performs a barrier function and includes: gingival epithelium, sulcus epithelium And attachment epithelium(see Fig. 2-2; 9-10, a).

The gingival epithelium is a multilayered squamous keratinized epithelium, into which the high connective tissue papillae of the lamina propria of the mucous membrane are embedded (described in Chapter 2).

Furrow epithelium forms the lateral wall of the gingival sulcus, at the apex of the gingival papilla it passes into the gingival epithelium, and towards the neck of the tooth it borders on the attachment epithelium.

Gingival sulcus(cleft) - a narrow slit-like space between the tooth and the gum, located from the edge of the free gum to the attachment epithelium (see Fig. 2-2; 9-10, a). The depth of the gingival sulcus varies between 0.5-3 mm, averaging 1.8 mm. When the groove depth is more than 3 mm, it is considered pathological, and it is often called a gingival pocket. After the tooth erupts and begins to function, the bottom of the gingival sulcus usually corresponds to the cervical part of the anatomical crown, but with age it gradually moves, and ultimately the bottom of the sulcus may be located at the level of the cement (Fig. 9-11). The gingival sulcus contains fluid that is secreted through the attachment epithelium, desquamated cells of the sulcus and attachment epithelium, and leukocytes (mainly neutrophil granulocytes) that have migrated into the sulcus through the attachment epithelium.

Rice. 9-10. Attachment epithelium. Migration of leukocytes from the lamina propria of the gingival mucosa into the attachment epithelium.

a - topography; b - microscopic structure of the area shown in fragment a. E - enamel; C - cement; DB - gingival sulcus; EB - sulcal epithelium; GD - gingival epithelium; EP - attachment epithelium; SChD - free part of the gum; G - gingival groove; PSD - attached part of the gum; SA - proper lamina of the mucous membrane; KRS - blood vessel; IBM - internal basement membrane; EBM - outer basement membrane; L - leukocytes.

The sulcus epithelium is similar to the gingival epithelium, but is thinner and does not undergo keratinization (see Fig. 2-2). Its cells are relatively small in size and contain a significant amount of tonofilaments. The border between this epithelium and the lamina propria of the mucous membrane is smooth, since there are no connective tissue papillae here. Both the epithelium and connective tissue are infiltrated with neutrophilic granulocytes and monocytes, which migrate from the vessels of the lamina propria towards the lumen of the gingival sulcus. The number of intraepithelial leukocytes here is not as high as in the attachment epithelium (see below).

Attachment epithelium- multilayer flat, is a continuation of the epithelium of the groove, lining its bottom and forming a cuff around the tooth, firmly connected to the surface of the enamel, which is covered with the primary cuticle (see Fig. 2-2; 9-10, b). The thickness of the layer of attachment epithelium in the area of ​​the bottom of the gingival sulcus is 15-30 layers of cells, decreasing in the direction of the neck to 3-4.

Rice. 9-11. Displacement of the periodontal junction area with age (passive tooth eruption).

Stage I (in temporary teeth and in permanent teeth during the period from the eruption of permanent teeth to 20-30 years of age) - the bottom of the gingival sulcus is at the level of the enamel; Stage II (from 0 to 40 years and later) - the beginning of growth of the attachment epithelium along the surface of the cement, displacement of the bottom of the gingival sulcus to the cement-enamel boundary; Stage III - transition of the epithelial attachment area from the crown to the cement; Stage IV - exposure of part of the root, complete movement of the epithelium to the surface of the cement. At stages I and II, the anatomical crown is larger than the clinical one, at I"IY they are equal, and at (V) the anatomical crown is smaller than the clinical one." Some authors with All 4 stages are considered physiological, the other - only the first two. 3 - enamel; c - cement; EP - attachment epithelium. White arrow - position of the bottom of the gingival sulcus. The figures on the left show changes in the area indicated in the figure on the right with a black arrow.

The attachment epithelium is unusual morphologically and functionally. Its cells, with the exception of the basal ones, lying on the basement membrane, which is a continuation of the basement membrane of the sulcus epithelium, regardless of their location in the layer, have a flattened shape and are oriented parallel to the surface of the tooth. The surface cells of this epithelium provide attachment of the gum to the tooth surface using hemidesmosomes associated with the second (inner) basement membrane. As a result, they are not subject to descalation, which is unusual for cells of the surface

layer of stratified epithelium. Desquamation is experienced by cells lying under the surface layer of the attachment epithelium, which are displaced towards the gingival sulcus and sloughed into its lumen. Thus, epithelial cells from the basal layer are displaced simultaneously towards the enamel and the gingival sulcus. The intensity of desquamation of the attachment epithelium is very high and is 50-100 times higher than that in the gingival epithelium. The loss of cells is balanced by their constant new formation in the basal layer of the epithelium, where epithelial cells are characterized by very high mitotic activity. The rate of renewal of the attachment epithelium under physiological conditions is 4-10 days in humans. After its damage, complete restoration of the epithelial layer is achieved within 5 days.

In their ultrastructure, the cells of the attachment epithelium differ from the epithelial cells of the rest of the gum. They contain more developed GES and the Golgi complex, while tonofilaments occupy a significantly smaller volume in them. The cytokeratin intermediate filaments of these cells are biochemically different from those in the gingival and sulcus epithelial cells, indicating differences in the differentiation of these epithelia. Moreover, the attachment epithelium is characterized by a set of cytokeratins that is generally not characteristic of multilayered epithelia. Analysis of surface membrane carbohydrates, which serve as a marker for the level of differentiation of epithelial cells, shows that in the attachment epithelium there is a single class of carbohydrates, which is typical for poorly differentiated cells, for example, basal cells of the gingival and sulcus epithelium. It has been suggested that maintaining attachment epithelial cells in a relatively undifferentiated state is important to preserve their ability to form hemidesmosomes, which provide connection between the epithelium and the tooth surface.

The intercellular spaces in the attachment epithelium are widened and occupy about 20% of its volume, and the content of desmosomes connecting epithelial cells is reduced four times compared to that in the sulcal epithelium. Due to these features, the attachment epithelium has a very high permeability, ensuring the transport of substances through it in both directions. Thus, from saliva and from the surface of the mucous membrane, a massive entry of antigens into the tissues of the internal environment occurs, which may be necessary for adequate stimulation of the function of the immune system. At the same time, many substances are transferred in the opposite direction - from the blood circulating in the vessels of the lamina propria of the mucous membrane, into the epithelium and further into the lumen of the gingival sulcus and saliva as part of the so-called gingival liquid

tee. In this way, for example, electrolytes, immunoglobulins, complement components, and antibacterial substances are transported from the blood. Antibiotics of some groups (in particular, the tetracycline series) are not simply transferred from the blood, but accumulate in the gums in concentrations 2-10 times higher than their levels in the serum. The volume of gingival fluid containing proteins and electrolytes and constantly secreted into the lumen of the gingival sulcus is negligibly small under physiological conditions; it increases sharply with inflammation.

In the expanded intercellular spaces of the epithelium, numerous neutrophil granulocytes and monocytes are constantly detected, which migrate from the connective tissue of the gingival lamina propria into the gingival sulcus (see Fig. 9-10, b). The relative volume they occupy in the epithelium in clinically healthy gums can exceed 60%. Their movement within the epithelial layer is facilitated by the presence of expanded intercellular spaces and a reduced number of connections between epithelial cells. The attachment epithelium lacks melanocytes, Langerhans and Merkel cells.

In periodontitis, under the influence of metabolites secreted by microorganisms, the attachment epithelium can grow and migrate in the apical direction, ending with the formation of a deep gingival (periodontal) pocket.

lamina propria of the mucous membrane in the area of ​​the periodontal junction it is formed by loose fibrous tissue with a high content of small vessels, which are branches of the gingival plexus located here. Granulocytes (mainly neutrophils) and, in smaller numbers, monocytes and lymphocytes, which move through the intercellular substance of the connective tissue, are continuously evicted from the lumen of the vessels in the direction epithelium. Next, these cells penetrate into the attachment epithelium (partly into the sulcus epithelium), where they move between epithelial cells and, ultimately, move into the lumen of the gingival sulcus, from where they enter the saliva. The gums, in particular the gingival sulcus, serve as the main source of leukocytes, which are found in saliva and turn into salivary corpuscles. The number of leukocytes migrating in this way into the oral cavity is normally, according to some estimates, about 3000 per minute, according to others - an order of magnitude higher. Most of(70-99%) In the initial period after migration, these cells not only remain viable, but also have high functional activity. With pathology, the number of migrating leukocytes can increase significantly.

Factors determining the migration of leukocytes from the vessels of the lamina propria of the mucous membrane through the epithelium of the region

the dentogingival junction into the gingival sulcus, and the mechanisms that control the intensity of this process have not been fully determined. It is assumed that the movement of leukocytes reflects their response to chemotactic factors secreted by bacteria that are located in and around the furrow. It is also possible that such a high number of leukocytes is necessary to prevent the penetration of microorganisms into the relatively thin and non-keratinizing epithelium of the sulcus and attachment and underlying tissues.

It has been suggested that cells in individual areas of the lamina propria have different effects on the epithelium, mediated by cytokines and growth factors. This is what determines the differences in the nature of its differentiation described above.

In dentistry, as its techniques improve and new treatment technologies emerge, the number of oral problems being solved is growing.

But some of them, for example, atrophy of the alveolar process, occupy a special place when it is much easier to prevent the development or stop the pathological condition at the initial stage than to treat it.

Definition

The alveolar process is one of the anatomical components of the upper jaw to which the teeth are attached. This formation, but already on the lower jaw, is called the alveolar part.

The alveolar bone itself is identified with osteons that maintain connection with the components of the spongy dense substance.

The outside of the process is lined with a thin layer of cortical cells. In its structure it has the following components:

• labial or buccal wall (external);
• lingual wall (internal).

On the upper jaw, all the walls are connected behind the third permanent unit, and on the lower jaw they pass into the maxillary ramus. In the space between them are the alveoli (sockets) in which the teeth are located.

Its length in middle-aged people normally ranges from 48.5 mm to 62 mm (on average this value is 56 mm). The thickness also has different indicators, and varies from 7.0 mm to 13.4 mm.

Moreover, on both jaws the height of all processes increases from the incisor to the canine, and vice versa, its decrease is observed from the first premolar.

With age, there is a decrease in the size of the process, and as a result, a deterioration in the stability of the chewing elements.

Normally, their development parallels the process of human maturation, and directly depends on the presence of teeth.

Important! The processes that form immediately after the appearance of teeth cease to exist with their loss.

Following the loss of a tooth, irreversible changes in the bone begin. It gradually loses its properties - it softens, turns into a gelatinous mass, decreases in size and reaches the edges of the jaw.

Reasons for the development of pathology

At a young age and in the absence of inflammatory processes, all bone tissue cells are in use. Due to their destructive and regenerative abilities, the bone has the ability to be completely renewed.

This process is slow, and entire cell replacement occurs once every 10 years. With age, the destructive ability of cells begins to dominate over the regenerative one, and by the age of 40, bone atrophy is a common phenomenon in dentistry.

The development of pathology is also facilitated by other reasons, which are conventionally divided into two groups - non-inflammatory and inflammatory factors.

The first group includes the following conditions:

• osteoporosis;
• periodontal disease;
• dysfunction of the parathyroid and thyroid glands;
• changes in the functioning of the ovaries in women;
• severe physical trauma to the jaw;
• uneven distribution of load on teeth;
• neoplasm in surrounding tissues or on adjacent bones of the face;
• congenital anatomical defects of the dental system;
• prosthetics if it was performed late or the prosthesis was chosen incorrectly.

The second group includes inflammatory diseases of the oral cavity and teeth:

• caries affecting the cervical region;
• periodontitis;
• gingivitis.

Important! Dentists note that degeneration of the processes can also develop against the background of other pathologies leading to forced extraction.

The video presents the mechanism of development of alveolar process atrophy.

Degrees of expression

According to the severity of atrophy, the pathological process is usually divided into 3 stages:

1. Easy. At this stage, the parameters of the ridge remain within normal limits, there is still dense, unchanged mucosa on it, and the tubercles are clearly visualized. At the first stage of atrophy, prosthetics can be successfully performed; the implanted implant will have good stability.
2. Medium-heavy. The mucous membrane is severely depleted, the bed has decreased in diameter and depth, and the tubercles are less pronounced. At this stage of the pathology, preparatory measures should be taken before prosthetics.
3. Sharp (full). The jaw is greatly reduced in size and its structure changes (becomes uneven), tubercles are not visualized, shifting of the dentition and damage to adjacent healthy units is observed.

Important! The atrophic process occurs at different speeds. In some people the condition may take years to develop, in others it can develop very quickly.

Pathology in the upper jaw leads to the formation of a flat palate, and in the lower jaw - to a protruding chin.

Classification

After tooth loss (regardless of the cause), a decrease in the jaw, a change in the pressure force on the bone of the chewing elements, insufficient supply of blood and nutrients, the formation of interdental pockets, deterioration of tissue trophism and exposure of the dental neck are observed.

To develop treatment tactics, it is important for the dentist to understand the degree of degeneration of the bone tissue of the bed and the condition of the process itself.

Based on these characteristics, several classifications of alveolar atrophy have been created. There are slight differences between them, but Each is based on the degree of severity of the process as the pathology develops.

According to Schroeder-Kurlyandsky

According to this classification, there are 3 degrees of pathology:

1. Lightweight. The anatomical structure of the mucosa on the appendage is still well preserved, and its height has not changed. In this condition, prosthetics will be successful, and the implant will not lose its stability.
2. Average. Thinning of the mucous membrane and a decrease in the diameter of the bed are observed. It is impossible to perform high-quality prosthetics without taking appropriate measures.
3. Full(heavy). The contours of the jaws are greatly smoothed, and the process itself is practically absent.

According to Kepler

1. Mild(or favorable degree). With varying degrees of mucosal dysplasia, against the background of the beginning of a decrease in tissue density and functionality, the alveolar process is quite well expressed.

   Prosthetics will have a good and lasting result, and the procedure itself will be quick and without complications.

2. Expressed. The process decreases in length and diameter, the mucous membrane is very thin.
3. Disproportional hypoplasia of two types. In the first case, the pathology is most pronounced in the incisors, and less so in the molars. In the second, the changes are most pronounced in the molars, and barely noticeable in the incisors.

According to Oksman

Oksman divided the development of pathology into four stages. He additionally introduces a difference in the degeneration process in the jaws:

1. Changes in the process on the upper jaw are practically invisible, but on the lower jaw the hypoplasia of the bed is pronounced.
2. The mentioned changes are also observed on both jaws, but vice versa.
3. The degenerative process occurs evenly on the jaws.
4. Destructive changes are uneven.

Treatment methods

Treatment of alveolar atrophy is aimed at increasing its diameter and height through several surgical procedures.

Correction of the alveolar process

It is performed for minor changes in the appendix that occur after surgery, removal of a tumor or osteomyelitis.

Restoring the previous volume of bone tissue is necessary both to obtain good support for the prosthesis and to improve aesthetics.

Correction takes place using several alveoloplasty techniques.

These include:

• Overlay manipulation. During this operation, an implant is placed along the length of the process crest. Restoration technology is carried out if the height of the alveolar is slightly less than normal, or if there are bumps, neoplasms and excess in the bone.
• Osteotomy and transposition of one of the bone walls. During the operation, the wall is broken, the cavity is filled with a special composite mass, and sutures are applied to speed up the regeneration process.
• Surgical manipulation performed inside the bone. Performed only after vertical osteotomy.

Upon completion of the plastic surgery, the patient must wear a bandage for the first 5-7 days, after which it is replaced with aligners, and only after 6-8 months, when the process has formed correctly, is it possible to place an implant.

Correction of the alveolar also includes the procedure of its extension (augmentation). Manipulation is necessary to increase its volume. It is usually performed before implants are inserted.

The following can be used as augmentation material:

• bone tissue taken from the patient himself (usually from the growth zone of the third molar);
• bone taken from a donor;
• animal graft (cow bone tissue is used);
• artificially grown material.

Any type of biomaterial is fixed with small titanium screws. All the considered manipulations are performed under anesthesia, since they are quite painful.

Relocation of the inferior alveolar nerve

It is carried out if destruction is detected only in the lower jaw, and the height of the bone edge is located below the inferior alveolar nerve by 1.0 cm or more. In such a situation, transposition (movement) of this nerve is carried out downward.

The manipulation takes place under general anesthesia, because... For successful transfer it is important that the patient remains motionless. Otherwise, if even minor voluntary movements are made, the nerve may accidentally be damaged or deformed, and inflammation may occur in the nerve fibers themselves.

After administering the anesthetic, the surgeon, based on volumetric computed tomography data, uses a special device along the line of the nerve to cut the tissue.

Through it, using a special instrument, the location of the nerve is changed by moving it to the side. Such manipulation frees up space for placing and securing the prosthetic structure.

The nerves are separated from it by a thin collagen membrane, and the outer area is filled with bone material.

Important! Typically, the procedure described above is carried out immediately before installation of the implant.

Planting the graft

Performed in case of severe atrophy or neglected condition. The graft can be autoplastic, alloplastic or explastic.

The last of the three options is used most often. During the operation, a frame is placed in the periostat from intact material, from which pins are removed for attaching a removable prosthetic structure.

Acrylic resin materials or cadaveric cartilage can be used to increase the height of the ridge.

Gingivosteoplasty

The operation is effective for severe (complete) atrophy of the processes. The procedure is carried out under anesthesia and involves the extension of the appendix with natural or artificial material in the form of bone cells.

The surgeon cuts the mucous membrane and periosteum along the edge of the gums and the tops of the gingival papillae, peels off a flap of tissue, removes the epithelium, pathological granulations and calculi.

Next, small pieces are taken from the edge of the bone cavity and used to make plastic material. The alveolar area is filled with paste, which is a mixture of sterile xenoplasty and small fragments of autologous bone.

The flap is returned to its place and fixed on the lingual side with polyamide sutures. Then a bandage with medicated paste is applied to the operated area, which speeds up the healing process.

Important! In cases of severe atrophy, gingivosteoplasty shows a positive result in 90% of all cases.

There are very few ways to restore the alveolar process, and in any case surgery is required. Each of the four methods requires a long period of rehabilitation and strict supervision by a doctor.

The video presents one of the methods for treating the atrophied lateral mandibular region.

Price

The cost of treatment directly depends on the severity of the pathology and the extent of the defect. So:

• correction of the alveolar process of 1-2 teeth will cost approximately 1,400 rubles;
• relocation of the inferior alveolar nerve costs from 2 thousand rubles;
• transplant planting - from RUB 3,500;
• gingivitis-osteoplasty - from 4 thousand rubles.

The prices shown are approximate. They may vary depending on the pricing policy of the dental clinic, the cost of the drugs and materials used.

You will have to pay separately for consultation with a specialist, diagnostic measures, and administration of anesthesia.

The alveolar processes consist of two walls: the outer - buccal, or labial, and the inner - oral, or lingual, which are located in the form of arcs along the edges of the jaws. On the upper jaw, the walls converge behind the third large molar, and on the lower jaw they pass into the ramus of the jaw.

In the space between the outer and inner walls of the alveolar processes there are cells - dental sockets, or alveoli (alveolus dentalis), in which the teeth are placed. The alveolar processes, which appear only after teeth erupt, almost completely disappear with their loss.

The alveolar process is part of the upper and lower jaws, covered with a thin cortical layer. The outer compact lamina forms the vestibular and oral surfaces of the alveolar bone. The thickness of the outer cortical plate varies between the upper and lower jaws, as well as in different areas of each of them. The internal compact lamina forms the inner wall of the alveoli.

On an x-ray, the cortical plate of the alveolus appears as a dense line, in contrast to the surrounding layer of cancellous bone tissue. Along the edge of the alveoli, the inner and outer plates close together, forming the crest of the alveoli. The alveolar crest is located 1–2 mm below the enamel-cement junction of the tooth.

Bone between adjacent alveoli forms interalveolar septa. The interalveolar septa of the anterior teeth have a pyramidal shape, in the area of ​​the lateral teeth they are trapezoidal.

Alveolar bone consists of inorganic and organic substances, among which collagen predominates. Bone tissue cells are represented by osteoblasts, osteoclasts, and osteocytes. These cells participate in the continuous process of tissue resorption and osteogenesis.

Normally, these processes are balanced, and they underlie the continuously occurring restructuring of the alveolar bone, which characterizes pronounced plasticity and adaptation of the bone to changes in the position of the tooth during its development, eruption and the entire period of functioning.

To assess the degree of bone resorption, it is necessary to take into account:
– difference in the thickness of the cortical plate;
– microhardness of the jaw bone;
– looping structure;
– direction of bone beams.

There are several parts of the alveolar process:
- external– facing the vestibule of the oral cavity, towards the lips and cheeks;
- internal– facing the hard palate and tongue;
- Part, on which the alveolar openings (sockets) and the teeth themselves are located.

The upper part of the alveolar process is called the alveolar ridge, which can be clearly observed after tooth loss and overgrowth of the alveolar sockets. In the absence of load on the alveolar ridge, its height gradually decreases.

The bone tissue of the alveolar process undergoes changes throughout a person’s life, as the functional load on the teeth changes. The height of the process varies and depends on many factors - age, dental diseases, and the presence of defects in the dentition.

Low height, that is, insufficient volume of bone tissue of the alveolar process, is a contraindication for dental implantation. In order for the implant to be secured, bone grafting is performed.

It is possible to diagnose the alveolar process using an x-ray examination.

The bone tissue of the alveoli consists of outer and inner cortical plates and the spongy substance located between them. The spongy substance consists of cells separated by bone trabeculae; the space between the trabeculae is filled with bone marrow (red bone marrow in children and youth, yellow bone marrow in adults). Compact bone is formed by bone plates with a system of osteons and is penetrated by channels for blood vessels and nerves.

The direction of the bone trabeculae depends on the direction of the mechanical load on the teeth and jaws during chewing. The lower jaw bone has a fine-mesh structure with a predominantly horizontal direction of trabeculae. The bone of the upper jaw has a coarse structure with a predominantly vertical direction of bone trabeculae.

Normal bone tissue function is determined by the activity of the following cellular elements: osteoblasts, osteoclasts, osteocytes under the regulatory influence of the nervous system, the hormone of the parathyroid glands (parathyroid hormone).

The roots of the teeth are fixed in the alveoli. The outer and inner walls of the alveoli consist of two layers of compact substance. The linear dimensions of the alveolus are less than the length of the tooth root, so the edge of the alveolus does not reach the enamel-cement junction by 1 mm, and the apex of the tooth root does not fit tightly to the bottom of the alveolus due to the presence of periodontium.

The periosteum covers the cortical plates of the alveolar arches. The periosteum is a dense connective tissue, contains many blood vessels and nerves, and is involved in the regeneration of bone tissue.

Chemical composition of bone tissue:

Mineral salts - 60-70% (mainly hydroxyapatite);

Organic substances - 30-40% (collagen);

Water - in small quantities.

The processes of remineralization and demineralization in bone tissue are dynamically balanced, regulated by parathyroid hormone (parathyroid hormone), also influenced by thyrocalcitonin (thyroid hormone) and fluoride.

Features of the blood supply to the bone tissue of the jaws.

The blood supply to the bone tissue of the jaws has a high degree of reliability due to the collateral blood supply, which can provide pulse blood flow by 50-70%, and another 20% from the masticatory muscles enters the bone tissue of the jaws through the periosteum.

Small vessels and capillaries are located in the rigid walls of the Haversian canals, which prevents rapid changes in their lumen. Therefore, the blood supply to bone tissue and its metabolic activity are very high, especially during the period of bone tissue growth and healing of fractures. At the same time, there is a blood supply to the bone marrow, which performs a hematopoietic function.

Bone marrow vessels have wide sinuses with slow blood flow due to the large cross-sectional area of ​​the sinus. The walls of the sinus are very thin and partially absent, the lumens of the capillaries are in wide contact with the extravascular space, which creates good conditions for the free exchange of plasma and cells (erythrocytes, leukocytes).

There are many anastomoses through the periosteum with the periodontium and the gingival mucosa. Blood flow in bone tissue provides nutrition to cells and transport of minerals to them.

The intensity of blood flow in the jaw bones is 5-6 times higher than the intensity of blood flow in other bones of the skeleton. On the working side of the jaw, blood flow is 10-30% greater than on the non-working side of the jaw.

The vessels of the jaws have their own myogenic tone to regulate blood flow in the bone tissue.

Innervation of the bone tissue of the jaws.

Nerve vasomotor fibers run along the blood vessels to regulate the lumen of blood vessels by changing the tonic tension of smooth muscles. To maintain normal tonic tension of the vessels from the cerebral cortex, 1-2 impulses per second are sent to them.

The innervation of the vessels of the lower jaw is carried out by sympathetic vasoconstrictor fibers from the superior cervical sympathetic ganglion. The vascular tone of the mandible can change quickly and significantly when the mandible moves during chewing.

The innervation of the vessels of the upper jaw is carried out by parasympathetic vasodilator fibers of the trigeminal nerve nuclei from the gasserian ganglion.

The vessels of the upper and lower jaws can simultaneously be in different functional states (vasoconstriction and vasodilation). The vessels of the jaws are very sensitive to the mediator of the sympathetic nervous system - adrenaline. Thanks to this, the vascular system of the jaws has shunting properties, that is, it has the ability to quickly redistribute blood flow using arteriovenular anastomoses. The shunt mechanism is activated during sudden changes in temperature (during meals), which protects periodontal tissues.