RU2708982C1 - Method for determining a joint disk position of a temporomandibular joint by the mr image - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention refers to medicine, namely to dentistry and radiodiagnosis, and can be used for determining the joint disk position of a temporomandibular joint by MR image. MR tomography of the temporomandibular joint (TMJ) in a sagittal plane in a position of the closed mouth and an open mouth is carried out with measurement of a corner expressed in degrees. Position of an intermediate portion of the joint disk, an angle relative to the joint fossa of the joint is determined on the MR image of the TMJ in the position of the closed mouth. For this purpose, as shown in figure 2, on MR image of TMJ, vertex of joint tubercle A and vertex of posterior joint process B are connected by conditional line AB. Perpendicular CD to AB line is drawn from deepest point of arched ostrum of joint fossa C. Point of intersection of these lines D is the vertex of the angle BDE. One ray of this angle passes along a segment of the BD connecting the vertex of the angle D with the vertex of the posterior joint process B. Second angle beam connects its vertex D with the intermediate zone E of the joint disk. In position of closed mouth at value of angle from 60° up to 120° position of the joint disk is physiological, while increasing the angle value greater than 120° front displacement of joint disk is determined, while angle value is less than 60° posterior displacement of joint disk. If the joint disk is displaced, if the position of the open mouth is physiological, then the displacement of the disc with correction is determined. If the position of the joint disk does not change in the open mouth position, the disc is displaced without correction.

EFFECT: method provides fast and accurate determination of the joint disk position of a TMJ relative to a joint fossa, which remains constant in the patient and which can be considered a permanent reference point.

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Description

The invention relates to medicine, in particular to dentistry and can be used in dentistry in the diagnosis and in order to control the treatment of patients to determine the position of the articular disc of the temporomandibular joint (TMJ).

Known methods for determining the position of the articular disc of the TMJ by the location of the intermediate zone of the disc or its posterior stripe relative to the anterior bulge of the articular condyle and posterior slope of the articular tubercle [Manfredini D. Temporomandibular disorders. Modern concepts of diagnosis and treatment. - M .: Alphabet of the dentist, 2013 .-- 506 p .; Xavier, T. et al. MR imaging of temporomandibular joint dysfunction: a pictorial review. // Radiographics. 2006; 26: 765-81]. The disadvantages of these methods are: lack of accuracy in determining the position of the articular disc relative to other structures of the TMJ; the possible displacement of the articular condyle of the TMJ is not taken into account, which can lead to false-positive results of determining the position of the articular disc.

A known method for determining the position of the articular disc of the TMJ in relation to the dial of the watch [Manakova Ya. L., Dergilev AP Magnetic resonance imaging of the temporomandibular joints in outpatient practice // REJR. - 2012. - Volume 2, No. 4. - S. 37-45]. This method is successfully used in medicine, but has a drawback, since the position of the articular disk is determined conditionally, "by eye" without establishing a constant reference point, the relative of which determine the position of the articular disk. This method is taken by us as a prototype.

The basis of the invention is the task of determining the position of the articular disc in the MP image of the TMJ in the sagittal plane, which allows for a more accurate diagnosis of TMJ dysfunction and to monitor the effectiveness of the treatment of this pathology.

This problem is solved in that the position of the articular TMJ disc is determined by the location of the intermediate zone of the disc relative to the articular fossa and measured in degrees.

The inventive method allows you to determine the position of the joint disk of the TMJ patient both at the diagnostic stage and at the end of the dental treatment, which allows you to compare the results and evaluate the effectiveness of treatment measures.

In the practice of medicine, it is known to determine the position of the TMJ articular disc in relation to other structures of the joint or in relation to the watch dial. However, these methods have flaws and inaccuracies.

In the proposed method, the determination of the position of the articular disc relative to the articular fossa of the TMJ, measured in degrees, is used for the first time.

To solve the above problem, we studied MP tomograms of patients with intact dentition, patients with partial absence of teeth, patients with dentoalveolar anomalies and deformations, with carious and non-carious lesions of the teeth, as well as MP tomograms of patients after dental treatment.

The application of the method in dentistry allows you to have a positive impact on the diagnosis and quality assessment of dental treatment to restore the functions of TMJ.

The method is illustrated by figures 1, 2, which are presented in the form of photographs:

Photo 1. - drawing on the MP tomogram of the TMJ a conditional line connecting the tops of the articular tubercle and the posterior articular process and drawing a perpendicular to this line from the deepest point of the articular fossa

Photo 2. - drawing on the MP tomogram of the TMJ angle that determines the position of the intermediate zone of the articular disc.

The method for determining the position of the articular disc of the temporomandibular joint according to the MP image is as follows. MRI of the TMJ to the right and left was performed for patients in two positions: in the closed mouth position and in the open mouth position. On the MP tomogram of the TMJ (Figure 1), the apex of the articular tubercle A and the apex of the posterior articular process B were connected by the conditional AB line. From the deepest point of the arch of the articular fossa B, the perpendicular VG was lowered to the AB line. The intersection point of these lines G is the apex of the BHD angle (Figure 2), which determines the position of the articular disc. One ray of this angle passes along the segment BG connecting the vertex of the angle G with the vertex of the posterior articular process B. The second ray of the angle connects its vertex G with the intermediate zone D of the articular disk (circled by a line).

For the physiological, the position of the articular disc was taken at an angle of 60 to 120 °. Accordingly, with an increase in this angle, we are talking about the ventral (anterior) dislocation (displacement) of the articular disc, while decreasing it - about the posterior dislocation.

The proposed method differs from the existing ones in that it allows you to quickly and accurately determine the position of the TMJ joint disk relative to the articular fossa, which remains unchanged in the patient and which can be considered a constant reference point.

An example of a specific implementation.

Example 1

Patient V., 30 years old, turned to the orthopedic dentist with complaints of clicks in the TMJ area on the right when opening and closing the mouth, for displacement of the lower jaw when opening the mouth. The examination revealed the presence of clicks in the right TMJ when opening and closing the mouth (double reciprocal click), deviation of the lower jaw to the right (S-shaped shift of the lower jaw when opening the mouth), opening the mouth up to 37 mm, palpation of the masticatory muscles and TMJ is painless. Diagnosis: snapping jaw (according to ICD-10 K07.61).

The patient is referred to MRI of the TMJ on the right and left in the closed and open mouth positions. According to MRI: with a closed mouth, the position angle of the articular disc on the right was 140 °, which characterized the anterior displacement of the right articular disc; the angle of the left articular disc is 110 °, which indicates the physiological position of the disc. With an open mouth, the positions of the articular discs on the right and left are physiological. Thus, MRI data indicate an anterior displacement of the right articular disc with reposition (reduction).

The patient was prescribed a comprehensive dental treatment, including chewing muscle myogymnastics, selective grinding of teeth and splint therapy (treatment with occlusal splints). After the course of treatment, the disappearance of clicks in the TMJ and the displacement of the lower jaw when opening the mouth were observed. The control MRI of the TMJ showed the physiological position of the articular discs on both sides (the position angles of the right and left articular disc are 120 ° and 110 °, respectively).

Example 2

Patient K., 33 years old, turned to an orthopedic dentist with complaints of painful and limited opening of the mouth. Pain occurred in the TMJ area on the right and left. The examination revealed the following: opening the mouth up to 30 mm, palpation of the masticatory muscles painful on the right and left, painful palpation of the TMJ. Diagnosis: pain of TMJ (according to ICD-10 Syndrome of pain of TMJ K07.60), parafunction of masticatory muscles.

The patient is referred to MRI of the TMJ on the right and left in the closed and open mouth positions. According to MRI: with a closed mouth, the angle of the articular disc on the right was 120 °, the angle of the left articular disc is 100 °, which indicates the physiological position of the discs. With an open mouth, the positions of the articular discs on the right and left are physiological. Thus, MRI data indicate the absence of displacements of the articular discs to the right and left.

The patient was prescribed a comprehensive dental treatment, including chewing muscle myogymnastics, selective grinding of teeth and splint therapy (treatment with occlusal splints). After the course of treatment, the disappearance of pain and the restoration of the normal amplitude of the opening of the mouth to 40 mm were observed.

Example 3

Patient P., 36 years old, went to the orthopedic dentist with complaints of severe pain in the TMJ on the right and left, and limited opening of the mouth. The examination revealed a limitation of mouth opening to 29 mm, palpation of the masticatory muscles and TMJ on the right and left painful. Diagnosed with ICD-10 Syndrome of pain dysfunction of TMJ K07.60.

The patient is referred to MRI of the TMJ on the right and left in the closed and open mouth positions. According to MRI: with a closed mouth, the position angle of the articular disc on the right was 140 °, which characterized the anterior displacement of the right articular disc; the angle of the left articular disc is 150 °, which indicates an anterior displacement of the articular disc to the right and left. With an open mouth, the position of the articular discs on the right and left does not change. Thus, MRI data indicate anterior displacement of the right and left articular disc without reduction (reduction).

The patient was prescribed a comprehensive dental treatment, including chewing muscle myogymnastics, selective grinding of teeth and splint therapy (treatment with occlusal splints). After the course of treatment, pain in the TMJ and chewing muscles disappeared, and the mouth opened up to 38 mm. The control MRI of the TMJ showed the physiological position of the articular discs on both sides (the position angles of the right and left articular discs are 120 °).

Thus, the claimed method provides an accurate assessment of the position of the articular TMJ disc relative to the invariable structures of the TMJ, is simple to use, and relatively quickly performed.

Claims (1)

A method for determining the position of the articular disk of the temporomandibular joint according to the MP image, including magnetic resonance imaging of the temporomandibular joint (TMJ) in the sagittal plane in the position of the closed mouth and open mouth with determining the position of the articular disk and when it is displaced, the presence or absence of the disk alignment, characterized in that on the MP image of the TMJ in the closed mouth position, the position of the intermediate zone of the articular disc, expressed in degrees of the angle relative to the articular fossa of the TMJ, is determined; for this, as shown in figure 2, on the TMJ image, the conditional line AB connects the top of the articular tubercle A and the top of the posterior articular process B, from the deepest point of the arch of the articular fossa B lower the perpendicular VG to the AB line, the intersection point of these lines G is the vertex of the BHD angle, one ray of this angle passes along the segment of the BG connecting the vertex of the angle G with the vertex of the posterior articular process B, the second ray of the angle connects its vertex G to the intermediate zone D of the articular disc; in the closed mouth position with an angle value from 60 ° to 120 °, the position of the articular disc is physiological, with an angle value greater than 120 °, the anterior displacement of the articular disc is determined, with an angle value of less than 60 °, the posterior displacement of the articular disc; in case of displacement of the articular disk, if its position is physiological in the position of the open mouth, then displacement of the disk with repositioning is determined, if the position of the articular disc is not changed in the position of the open mouth, then displacement of the disc without repositioning is determined.

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