Size of roots surface of various teeth by Cbark R A, 1969
Cbark R A, 1969
Jaw
Teeth
Number
x ²
x Surface in mm²
²
Standard deviation in mm²
Top
3456
Bottom
3¯
4¯
5¯
6¯
Forces for moving of separate teeth select in view of the area of roots of teeth, direction of their moving, kind of moving - inclined or case in view of properties of orthodontic wire. Fig. 23.
, , . . 23.
Fig.23. Average sizes of the area of surface of roots of permanent teeth of top and bottom jaws in mm² by Djensen
. 23 ²
8. Bending and imposing of dental arches
The technique of bending, imposing and removal of dental arches has some distinctions caused by application of various systems of fixed devices, used for orthodontic treatment. However is available and much in common, that are presented in this section.
Bending of dental arches
Wire arches round or rectangular bend from an orthodontic wire of various diameter and section which select corresponding to a phase of orthodontic treatment.
Round arches. Moving of teeth makes by means of a round wire, and also braided, consisting of 3 and a lot of metal strings (twistflex). The braided wire is very elastic, flexible, and strengthening. It allows to move teeth, and also to expand dental numbers by means of small forces. Use also round arches in diameter of 0,014, 0,016; see fig.24.
Rectangular arches. Select a wire with corresponding sections depending on the selected types of brackets and phases of treatment. (Figs. 25-28.)
For standard arch prepare from legated chrome-nickel or chrome-cobalt steel. In some special orthodontic wires, for example Elgiloy or Nitinol there are special additives. Technology of their manufacturing is the secret of the firm making these sorts of wire.
Wire arch probably to bend from direct piece of wire or to use standard preparation with necessary radius of curvature in anterior site.
At application of standard edgewise-technique do bends of the first, second and third order.
Bends of the first order
These are step-shaped bends which are carried out before tubes more often on basic first permanent molars. Arch approach to a vestibular surface of crowns of the second premolars at their correct arrangement.
Fig. 24. Expansion of dental number of the top jaw, creation of place for lateral incisors and their establishment in correct position
Fig. 25. Rotation of axes of anterior teeth-crowns in a vestibular direction, roots - in oral
Fig.26. Elimination of turn on an axis of the second permanent molars by a bend of the ends of arch inside
Fig.27. Prevention of mesial inclination of basic molars by bending of the ends of the arch in a vertical direction aside of dental cervix
Fig. 28. Gearing of elastic ring for the end of tube on molar promotes its undesirable turn on axis (1) and mesial inclination (4); gearing for hook located more close to mesial surface of tooth (2,5) or for hook, being with the lingual part of band (3), promotes establishment of tooth in correct position.
Bends of the second order
These are bends in the vertical direction, giving to rectangular arch in lateral sites a wavy aspect. They are necessary for correction of inclination of axes of lateral teeth rather occlusal plane. Axes of molars in norm have the certain corners of inclination in mesio-distal direction. At bending of rectangular arch in anterior site uses the blue shaper of arches which is universal for standard edgewise-technique. In it there are 5 flutes for a wire thickness of 0,41 mm (0,016″); 0,43 mm (0,017″); 0,45 mm (0,018″); 0,5 mm (0,020″); 0,55 mm (0,022″). All 5 flutes are located under a corner 0º. Dentaurum, Germany manufactures shapers of 4 kinds which differ on color: blue, red, silver and gold. They are intended for reception of various curvature of anterior site of dental arches from a wire of various diameters in view of features of arrangement of slots in brackets. To bending of anterior site of an arch apply the shaper of corresponding colors (0,41 0,41 mm) (0,016″); 0,45 0,63 mm (0,018″ 0,25); 0,54 0,71 mm (0,022″ (0,028). Each of these three shapers is calculated on what-or one section of a wire, but has 5 directing flutes, allowing bending rectangular arch under a corner of various sizes: 0 º, 7 º, 10 º, 13 º and 16 º.
Before reception of semicircular bend corresponding to individual normal form of anterior site of dental arch, spend measurement of this site by special elastic plastic ruler.
Bends of the third order - carry out at application of standard edgewise-technique in which slot is perpendicular to longitudinal axis of teeth. Bends are intended for rotation of axes of anterior teeth concerning to lateral teeth that the arch inserted in slots of brackets, rejected crowns of anterior teeth in vestibular direction, and their roots - in oral. Due to elastic properties of arch its potential energy is transferred through bracket to a tooth and causes its deviation.
Modernization of standard edgewise-technique consists that the arrangement of slot of brackets in others techniques and systems not parallel to cutting edge of incisors, and is under the certain corner, brackets are executed with slanting slot in relation to their basis. In this connection at introduction with a pressure of arch in slanting slots of brackets, strengthened on anterior teeth and after its fixing, receive similar effect since the oral inclination of roots of incisors and their vestibular inclination of crowns up to a normal arrangement is programmed by the form and the corner of inclination of slot in brackets.
Except for the described arches in the period of a replaceable bite apply, Utility-arch, - basic, strengthened at application of Ricketts bioprogressive technique in the period of a replaceable bite. Such arch leans on molars and incisors and due to square-shaped bends bypasses canines and premolars.
Partial arches apply to rapprochement of incisors at presence of diastema, and also for distal moving of canines after removal of the first premolar.
After imposing of arch its ends behind tubes cut with pliers-cutters or cut by means of special saw with distal protection. Under indications they bend under a corner that protects to slip out of arches. If necessary of mesial moving of lateral teeth at each reception of the patient the ends of arch gradually extend with distal part of tubes and again bend; surpluses of the ends delete.
9. Versions of the springs bent on arches
For moving of teeth on significant distance, at impossibility to change a level of arrangement of separate teeth to establish and fix an arch in locking attachments - brackets for increase of elasticity of arch on it bend springs and loops.
Distinguish springs of direct and return action. Horizontally located springs (T-shaped, -shaped, - figurative across) apply to vertical moving of teeth, namely dento-alveolar lengthening or shortening. Vertically located springs are intended for separation of teeth (the expanding open spring) or their rapprochement (the pulling together closed spring).
Except for individually bended springs on arches use special springs in the form of standard preparations or prepare for them individually from pieces of the round or rectangular wire. To rapprochement or disclosing of a place between them apply standard helicoids springs of teeth. The spring strengthened in locking attachment, by virtue of the elasticity is unbent and provides moving of tooth to a necessary direction.
The more bends on a spring, it renders smaller force of action on teeth. In connection with dearness of its orthodontic wire it is necessary to spend economically. For this purpose important to know the length of wire necessary for bending of each kind of spring. In Ricketts technique on arches bend the various springs allowing without risk of an overload of paradontium to move teeth of them both in the period of replaceable, and in the period of constant bite.
10. Fixation of arches in brackets
For fixation of arches in locking attachments, after their accommodation in slot of bracket, impose ligatures and other appliances.
Apply metal ligatures, manufactured from a soft steel wire in diameter 0,25 mm (0,010 ″) and 0,3 mm (0,012 ″). For a twisting of ligature uses needle holder or special ligature instrument. Its twisting spends at distance from bracket on 5-6 mm at its constant tension. Watch that ligature has been tightening strong. After that ligature grasp with needle holder or other instrument close to the lock and finally do one or two turns. The ends of ligature cut at distance on 4-5 mm from bracket also bend them under arch in direction of rotation, namely from cutting edge aside of gums so that they were not unbent at chewing food. Check with finger, whether stirs the ligature. If it injures mucous membrane of lips or cheeks the patient can impose on this site a ball of the softened wax. If the arch is turned out from the lock it insert into a slot, using pliers for bending a rectangular arch then fix of metallic ligature. If it is not obviously possible to insert the arch into the lock gradually tighten to the arch a tooth by means of ligature wire for locking attachment or use for these purpose elastics.
Apply various bandages; impose them separately on each pair of parallel located wings of bracket or at once on 4 wings, it is possible for maintenance of reliable fixing across a wire. Fig. 31.
Fig. 31. Kinds of preparations of ligature bandages (1) and variants of their imposing on brackets for strengthening of dental arches (2-4).
. 31 (1) (2-4).
Except for a wire arch use rings, elastics, executed of plastic material. These plastic ligatures strongly thumpin oral cavity in this connection are necessary to replace them through short time intervals 2-3 days. Plastic ligatures elastic are executed from special grades of elastic plastic, they it is fewer thumpsin oral cavity. It is possible to replace them in 30-40 days. Except for that to tightening of teeth apply chains elastic.
11. Recommendations on care of oral cavity at treatment by fixed devices
After fixing of the fixed device it is necessary to acquaint the patient with recommendations on care of oral cavity.
1. To be on each reception to the orthodontist, having at itself a tooth-brush, a tooth-paste, a handkerchief
2. After strengthening of the device within day it is impossible to use firm and viscous food, during all period of treatment it is necessary to limit bite of greater pieces of rigid vegetables, fruit, meat, etc. foodstuff. It is better to cut off knife small slices and to chew their by lateral teeth. It is forbidden to use a chewing gum, viscous food, sweets-toffees. The rough, rigid and viscous food can damage the complex and expensive device.
3. Do not try to remove the device fixed on teeth. First it will cause some inconveniences if they significant or there is an irritation of mucous membrane of lips, cheeks to the doctor before the appointed term. Temporarily before arrival to the doctor impose a slice of cotton wool on the site of the device causing irritation, or stick its with softened wax given by the doctor.
4. Contain teeth and the device in cleanliness. Teeth needs to be cleaned cautiously, with soft brush, it is desirable after each reception of food, and also in the morning and in the evening. If there is no opportunity to clean teeth after reception of food, it is necessary to rinse repeatedly the mouth with water. Better is to use foamy tooth-pastes. The bad hygienic maintenance of oral cavity can lead to infringement of enamel of teeth and deterioration of condition of mucous membrane of gingival edges.
5. To the doctor it is necessary to address ahead of schedule in cases of coming off details of the device from teeth, shaking of dental arch, inconveniences at using the device. The come off details should be kept in the intact kind and transfer their to the doctor.
12. Treatment of the basic nosological forms of dento-maxillo-facial anomalies
Action of fixed devices is carried out due to elastic properties of dental arches; springs; spirals; elastic chains; mono-, intermaxillary and extraoral rubber draft. Edgewise-systems - power system with application of rectangular wire. Through locking attachments brackets the force of action of arch, springs is transferred to teeth in three directions; sagital, vertical, transversal, and also can be directed on turn of a tooth around of its longitudinal axis. Probably to case move teeth, and also to carry out moving of roots and crowns of teeth in vestibulo-oral and mesio-distal directions.
To treatment apply various systems and techniques of fixed dental arch of orthodontic devices. The simplest ways of treatment use for elimination of anomalies of position of separate teeth if they are not combined with sagital, vertical and transversal anomalies of a bite. To them concerns elimination of diastema, distal moving of canines after removal under orthodontic indications of separate teeth. Such treatment can be carried out by means of partial (section) rectangular arches of Ricketts bioprogressive technique, a combination Utility-arches with section under the offer of the named author, and also by means of standard edgewise-technique, straight-wire - technique and others.
13. Ricketts bioprogressive therapy
Ricketts has developed technique of treatment of dento-maxillo-facial anomalies in the both period of replaceable and constant bite by means of Utility-arches and partial arches. Partial arches probably to apply to elimination of diastema; distal moving of canines on a place of removed the first premolars, tightening of teeth, and stabilization of their position. Them probably to apply separately and in a combination to a Utility-arch. Fig. 32-33.
Ricketts used rectangular arches section 016″ 016 ″ and. 016 ″ 022 ″.
At application of this technique of the arch bend from rather of soft orthodontic wire - Elgiloy blue, developing small forces, similarly to that which is applied in light-wire technique.
For basic molars apply the double tubes fixing the ends of dental arches. The ends of a so-called Utility-arch fix in the rectangular tubes located more close to gingival edge, and the ends of partial arches - in the tubes located more close to their chewing surface.
Utility-arch named roundabout leans on incisors and the first permanent molars. It bend as for top, so for bottom dental numbers in view of their due length. With this purpose measure the mesio-distal sizes of crowns of 12 teeth on each jaw (654321 |123456), summing width of 4 incisors crowns of each jaw with the purpose of definition of the size of median site of the arch and width of canines and premolars crowns with the purpose of definition of the sizes of lateral sites.
Fig. 32. Fabrication stages of a Utility-arch from the Elgiloy blue wire section 0,4 0,4 mm; measurement of segments of dental some (1,2); consecutive bending of roundabout arch (3)-contours of its anterior site (4), change of inclination of lateral sites of arch (6,8); the tender of lateral sites of arch in relation to anterior on 15-20º (9) and the ends of arch in the field of molars on 45º (10); assignment of the ends of an arch from tubes on 10 mm (11).
Fig.33. Utility arch, the arrangement of its ends in basic tubes on molars.
.33 , .
First bend the arch for bottom dental of some and begin moving teeth of the bottom jaw, especially at treatment of anomalies of a neutral bite after removal, under the orthodontic indications, of the first premolars on top and bottom jaws.
After measurement of dental arches and calculations start bending of arch from the right lateral site to left. By means of the ruler measure distance from the mesial end of tubes on basic molar up to lateral surface of lateral incisor. The end of arch entering into a tube, should be equal on the average 10 mm. Ahead of molar on the bottom jaw arch bend downwards under a right angle and through 4 mm the second bend direct it parallel to occlusal plane. At level of mesial surface of canine crown bend the arch in a vertical direction and again through 4 mm in horizontal. After that, symmetrically bend the left part of arch.
Lateral sites of Utility-arch have below of canines and premolars cervices. The median site of arch should have the ideal form with correct semicircular bend of necessary diameter.
After end of bending of arch and creation of rotundity in its anterior site by means of the special shaper, the ends of arch bend inside under a corner of 20-30º for prevention of turn of basic molars. Except for that the ends of arch bend in a vertical direction on 30º. In the further the arch fix in brackets on incisors providing the establishment of the last in correct position.
It is important to fix the first permanent molars that they were not displaced distal under influence of counteracting forces that is especially important at indications to distal moving of canines and oral moving of cutters.
For dento-alveolar shortening in anterior site of dental numbers of the bottom jaw it is necessary unbends the ends of arch downwards on 45º. Thus after accommodation of the ends of Utility-arch in tubes its anterior site should displaced at a level of a transitive fold of mucous membrane in anterior site. At strengthening of median site of arch in brackets, it is necessary to track, that there was no overturning of molars in distal direction. It is important, that the first molars owing to rotation of roots were displaced in cortical direction, i.e. aside of strong bone layer. With this purpose the ends of arch bend aside tongue oral on 20º that provides achievement of correct occlusion of molars of the bottom jaw with molars of the top jaw. To prevent undesirable lingual moving of molars crowns the ends of arch allocate from tubes on 0,5cm, i.e. expand it.
At close position of anterior teeth on the bottom jaw it is possible to bend T-shaped springs to establish teeth in dental arch.
For prevention of inclination of incisors crowns of the bottom jaw in a vestibular direction, at their moving inside, it is necessary to bend by rotation of anterior site of arch for promotion of roots of teeth. Such, by reach dento-alveolar shortening in anterior site of dental arch and inclined moving of incisors.
Modified Utility-arches are intended for expansion of dental arches, mesial moving of groups of teeth, corrections of position of separate teeth.
14. Diastema
Depending on the arrangement of longitudinal axes of the central incisors in relation to a median plane of the face, median palatal ridge of the top jaw, a median plane of the bottom jaw distinguish 3 kinds of diastema: 1. lateral deviation of the central incisors crowns at a correct arrangement of tops of their roots; 2. case lateral displacement of incisors and almost parallel arrangement of their longitudinal axes; 3. mesial inclination of incisors crowns and lateral deviation of their roots.
The fixed arch device select at indications to case mesial moving of incisors for elimination of diastema of 2 kind or if necessary in a greater degree to pull together roots of the central incisors, than their roots - at diastema of 3 kind.
For treatment of diastema of 1st kind, at indications to mesial inclination of teeth crowns easier to apply the removable device with various kinds of springs; hands-shaped; with a curl; the wound springs which have been put on a vestibular arch at small incisal overlapping and rubber draft from the vestibular and oral parties of incisors crowns.
For elimination of diastema of 2nd and 3rd kinds the fixed device adjusts bands to crowns of the central incisors, weld on them brackets, strengthen bands by means of phosphate - or visphat-cement. In day bend a piece of rectangular wire. Its ends bend oral that they did not injure a lip and strengthen this piece in slot of bracket.
For rapprochement of incisors usually use 2 connected bands from chain elastic.
At indications to moving to median line of one tooth, and another - more often a canine - in lateral direction are used bands on the central incisors and canines with brackets. Partial arch put on springs in the field of lateral incisors which move apart basic teeth. Springs should be on 1/3 or 1/2 longer than interval between basic teeth.
15.Distal moving of canines on a place of removed the first premolars
For distal moving of canines, at application of Ricketts technique, prepare partial loopy arches - retractors. They bend from Elgiloy blue wire. Use weak forces due to pulling up behind of retractor on 1 mm and bending of the ends of an arch behind of tubes on basic molars.
Retractor for the top canine consists of vertical loops and four curls (Fig. 36-39).
Fig. 36 Forms and fabrication stages of section wire retractor for canines of the top (1, 2) and the bottom (3,4) jaws.
. 36. (1, 2) (3,4) .
Fig.37. Variant of pulling together teeth Utility arch from Elgiloy blue wire section 0,4 0,4 mm in combination to section arches and intermaxillary draft. Stages of arch bending.
.37. 0,4 0,4 . .
Fig.38. Utility arch for top dental numbers in combination to section arches and intermaxillary draft
. 38. .
Fig.39. Utility arch for top dental numbers with bends double delta in combination to intermaxillary draft. Fabrication stages of arch.
For its manufacturing take a piece of a wire in length of 70 mm. The ends of loops bend under a corner of 45º so, that between them is formed the right angle that prevents promotion of a moved canine and it distal inclination. On anterior site of retractor bend ringlet providing pressure upon the moved canine with mesial party of its crown in distal direction. In 3-4 weeks after strengthening of retractor it activate up to 3 mm. To avoid turns of canines and molars crowns, do bends in palatal direction, equal of 45º.
At manufacturing of retractor for canine of the bottom jaw take a piece of a wire in length 60 cm, developing greater force, than for retraction of canine of the top jaw. Such retractor consists of two vertical loops and 2 spiral curls.
To prevent overturning of the canine and the second premolar in alveolar space of the removed tooth horizontally located sites of retractor bend behind of vertical loops aside of gingival edges. Retractor is activated up to 2-2,5 mm. Horizontal part of retractor bend on 20-45º to avoid rotation of a teeth.
At activation of retractor:
- on 1mm develops the force equal 75 g
- on 2 mm - // - - // - 220 g
- on 3 mm - // - - // - 300 g.
After removal of first premolars, on both jaws at a neutral bite, and partial distal moving of canines of the bottom jaw, during elimination of close position of anterior teeth, start to distal moving of canines of the top jaw. Having finished moving of canines, block their position by means of ligature and move incisors on the released place.
To change inclination of a longitudinal axis of canine and in particular sites of root in mesio-distal and vestibulo-oral directions probably by means of fixed devices, application of rectangular arch and edge-wises, i.e. uses of the multi-element fixed device (Fig.40).
Fig.40. Form and fabrication stages of Utility arch with springs double delta for shortening of dental arch.
At indications correct position of mesial inclined second permanent molars (Fig. 41).
.40. ,, ,, .
(P.41).
Fig. 41. Section arches with T-shaped bends from similar wire (1). Fabrication stages of arches (2, 3). Arch for correction of an inclination of 47 from a wire 0,45 0,55 mm (4).
. 41. - (1). (2,3). 7‾| 0,45 0,55 (4).
16. Distal bite of gnathic and
gnatho-cranial versions
Distal bite of dento-alveolar versions usually arrange in the period of change of teeth by means of orthodontic devices.
At gnathic and gnatho-cranial disorders which define on the basis of studying of lateral teleroentgenograms of head, in the final period of temporary bite, and also in the period of active growth of jaws in the age of from 5,5 years till 13-14 years it is expedient to apply functional-operating orthodontic devices (a regulator of functions by Frenkel of 1st type, Klammt open activator, Balters, Jason and Horoshilkina-Tokarevich bionators, etc.). After the termination of active growth of jaws for end of treatment apply for the period of 6-10 months fixed dental arch devices. Before the beginning of such treatment define its problems - achievement of neutral occlusion of canines, increase of the bite, elimination of abnormal inclination of axes of incisors, elimination of sagital cracks between incisors, at distal bite with protrusion of incisors of the top jaw.
At corresponding indications - individual macrodentia, family similar anomalies of a bite, under developingof the bottom jaw and it apical basis, sharply expressed close position of teeth and lack of the place for separate from them (more often lateral incisors and canines) for elimination of distal bite it is expedient to remove the first permanent premolars only on the top jaw or on top and bottom jaws. Removal of the first temporary molars together with follicles of the first premolars in the age of 8,5 years provides change of inclination of axes of follicles of canines, them distal displacement by self-control aside the least resistance, namely on a place of the removed follicles of premolars, and eruption in dental arch. Such medical action in combination to massage (manual, vibrant-vacuum, etc.) and with application of functional-operating devices provides positive results of treatment.
Before the beginning of treatment after the analysis of data of the anamnesis, studying of lateral teleroentgenograms of head, models of jaws, definitions of the form of the face, the constitution of the patient and family features of its development it is important to select a method of treatment of distal bite, to think over ways of maintenance of stability of basic lateral teeth at moving of anterior in view of laws of biomechanics, to define the forecast of treatment and its end results.
Use of Dentoforma-Unit (Tpodont) - adaptations for experimental check of correctness of bend of arch, direction of moving of teeth facilitates work of the orthodontist. After accommodation and fixing of bonded arch in brackets, on the special phantom teeth executed with roots, placed in a special wax basis in occludator, heat up such appliances and analyze of direction of moving of teeth under influence of dental arches.
In cases of wrong bending of arch to what testifies corresponding moving of teeth, the arch correct and experimentally reach its correct influence on teeth. Only after that fix the arch on teeth of the patient that reduces medical mistakes up to minimum.
After bending of wire arch, introduction of its ends in the basic tubes which are being on molars, in the beginning impose ligature bandages on wings of brackets in which the arch is completely entered into a slot. Use wire ligature bandages or elastics ligature. After that cautiously strengthen arch in other locks, not putting greater efforts to not cause deformation of the arch and the overload paradontium of separate teeth. If the tooth is turn on axis the ligature spend under the arch and impose it on wings of bracket, the most removed from the arch.
Chains from elastic chain apply to fixing the arch only at presence of cracks between teeth for their reduction.
At the subsequent receptions of patient the doctor should specify its sensations, the complaint, to check fixing of each band and bracket, quality of the hygienic maintenance of oral cavity. At long using of fixed arch technique it is desirable to remove bands after 6-8 months, to check up the condition of enamel of teeth and again to strengthen them, that is necessary for the prevention of enamel decalcination. At application of bands-technique it is shown remineralising therapy and oral hygiene care by cleaning of teeth by fluoride containing pastes.
On regular basis it is necessary to activate the arch, to watch occurrence of teeth mobility, and also complaints to them sensitization.
Important on regular basis to supervise moving of teeth by measurement of distances between cutting edges of incisors, cusps of other teeth in transversal, sagital and vertical directions. Obtained data at each reception of the patient write down in the case record and compare to the sizes received at primary and last measurement of diagnostic models of jaws.
At the open bite, plural adentia, retention of teeth or their early loss it is necessary to fix in a bite initial diagnostic models of jaws by means of wax bases with bite platens that provides more exact determination of moving of teeth during treatment.
Change of angulations of incisors and basic molars can be specified by teleradiological research of a head and comparison of the received data with data of primary researches.
At planning of orthodontic treatment and during its carrying out it is important to provide under indications steady position of basic molars, i.e. them anchorage. Thus it is necessary to calculate force of action of the device, force of counteraction equal to it, an opportunity and ways of maintenance of steady position of basic teeth.
At application of the big force of action of the device, strong pressure upon of the tooth periodontium, it does not move or moves extremely slowly. Important correctly to operate applied force.
Stability of basic teeth depends from:
1) The areas of roots of basic and moved teeth; the greater is area of roots of teeth, the greater force is required for their moving and on the contrary;
2) Demanded direction of moving of teeth; in mesial direction to move teeth it is easier, it is required to put smaller force; in distal direction - it is more difficult, it is required to put greater force since this direction opposite to growth and physiological displacement of teeth;
3) Presence of obstacle on a way of moved tooth - near the located adjoining tooth - occurs case moving for which realization greater force is required; absence of obstacle on a way of moved tooth, for example distal moving of canine on a place of removed the first premolar, under influence of the enclosed relative small force the tooth bends aside the least resistance.
Anchorage of basic teeth probably to reach due to:
1) Inclusions in support of a lot of the teeth having the sufficient area of roots, for example the first and second permanent molars;
2) Bends on the ends of arches between the second premolars and the first permanent molars under a corner of 30º to occlusal planes, but in an opposite direction from it, which interfereto displacement of basic teeth;
3) Use of incisors as a support with the purpose of prevention of their inclination at influence of the forces directed on them in oral or vestibular directions; due to corresponding to vertical move and turning incisors of bends of rectangular arch, its insertion with effort in slots of brackets, strengthening with ligature bandages that raises resistibility of incisors to inclination;
4) Inclusions in the block of palatal and lingual arches fixed on basic molars which counteract their overturning and displacement;
5) Applications of intermaxillary and extraoral drafts when counteracting force is transferred to an opposite jaw, a nape or a neck.
At application of removable plate for the top jaw with springs with a curl or springs of double draft for distal moving of canines on a place of the removed first premolars it is expedient to provide stability of basic teeth. With this purpose for prevention of mesial displacement of the second premolars and the first permanent molars use vestibular dental arch with a support of its ends on mesial surface of crowns of the second premolars, and also Adams clasp on 6 | 6 and bite platform for incisors of the bottom jaw. It is desirable to provide prints of cutting edges of anterior teeth of the bottom jaw that increases a support of the device on the platform and prevents its displacement. At application of such device anchorage lateral teeth will be rather sufficient since canines move in distal direction not having a barrier and consequently inclined. Thus the can be used force of their moving equal to 30 g on everyone canine. However at such situation it is possible mesial displacement of teeth of the top jaw - premolars and molars, and also anterior teeth that will promote increase of sagital crack of between incisors. The increase of force for distal moving of canines will promote increase of mesial moving of other teeth.
Other mechanism of influence by the fixed arch device, in particular of section arches by Ricketts. For distal moving of canines with their help should be enclosed greater force since to inclination of canines interferethe rectangular arch, therefore moving of canines occurs more slowly. Anchorage of the first permanent molars provide with use of a rigid rectangular wire arch and brackets, interfering to inclination of teeth. However, and at such way of treatment can occur mesial moving of basic teeth that prevent application of extraoral drafts. The arch develops at case moving of teeth force of friction; in this connection apply rubber rings force in 3 times of greater in view of braking properties of the arch. Mesial moving of basic teeth is desirable only at presence of surpluses of the place which have remained after removal of first premolars and the establishment of canines in dental arch. In this connection the opportunity of the control of moving of basic teeth is advantage of application of fixed devices before application of removable.
Distal bite with protrusion of incisors of the top jaw (class II by Angle). Elimination of sagital cracks between incisors - one of the purposes of treatment of this anomaly of a bite. If as a result of orthodontic treatment in the period of a replaceable bite with application of is functional-operating orthodontic devices have been reached the sufficient increase in the sizes of the bottom jaw and growth inhibition top the subsequent correction of position of teeth can be provided by means of fixed arch orthodontic devices - edgewise-technique without removal of a separate teeth. During treatment expand dental arches, correct their form, the torck and angulations of teeth, reach plural contacts between dental numbers and provide long retention of the reached results up to inter-conditionality of the form and function in dento-maxillo-facial area.
To thicket at treatment of distal bite with protrusion of incisors of the top jaw at individual macrodentia, gnathic and cranial disorders remove under orthodontic indications of separate teeth, more often the first premolars.
Arrangement of teeth of anterior segment of the bottom jaw, namely their vestibulo--oral inclination, in the end of orthodontic treatment should be analogous to position in the beginning of treatment. Is admissible correction of turns on axes of these teeth, their alignment, but it is not necessary to aspire to normalization of size of inter-incisive corner as axial position of incisors of the bottom jaw is determined by influence of muscular tone of a lower lip and tongue and these teeth are in zone of muscular balance. If corners of inclination of axes of anterior teeth of the bottom jaw will be changed, it is the precondition to recidivate of anomaly. Position of anterior teeth of the top jaw, probably change at elimination of sagital cracks between incisors. Improvement of parity of incisors crowns of the top jaw and lower lip favorably for achievement of steady results of treatment.
The vestibular deviation of incisors of the bottom jaw and expansion of its dental arch in the field of canines during correction of close position of teeth can lead in the further recidivate to anomaly.
The best results of treatment can be reached by distal moving of canines of the bottom jaw after the preliminary analysis of their axial inclination during studying the lateral teleroentgenogram of the head. Canines of the bottom jaw should be moved distal so that began possible to correct position of incorrectly located incisors. Canines of the top jaw should be established in neutral position in relation to canines of the bottom jaw and after that to start elimination of sagital crack between incisors.
After removal of the first premolars at distal moving of canines on their place it is impossible without of corresponding indications to admit mesial displacement of lateral teeth. With this purpose it is possible to take advantage of intermaxillary support and draft (Fig.42). However thus it is necessary to watch, that has not occurred excessive mesial displacement of lateral teeth of the bottom jaw.
