Ministry of health ukraine
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  MINISTRY of HEALTH UKRAINEVINNYTSYA NATIONAL MEDICAL UNIVERSITY to the name of N.Pirogov "It is ratified" on a methodical conference departments of stomatology of child's age Manager of department associate professor G.Filimonov " " 20 METHODICAL POINTING FOR INDEPENDENT WORK OF STUDENTS AT PREPARATION TO PRACTICAL (SEMINAR) EMPLOYMENT
Vinnytsya 2011
4. Task for independent labour during preparation to employment. ^
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^ Name such models of jaws, that is used orthodontist for realization of biometrical researches and comparison of the got results during orthodontic treatment, diagnostic models. For making of diagnostic models of jaws it is necessary full and clearly to turn out dental rows, alveolar sprouts, transitional fold of mucous membrane with the reflection of bridles of lips and tongue and bands ; sky, subglossal area and supramaxillary humps. Rice. 1. Registration of socle of diagnostic models of jaws. It is better to work with the diagnostic models poured off from a museum or to the supergypsum. Bases of models design by means of the special adaptations - rubber forms - or cut the corners of socle in accordance with the line of fangs. Bases of models of overhead and lower jaws must be parallel to the masticatory surfaces of lateral teeth (rice. 1). On models mark the last name, name of patient, eyelids and date of removal of imprints. For determining size of teeth, dental rows, apical bases of jaws the modified trammelhead or special measuring devices, and also different adaptations, apply as ortho cross symetroskopa, ortho meter. The studies of diagnostic models of jaws conduct in three mutually perpendicular planes: middle-sagital, vertical and horizontal (transversal) and in three corresponding to them directions: sagital, vertical and horizontal. ^ V.Ustymenko (1955) suggests to distinguish three forms of frontal teeth of permanent bite : rectangular, three-cornered or cuneiform and oval. In orthodontic practice usually measure three sizes of teeth : width, height and thickness. Most often measure the mesio-distal sizes of teeth, id est width - at all teeth at the level of the most protuberant part of crown of the tooth (equator), and at lower chisels - at the level of cutting edge (table. 1, 2). A table is a 1 Middle width (in a mm) of temporal teeth (for Wetzel)
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Comparing of the measured width of crowns of temporal and permanent teeth to their average size, that it is resulted in tables, allows to define the changes of their sizes (macro- and micro respondents). The width of crowns of temporal and permanent teeth is different. Sum of width of crowns of overhead permanent chisels in middle on a 7,1 mm more than temporal, and lower - on a 5,3 mm At the vestibular or oral location of central chisels location for these teeth is determined the by measuring of distances between the pin points of nearby teeth (mesial and distally). Comparison of width of crowns of the anomalously located teeth and presence of place (a size of intervals is between teeth) that is for them in a dental row allows to define a presence or deficit of place. Deficit of place on 1/2 and a more width of crown of the anomalously located tooth for the choice of method of treatment is an absolute testimony to moving away of separate teeth. The height of coronal part of frontal teeth is measured from the cutting edge of tooth to his o the cervical limits in the meadle of vestibular surface, and at lateral teeth - from the middle of cheek tubercle to the o the cervical limit. The thickness of crowns of teeth is measured for frontal and lateral teeth as their vestibular-oral size. ^ Tonn defined straight proportional dependence between the sum of width of crowns of overhead and lower chisels at a permanent ortognatic bite. The index of Tonn equals 1,35. SI : Si = 1.35 (1) where SI is a sum of width (mesio-distal sizes) 4 overhead chisels, an of Si is a sum of width (mesio-distal sizes) 4 lower chisels. Due to this formula it is possible to define the deficit of place for overhead chisels and individual macro respondents. Absolute macro respondents is diagnosed in those cases, when the sum of width of crowns of overhead permanent chisels equals or anymore a 35,0 mm, and lower are a 27 mm and anymore. Relative or individual macro respondents is determined taking into account the form of face. For the narrow and prolonged face of SI = a 33-34 mm, an of Si a 26-27 mm. Macro respondents is diagnosed for the sums of width of crowns of overhead permanent chisels of less than, than a 28 mm, and lower is a less than 20 mm Comparing the data got during calculations in accordance with a formula (1) and as a result of measuring of width of overhead chisels, get the size of insufficiency of place for chisels. ^ Comparisons over of data, that got according to calculations after a formula 2 with the sum of mesio-distal sizes of 4th chisels on the diagnostic models of the inspected patient allows to draw conclusion about the presence of relative macro respondents , that can bring to congestion of frontal teeth of different degree of weight. Dolgopolova defined on methodology that was worked out Tonn, correlation of sum of width of crowns of temporal overhead and lower chisels and confirmed their intercommunication at a temporal ortognatic bite. The index of Dolgopolova ої equals 1,3. Gerlah set, that correlation of sizes of overhead and lower chisels depended on the depth of the chisel ceiling. At a direct permanent (ortogenic) bite the index of Gerlah equals 1,23. Malygin defined correlation of sizes of overhead and lower chisels at a permanent supraocclusion. Index of Malygin equals 1,42. Determination of length of dental rows Determinations of length of dental row conduct after the method of Nаnсе. For this purpose a ligature wire is placed from the distal surface of one first permanent molar of parties of dental row through the middle of masticatory surfaces of lateral teeth and cutting edges of frontal to the distal surface of the first permanent molar of opposite side, giving to the wire of form of dental row. Length of dental row must equal the sum of mesio-distal sizes 12 permanent or 10 temporal teeth. ^ In a period a permanent bite for determination of rtansversal sizes of dental rows apply methodology of Pont (1907), that is built on straight proportional dependence between the sum of mesio-distal sizes of 4 th overhead chisels and breadthways between first premolars and by the first molars on overhead and lower jaws. For this purpose Pont offered measuring points on overhead and lower jaws, that gather during closing of dental rows of permanent оrtognatic bite, and accordingly the width of dental rows in these points is identical (rice. 2). Rice. 2. Measuring points of Pont and determination of width of dental rows. On the first premolars the width of supramaxilla is measured between points that is located in the meadle of intertubercular fissures and on a lower jaw is a distal point of first premolar , that is a tangent to second premolars (pin point between premolars, and more precisely distal point distal to the devil-fish of cheek hump of first premolars). On the first molars the width of supramaxilla is measured between points in the front deepening of longitudinal фісури, and on a lower jaw - between the apexes of distal cheek tubercles of the first molars at a four tubercle molar or medium buccal at five tubercle . Pont defined indexes in accordance with that it is possible to define the indexes of width of dental rows in the area of premolars and molars depending on the sum of mesio-distal sizes of 4th overhead chisels.  According to Korkhaus, in a variable bite instead of measuring points on premolars take the distal lunes of the first temporal molars on a supramaxilla or their distal cheek tubercles on a lower jaw. ^ (1939) corrected in index numbers. From data of these authors, a premolars index equals 85, and molar - 65. In practical work it is recommended to use the table offered by them. A table is 3 Indexes (in a mm) of width of dental rows after to data of Linder - Hart
Determination of sagital sizes of dental rows Rice. 3. Determination of length of front segment of overhead dental arc is after Korkhaus |
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