The dental apparatus and the respiratory organs of the skull are closely related. Respiratory tract defects lead to mouth breathing and abnormalities in the development of the dental apparatus. Elimination of dental anomalies does not guarantee against recurrence of dental diseases and encourages the improvement of methods of comprehensive examination and diagnosis. There are many methods for determining the transverse parameters of the facial skull: by diagnostic models or by frontal teleradiography. These methods do not always reflect the true position of the facial skull. We have proposed a method of measuring the transverse dimensions of the upper jaw and upper respiratory tract using computed tomography, which through the use of appropriate mathematical modeling can improve the diagnosis of respiratory organs and dental apparatus during orthodontic treatment.
In the clinic of the dental medical center of the National Medical University. O.O. Bogomolets underwent orthodontic treatment of children with the first form of gnatal mesial occlusion according to Betelman. Treatment of mesial occlusion was performed using a fixed device for transverse dilation of the upper jaw. From the patients treated, we selected a group of 17 boys and 20 girls. Children aged 7 to 12 years had the first molars, clinically established 3rd or 2nd grade molar defects, congestion of more than 3 millimeters and nasal breathing problems. Before and after treatment with computed tomography, three distances of the upper jaw were measured: between the medial-palatine mounds of the first permanent molars, between the bones of the alveolar arch at the level of the resistance center of the first permanent molar, and between the cortical plates of the basal arch at the resistance center of the first permanent molars. In addition, three distances of the upper respiratory tract were measured: between the lateral points of the nasal walls at the level of the large palatal canals, between the lateral points of the nasal walls at the level of the large palatal canals and between the rudiments of the canines at the level of the pear-shaped opening.
The results of changes in these parameters of the facial skeleton were subjected to statistical processing to determine the maximum and minimum values, mean, confidence interval. Testing the hypothesis of the normal distribution of sample data by the Shapiro-Wilk test showed that the frequency distribution of measurement data in the samples is close to normal.
The closeness of the relationship between the parameters of the facial skeleton was assessed by the correlation coefficient and the adequacy of these coefficients - by Student’s criterion. As a result, there was no statistically significant dependence of the change in the distance between the medial palatine mounds of the first permanent molars on changes in the distances between the bones of the alveolar arch at the resistance center of the first permanent molar, between the cortical plates of the basal arch at the level of the center of resistance of the first permanent molars and the lateral points of the nasal walls at the level of the large palatal canals. It is shown that the change in the distance between the lateral points of the nasal walls at the level of the large palatal canals is statistically weakly related to the change in the distance between the medial palatal mounds of the first permanent molars and is not related to other parameters considered.
Linear regression equations were constructed between the parameters of the change in the transverse dimensions of the facial skeleton. Verification of these models by Fisher's parameter showed their adequacy in general. Additional verification of the adequacy of the constant coefficients included in these models, according to Student's test, showed that the free member in the model changes the distance of the upper respiratory tract between the lateral points of the nasal walls at the level of the large palatal canals from the change in the distance between the cortical plates of the basal arch at the level of the center of resistance of the first permanent molars is not statistically significant. The rejection of the free term in this regression dependence led to an increase in the Fisher and Student criteria, which indicates an increase in the adequacy of this equation. The obtained regression equations allow predicting the change of some transverse dimensions of the facial skeleton depending on the change of others in the treatment of mesial occlusion and thus can improve the diagnosis of patients.
A STUDY ON THE CROWN MORPHOLOGY IN HUMAN PERMANENT MOLARS AND THE SECOND MILK MOLARS : First Part Crown Morphology in the Teeth of Upper Jaw