RU2838779C1 - Method for determining head extension in musculo-articular dysfunction of temporomandibular joint by means of cone-beam computed tomography - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention refers to medicine, namely to dentistry, and can be used in diagnosing cervical spine pathologies in the patients with musculo-articular temporomandibular joint dysfunction (MATMJD). Method comprises performing cone-beam computed tomography (CBCT) of facial part of skull with size of 200×170 mm with capture of first three cervical vertebrae. Following points are marked and connected on a sagittal section of the CBCT: point B, corresponding to the opistion, in the middle of the distal surface of the entrance to the large opening of the occipital bone, point A, located on surface of palatal bone, as in Fig. 9, and point C, the upper surface of the spinous process of the first cervical vertebra, closest to point B, which form an angle with the vertex at point A. A BAC angle is measured with jaws closed in a central occlusion and with mouth opening. Linear index of head extension is determined by constructing a straight line from point B to point C with jaws closed in the central occlusion and with mouth opening. If observing a decrease of these values on opening the mouth as compared to the position of the jaws closed in the central occlusion, a head extension is determined.

EFFECT: method provides more accurate diagnosis of the MATMJD by detecting the cervical pathology.

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Description

The invention relates to the field of medicine, namely to dentistry, and can be used in diagnosing pathologies of the cervical spine in patients with muscular-articular dysfunction of the temporomandibular joint (MADTMJ).

There are many opinions about the relationship between pathologies of the temporomandibular joint (TMJ) and the cervical spine. Many authors have proven the anatomical and functional relationship between the dental apparatus and the cervical spine. Clinical studies have shown that the masticatory muscles and neck muscles function together in a stereotypical way during rhythmic movements, which confirms the dependence of their bioelectrical activity on the position of the cervical vertebrae. [Ovsyannikov K.A. Functional state of the masticatory and cervical muscles of patients with terminal defects of the dentition // Bulletin of Novgorod State University. 2018. No. 2 (108). URL: https://cyberleninka.ru/article/n/funktsionalnoe-sostoyanie-zhevatelnyh-i-sheynyh-myshts-bolnyh-s-kontsevymi-defektami-zubnyh-ryadov].

Today, the issue of choosing diagnostic methods for TMJ diseases is very relevant, due to their widespread occurrence [Bezrukov, V.M. Temporomandibular joint disease / V.M. Bezrukov, V.A. Semkin, L.A. Grigoryants: study guide. - M.: GEOTAR-MED, 2002. - 48 p.].

Despite the wide variety of methods, the main method of diagnosing TMJ pathologies is the X-ray method. The use of panoramic radiographs allows the doctor to visualize only the bone structure of the joint in one projection, therefore it is limited to excluding obvious pathologies [Bulycheva E.A. Study of X-ray changes in dysfunctions of the temporomandibular joints complicated by parafunction of the masticatory muscles Text./ E.A. Bulycheva // Institute of Dentistry. - 2008. - No. 1. - 44-47].

Cone beam computed tomography (CBCT) provides greater detail of bone tissue, visualizes images in several planes with a minimum dose of radiation. These images allow the doctor to obtain maximum diagnostic information using one diagnostic method. [Pautov I.Yu. Computed tomography in diagnostics of internal disorders of the temporomandibular joint: author's abstract. diss. candidate of medical sciences / I.Yu. Pautov. - M., 1996. - 15 p].

The method for determining head extension in TMJ using CBCT allows us to identify signs of functional changes in the cervical spine in patients without using additional diagnostic methods, thereby expanding the diagnostic capabilities of standard methods.

Despite the authors' interest in the problem of the relationship between TMJ dysfunction and functional changes in the cervical spine, methods of X-ray diagnostics for determining head extension when opening the mouth have not been described previously in Russian literature. A method for identifying biomechanical disorders using instrumental methods for determining the mobility of the cervical spine is known. The mobility of the cervical spine is examined in a patient sitting position in six mutually perpendicular directions, including extensional ones, to the muscle barrier. The technique allows determining lateroflexion and extension of the cervical spine to identify biomechanical disorders of the musculoskeletal system [Patent RU 24781, 2002]. The disadvantage of this method is the insufficient accuracy of determining angular parameters, in contrast to accurate numerical measurements using CBCT. In addition, there are no clinical data on the use of this method in patients with MSTMD.

The closest analogue is the method for determining indications for osteopathic treatment in patients with dentoalveolar anomalies and musculoarticular dysfunctions of the temporomandibular joint, characterized by the fact that the patient's neck extension angle is determined first with a closed mouth in the usual occlusion, while the patient directs his or her gaze downwards, and then with an open mouth, while the patient directs his or her gaze upwards, after which the amplitude of mouth opening is determined, first in the usual head position, then in maximum neck extension. If the neck extension angle with an open mouth is less by at least 5.35±1.1° than the neck extension angle with a closed mouth in the usual occlusion, or the mouth opening amplitude in the neck extension position is less by at least 3.41±1.53 mm than in the usual head and neck position, then the patient needs to be treated by an osteopath before dental intervention. To implement the method, a device according to patent RU 24781 [Patent RU 2777186, 2022] is used.

The disadvantages of the prototype are the need to use a special device to determine head extension, as well as insufficient accuracy in determining angular parameters, in contrast to data obtained using CBCT.

The objective of the invention is to develop a method for determining head extension in patients with MSTMD using CBCT of the TMJ with the capture of the first three cervical vertebrae in central occlusion and with the mouth open, and to determine the dependence of the change in the position of the head relative to the change in the position of the lower jaw.

The technical result is an increase in the accuracy of TMJ MS diagnostics by determining the presence of pathology in the cervical spine.

The invention is illustrated by the following figures:

Figure 1 shows a screenshot of the Planmeca Romexis viewer program, which is used to visualize CBCT. It is presented in three reformats with visualization of the 3D model. On the axial section, central landmarks of the coronal and sagittal sections are built to obtain accurate examination results. The position of the mouth of patient No. 1 is in central occlusion.

Figure 2 is a screenshot of the Planmeca Romexis viewer program screen for patient #1 in the open mouth position. On the axial section, the central landmarks of the coronal and sagittal sections are aligned in the same way as on the first image.

In figure 3 - on the sagittal section of the CBCT of patient No. 1, the angle of head extension in central occlusion is determined, where: point A is the apex of the angle, the surface of the palatine bone, point B is the opisthion, formed by the middle of the distal part of the entrance to the foramen magnum of the occipital bone, point C is the upper surface of the spinous process of the first cervical vertebra.

Figure 4 is a sagittal CBCT section of patient #1 in the open mouth position. The figure clearly shows a decrease in the extension angle due to the patient's head tilt.

In figure 5 - on the sagittal section of the CBCT of patient No. 1 in the position of central occlusion of the jaws, the linear index of head extension was determined by constructing a straight line from the opisthion - point B, to the upper surface of the spinous process of the first cervical vertebra - point C, between the surfaces located closest to each other.

Figure 6 shows a sagittal CBCT section of patient #1 in the open mouth position. The linear index of head extension when opening the mouth is determined.

Figure 7 is a screenshot of the Planmeca Romexis viewer program. CBCT of patient #2 is presented in three reformats with visualization of the 3D model. The central landmarks of the coronal and sagittal sections are lined up on the axial section. The position of the mouth of patient #2 is in central occlusion.

Figure 8 shows a screenshot of the Planmeca Romexis viewer program screen for patient #2 in the open mouth position.

In figure 9 - on the sagittal section of the CBCT of patient No. 2, the angle of head extension in central occlusion is determined, where: point A is the apex of the angle, the surface of the palatine bone, point B is the opisthion, point C is the upper surface of the spinous process of the first cervical vertebra.

Figure 10 shows a sagittal CBCT section of patient #2 in the open mouth position. A similar extension angle was determined. No changes in the indicators were observed.

In figure 11 - on the sagittal section of the CBCT of patient No. 2 in central occlusion, the linear index of head extension was determined by constructing a straight line from the opisthion - point B, to the upper surface of the spinous process of the first cervical vertebra - point C, between the surfaces located closest to each other.

Figure 12 shows a sagittal CBCT section of patient #2 with the mouth open. The linear extension index of the head was determined when opening the mouth. There was no change in the linear extension index.

The proposed method for determining head extension in TMJ is performed as follows: patients undergo CBCT of the facial part of the skull on the Planmeca ProMax 3DMaxProFace device, the size of the study is 200×170 mm, capturing the first three cervical vertebrae in the position of the jaws closed in central occlusion and with the mouth open. The measurement of the necessary parameters is performed in the Planmeca Romexis® viewer program and does not require additional software.

When conducting this study, it is necessary to take into account the strict position of the head, using a device to fix the position or with the help of guiding rays.

Before the start of the measurement, on each image in the axial reformat, the orientation lines of the sagittal and axial planes are constructed to obtain accurate results of the patient's examination regardless of the position of the head (Fig. 1, Fig. 2, Fig. 7, Fig. 8). Construction of the extension angle begins with the designation of craniometric points, which are sequentially connected to each other. The head extension angle is formed by point B, which corresponds to the opisthion, the middle of the distal surface of the entrance to the foramen magnum of the occipital bone, connected to point A, the apex of the angle, the surface of the palatine bone, and point C, located closest to point B, the upper surface of the spinous process of the first cervical vertebra (Fig. 3, Fig. 8).

The angle is constructed sequentially on the sagittal CBCT section in the position of the jaws closed in central occlusion, then the same measurements in the position of the open mouth (Fig. 3, Fig. 4, Fig. 8, Fig. 9).

The linear index of head extension when opening the mouth is determined by constructing a straight line from the opisthion - point B to the upper surface of the spinous process of the first cervical vertebra - point C. This straight line connects the protruding points located closest to each other, first in the position of the jaws closed in central occlusion, then when opening the mouth (Fig. 5, Fig. 6, Fig. 10, Fig. 11).

After determining the numerical indices of extension, they are compared. When the angle of the VAC and the distance of the BC decrease when opening the mouth, the extension of the head is determined. These indices enable the doctor to assume that patients with MSDMHD have pathology of the cervical spine and a disorder of the coordinated work of the masticatory muscles.

Advantages of the proposed method:

1. Increasing the accuracy of TMJ MS diagnostics without the use of additional research methods.

2. Determination of the relationship between the pathology of the TMJ and the cervical spine in order to assess the need for correction of postural disorders by an osteopath before starting dental treatment.

The proposed method was used in 78 patients with an established diagnosis of TMJMD. Each patient underwent measurements according to the claimed method. According to the obtained data, 45 out of 78 patients had head extension when opening the mouth, which indicates a high need for patients to correct postural disorders before starting dental treatment. According to the obtained data, the patients were divided into two groups. The group of patients who did not have a change in the angle of the TMJ and the linear index of the extension of the TMJ when opening the mouth was called the control group - 33 people. The group in which the angle of the TMJ and the linear index of the extension of the TMJ decreased when opening the mouth was called the diagnostic group - 45 people. The analysis of variables was performed using parametric and nonparametric statistics, the description of the obtained data was performed using standard methods of variation statistics with the calculation of the mean, error of the mean, minimum and maximum values, median and interquartile distance. Differences were considered reliable at a significance level of p < 0.05.

The value of the angle of the VAS in patients of the control group was 7.89±3.51°, with mouth opening in the same group 7.02±4.01°. The linear index of the VAS in patients of the control group in the position of jaws closed in central occlusion is 10.04±3.27 mm, with mouth opening the index of the VAS in the same group becomes 9.87±3.04 mm, which is almost identical and may differ due to statistical error. The value of the angle of the VAS in the diagnostic group was 8.24±4.51°, with mouth opening 2.12±1.15°. The linear index of the BC in the diagnostic group in the position of the jaws closed in central occlusion corresponds to 11.2±3.12 mm, and when opening the mouth, the index of the BC in the same group is 3.04±2.47 mm, which indicates head extension in patients of the diagnostic group and the need for correction of postural disorders by an osteopathic physician before starting dental treatment.

The essence of the invention is illustrated by the following clinical examples.

Example 1. Patient #1, a 39-year-old woman, came to the clinic complaining of crunching and pain in the joint when chewing, increased fatigue, and neck pain. She had not previously consulted a dentist about this problem. After collecting the anamnesis, the diagnosis was: muscular-articular dysfunction of the temporomandibular joint. A CBCT of the facial part of the skull was performed, capturing the first three cervical vertebrae in the position of the jaws closed in central occlusion and with the mouth open, size 200×170.

Using the Planmeca Romexis® viewer software, a study was conducted on the proposed method for determining head extension first in central occlusion and then when opening the mouth.

Before the measurement, the sagittal and axial plane orientation lines were built on each image in the axial reformat so that the angular and linear indices in different head positions were as close as possible to the initial ones (Fig. 1, Fig. 2). It was revealed that in the position of the jaws closed in the central occlusion, the angle of extension BAC≅7.80° (Fig. 3). When determining the same angle in the open mouth position, the BAC index≅1.91° (Fig. 4), which differs by 5.98° from the angle in the central occlusion and indicates head extension when opening the mouth.

The linear index of the cervical spine in the position of the jaws closed in the central occlusion is ≅12.50 mm, when opening the mouth this index decreases by 9.28 mm and becomes ≅3.22 mm, which confirms the extension of the patient's head when opening the mouth (Fig. 5, Fig. 6). The presence of head extension when opening the mouth allows the doctor to assume the presence of pathology of the cervical spine and refer the patient to an osteopath to confirm the diagnosis and undergo the necessary treatment. During the appointment with the osteopath, the following was revealed: during examination from the front, lateroflexion of the head is determined to the right, the right shoulder is higher, the waist triangle is more pronounced on the right, the navel is along the midline, the right anterior superior iliac spine is higher, valgus position of the knee joints, more pronounced on the left with insignificant external rotation, flat valgus deformity of the feet, more pronounced on the left. When examined from the side, the posture is lordotic, the cervical lordosis is smoothed out, the thoracic kyphosis is increased, the lumbar lordosis is increased, pelvic anteversion is noted, the knee joints are in slight hyperextension, more on the right, the longitudinal arch of the feet is flattened. When examined from behind, left-sided C-shaped scoliosis is determined, the right shoulder blade is higher. The dominant somatic dysfunction is the cervical spine region, the local level is C _I -C _II , C _II -C _III , which confirms the combined pathology of the MSDMJ with the pathology of the cervical spine in this patient.

Example 2. Patient #2, a 23-year-old man, came to the clinic complaining of crunching sounds while eating, no pain, free mouth opening, deviation when opening the mouth. This is the first time he has come to the dentist with this problem, planning orthodontic treatment. After collecting the anamnesis, the diagnosis was: muscular-articular dysfunction of the temporomandibular joint. A CBCT scan of the facial part of the skull was performed, including the first three cervical vertebrae in the position of the jaws closed in central occlusion and when opening the mouth, size 200×170.

Before measuring the extension parameters, orientation lines of the sagittal and axial planes were constructed on each image in the axial reformat (Fig. 7, Fig. 8).

It was revealed that in the position of the jaws closed in central occlusion, the angle of extension BAC≅7.50° (Fig. 9). When determining the same angle in the position of the open mouth, the indicator BAC≅7.34° (Fig. 10), which is practically identical to the first value, differs due to statistical error.

The linear index of the cervical spine in the position of the jaws closed in the central occlusion is ≅13.30 mm, when opening the mouth this index corresponds to ≅13.06 mm, which indicates that there is no extension of the head when opening the mouth (Fig. 11, Fig. 12). The absence of extension of the head when opening the mouth allows the doctor to exclude pathology of the cervical spine in this patient and make a plan of the necessary treatment. During an appointment with an osteopath, the following was revealed: during an examination from the front, the posture is symmetrical, the navel is along the midline, the right anterior superior iliac spine is higher, there is slight flat valgus deformity of the feet on both sides. When examining from the side, the cervical lordosis is preserved, the thoracic kyphosis is pronounced, the lumbar lordosis is somewhat smoothed out. The dominant somatic dysfunction is the lumbar spine region, the local level is L _V -S _I . This confirms the absence of pathology of the cervical spine in the patient.

Claims (1)

A method for determining head extension in case of muscular-articular dysfunction of the temporomandibular joint, including measuring the angle of extension in the position of the jaws closed in central occlusion and when opening the mouth, characterized in that cone-beam computed tomography (CBCT) of the facial part of the skull measuring 200×170 mm is performed with the capture of the first three cervical vertebrae, on the sagittal section of the CBCT the following points are marked and connected: point B, corresponding to the opisthion, the middle of the distal surface of the entrance to the foramen magnum of the occipital bone, point A, located on the surface of the palatine bone, as in Fig. 9, and point C - the upper surface of the spinous process of the first cervical vertebra, located closest to point B, which form an angle with the apex at point A, determine the values of the angle BAC first in the position of the jaws closed in central occlusion, then when opening the mouth, determine the linear indicator of the extension of the head by constructing a straight line from point B to point C, first in the position of the jaws closed in central occlusion, then when opening the mouth, compare the values of the angle BAC and the distance BC in the position of the jaws closed in central occlusion and when opening the mouth, with a decrease in these indicators when opening the mouth, determine the extension of the head.