RU2760384C2 - Method for graphic recording of the trajectory of movement of the head of the mandible based on ultrasonography - Google Patents

Abstract

FIELD: medicine.SUBSTANCE: invention relates to medicine, namely to dentistry and diagnostics using ultrasonic waves (U/S), and is intended for use in assessment of the condition of the temporomandibular joints (TMJs) by means of graphic recording of the movement of the articular head. U/S scanning is performed, and video recordings of the TMJ area are obtained, depicting the process of movement of the articular head when the mandible is lowered and raised. The individual trajectory of movement of the articular head is therein recorded by tracking of the movements of the articular head frame-by-frame in real time by setting a marker point on the top thereof and exporting the results to electronic spreadsheets, followed by plotting and mathematically analysing the plots. A video sequence reflecting the entire cycle of movement of the mandible is produced, consisting of 5 sequences of ultrasonic frames. Each video file depicts the right or left TMJ during the movement of the mandible and has 60 frames, and the distance of movement of the point at the top of the head of the mandible corresponds to the translational movement of the head from the glenoid fossa from the state of the closed mouth, the joining of the dental rows to the maximum lowering of the mandible by the patient.EFFECT: method provides a possibility of differential diagnostics of TMJ disorders due to continuous tracking in real time, a possibility of assessing the state of the complex of tissues included in the TMJ: muscles, ligamentous apparatus, disc, and approaching the selection of therapy reasonably.1 cl, 4 tbl, 7 dwg, 2 ex

Description

The invention relates to medicine, namely to dentistry and diagnostics using ultrasonic waves (ultrasound), and can be used to assess the state of the temporomandibular joints (TMJ) by graphically recording the movement of the articular head. A detailed analysis of the nature of the trajectory of movement of the articular head will allow assessing the state of the complex of tissues included in the TMJ: muscles, ligamentous apparatus, disc and reasonably approach the choice of therapy, based on the principle of differential diagnosis of TMJ disorders.

To assess the state of the temporomandibular joint, X-ray methods are traditionally used, which have harmful ionizing radiation. Ultrasound, as one of the most common imaging methods in medical practice, has certain advantages, which include: no radiation exposure, the possibility of a dynamic study, relative simplicity, accessibility, the ability to perform a study near the patient's chair in real time, good information content, relatively low cost. In particular, ultrasound can be used to assess the state of the temporomandibular joint and other joints of the musculoskeletal system. Unlike other typical imaging techniques such as Cone Beam Computed Tomography (CBCT) and Magnetic Resonance Imaging (MRI), the great advantage of using ultrasound to visualize the TMJ and other joints is that the examination can be done in real time. ... This means that the condition of the joints can be assessed during their movement with various functional tests.

There are known methods that allow analyzing the movements of the lower jaw (LF), including:

Method for digital tracking of articulation (Patent No. 2696941 RF IPC A61C 19/045, publ. 07.08.2019). This method is intended for video recording of the movement of the lower jaw by tracking a marker point (bent clasp) installed in the interdental space. The disadvantage of this method is that a bent wire clasp is taken as a marker point, which cannot be fixed on a light-cured composite material identically when registering the movement of the lower jaw during repeated examinations.

A method for visualizing the temporomandibular joint (Patent No. 2269932 RF IPC А61В 8/00, publ. 20.02.2006) using ultrasound. This method makes it possible to visualize the TMJ structures in real time using ultrasound scanning, however, it does not provide a graphical registration of the trajectory of movement of the articular head, but a purely subjective assessment of the nature of the trajectory of movement of the articular head by the operator on the monitor of a personal computer.

The closest to the claimed solution in terms of a set of essential features is a method of graphically registering the trajectory of movement of the articular head during various movements of the lower jaw relative to the hinge axis (center of the joint head) - axiography (Slavicek R. The Masticatory organ: functions and dysfunctions. - Klosterneuburg, 2002). This method allows you to assess the quantitative indicators and qualitative features of the trajectory of the movement of the lower jaw. The assessment of the state of the temporomandibular joint is carried out on the basis of studying the quality of axiograms, which changes as a result of structural and functional disorders of the temporomandibular joint. The curves recorded by the device reflect the trajectory of movement of the articular heads and the TMJ disc. The axiogram is characterized by the curvature, length and angle of the articular path. Based on the axiography of the temporomandibular joint, the trajectory, size, shape, coincidence of the curves with various movements of the lower jaw, characterizing the state of the temporomandibular joint and the intra-articular disc, are studied.

The general properties of our invention and axiography are:

1. Methods of registration of movements of the lower jaw are digital;

2. Both methods are non-invasive and safe for receiving and processing the movement of the lower jaw;

3. Ability to assess qualitative and quantitative parameters (geometry of the trajectory of movement), symmetry of the trajectory of movement, undulating curvature of the trajectory in different phases of the movement of opening the mouth, asynchronous joint movements, divergence of trajectories of opening and closing the mouth.

The disadvantages of axiography include the fact that a methodologically important, but difficult stage is the detection and registration of the hinge point, on which the reliability of plotting the movement of the lower jaw depends. The disadvantages of axiography also include the need to use accompanying equipment (facial arch, recording arch, paraocclusal fork, articulator), the difficulty of orienting the facial arch during repeated examinations to obtain identical conditions for recording the movements of the lower jaw. In addition, due to the remoteness of the system sensors from the true moving points, projection errors are possible during data acquisition. The technique of electronic axiography using the paraocclusal “fork” has its own difficulties: with deep incisal overlap, it is difficult to fix the paraocclusal “fork”, during the study it can shift, which will lead to distortions of the diagnostic results. Thus, the complexity and high cost of the hardware and software part required for the implementation of the method, the availability of special skills among the personnel, and the bulkiness of the equipment do not allow for effective axiography in medical institutions of any level, as well as in children.

The technical objective of this invention is to develop a non-invasive method for recording the movements of the lower jaw by continuous tracking in real time with visualization of the soft tissue structures of the temporomandibular joint by ultrasound.

The technical problem posed is solved by the fact that with the help of an ultrasound scanner and various types of sensors, video recordings of scanning the temporomandibular joint region are obtained in a medical format. All videos show the process of movement of the lower jaw during lowering and raising. The creation of the trajectory of movement of the articular head with subsequent expert annotation of the data is carried out in a specialized software package.

The method provides registration and visualization of the movement of the articular head along the trajectory obtained by moving the marker point installed at the apex of the articular head. To visualize the TMJ, ultrasound is performed during the maximum lowering and raising of the lower jaw until the dentition closes. The apex of the articular head was taken as a reference point for setting the marker point on each frame of the video series, reflecting the entire cycle of movement of the lower jaw: from the state of the closed mouth to the maximum lowering of the lower jaw. As a result, the trajectory of movement of the head of the lower jaw along the articular path is built during articulation with various functional tests. The prepared subset consisted of 5 sequences of ultrasound frames. Each video file depicted the right or left temporomandibular joint during movement of the mandible and had an average of 60 frames.

The technical result achieved by the implementation of this method is to increase the accuracy in describing the process of movement of the lower jaw on the ultrasound images of the temporomandibular joint.

The essence of the method is illustrated in FIG. 1, on which the expert marked the trajectory of movement of the articular head when lowering and raising the lower jaw. Sequentially depicted video frames, in which a line connects all the positions of the marker point in the previous frames to obtain the full trajectory of movement of the articular head:

a) The trajectory of movement of the articular head, reflecting the full cycle of lowering (lower line) and raising the lower jaw (upper line);

b) The marker point is set at the apex of the articular head (0) - the beginning of the trajectory with closed dentition;

c) The middle of the trajectory when lowering the lower jaw (0-1);

d) Full trajectory of lowering of the lower jaw (0-2);

e) The middle of the path when raising the lower jaw (upper line) (0-3);

f) Full trajectory of movement of the articular head when closing the dentition after raising the lower jaw (0-4).

As a result of plotting, quantitative characteristics are obtained: the length of the articular path, speed (Table 1).

The specified technical result is achieved due to the fact that in the method of ultrasonic digital tracking of the lower jaw, including ultrasound of the temporomandibular joint during movement of the lower jaw, followed by transferring the obtained video files to a software package designed for editing video and dynamic images, in which frame-by-frame tracking of the movements of the articular head by placing a marker point on its top and calculating the "xy" coordinates, with further exporting the numerical results to spreadsheets and plotting the LF trajectory.

As is clear from the description, during dynamic scanning of the temporomandibular joint region, the movement of the point at the apex of the head of the lower jaw was measured at a distance that corresponded to the translational movement of the head from the glenoid fossa forward with the maximum possible lowering of the lower jaw by the patient.

Application of the method in medical institutions, including children and adults, as one of the stages of a comprehensive examination of patients with subsequent storage of diagnostic data in the form of a video protocol to determine criteria that provide stable articulation in clinically healthy research subjects, monitoring and control of the quality of treatment.

The proposed method for graphical registration of the movement of the articular head makes it possible to obtain various quantitative indicators, including the relative coordinates of moving marker points, the speed of movement of the head of the lower jaw, the length of the path traveled and its trajectory.

This method will contribute to a reliable and objective diagnosis of TMJ disorders and the preparation of a well-founded treatment plan, and also be considered as an additional method for examining the state of the TMJ for axonometry.

In the course of studies carried out as part of the development of the proposed method, the results of geometric architectures of articulation were obtained for different tests, characterizing the movements of the lower jaw in clinically healthy people and in patients with TMJ disorders. A detailed analysis of the nature of the trajectory of movement of the articular head will allow assessing the state of the complex of tissues included in the TMJ: muscles, ligamentous apparatus, disc and reasonably approach the choice of therapy, based on the principle of differential diagnosis of TMJ disorders.

The proposed method can be implemented by dentists and ultrasound diagnostics in medical institutions.

Determination of the individual characteristics of the movement of the TMJ head during treatment will prevent the development of disorders in the temporomandibular joints.

The effectiveness of the method is demonstrated by the following clinical examples.

Patient V., 20 years old, applied to an orthodontics clinic with complaints of incorrect position of the teeth.

Results of clinical examination methods:

Face configuration not changed

Opening the mouth free, in full. Palpation of the muscles and areas of the temporomandibular joint is painless.

On examination of the mouth: the mucous membrane is pale pink, moderately moist.

Provisional diagnosis: Neutral occlusion. Crowded position of the frontal group of teeth on the upper and lower jaws.

The patient was recommended: cone-beam computed tomography of the maxillofacial region, ultrasound of the TMJ with registration of the articular pathway, anthropometry of the dentition, orthodontic treatment.

In the complex of diagnostic measures, an ultrasound of the temporomandibular joint was performed with a record of a mouth opening-closing test. On ultrasound scans, in accordance with the developed protocol, frame-by-frame marking of images of registration of the movement of the articular head was made. FIG. 2 shows the trajectory of movement of the articular head (C) on the ultrasound image of the TMJ (right) during the lower jaw lowering-raising test; on the coordinates of the marker point, a line diagram is constructed (Table 2, Fig. 3). Based on the study of the configuration of the trajectory, the coincidence or parallelism of its sections was determined when lowering and raising the lower jaw.

Patient N., 30 years old, turned to the orthodontics clinic with complaints of incorrect position of the teeth, clicks in the temporomandibular joint on the left when opening the mouth.

Results of clinical examination methods:

Face configuration not changed

Opening the mouth is accompanied by a click in the temporomandibular joint region on the left. Palpation of the muscles and the temporomandibular joint is painless.

On examination of the mouth: the mucous membrane is pale pink, moderately moist.

Preliminary diagnosis: distal occlusion. Sagittal incisal disocclusion. Partial absence of teeth in the lower jaw. Secondary deformities of the dentition.

The patient was recommended: cone-beam computed tomography of the maxillofacial region, magnetic resonance imaging of the TMJ, ultrasound of the TMJ with registration of the articular pathway, orthodontic treatment, rational prosthetics.

In the complex of diagnostic measures, an ultrasound of the temporomandibular joint was performed with a record of a mouth opening-closing test. On ultrasound scans, in accordance with the developed protocol, frame-by-frame marking of images of registration of the movement of the articular head was made. FIG. 4 shows the trajectory of movement of the articular head on the ultrasound image of the temporomandibular joint (left) during the test of lowering and raising the lower jaw: in the section of the trajectory corresponding to the middle phase of lowering of the lower jaw (1), the deviation of the graph is visualized; a line diagram is constructed based on the coordinates of the marker point (Table 3, Fig. 5). Thus, on the basis of studying the configuration of the trajectory, its deviation from the norm is determined - a broken type.

Patient B., 25 years old, turned to the orthodontics clinic with complaints of incorrect position of the teeth, clicks in the TMJ on the right when opening the mouth, chewing food.

Results of clinical examination methods:

Face configuration not changed

Opening the mouth is accompanied by a click in the temporomandibular joint on the right. Palpation of the muscles and the temporomandibular joint is painless.

On examination of the mouth: the mucous membrane is pale pink, moderately moist.

Provisional diagnosis: Distal occlusion. Sagittal incisal disocclusion. Crowded position of the teeth in the upper and lower jaws.

The patient was recommended: cone-beam computed tomography of the maxillofacial region, magnetic resonance imaging of the TMJ, ultrasound of the TMJ with registration of the articular pathway, orthodontic treatment, rational prosthetics.

In the complex of diagnostic measures, an ultrasound of the temporomandibular joint was performed with a record of a mouth opening-closing test. On ultrasound scans, in accordance with the developed protocol, frame-by-frame marking of images of registration of the movement of the articular head was made. FIG. 6 shows the trajectory of movement of the articular head on the ultrasound image of the TMJ (right) during the lower jaw lowering-raising test: in the trajectory segment corresponding to the middle phase of lower jaw raising (3), the graph has a wavy configuration; a line diagram is constructed based on the coordinates of the marker point (Table 4, Fig. 7). Thus, on the basis of studying the configuration of the trajectory, its deviation from the norm is determined - the broken type.

Brief description of the figures.

FIG. 1 shows sequentially video frames, in which a line connects all the positions of the marker point in the previous frames to obtain a complete trajectory of movement of the articular head: the trajectory of movement of the articular head when lowering and raising the lower jaw is shown.

a) The trajectory of movement of the articular head, reflecting the full cycle of lowering (lower line) and raising the lower jaw (upper line);

b) The marker point is set at the apex of the articular head (0) - the beginning of the trajectory with closed dentition;

c) The middle of the trajectory when lowering the lower jaw (0-1);

d) Full trajectory of lowering of the lower jaw (0-2);

e) The middle of the path when raising the lower jaw (upper line) (0-3);

f) Full trajectory of movement of the articular head when closing the dentition after raising the lower jaw (0-4).

FIG. 2 shows the trajectory of movement of the articular head (C) on the ultrasound image of the temporomandibular joint (right) during the test of lowering and raising the lower jaw in a patient in the absence of clinical manifestations of TMJ disorders.

FIG. 3 is a line diagram showing the movement of the articular head-trajectory, built in a coordinate system for a patient in the absence of clinical manifestations of TMJ disorders.

FIG. 4 shows the trajectory of movement of the articular head on the ultrasound image of the temporomandibular joint (left) during the test of lowering and raising the lower jaw in a patient with a click in the area of the temporomandibular joint on the left: in the section of the trajectory corresponding to the middle phase of lowering of the lower jaw (1), a deviation of the graph is visualized

FIG. 5 shows a line diagram reflecting the movement of the articular head-trajectory, built in the coordinate system of a patient with a click in the temporomandibular joint region (1).

FIG. 6 shows the trajectory of movement of the articular head on the ultrasound image of the temporomandibular joint (right) during the test of lowering and raising the lower jaw in a patient with a click in the area of the temporomandibular joint on the right: in the section of the trajectory corresponding to the middle phase of raising the lower jaw (3), a wave-like configuration of the graph is visualized.

FIG. 7 is a line diagram showing the movement of the articular head-trajectory, built in the coordinate system of a patient with a click in the temporomandibular joint region (3).

Table 1 contains the coordinates of the marker point when it is tracked on video recordings of the movement of the temporomandibular joint head on ultrasound scans, as well as data on the length of the articular path and speed of movement.

Tables 2, 3, 4 show the coordinates of the marker points along the X and Y axes, on the basis of which the graph-trajectory of movement of the articular head is constructed.

Claims (1)

A method for graphically recording the trajectory of movement of the head of the lower jaw, including ultrasound scanning and obtaining video recordings of the temporomandibular joint area, which captures the process of movement of the articular head during lowering and raising of the lower jaw, characterized in that the individual trajectory of movement of the articular head is recorded by frame-by-frame tracking, in real time, movements of the articular head by setting a marker point at its apex and exporting the results to spreadsheets with subsequent plotting and mathematical analysis, while producing a video sequence that reflects the entire cycle of movement of the lower jaw, consisting of 5 sequences of ultrasound frames, each video file depicts the right or left temporomandibular joint during the movement of the lower jaw and has 60 frames, and the distance of movement of the point at the apex of the head of the lower jaw corresponds to the translational movement of the head from the glenoid fossa from the state of the closed mouth, closure of the dentition to m maximum lowering of the lower jaw by the patient.

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