Open bite: causes, symptoms, diagnosis, treatment

According to the literature, open bite (mordex apertus) occurs in 1.7% of children, and more often in older age than in younger.

This type of bite is 1-2% of the total number of its violations.

[1], [2]

What causes an open bite?

Open bite is usually associated with rickets, underdevelopment of the intermaxillary bone, bad habits, insufficient biological potency to erupt, which is expressed by the retention of teeth or too late their eruption. Of great importance is the disruption of nasal breathing in early childhood.

Open bite is not an independent nosological form of the disease, but only a symptom of one of the many violations of the dento-jaw system. So, it can arise as a result of underdevelopment of one of the alveolar processes (upper or lower jaw) or both

Open bite may be a symptom of excessive development and protrusion of the entire upper or lower jaw or only its frontal region. In all these cases, biting food is impossible because of the lack of contact between the frontal teeth. Thus, with an open bite, there is no contact between the anterior and lateral teeth both vertically and horizontally.

There are 4 forms of open bite:

• I - appeared on the soil of deformations of the frontal part of the upper jaw;
• II - caused by deformation of the distal part of the upper jaw;
• III - caused by deformation of the lower jaw;
• IV - arising due to deformation of both jaws.

Symptoms of open bite

Symptoms of open bite is characterized by the fact that when the teeth are closed, a more or less pronounced vertical slit-like gap is created between the frontal and lateral teeth of the upper and lower jaw.

Symptoms of open bite are largely determined by the extent of the slit in the vertical and horizontal directions. Depending on the vertical size, three degrees of shear are distinguished:

1. up to 2 mm;
2. from 3 to 5 mm;
3. 5 mm and more.

By the extent, too, there are 3 forms of a gap:

1. Do not articulate all frontal teeth or part of them;
2. Do not articulate the frontal teeth and premolars;
3. Articulate only the second molars.

As a result of these changes, the mouth of the patient is open or semi-open, the lips do not close. Frontal teeth often bear more or less pronounced signs of hypoplasia. The line of the cutting edges of the frontal teeth is concave. In this case, the open bite can be caused by the concavity of one (upper or lower) occlusal curve, and both.

There is excessive development of alveolar processes in the lateral sections of the jaws and underdevelopment in the anterior part, especially of the intermaxillary bone.

The degree of dissociation of teeth in the frontal region can reach up to 1.5 cm or more. The upper lip in some cases assumes an elongated position, the lower lip fold is smoothed, as patients strenuously seek to hide their deficiency, trying to cover their mouth.

In other cases, with inactivity of the circular muscle of the mouth, the upper lip can be shortened, underdeveloped and flattened. At the same time, the mouth slit gap and has oval outlines, which makes speech ambiguity and splashing of saliva during the conversation.

The constant dryness of the mucous membrane of the gums and the tongue leads to their chronic inflammation.

Such patients are closed, shy, feel their own inferiority.

Violation of occlusion and articulation leads to a significant disruption of the function of chewing - the impossibility of biting off and hampering the crushing and grinding of food.

According to the data of masticiography, the total chewing period and the number of chewing waves in all the examined patients were increased.

The period of the initial crushing of food (normally 1-2 s) in patients lasts from 3 to 10 s, and the duration of the masticatory period (in the norm of 14-14.5 s) increases to 44 seconds.

As a result of the masticatory dysfunction, when the open bite is combined with the deformation of both jaws, the loss of chewing efficiency reaches 75.8%, with a combination of open bite and deformity of the maxilla it decreases by 62.1%, and when combined with deformity of the lower jaw, by 47.94%. The loss of chewing efficiency in different patients varies from 27 to 88%.

The violation of the masticatory function leads to various gastrointestinal disorders (approximately in 30% of patients).

Patients complain of a violation of the act of chewing (biting and chewing food), a non-aesthetic appearance due to the lengthening of the lower third of the face.

When a combination of open bite with proge-iey patients is depressed due to the protrusion of the chin department predacious facial expression.

Often they feel dry mouth as a result of the predominance of oral, rather than nasal breathing. In addition, patients complain of a plentiful deposition of tartar in the region of inactive (not closed with antagonists) teeth.

Diagnosis of open bite

Diagnosis of open bite should be carried out taking into account the need to identify other, accompanying or secondary dento-maxillary deformities, so that, based on such a detailed diagnosis, the doctor could determine the prospect of conservative and surgical treatment. It is advisable to follow the classification of PF Mazanov, who distinguishes four forms of open bite:

• I - open bite, combined with underdevelopment or deformation of the anterior part of the alveolar process of the upper or lower jaw;
• II - open bite, combined with the mandibular prognathia;
• III - open bite, combined with maxillary prognathia;
• IV - mixed form, in which an open bite is combined with an anomaly of development of one or both jaws, alveolar processes and teeth.

AV Klementov (1957) recommends still distinguishing three degrees of each form of an open bite:

1. the distance between the first upper and lower incisors is less than 0.5 cm;
2. this distance is from 0.5 to 0.9 cm;
3. distance between the incisors 1 cm and more, but without signs of the beginning of articulation of the teeth.

This classification differs from the others in that it covers all types of open bite, including as a component of a more complex deformation of the entire dento-jaw system.

To determine the distance between incisors, A. V. Clementov proposes to use a triangular plate of plexiglas with a scale applied.

[3], [4], [5], [6], [7]

Treatment of open bite

Treatment of open bite can be conservative (orthodontic), surgical and combined, depending on the age of the patient, the nature and severity of deformation. So, in early childhood, the treatment is usually orthodontic, and its method depends on the age of the child and the clinical picture.

In the period of milk bite, for example, resort to preventive measures aimed at reducing the effect of the pathogenetic factor (rickets, bad habits, etc.). For this, in addition to general therapeutic effects, a specially designed miogymnastics and a chin with an elastic extension from below to the top are used.

In the period of the replaceable occlusion, in addition to myogymnia, biological and hardware methods of treatment are used, which increase the bite of the crown (for example, the sixth teeth) or the kappa, and so on.

In older children (in the second half of the shift and in the period of permanent bite), therapeutic measures should be aimed at strengthening the development of the anterior segment of the alveolar processes: intermaxillary traction by F. Vasilevskaya, contacting "points" in articulating teeth, a springing arch of Engl and and so forth.

Basic types of surgical procedures with open bite

Some of the operations have already been discussed in the section on excessive development of the lower jaw.

Two variants of sparing osteotomy of the anterior section of the upper jaw according to Yu. I. Bernadsky

• I variant is indicated in cases when the open bite is caused by underdevelopment of the anterior part of the alveolar process of the upper jaw in the absence of signs of its protrusion forward. In this case, it is only necessary to lower the resected portion of the jaw downward in order to obtain contact with the lower teeth.
• The second variant of the operation is applicable when the open bite is combined with protrusion (protrusion) of the anterior segment of the alveolar process and the entire group of upper frontal teeth.

Both variants of the operation have much in common with similar operations of Cohn-Stock, Spanier (Figure 296), GI Semenchenko, PF Mazanov, Wassmund, and others.

My technique differs, first, in that it provides submucous bone osteotomy both from the side of the mouth and from the oral cavity (from the palatine side). Thus, it is possible to avoid dissection of the mucous membrane, its wide detachment, and the necrosis of the entire mobilized frontal section of the upper jaw in the postoperative period. Secondly, not produced any horizontal incision of the mucous membrane in the piriform aperture and nasal septum, limited only by its detachment and submucosal fracture of the base of the nasal septum. Therefore, my technique provides for maximum preservation of all sources of blood supply to soft tissues within the jaw.

I variant of the operation is distinguished by the fact that the osteotomy is made extremely thin (# 3) fissure and spear-shaped burs. In this case, it is possible to avoid a significant loss of bone substance along the line of osteotomy and thereby prevent the displacement of the mobilized fragment of the jaw back, providing him with the possibility of the necessary displacement only downwards.

In the second variant, the osteotomy is performed not with a thin boron, but with a wide (0.5-0.6 cm) cutter so that simultaneously with mobilization of the anterior fragment of the upper jaw it is also possible to resect its part, which allows to shift the alveolar process and the anterior group of teeth not only downwards, and eliminate the 2 defects - open bite and prognathion.

Therefore, I variant of the operation is only an osteotomy, and II - a combination of osteotomy with partial resection of the osteotomy bone substance.

Method I of variant submucosal operation

Make small (6-8 mm) vertical incisions of the mucosa and periosteum from the vestibular and lingual sides along the roots 5 | 5 teeth. Peel the mucosa and periosteum from both sides of the alveolar process within 543 | 345 teeth. Separate the soft tissues from the side of the mouth with a special angular raspator to the lower edge of the pear-shaped aperture, and from the palate to the median palatal suture; in the region of the edge of the pear-shaped aperture and the bottom of the nasal cavity, the mucous membrane is cut off inside to the anterior nose awn.

The soft tissues, detached on the threshold of the mouth, are taken on a narrow flat hook-holder, the boron is brought under them (№3-5) and starting from the edge of the pear-shaped aperture, the outer plate of the compact jaw material is cut (it is important not to damage the tip of the canine root and not periodontitis of the teeth).

The osteotomy line in the region of the alveolar process leads between the root of the canine and the first small molar tooth or between the roots of small molars (the place of osteotomy is chosen before the operation - during the "rehearsal" of the future operation on gypsum models). In this case, a clearly defined root elevation (juga alveolaria) of the canine is a good reference point. Gradually deepening, dissect burs (which often have to be changed, as they are quickly clogged with bone chips) spongy part of the bone.

By pushing the detached soft tissues on the palate with a narrow and flat tool (L-shaped), the same burs produce an osteotomy along the line connecting the spacing between the roots 43 | 34 teeth and a point on the sagittal palatine seam at level 4 | 4 teeth, so as not to damage the powerful neurovascular bundle that emerges on the palate from the incisive hole.

Then make a vertical incision (0.5 cm) of the skin in the area of the base of the anterior edge of the septum of the nose (immediately above the anterior nasal awn) and at this level exfoliate (narrow and thin rasparator) the mucosa from the base of the membranous part of the septum of the nose, dissect it with a scalpel or scissors from the front back to 1.5-2 cm. Thus, the connection of the osteotomized portion of the jaw with the cartilage of the septum of the nose is disturbed. If at the same time the front fragment of the jaw is nevertheless held by unpeeled bridges of the spongy part, a narrow chisel is inserted into the osteotomy gap and gently struck with a hammer. After that, the bone becomes completely mobile.

The mobilized fragment of the upper jaw is lowered down and set in the correct position relative to the teeth of the lower jaw. Apply seams (from the vein), connecting between the detached gingival papillae from the vestibular and lingual sides, as well as 1-2 seams on the skin in the region of the base of the septum of the nose. Using a thin steel or aluminum wire (2 mm in diameter), place a smooth tooth-brace on the upper jaw; it is also possible to impose an immobilizing tire from the vein and fast-hardening plastic. They take it off in 5-6 weeks.

In this method, you can do without various kinds of splinting apparatus.

II variant of submucous operation

II variant submucosal surgery begins with the removal of 4 | 4 or 5 | 5 teeth; the width of the crowns of these teeth usually corresponds to the distance to which the frontal portion of the upper jaw must be moved behind. It is better to remove those premolars that are abnormally located (vestibularly or orally). After that, soft tissues are peeled in the same way as in the first variant of the operation.

The osteotomy is performed directly through the alveolus of the removed tooth, using a milling cutter corresponding to the diameter of the width of the bone band to be resected (i.e., turning it into chips during the rotation of the milling cutter). The width of this strip should be the same everywhere and, in turn, correspond to the distance to which the surgeon moves the anterior section of the upper jaw to the back (this is determined before the operation on gypsum models, as in the above-described prognosis interventions).

If the subperiosteal bed is close to inserting a milling cutter of the desired width, you can use a clawed scalpel to vertically dissect the periosteum, while retaining the integrity of the mucous membrane.

After cutting the periosteum over the site of the forthcoming osteotomy, it is possible to insert into the submucosal niche even the thickest metal milling cutter.

All subsequent stages of the operation are performed in the same way as for the first version of the operation.

The mobilized fragment of the jaw is displaced posteriorly, turning the cutting edges of the teeth downward, into a normog- netic position. After this, an excessive number of soft tissues usually appear at the place of the resection-osteotomy performed. This should not confuse the surgeon, as they are soon smoothed out themselves.

At the end of the operation, the rollers formed by soft tissues need to be sewn "on yourself" so that there is no gap between the bone and the detached tissue.

Moved posteriorly and downward, a fragment of the jaw is fixed with one of the edentate wire or plastic (extramarately manufactured from fast-hardening plastic) tires for 5-6 weeks.

In conclusion, it is necessary to give several recommendations on the conduct of the described options for the operation.

If during the osteotomy, despite the precautions taken, the vascular-neural bundle will intersect near the tip of the canine or small molar tooth, one should not rush with their depilation and sealing, since it is established that after crossing the neurovascular bundle at the apex of the tooth root Blood supply and innervation are restored. If this does not happen in 2-3 months (which can be checked using an electrodontodiagnostic apparatus), the tooth should be trepanized, the pulp should be extracted from it and sealed.

If perforation of the mucous membrane of the maxillary sinus occurs during surgery, this should not cause much anxiety, since after fixation of the mobilized fragment of the jaw in the new position, the possibility of infection of the sinus from the oral cavity is usually eliminated. In addition, such small focal lesions of the healthy mucous membrane of the maxillary sinus are not complicated by diffuse traumatic sinusitis.

In the case of the perforation of the mucous membrane of the maxillary sinus, we recommend that the patient, for 5-7 days, take naphthysine or sanorin 3-5 drops 2-3 times a day to ensure free outflow of exudate from the damaged sinus to the nasal cavity.

To prevent overheating of the bone during sawing, burs should be periodically irrigated with cold isotonic sodium chloride solution or 0.25% of novocaine. For this, the blunted end of a long injection needle is brought to the place of the osteotomy from time to time, and the cutting line and the heated burr are sprayed from the syringe.

Osteotomy of the frontal section of the upper jaw according to PF Mazanov

Make vertical sections of the mucous membrane and periosteum in the direction from the outer edge of the pear-shaped aperture to 5 | 5 teeth. Peel the medial edges of the flaps, both right and left, to the level of the prospective osteotomy line, that is, up to 4 | 4 teeth.

Then delete 4 | 4 (or 5 | 5) teeth outside the occlusion, and form "tunnels" by peeling the mucous membrane and periosteum from the palate in the direction from the alveolus of the removed tooth to the left of the alveolus of the opposite side.

Produce an osteotomy of the bone plate of the upper jaw boron from the side of the lip and from the side of the palate. Make a horizontal incision of the mucosa and periosteum slightly higher than the transitional fold at the base of the opener. Separate the opener and provide mobility of the anterior fragment of the upper jaw.

Shift this fragment into the bite with the lower jaw, superimpose the seams on the mucosal-supra-gingival flaps and fix the mixed fragment of the upper jaw with rubber rings by the hooks of the shiniruyushih devices.

Consequently, in contrast to the above-described similar operations using our methodology, the operation of PF Mazanov, firstly, does not provide for the preservation of the integrity of the mucosa and periosteum from the vestibular side (which are dissected vertically) and at the base of the septum (cut horizontally). Thus, the blood supply to the frontal jaw is impaired. Secondly, PFMazanov's method provides not single-jaw, but intermaxillary fixation of the resected anterior fragment of the jaw, as a result of which the patient is forced to stay with his mouth closed for a long time .

As shown by experimental studies, 1.5-6 months after the surgery, according to Yu. I. Vernadsky, the morphological changes in the pulp of the teeth are less pronounced than in the operations performed by PF Mazanov, KVTkzhalov; the odontoblast layer was changed insignificantly, the number of rows of these cells was increased only up to 8-10, the pulp showed the accumulation of macrophages, the active process of fibrillation and development of granulation tissue fields.

These data support the feasibility of preserving continuity of the muco-periosteal flap in the alveolar bone of the upper jaw and the body in the osteotomy zone and osteoektomii, t. E. Submucosa-tunnel approach to the bone. In addition, accelerated healing of bone and soft tissue wounds, the preservation of the pulp of the teeth of the upper jaw is facilitated by active contraction of mimic and chewing muscles immediately after the operation, which is impossible to achieve with intermaxillary immobilization.