RU2300314C1 - Method for estimating hard palate height - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: method involves taking imprint from the maxilla. Control diagnostic plaster model is manufactured. Real height of patient hard palate is measured as perpendicular height drawn from the deepest palatine vault point to the line connecting interdental papillae tops between the second and the first premolars. Optimum value of individual hard palate height is measured. Naso-maxillary complex height is measured for this purpose as distance from nasion point to the point of intersection of Dreyfus line with occlusion plane. The obtained value is substituted into formula H=(r_n-OcP)/k, where H is the optimum value of individual hard palate height, r_n-OcP is the distance from nasion point to the point of intersection of Dreyfus line with occlusion plane of patient. K=4 is the coefficient of the optimum value of individual hard palate height. The calculated value is compared to the real one for determining difference used as anomaly expression degree criterion to draw conclusions whether norm or marked anomaly takes place.

EFFECT: high accuracy in estimating orthodontic disorder degree.

3 dwg, 1 tbl

Description

The invention relates to medicine, namely to dentistry, orthodontics, and can be used to assess anomalies of the dentition.

Known methods for measuring the parameters of the hard sky. Among them, "Method for determining the area of the hard palate" - SU patent No. 1618408.

Also known is the "Measurement method on gypsum models of the jaw, such as the palatine arch" - patent RU 2103945. In this method, the gypsum model is mounted on a horizontal two-coordinate table and a thin laser beam scans the surface of the palatine arch in a sagittal or transverse direction with a certain step of discreteness, the diffuse component of the spot the laser beam is sent to the photodetector of the optoelectronic receiving head and then to the processing unit for recording display and storage.

Also known is the “Method for measuring the volume of the arch of the hard palate” - patent RU 2172622. An impression from the upper jaw is made with an elastic impression mass. A cast model of the upper jaw is cast according to the cast, and the neck of the teeth is isolated on the model with a pencil. Behind the posterior surfaces of the first permanent molars, a horizontal groove is carried out with a depth of 1.0 mm with a dental spatula. Cut the plate of the dental base wax, the width of which is equal to the distance between the back surfaces of the permanent upper first molars, and the height is the distance between the furrow in the hard palate and the line connecting the posterior chewing tubercles of the permanent upper first molars. A contour repeating the shape of the hard palate in the area of the furrow is cut along one edge of the wax plate corresponding to its width. The gypsum model of the upper jaw is coated with an insulating liquid. The edge of the wax plate, repeating the shape of the sky, is heated above the flame and inserted tightly into the furrow, perpendicular to the surface of the hard palate. If there is a defect in the dentition due to the absence of a tooth, then it is filled with warmed basic wax. The model is placed on a horizontal surface. In a medical syringe with a capacity of 20 ml, water with a temperature of 20 ° C is drawn up to a mark of 20 ml and from the cannula it is released into the area of the hard palate until the liquid level reaches the pencil marks in the area of the neck of the teeth. After that, the graduated scale of the syringe determines how many milliliters of water was released. Given that 1 ml of water at 20 ° C corresponds to 1 cm, the volume of the arch of the hard palate in cubic centimeters is obtained.

All three methods are reduced to the determination of significant parameters of the hard palate in gypsum models obtained from impressions of the upper jaws of patients.

However, in all these methods, far from all the parameters important in the practical work of the orthodontist are measured, in particular, the height of the hard palate is not measured. This parameter is not just important, but in some cases is crucial in assessing pathologies of the dentofacial system.

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зубов. Полученные результаты сопоставляют с данными, характерными для ортогнатического прикуса, и оценивают выраженность аномалий.Known from the scientific literature, a method of measuring the height of the hard palate [Guide to orthodontics / Ed. F.Ya. Khoroshilkina. - 2nd ed., Revised. and add. - M .: Medicine, 1999. S. 120-121.], In which the height of the sky is measured using a three-dimensional compass or Korkhaus symmetrograph with a shearing lattice at the level of the first premolars and the first permanent molars. When cutting in the frontal plane, the cutting grating is installed on the measuring points of Pont on premolars and then on molars. In accordance with the location of the ends of the needles of the symmetrograph, the contours of the teeth from the vestibular, chewing and lingual surfaces are drawn on a paper tape with a millimeter grid, then the contours of the alveolar process on the right and left halves of the jaw to the transition fold of the mucous membrane from the vestibular surface and to the middle of the arch of the palate from the lingual surface. They make sure that the needles easily touch the model of the jaw and do not slide down the slope of the alveolar process. After this, the median plane is marked and a tangent to the tubercles of the premolars and molars is carried out with orientation to the median palatine suture. In the drawing, determine the height of the arch of the sky at

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teeth. The results are compared with data characteristic of an orthognathic bite, and the severity of the anomalies is assessed.

However, this method does not take into account the individual parameters of the naso-maxillary complex.

Closest to the claimed one is the method in which the index of the height of the sky is calculated according to the method of P. Berzbach, for which the necessary parameters are measured on gypsum models of the jaws - the height of the sky and the width of the dentition and then calculated by the formula:

moreover, the height index of the sky was determined by N.V. Pankratova for children aged 7-12 years with physiological occlusion and equal to 31-32 [Persia L.S. Orthodontics. Diagnosis and treatment of dentofacial anomalies: a guide for doctors. - M.: Publishing House "Medicine", 2004, p.77-78].

However, the above method does not take into account the individual parameters of the structure of the patient’s face, it is justified and limited to use for children aged 7 to 12 years.

The objective of the proposed method is to assess the deviations of the height of the hard palate from the optimal, appropriate and possible for this patient, taking into account the vertical parameters of the maxillofacial region.

The essence of the claimed invention lies in the fact that in the method for assessing the height of the patient’s hard palate, during which a clinical examination is carried out, an impression is taken from the upper jaw, a gypsum test and diagnostic model is made, and the actual height of the patient’s hard palate is measured on it as the perpendicular value coming from the most deep point of the palatine arch to the line connecting the tops of the interdental papilla between the second premolar and first molars, and judge the norm or severity of the anomaly, additionally determine the wholesale mal individual height hard palate, which measure the height of the patient's maxillary naso-complex as the distance from nasion point to Dreyfus line intersection with the occlusal plane, the obtained value is substituted in a ratio of:

where H is the optimal individual height of the hard palate;

r _n-OcP is the distance from the nasion point to the point of intersection of the Dreyfus line with the patient's occlusion plane;

k = 4 is the coefficient of the optimal individual height of the hard palate;

then, the obtained value is compared with the actual height of the hard sky and their difference is determined, which serves as a criterion for the severity of the anomaly.

The technical result of the proposed method lies in the possibility of a medical assessment of orthodontic disorders by technical methods and means, and some technical methods have not been used previously to draw conclusions about the degree of discrepancy with the optimal anatomical proportions, namely, the height of the sky. This discrepancy in the height of the sky affects not only the esthetics of the patient’s face, but also the vital functions - chewing, breathing and speech, depending on the degree of anomaly. The unknown of the technique is the use of an external parameter, the height of the naso-maxillary complex, from the point of greatest depth at the border of the forehead and nose to the intersection of the Dreyfus line with the occlusal plane to estimate the anomalies in the vertical size of the hard palate. By this parameter, measured from the outside of the patient’s face, they judge the value of the parameter inside - in the oral cavity. This technique has not received fame to date due to the beginning and still insufficient development of this branch of dentistry - research orthodontics. This also explains the receipt of a new parameter - a correction factor equal to four units. This anatomical pattern, obtained and verified, confirmed on hundreds of patients (by the department staff under the guidance of the authors of this invention — the heads of the departments of the dental faculties of medical universities of Volgograd and Saratov — Dmitrienko S.V. and Lepilin A.V.) will make it possible in the conditions of modern dental surgeries to provide orthodontic consultation on correcting occlusion pathology and improving the aesthetics of the face, which in recent years has been practically demanded more and more and population groups.

The inventors have established the value of the ratio between the vertical size of the nasomaxillary complex and the height of the hard palate in individuals with an orthognathic bite, regardless of the cranial and facial indices, age and gender of the patients. This ratio value is of the order of 4.0 for several hundred patients. This value is confirmed in the vast majority of patients and is recommended for practical accounting in the practical work of dentists and orthodontists.

The following table fragment characterizes the measurements taken by the authors for groups of examined patients.

Morphometric parameters The sizes of the head, face and sky (in mm) in individuals: male female P M ± m M ± m r _n-OcP 68.95 0.34 64.03 0.42 <0.05 Sky height 17.23 0.09 16.01 0.11 <0.05 where M is the arithmetic mean value; m is the average error of representativeness; p is the probability of a possible error.

The method is illustrated using the illustrations of figures 1, 2, 3, which indicate significant points between which measure the distances included in the claims in the form of distinctive features. Figure 1 shows the control and diagnostic models and photographs of the patient, figure 2 shows the mechanism for measuring the actual height of the hard palate, figure 3 - the mechanism for measuring the height of the naso-maxillary complex.

The method is as follows. During the examination of the patient, the height of his naso-maxillary complex is determined. To determine this parameter, it is recommended to obtain an x-ray image of the patient’s head in a lateral projection (tele-roentgenogram). In this picture, the value of the naso-maxillary complex of the patient’s face is determined by the distance from the nasolabial suture point nasion to a significant point located at the intersection of the Dreyfus line with the occlusal plane. Measure the value in mm and fix the result, divide it by a correction factor. The result of the division is the optimal value of the height of the patient's palate. In this invention, the correction factor is 4 units and is called the coefficient of the optimal individual height of the hard palate, which is equal to the ratio of the height of the naso-maxillary complex to the optimal individual height of the hard palate.

An impression is taken from the upper jaw with the obligatory obtaining of a clear imprint of the hard palate and the dentition, according to which a control and diagnostic model of the upper jaw is made, on which the actual value of the height of the patient's hard palate is measured according to standard rules using a Korkhaus symmetrograph. Using a lattice of a symmetrograph (for example, see Persin L.S. Orthodontics, 2004, M., Medicine, p.77) installed in the transverse direction, measure the height of the arch of the sky from the deepest point on the transverse contour of the sky to the line, connecting the tops of the interdental papillae between the second premolars and the first molars. The obtained actual value of the height of the hard palate is compared with a similar one (obtained at the beginning of the method) and the difference in their values, if any, judges the severity of the pathology and selects recommendations on the correction of the dentofacial system of the patient depending on the degree and nature of the violations.

It is possible to measure these parameters, which are used subsequently to assess the height of the hard palate, directly on the patient. The patient is placed in a sitting position in the dental chair. Lips must be closed. It is recommended, as a rule, to first measure the external necessary parameter of the face - the distance from the deepest place on the border of the forehead and nose - the nasion point to the significant point located at the intersection of the Dreyfus line with the occlusal plane, which corresponds to the midpoint of the lips closing. Using an anthropometer, this measurement is carried out by setting one bar on the nasion point, the other - in the middle of the lips closing line. Measure the value in mm, fix the resulting value. Divide it by a correction factor and get the optimal value of the height of the patient's palate. Then, the actual value of the patient’s hard palate is measured according to standard rules using a Corkhouse symmetrograph, making a preliminary impression and a plaster diagnostic model of the upper jaw. Set the lattice of the symmetrograph [for example, see Persin L.S. Orthodontics, 2004, M., medicine, p.77] in the transverse direction from the deepest point on the transverse contour of the sky to the line connecting the tops of the interdental papillae between the second premolar and first molars. The obtained actual value of the height of the hard palate is compared with a similar one (obtained at the beginning of the method) and, if there is a difference in their values, they judge a pronounced pathology, and choose recommendations for correction of the dentoalveolar system of the patient depending on the degree and nature of the violations.

Example

Patient N., 18 years old, was admitted to the clinic of the Department of Pediatric Dentistry of the Volgograd Medical University with complaints of protrusion of the front teeth. During the clinical examination, the diagnosis was made: "distal occlusion, deep incisal occlusion, narrowing of the upper and lower dentition, protrusion of 12, 11, 21, 22 teeth, asymmetric diastema in the upper jaw and trem between 11 and 12, 12 and 13, oral breathing "(figure 1).

An impression is taken from the upper jaw with the obligatory obtaining of a clear imprint of the hard palate and the dentition, according to which a control and diagnostic model of the upper jaw is made, on which the actual value of the height of the patient's hard palate is measured according to standard rules using a Korkhaus symmetrograph. Using a symmetrograph grating installed in the transverse direction, measure the height of the arch of the sky from the deepest point on the transverse contour of the sky to the line connecting the tops of the interdental papillae between the second premolar and first molars. When studying diagnostic models, it was found that the height of the hard palate is 20.7 mm (figure 2).

To determine the optimal size of the individual height of the hard palate of patient N., the height of the naso-maxillary complex of her face was determined on a teleradiogram in lateral projection according to the distance from the nasion point to the intersection point of the Dreyfus line with the occlusal plane. As a result, a value of 69.52 mm was obtained. (figure 3).

To determine the optimal individual height N. of the hard palate of patient N., the obtained value of 69.52 mm was reduced by 4 times. As a result of the measurements, it was found that the optimal height of the hard palate is 17.4 mm.

Thus, comparing the obtained value of the appropriate norm - the standard with the real one, we established the need to reduce the height of the hard palate by 3.3 mm, which is an indication for the use of a whole range of measures during the orthodontic treatment of this patient.

Claims (1)

A method for assessing the height of the patient’s hard palate during which a clinical examination is performed, an impression is taken from the upper jaw, a gypsum test and diagnostic model is made, the actual height of the patient’s hard palate is measured on it as the perpendicular going from the deepest point of the palatine arch to the line connecting the tops interdental papillae between the second premolar and first molars, and judge the norm or severity of the anomaly, characterized in that it further determines the optimal individual height of the hard th sky, which measure the height of the patient nazomaksillyarnogo complex as the distance from nasion to the intersection point of the line from the occlusal plane Dreyfus, the value obtained is substituted into the relation

where H is the optimal individual height of the hard palate; r _n-OcP is the distance from the nasion point to the point of intersection of the Dreyfus line with the occlusal plane of the patient; k = 4 is the coefficient of the optimal individual height of the hard palate, then, the obtained value is compared with the actual height of the hard sky and their difference is determined, which serves as a criterion for the severity of the anomaly.

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