RU2770110C1 - Method for restoring the optimal height of the lower third of the face with second and third degree generalized pathological tooth erasure - Google Patents

Abstract

FIELD: medicine.SUBSTANCE: invention relates to medicine, namely dentistry. The height of the central occlusion is determined using wax bases with bite rollers by the classical anatomical and physiological method. The distance from the apex of the interdental papilla to the prosthetic plane on the lower jaw is measured. The optimal amount by which it is necessary to increase the height of the lower third of the face according to the formula: Nopt =(Nnor-2)/2 is calculated. Here, Nnor is the distance from the tip of the alveolar ridge of the upper jaw to the cutting edge of the lower incisors in a state of central occlusion, Nopt is the optimal value for increasing the bite height. The chewing surface is restored with the help of temporary plastic crowns, followed by replacement with permanent orthopedic structures, increasing the bite height by the value found using the formula.EFFECT: method makes it possible to restore the height of the lower third of the face with generalized pathological erasibility of teeth of the second and third degrees of severity, calculating the necessary amount to heighten occlusion, to perform prosthetics of the dentition taking into account the found value with increased erasure.1 cl, 6 dwg, 3 ex

Description

The invention relates to medicine, namely to dentistry. The need to increase the height of the lower third of the face arises with combined and partially removable prosthetics, including against the background of a decompensated form of increased abrasion. The average age of persons requiring bite correction is 46.5 years. This category of citizens requires not only the replacement of a partial defect of the teeth, but also the simultaneous normalization of the height of the lower third of the face, the creation of maximum occlusal contacts of the dentition. In this case, certain temporary difficulties arise, since the literary sources contain conflicting information about the methods and methods for gradually overestimating the bite height in order to restore physiological occlusion. Height normalization occurs with the use of temporary (provisional) crowns, followed by replacement with permanent constructions, and partially removable dentures made of different materials.

A known method of restoring the spatial arrangement of the lower jaw in the process of orthopedic treatment (patent N 2221520, Pokatova A.G., Bragin E.A., 20.01.2004, bull. No. 2). After a clinical and radiological examination of the dentition, the necessary surgical, therapeutic and orthopedic preparation of the oral cavity for prosthetics is carried out. Then, the abutment teeth are prepared for the manufacture of plastic dental structures. Obtain impressions from the upper and lower jaws with an alginate impression mass. With an unfixed height of the lower part of the face, wax templates with occlusal rollers are made, and under the control of electromyography, this height is determined and fixed (in this case, the maximum bioelectric activity of the masticatory muscles is observed). With a fixed height of the lower third of the face, but an unfixed position of the lower jaw, this stage is not carried out. Further, on plaster models of the jaws, temporary plastic crowns and bridges (or partial removable lamellar dentures) are made. The constructions are fitted onto the abutment teeth and are refined with the help of fast-hardening resin in the patient's mouth. Then, under the control of electromyographic parameters, repeated correction of occlusal relationships is carried out. The prostheses are fixed on the abutment teeth using materials for temporary fixation (zinc oxide-eugenol materials, calcium-containing cements). Inaccuracies in occlusal relationships during sagittal and transversal movements of the lower jaw (blocking moments) can be repeatedly corrected in the process of adapting patients to temporary structures until they are completely used to them. When carrying out remote prosthetics, the abutment teeth can be additionally prepared (if necessary) taking into account the new or restored relationship between the dentitions of the upper and lower jaws. Then two-layer casts are obtained with a silicone impression mass in a single step. Plastic crowns or bridges are used as a matrix into which a corrective silicone impression paste is applied. At the same time, the bulk of the silicone impression material is kneaded and applied to the impression tray, which is covered with a thin layer of correlating paste. Then the spoon is inserted into the oral cavity and placed on the jaw. After the impression is removed, working models are cast together with plastic crowns, which are installed and fixed in the interframe space of the articulator in the position of central occlusion using temporary plastic structures. The position of the lower jaw obtained with direct prosthetics allows you to individually adjust the articulator, save and reproduce this position on permanent dentures.

The disadvantages of this method are: the need for manufacturing and multiple correction provisional crowns; a high probability of errors in obtaining impressions using provisional crowns used as a matrix; lack of control of the position of the TMJ head. It should also be noted that constant relining leads to a deterioration in aesthetics due to the staining of plastic crowns and their fragility.

There is a known method for restoring the optimal height of the lower third of the face (patent No. 2020106527, Sungurov M.V., Nazarov A.M., 01.12.2020. Bull. No. 34), including determining the therapeutic position of the lower jaw in five stages. At the first stage, impressions are obtained from the patient's upper and lower jaws and the jaw models are cast from high-strength gypsum, belonging to the IV category of hardness. The jaw models are fixed in the articulator according to the data of the facial arch. Using the anatomical and physiological method, the phonetic method and the LVI vertical index, the therapeutic height of the lower third of the face is determined. Then, medical myorelaxation of masticatory muscles is performed with botulinum toxin type A. At the second stage, 3 weeks after drug muscle relaxation, the therapeutic height of the lower third of the face is re-determined. The jaw models are dissociated in the articulator, taking into account the data obtained when determining the height of the lower third of the face. Wax modeling of the occlusal surface of the chewing teeth and the frontal group of teeth is carried out on plaster models of the jaws, duplication of plaster models of the jaws with the occlusal surface of the chewing teeth modeled with wax and the frontal group of teeth. A kappa is made to separate the bite to a certain new therapeutic height. Next, control examinations of the patient are carried out once a month for three months. With positive dynamics and no complaints, they proceed to the next stage. At the third stage, temporary composite overlays for chewing teeth are made and the frontal group of teeth is restored using the MockUp technique. Silicone keys are obtained from duplicated plaster models of the jaws with wax-modeled occlusal surfaces of the chewing teeth and the frontal group of teeth. The composite material is layer-by-layer introduced into the silicone key and applied to the plaster model, on which no wax modeling of the teeth was carried out, while the polymerization of the composite material is carried out. Thus prepared temporary occlusal overlay is removed from the impression and then, after etching the hard tissues of the tooth and applying a primer, it is fixed in the patient's oral cavity with a composite fluid material. Further, self-polymerizing composite plastic is introduced into the silicone keys and the frontal group of teeth is restored using the MockUp technique. A kappa is made to establish the height of a new physiological rest. Carry out control examinations of the patient once a month for three months. At the fourth stage, after 3 months, the optimal position of the lower jaw in the horizontal plane is determined by the method of transcutaneous electrical nerve stimulation, using the Myomonitor apparatus. The new position of the lower jaw is fixed using a silicone register. Impressions are obtained from the patient's upper and lower jaws and jaw models are cast from high-strength gypsum, belonging to the IV category of hardness. The jaw models are fixed in the articulator according to the data of the facial arch on silicone registers obtained after transcutaneous electrical nerve stimulation, the models are analyzed in the articulator.

Temporary composite overlays are corrected in the oral cavity under the control of the bite register obtained after transcutaneous electrical nerve stimulation. Next, control examinations of the patient are carried out once a month for three months. The fifth stage is the replacement of temporary composite restorations with permanent orthopedic structures made of materials based on lithium disilicate or zirconium dioxide in a fragmentary manner, under control of the height of the occlusion. Mouth guards are made to maintain the established new height of physiological rest. The disadvantages of the method are the significant time required for therapeutic measures; the need to use additional medical diagnostic equipment.

As a prototype, we choose a method for treating patients with decompensated and subcompensated forms of increased tooth wear (patent No. 2615121, R.A. Fadeev. N.V. Prozorova, K.Z. Ronkin, A.V. Emgakhov, K.N. Markasov, P. V. Lee, E. A. Ponomareva, I. V. Martynov, M. R. Fadeeva, 04/03/2017, Bull. No. 10), which consists in obtaining models of the upper and lower jaws from durable gypsum of category IV muscle relaxation of the masticatory and cervical muscles by the method of transcutaneous electrical nerve stimulation, determine the interalveolar height and position of the lower jaw under the control of electromyography and gnathography using a silicone register, fix the jaw model in the articulator according to the data of the facial arch and the previously obtained register, wax modeling of the chewing surface of worn teeth , get an impression from the dentition after wax modeling using a transparent silicone mass and, based on the obtained silicone impression, create a composite restoration of the chewing surface of the teeth.

Creating a composite restoration of the chewing surface of the teeth can be done in two ways.

In the first variant, to create a composite restoration of the chewing surface of the teeth, two pairs of jaw models are used, the composite material is introduced layer by layer into the previously obtained silicone impression, applying it to the plaster model, on which the teeth were not modeled, while polymerizing the composite material, the prepared occlusal lining is removed from the impression and fixed in the patient's oral cavity with a composite fluid material after etching the hard tissues of the tooth and applying a primer.

In the second option, to create a composite restoration of the chewing surface of the teeth, one pair of jaw models is used, according to which, after wax modeling of the chewing surface of worn teeth, a silicone impression is obtained, the resulting silicone impression is cut into three parts: vestibular, oral and central, and the central part is removed, then, having chosen the color of the occlusal overlays, first applying the vestibular part of the silicone impression to the dentition and filling it with a solid composite material, it is polymerized with a light-curing lamp, then the oral part of the impression is applied to the dentition and the oral surface of the occlusal overlay is also prepared, after which the method of direct restoration the central part of the occlusal lining is prepared and the occlusal linings are polished with slightly abrasive discs and polished with rubber shaped heads (patent No. 2615121, R.A. Fadeev. N.V. Prozorova, K.Z. Ronkin, A.V. Markasov, P.V. Lee, E.A. Ponomarev. I.V. Martynov. M.R. Fadeev. 04/03/2017. Bull. No. 10).

The disadvantages of the prototype is that composite restorations are not replaced by orthopedic structures made of more durable material, as well as the lack of control of the position of the TMJ head.

The purpose of the invention is the normalization of the height of the lower third of the face with increased erasure of the second and third severity.

This goal is achieved by the fact that a patient with a pronounced decrease in the height of the occlusion is installed in the oral cavity with wax bases with bite ridges that overestimate the occlusion by 2 mm. Next, the patient is subjected to MS CT morphometry of the TMJ, according to which no shift of the articular head was noted. Bite patterns are made to the height of central occlusion, the distance from the top of the alveolar ridge of the upper jaw to the cutting edge of the lower incisors is measured. If the lower teeth are missing, then the height is determined by the chewing edge of the lateral group of teeth. With severe atrophy of the alveolar ridge in the frontal section, the height is measured from the top of the alveolar ridge of the lateral group of teeth, focusing on the median height of the ridge.

The optimal value is calculated by which it is necessary to increase the height of the lower third of the face in patients with 2 and 3 degrees of severity of the decompensated form of increased abrasion according to the formula:

Nopt=(Nnor - 2) / 2, where

Nnor - distance from the top of the alveolar ridge of the upper jaw to the cutting edge of the lower incisors in a state of central occlusion;

Nopt - the optimal value for overestimating the height of the bite.

The chewing surface is restored with the help of provisional plastic crowns, followed by replacement with permanent orthopedic structures, increasing the bite height by the value found by the formula. Also, the height of the lower third of the face can be restored with partially removable immediate prostheses.

Since an increase in height within 2 mm does not affect the movement of the TMJ joint in any way, we have proposed a mathematical formula where 2 is a constant. The value of the formula is determined in mm. To get the value, you need to make a calculation: 2 is subtracted from the number of normal bite height (which is a constant value) and divided by the number 2.

Examples of specific implementation.

Example 1

Patient A., 63 years old, complained of unsatisfactory aesthetics and severe tooth wear. There were also complaints about an unsatisfactory appearance: pronounced nasolabial folds, drooping corners of the mouth. Before starting treatment, the patient underwent a preliminary examination. A photo report was made. There was an increased abrasion of hard tissues of all teeth of the 2nd degree of severity, a decrease in the height of the lower third of the face (Fig. 1).

The diagnosis was made: K03.0. Increased abrasion of hard tissues of teeth. Decrease in the height of the lower part of the face.

A treatment plan has been drawn up.

1. Determining the height of the lower third of the face using the anatomical and physiological method.

2. Measurement of the distance from the top of the gingival papilla in the upper jaw to the occlusal plane.

3. Calculation of the required value for overestimation of occlusion using the proposed mathematical formula.

4. Dental prosthetics, taking into account the found value. Impressions were taken from the upper and lower jaws. We made wax bases with bite ridges, followed by determination of the height of the lower third of the face by the anatomical and physiological method. The patient underwent computed tomography of the TMJ. Computed tomography revealed a displacement of the lower heads to the top of the articular tubercle. The distance was measured from the top of the gingival papilla to the occlusal plane drawn along the teeth of the lower jaw. The number 15 was received. According to the proposed formula, the following calculations were made:

Nopt=(15-2)/2

A value of 6.5 mm was obtained. The teeth were prepared for full crowns, impressions were obtained, ceramic-metal bridges were made for the upper and lower jaws with an overestimation of the bite height by 6-7 mm (Fig. 2, 3). The next examination of the patient in a week. Conducted a second examination of computed tomography in order to identify the position of the elements of the TMJ. Positive dynamics was noted, the optimal position of the heads of the lower jaw is observed. There are no complaints about clicks and pain in the TMJ when opening the mouth.

Example 2

Patient, 66 years old, with increased severe abrasion with a significant loss of interalveolar height and displacement of the articular head posteriorly and downwards according to CT (Fig. 3).

The patient complains of abrasion and destruction of teeth, problems with eating, difficulties in the formation of a food bolus; night grinding of teeth and compensation for this defect by laying the tongue in the interdental space. When chewing food, the patient also notes pain that occurs due to trauma to the interdental papillae. In FIG. 4 shows the closure of antagonist teeth in the anterior region in a patient with significant abrasion and a decrease in interalveolar height.

The patient was assessed the height of the lower third of the face using wax bases with bite ridges using the anatomical and physiological method. Computed tomography (CT) of the jaws was performed to calculate the position of the TMJ structures relative to each other (left and right sides), which showed displacement of the articular head anteriorly from the articular tubercle (Fig. 4).

The patient measured the distance from the top of the incisive papilla to the occlusal plane, which was 17 mm. According to the proposed formula, the following calculations were made:

Nopt=(17-2)/2

A value of 7.5 mm was obtained. The patient made cast stump pin tabs (Fig. 5). The teeth were prepared for full crowns, impressions were obtained, and provisional bridges were made with an overestimation of the bite height by 7.5 mm (Fig. 6). Two weeks later, metal-ceramic bridges were installed on the upper and lower jaws. The next examination of the patient was carried out in a week. Conducted a second examination of computed tomography in order to identify the position of the elements of the TMJ. Positive dynamics was noted, the optimal position of the heads of the lower jaw is observed. There are no complaints about clicks and pain in the TMJ when opening the mouth.

Example 3

A 63-year-old patient complains of a violation of the aesthetics of the teeth, a decrease in the height of the crowns, and a violation of the process of chewing food. After examination, the diagnosis was made: increased erasure of hard dental tissues of moderate severity, generalized form.

Impressions of the jaws were obtained from the patient, wax bases with bite rollers were made, the height of the bite in the state of central occlusion was determined using the anatomical and physiological method. In the state of central occlusion, the distance from the top of the gingival papilla to the level of the prosthetic plane was measured, which was 16 mm.

According to the proposed formula, the following calculations were made:

nopt=(16-2)/2

A value of 7 mm was obtained. The patient underwent teeth preparation for full crowns, impressions were obtained, and provisional bridges were made with an overestimation of the bite height by 7 mm. Two weeks later, metal-ceramic bridges were installed on the upper and lower jaws. The next examination of the patient was carried out in a week. Conducted a second examination of computed tomography in order to identify the position of the elements of the TMJ. Positive dynamics was noted, the optimal position of the heads of the lower jaw is observed. There are no complaints about clicks and pain in the TMJ when opening the mouth.

This method is simple for an orthopedist (determination of central occlusion), understandable and does not take much time. A prerequisite for this method is to control the location of the TMJ on a dental computed tomograph at rest (at the beginning of treatment) and at the final stage of restoring height.

Claims (1)

A method for restoring the optimal height of the lower third of the face in case of generalized pathological abrasion of teeth of the second and third degree, including determining the optimal height of the lower third of the face, characterized in that the height of the central occlusion is preliminarily determined using wax bases with bite ridges by the classical anatomical and physiological method, the distance from the top of the interdental papilla to the prosthetic plane on the lower jaw, calculate the optimal amount by which it is necessary to increase the height of the lower third of the face according to the formula: Nopt=(Nnor-2)/2, where Nnor is the distance from the top of the alveolar ridge of the upper jaw to the cutting edge of the lower incisors in a state of central occlusion; Nopt is the optimal value for overestimating the height of the occlusion, the chewing surface is restored with the help of provisional plastic crowns, followed by replacement with permanent orthopedic structures, inflating the height of the occlusion by the value found by the formula.

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