Title:
Method and apparatus for orthodontic treatment
United States Patent 3916526


Abstract:
The apparatus for the orthodontic treatment of teeth which form a dental arch includes a 0.016 inch by 0.022 inch rectangular arch wire, labial brackets having a 0.016 inch slot, buccal brackets having a 0.022 inch slot, and two-way buccal tubes. The two-way buccal tubes have a two-way slot for anchoring the arch wire regardless of whether the 0.016 or the 0.022 dimension is in the vertical position. The arch wire, therefore, can initially be secured to the dental arch with its 0.016 inch dimension being vertical. Then the arch wire may be twisted 90° at the junctures of the anterior and posterior teeth and be secured to the dental arch by inserting the vertical 0.016 dimension of the arch wire into the 0.016 slot of the labial brackets and by inserting the vertical 0.022 dimension of the arch wire into the 0.022 slot of the buccal brackets. In both instances the two-way tube can anchor the arch wire. The apparatus further includes a locking mechanism to lockingly engage the headgear hook of a headgear to the arch wire. Also an anti-friction spring is used to prevent friction between a bracket and the arch wire through the application of a counter moment to a tooth. This allows the tooth to slide along the arch wire when an elastic force is applied to the tooth.



Inventors:
SCHUDY FRED FRANK
Application Number:
05/358972
Publication Date:
11/04/1975
Filing Date:
05/10/1973
Assignee:
SCHUDY; FRED FRANK
Primary Class:
Other Classes:
433/5, 433/17, 433/20
International Classes:
A61C7/30; (IPC1-7): A61C7/00
Field of Search:
32/14
View Patent Images:
US Patent References:
3464114DENTAL ATTACHMENT WITH COOPERATING EXTENSION OR SOCKET1969-09-02Brader
3408739Orthodontic bracket1968-11-05Johnson
2908974Orthodontic attachment1959-10-20Stiften
2381128Orthodontic bracket spring1945-08-07Laskin
0523192N/A1894-07-17



Primary Examiner:
Peshock, Robert
Attorney, Agent or Firm:
Robinson, Murray Conley Ned Rose David Alan L.
Claims:
I claim

1. An orthodontic apparatus for the treatment of the anterior and posterior teeth of a dental arch comprising:

2. An orthodontic apparatus as defined in claim 1 further including buccal tubes attached to two posterior teeth for anchoring said arch wire, said buccal tubes having a bore with a square cross-section of a dimension slightly larger than the large dimensioned side of the arch wire and means disposed within said bore to limit the rotation of said arch wire when said arch wire is inserted within said bore with the large dimensioned side vertical or horizontal.

3. An orthodontic appliance as defined in claim 1 wherein one of the dimensions of said rectangular cross-section is .016 inches.

4. An orthodontic appliance as defined in claim 1 further including calibrations on said arch wire for sizing said arch wire element with the dental arch.

5. An orthodontic appliance as defined in claim 1 further including locking means disposed on said arch wire adapted for locking engagement with a headgear to hold said arch wire element in position.

6. A buccal tube for securing an arch wire having a rectangular cross-section with a large dimensioned side and a small dimensional side to a tooth comprising:

7. A buccal tube as defined in claim 6 wherein said means includes at least one square cross-sectioned stop member disposed in one or more longitudinal corner of said bore; said stop member having a dimension slightly smaller than the difference between the dimension of the large dimensioned side and the small dimensioned side of the arch wire.

8. An orthodontic apparatus as defined in claim 1 further including means for shifting a tooth along said arch wire substantially without friction between one of said brackets and said arch wire comprising:

9. An orthodontic apparatus as defined in claim 8 wherein

10. An orthodontic apparatus for the treatment of a dental arch composed of anterior teeth and posterior teeth comprising:

11. An orthodontic appliance for receiving and securing the terminal ends of a rectangular cross-sectioned arch wire to a tooth, comprising:

12. An orthodontic appliance comprising:

13. An orthodontic appliance as defined in claim 12 wherein said anterior loops have an opening slightly larger than the diameter of said hook and said hook includes a groove.

14. An orthodontic appliance as defined in claim 13 wherein said anterior loops have an opening slightly larger than the diameter of the said hook and said hook has an arcuate diameter slightly smaller than the diameter of said anterior loops in said arch wire.

15. An appliance for straightening teeth comprising:

16. A buccal tube for anchoring a rectangular archwire having the dimensions 0.016 inches by 0.022 inches comprising:

17. An orthodontic apparatus for the treatment of a dental arch composed of anterior teeth and posterior teeth comprising:

18. An orthodontic appliance comprising:

19. An orthodontic appliance as defined in claim 18 wherein said loop has a opening slightly larger than the diameter of the arch wire and said hook includes an arcuate groove.

20. An orthodonic appliance as defined in claim 18 wherein said loop has an opening slightly larger than the diameter of the arch wire and said hook has an arcuate diameter equal to the diameter of said arch wire.

Description:
BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention pertains to orthodontic treatment and more particularly relates to a method and apparatus for the utilization of an arch wire.

2. Description of the Prior Art

The art of orthodontics is the correction of irregularities of the teeth. Typical orthodontic mechanotherapy during orthodontic treatment are the rotating of the teeth into proper position, the shifting of a tooth to close a void caused by the extraction of a tooth, the uprighting of the teeth in the dental arch, the aligning of the teeth in a proper arch form, and the coordinating of the lower dental arch with the upper dental arch. To achieve this mechotherapy certain orthodontic apparatus and appliances have been constructed. Such appliances include arch wires, brackets, buccal tubes, various springs, elastic bands, and headgear, to name a few.

The arch wire is a wire or band which is positioned around the outer periphery of the dental arch extending from the posterior teeth on one side of the arch to the posterior teeth on the other side of the arch. Similar arrangements are employed on both the upper and lower dental arches. The arch wire is secured to the teeth by brackets attached to each tooth by a metal band. The arch wire is anchored to one of the posterior teeth, generally the second molars, by means of a buccal tube which is likewise secured to the anchor tooth by a metal band.

In certain cases the dental arch is too small to accommodate all of the teeth whereby it is desirable to extract certain teeth to allow space for the alignment of the others. Appliances are then used to shift the teeth to close the void caused by the extraction of a tooth. Generally, an elastic band or thread is attached to the tooth to be shifted and to one or more anchor teeth. The elastic band causes the tooth to move towards the anchor teeth. However, under existing methods the bracket secured to the tooth to be shifted must slide on the arch wire since the arch wire is disposed in a horizontal slot in the bracket. Problems arise because the crown of the tooth will tend to tip due to resistance of the bone and gums around the root of the tooth. As the tooth tips the arch wire engages the edges of the slot in the bracket and tends to bind so as to cause friction between the arch wire and the bracket. Such friction retards the movement of the tooth.

One solution to this problem is to lengthen or widen the longitudinal length of the slot of the brackets to resist the binding tendency of the bracket and arch wire. However, the wider bracker reduces the distance between brackets leaving no space for hooks, loops, joints, and the like. The orthodontist has no working room which tends to increase work time not to mention the tension and frustration created for the patient and orthodontist. Greater force is required to seat the arch wire and more arch wires are required since the size of the wires have to be increased slowly to permit the threading of the wires through all the slots of the brackets due to the sharp bends required. The flexibility from one bracket to another is also decreased. Needless to say all operations have to be more exact due to the reduction of space.

A variety of sizes and shapes of arch wires are used during orthodontic treatment under present methods. Generally a series of round arch wires, having much resiliency, are used initially and their size is increased from 0.014 to 0.020 inches until the dental arch is sufficiently formed to use a square or rectangular arch wire having greater strength and rigidity to close voids and to level the dental arch. Likewise several different square or rectangular wires are used to increase the strength of the arch wire to stabilize the teeth in their new positions and to coordinate the upper dental arch with the lower dental arch.

Rectangular arch wires have a range of sizes. The rectangular wire size most often used is that of 0.018 × 0.025 as described in U.S. Pat. No. 3,076,265. Other rectangular arch wires are described generally in U.S. Pat. Nos. 2,566,414; 3,043,007; 3,052,028; 3,076,265; 3,091,857; 3,464,112; and 3,578,744. It should be noted that much resiliency in the arch wire is lost when the round arch wire is replaced for the 0.018 × 0.025 rectangular arch wire.

The rectangular arch wire is generally formed by hand and then installed. Methods of forming arch wires are described in U.S. Pat. Nos. 2,566,414 and 3,578,744. Often forming the arch wire by hand is time consuming due to inadequate means of measurement. Much time would be saved by accurate measuring means and preformed arch wires.

As described previously and in U.S. Pat. No. 3,494,034, the arch wire is anchored at each end to buccal tubes generally secured to the second molars. Such buccal tubes, previously used, limit the snug fit of the rectangular arch wire to one cross-sectional direction. To use the other cross-sectional direction or wires of another size, a loose fit could only be maintained within the tube. Heretofore all tubes and brackets only provided a precision fit where the longer cross-sectional dimension was in the horizontal position.

Various brackets, some of which are described in U.S. Pat. Nos. 1,280,628; 1,584,501; 1,890,487; 2,971,258; 3,043,007; 3,052,028; 3,076,265; 3,091,857; 3,128,553; and 3,302,288, are used to secure the different sized arch wires to the teeth. Generally such brackets have a slot which retains the arch wire. The arch wire is then secured to the bracket by a wire engaging device. Existing arch wire engaging devices or brackets are of three types. The first is a ligating bracket which requires the use of soft wire to tie the arch wire to the bracket. The second is a non-ligating bracket with a removable cover which may be secured to the bracket for holding the arch wire. The third type is a non-ligating bracket with an attached cover which secures the arch wire to the bracket.

In using a rectangular arch wire to level the posterior teeth, it is necessary to have a clearance between the rectangular arch wire and the inner surface of the slots in the buccal brackets to permit the teeth to slide on the arch wire as the posterior teeth shift into position. The arch wire cannot be permitted to completely fill the slots or to fit snugly therein since friction will occur between the brackets and the arch wire limiting the movement of the tooth. However, since the labial brackets on the anterior teeth have the same sized slots as the buccal brackets, there will be a gap between the wire and the labial brackets which is undesirable because the orthodontist then loses control of the anterior teeth. Therefore the anterior teeth begin to lose some of the proper alignment previously achieved while the orthodontist is attempting to level the posterior teeth.

To exert some pressure on the appliance to either move teeth posteriorly and/or prevent their movement anteriorly, a headgear is connected to the arch wire. The headgear generally includes an orthodontic headgear hook attached to the arch wire and an elastic band attached to the ends of the headgear hook for the application of pressure to the arch wire. A face bow is shown in U.S. Pat. No. 3,492,044. The prior art headgear have a hook attached to the arch wire and a loop on the headgear hook creating various disadvantages. Often the headgear comes disconnected from the arch wire during the night.

SUMMARY OF THE INVENTION

The apparatus for the orthodontic treatment of teeth includes an anti-friction spring which hooks to the rotating levers of the bracket secured to a tooth to be shifted into a void. The spring is affixed to the arch wire at various distances from the bracket. The spring provides a moment on the crown countering the moment on the root due to the gums and bone.

The apparatus also includes a 0.016 by 0.022 inch rectangular arch wire, labial brackets having a 0.016 vertical slot, buccal brackets having a 0.022 vertical slot, and two-way buccal tubes. This permits the orthodontist to level the posterior teeth while still maintaining control of the anterior teeth since the 0.016 vertical dimension of the arch wire fills the slots of the labial brackets but still permits a 0.006 inch gap in the slots of the buccal brackets to prevent any friction between the buccal brackets and arch wire.

The arch wire may be twisted 90° at the junctures of the anterior and posterior teeth whereby the 0.016 arch wire dimension fills the labial brackets and the 0.022 arch wire dimension fills the buccal brackets. This permits the orthodontist to control the anterior teeth and the posterior teeth at the same time; but yet the twisted arch wire will have its 0.016 dimension vertical when adjacent to the anterior teeth for added resiliency and will have its 0.022 dimension vertical when adjacent to the posterior teeth where more strength and rigidity are required.

The 90° twist makes maximum use of the strength of the arch wire and permits fewer removals and replacements of arch wires. Further the treatment is much easier on the patient and requires less time.

Another advantage is the use of one arch wire to take the place of two arch wires of different sizes.

Further the reduction of the size of the slots of the labial brackets from 0.018 to 0.016 increases the torquing capability and produces a lighter force.

The arch wire in the present invention is coded whereby a unique arch caliper is used to measure the length of the dental arch comprising the anterior teeth, and the length of the arch wire required. The caliper is applied to the dental arch to mark the location of the 90° twists and to indicate the length of the arch wire required. A calibrated preformed arch wire is then selected which has the proper dimensions. Such a device eliminates haphazard measurement and permits the use of preformed arch wires.

The present invention further includes two-way buccal tubes permitting the rectangular arch wire to be secured with either dimension in the vertical position.

The present invention further describes an orthodontic headgear hook and connector which elimnates an accidental removal of the headgear from the arch wire.

The method of orthodontic treatment comprises the steps of securing the arch wire in the untwisted position with the 0.016 dimension in the vertical direction to the labial brackets, buccal brackets, and two-way tubes; removing the arch wire; locating the junctures of the anterior and posterior teeth; twisting the arch wire 90° at these junctures; securing the twisted arch wire to the labial brackets by inserting the 0.016 dimension of the twisted arch wire being vertical into the 0.016 slot; securing the twisted arch wire to the buccal brackets by inserting the 0.022 dimension of the twisted arch wire being vertical into the 0.022 slot; and anchoring the twisted arch wire in the two-way tubes with the 0.022 arch wire dimension being vertical.

Another object of the present invention is to streamline orthodontic appliances by eliminating various removable auxillary attachments to rotate, torque, and upright teeth. The present invention permits the use of the edgewise technique in its simplest form.

Other objects and advantages of the invention will appear from the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

For a detailed description of a preferred embodiment of the invention, reference will now be made to the accompanying drawings wherein:

FIG. 1 is a side view of two arch wires secured and anchored to a set of teeth;

FIG. 2 is a plan view of a dental arch having two voids;

FIG. 3 is a side view of the dental arch shown in FIG. 2;

FIG. 4 is a front view of an anti-friction spring mounted on a tooth;

FIG. 5 is a view of the spring as indicated in plane 5--5 in FIG. 4;

FIG. 6 is a side view of one of the brackets shown in the environmental view of FIG. 1;

FIG. 7 is a plan view of an arch caliper;

FIG. 8 is a plan view of an arch wire having two 90° twists;

FIG. 9 is an enlarged view of one of the 90° twists in the arch wire shown in FIG. 8;

FIG. 10 is a plan view of a buccal tube and a portion of a band;

FIG. 11 is an end view of the buccal tube as indicated in FIG. 10;

FIG. 12 illustrates the end view of a variety of buccal tubes lettered A through E;

FIG. 13 is a plan view of a calibrated arch wire;

FIG. 14 is an end view of the calibrated arch wire of FIG. 13 showing the connectors for a face bow;

FIG. 15 is a plan view of a headgear hook for engagement with the connectors and arch wire of FIGS. 13 and 14;

FIG. 16 is a plan view showing a headgear hook attached to an arch wire; and

FIG. 17 is an end view of the headgear hook and arch wire of FIG. 16.

DESCRIPTION OF THE PREFERRED EMBODIMENT

A variety of appliances are utilized in orthodontics. In FIG. 1 there is shown an environmental view of a set of appliances. Those appliances include an arch wire 120, brackets 124, and a buccal tube 190 installed on an upper dental arch 10 and a lower dental arch 12. Referring now to the upper dental arch 10, arch 10 includes central incisors 14, lateral incisors 16, cuspids 18, first bicuspids 20, second bicuspids 22, first molars 24, and second molars 26. Of course a corresponding set of those teeth is located on the other side of dental arch 10. The central incisors 14, lateral incisors 16, and the cuspids 18 can be generally defined as the anterior teeth or front teeth, and the first bicuspids 20, second bicuspids 22, first molars 24, and second molars 26 can be generally defined as the posterior teeth or back teeth. A similar arrangement is found in the lower dental arch. An exception to the above will occur if one of those teeth has been extracted.

The hereinafter described appliances are utilized for orthodontic mechanotherapy to rotate and shift the teeth to achieve proper alignment. As shown in FIG. 1 brackets 124 are secured to the teeth and buccal tubes 190 are affixed to an anchor tooth such as the second molars. Then an arch wire is attached to the brackets 124 and anchored to buccal tubes 190 to provide a source of pressure and leverage for aligning the teeth.

Referring again to FIG. 1 a variety of arch wires have been used in the past during treatment which are of all sizes and shapes. Initially a series of preliminary arch wires are used which are round and have much resiliency. The preliminary round arch wires generally range from 0.014 to 0.020 inches in diameter. Later in the treatment rectangular wires are used which have greater strength and rigidity. In the present invention only two different arch wires are required, barring exceptional circumstances, first a preliminary round arch wire and then a rectangular arch wire.

In FIG. 1 it is seen that the arch wire 120 is inserted into a rectangular slot 122 in brackets 124, best illustrated in FIG. 6, which are secured to the teeth by metal bands 126 or may be by adhesive. Brackets 124 could be any of three types for securing arch wire 120. The first is a ligating bracket which requires the use of soft wire to tie the arch wire to the bracket. The second is a non-ligating bracket with a removable cover which may be secured to the bracket for holding the arch wire. The third type is a non-ligating bracket with an attached cover which secures the arch wire to the bracket 124. Any of these types may be used. However, FIG. 6 illustrates the first type which is preferred.

Buccal tubes 190 anchor the arch wire 120 and are generally secured to the two molars 26 by means such as metal bands 132 or possibly by adhesive.

The preliminary round arch wire (not shown) is formed and then installed on dental arch 10 shown in FIG. 1. The round arch wire is inserted into slots 122 of brackets 124 and a soft wire (not shown) is wrapped around bracket wings 134, 136 and the round arch wire to secure the round arch wire to brackets 124. The ends of the round arch wire are anchored by insertion within buccal tubes 190.

The preliminary round wire is used principally to rotate the irregular teeth into position and to place the teeth in general alignment for the application of the arch wire 120 shown in FIG. 1. After the removal of the preliminary round arch wire, arch wire 120 is installed to close any voids, to level the teeth and to produce fair arch form.

Where a tooth has been extracted, as for making room for the other teeth, a non-friction spring is illustrated in FIGS. 4 and 5. Referring now to FIGS. 2 and 3 a space 62 is shown in dental arch 64. To shift tooth 66 into space 62 an elastic band 76 is engaged to bracket 68 secured to tooth 66 by metal band 70 and is also engaged to buccal tube 72 on molar 74. Elastic band 76 may be an elastic thread or a rubber band. Elastic thread 76 is wrapped around bracket 68 and tube 72 and is then tied. A rubber band may merely be slipped over bracket 68 and tube 72.

Another method of closing a space is also shown in FIG. 2. To close space 78 by moving tooth 80, a hook 82 has been soldered or otherwise secured to the lingual side of metal band 84 on tooth 80. Another hook 88 is secured to the lingual side of metal band on molar 90. An elastic band 92 similar to band 76 is secured to hooks 82, 88.

During this treatment the molars 74 and 90 together with teeth 94, 96 respectively are an anchor by which a distal force is placed on teeth 66, 80 to move them into spaces 62, 78.

Referring specifically to the movement of tooth 66 since a similar movement is made of tooth 80, there is shown in FIG. 3 a tendency for the crown 98 of tooth 62 to tip in a clockwise direction 100 due to the resistance of the distal movement of the root 102 of tooth 62 by gum and bone at 104. This tipping causes arch wire 106 to bind within slot 108 of bracket 68. The binding increases the friction between bracket 68 and arch wire 106 because the edges of slot 108 bite into arch wire 106. The narrower the slot in bracket 68 the greater the increase in binding and friction.

Referring now to FIGS. 4 and 5 there is shown anti-friction spring 110. Spring 110 has a hook 112 on one end which engages the upper portion of rotating lever 114 on bracket 68. Spring 110 then bends around the lower side of bracket 68 and up under rotating lever 116 and arch wire 106. It then arches over arch wire 106 and is attached to arch wire 106 by means of hook 118 on the other end of spring 110 at a point on arch wire 106 some distance from tooth 68 in the distal direction. Spring 110 is thereby coiled around bracket 68 and attached to arch wire 106 causing a counterclockwise moment on tooth 66 to counteract the clockwise moment caused by bone and gums at 104. Spring 110 maintains tooth 68 in a substantially vertical plane as tooth 66 moves into space 62 thereby eliminating the binding and friction between bracket 68 and arch wire 106.

Referring now to FIG. 8, arch wire 120 is a filamentary member which may be a wire or a band which is formed around the outer periphery of the patient's dental arch 10 extending from the posterior teeth 20, 22, 24, 26 around anterior teeth 14, 16, 18 and to the other side of arch 10. Arch wire 120 is a strong resilient non-corrodible wire made of a metal such as stainless steel. Although prior arch wire designs had a variety of cross sectional configurations such as circular, square, and rectangular, arch wire 120 has an elongated cross-section, preferably rectangular but it could be elliptical, polygonal, trapezoidal, rhomboidal or the like, with the longest axis being defined as the longitudinal axis of the cross-section. Further wire 120 is preferred to have the cross-sectional dimensions of 0.016 inches by 0.022 inches as shown in FIG. 9.

To secure arch wire 120 to arch 10, brackets 124 shown in FIG. 1 include labial brackets 140 having a vertical slot dimension of 0.016 inches and buccal brackets 142 having a vertical slot dimension of 0.022 inches. Arch wire 120 is anchored by two-way buccal tubes 190, hereinafter described in detail, having a vertical and a horizontal slot dimension of 0.016 inches (see FIG. 11).

Arch wire 120 is installed on dental arch 10 with the 0.016 inch dimension in the vertical position (occlusalgingival) and the 0.022 inch dimension in the horizontal position (labial-lingual) around the anterior teeth and the posterior teeth. Since the 0.016 dimension is vertical, the 0.016 inch slot 122 of labial brackets 140 will be completely filled providing a precision fit between labial brackets 140 and arch wire 120. There will be a 0.006 inch gap or clearance in the 0.022 inch slot 122 of buccal brackets 142. Arch wire 120 will also fit snugly within the 0.016 inch slot of two-way tube 190.

The gap in buccal brackets 142 permits arch wire 120 to slide freely within the bracket as the posterior teeth shift into position during the leveling process. However, no control over the anterior teeth is lost since there is a precision fit between arch wire 120 and labial brackets 140. Further arch wire 120 is also well anchored to tubes 190 since there are no gaps. The fits between arch wire 120 and labial brackets 140 and tubes 190 prevent a rotation relative thereto.

Traditionally brackets have had either the dimensions 0.018 inches or 0.022 inches. By decreasing the width of the slot of the labial brackets 140 to 0.016 inches, greater torque may be placed on an individual tooth and a lighter force is required providing obvious advantages. Therefor by decreasing the size of slot 122 of labial brackets 140 the orthodontist can obtain a maximum torquing capability not before attained. This means a minimum number of arch wires used with a minimum number of removals.

To obtain parallel roots and to coordinate the lower dental arch with the upper dental arch, arch wire 120 is removed and is either reformed as hereinafter described or replaced by a preformed arch wire as hereinafter described. It is preferred that a preformed arch wire be used because of the convenience and because of the time saved. There is shown in FIG. 7 a new and unique arch caliper 150 permitting the use of preformed arch wires. Caliper 150 includes an arcuate bow 152 and a pin 154. Bow 152 and pin 154 are made of a slender non-corrodible metal or plastic wire-like member. Bow 152 attaches to pin 154 at 156 near one end of pin 154 leaving a projection 158 at that end. On the other end of pin 154 a handle 160 may be formed, such as a loop or the like, to operate caliper 150. A series of anatomical markings 162 and a series of size markings 164 are provided on arcuate bow 152. Identical markings 180, 182 respectively are placed on the preformed arch wire 120 shown in FIG. 8 as hereinafter discussed. Anatomical markings 162 include colored rings on bow 152 to determine the length of the arch from the juncture 166 of central incisors 14 to the juncture 168 of cuspid 18 and first bicuspid 20 shown in FIGS. 7 and 8. From this measurement the length of the anterior arch of the anterior teeth may be determined. Size markings 164 are provided to measure the length of dental arch 10 by determining the distance from juncture 166 between central incisors 14 to the second molar 26. Markings 162, 164 are merely calibrations or indicia which may be numerical or not. They may be scored onto caliper 150 and arch wire 120 or may be colored rings as shown in FIGS. 7 and 8. No actual numerical measurements are required since by knowing the color markings 162, 164, a proper preformed arch wire having the same markings may be selected.

In operation caliper 150 is inserted into the patient's mouth so as to partially circumscribe the dental arch to be fitted. Projection 158 is positioned at juncture 166 between central incisors 14 while arcuate bow 152 extends around one side of the dental arch 10. The position of the anatomical markings 162 and size markings 164 with reference to juncture 168 and second molar 26 respectively are thereby indicated. Obviously these measurements are quite easy to make using caliper 150 and such a task can easily be delegated by the orthodontist.

Having the sizes of the dental arch 10, a proper preformed arch wire may be selected having the same markings thereby having the proper lengths. Arch wire 120 may be either reformed by hand by the orthodontist or the orthodontist can be provided with an array of preformed arch wires from which to choose. In the present invention, the orthodontist may have the convenience of selecting a preformed arch wire.

In the reformed arch wire 120 twists 172 are made in wire 120 at the junctures 168 between the cuspids 18 and first bicuspids 20. Twist 172 is illustrated in the enlarged view of FIG. 9. As wire 120 is formed into an arch for positioning around dental arch 10, an arcuate portion 174 and two linear portions 176, 178 are formed. This formation and twists 172 form arch wire 120 so that the longitudinal axis of the cross-section of wire 120 is substantially perpendicular to the occlusal plane, i.e., the plane of dental arch 10 along the arcuate portion 174 and will be juxtaposed with the anterior teeth when installed. Further the longitudinal axis will be substantially parallel to the occlusal plane along linear portions 176, 178 and will be juxtaposed with the posterior teeth when installed.

In essence this method combines two arch wires into one because the arcuate portion 54 will have the longitudinal axis of wire 120 in the horizontal position thereby being very resilient for the anterior teeth and the linear portions 176, 178 will have the longitudinal axis of wire 120 in the vertical position thereby emphasizing the strength and rigidity of wire 120 for the posterior teeth.

Preferably the twist 172 in wire 120 will be a 90° rotation of wire 120 at the determined location. However, it must be understood that the twist need not be exactly 90° but may be for example approximately an 83° twist or approximately a 97° twist depending upon the mechanotherapy required. Often the labial and buccal sides of the anterior and posterior teeth are not vertical within the month thereby requiring a twist 172 to be slightly greater or smaller than 90°.

By utilizing caliper 150 arch wire 120 may be preformed. The anterior arch measurement, by means of anatomical markings 162, will determine the location of twists 172, and the dental arch measurement, by means of size markings 164, will set the length of wire 120. To further simplify the selection of the proper preformed arch wire, calibrations have been disposed on wire 120 at 180 for the anatomical reading and at 182 for the size reading thereby corresponding to markings 162, 164.

FIGS. 10 and 11 illustrate the preferred buccal tube 190 for anchoring reformed arch wire 120. Tube 190 is a two-way tube which may be made of stainless steel, plastic, or an alloy of gold, platinum and irridium. Tube 190 has a longitudinal bore 192 extending mesial-distally and also has a generally square cross-section with dimensions of 0.022 inches. However, a stop 194 of a generally isosceles triangular cross-section having a side of 0.006 inches, the difference between the dimensions of arch wire 120, is milled, molded or in likewise fashion secured in the occlusal-buccal corner 196 of tube 190. Stop 194 permits arch wire 120 to be secured from rotation within tube 190 regardless of whether the 0.016 inch or the 0.022 dimension is edgewise or in the ginguval-occlusal axis and to provide a precision fit of wire 120 within tube 190. The 0.006 inch dimension permits a 0.006 inch clearance on the buccal side of the tube 190 if the 0.022 inch dimension is vertical and also permits a 0.006 inch clearance on the occlusal side of the tube 190 if the 0.016 inch dimension is vertical. However, in both cases, stop 194 arch wire 120 in position and prevents rotation. Buccal tube 190 may either be secured, as by brazing, to a metal band 198 extending around the anchor tooth or be secured by an adhesive.

Referring now to FIG. 12 there is shown five other embodiments of tube 190. Embodiment A comprises four stops 200 which has the advantage of holding arch wire 120 from rotation at four locations. In essence embodiment A includes two rectangular bores through tube 202 each having the same dimensions as wire 120 and are perpendicular to each other with a common mesialdistal axis. Embodiment B also has four stops 204 of the form of stop 194 in FIG. 16 except that a stop has been located in each longitudinal corner of tube 206. Embodiments C and D provide square shouldered stops 208 and 210 respectively. Embodiment E has two projections 212, each providing a positive stop to the rotation of wire 120 depending upon the dimension which is vertical.

As the preformed arch wire 120 is installed on arch 10, the .016 dimension of arch wire 120 will face the anterior teeth and will completely fill the 0.016 slots of labial brackets 140 thus providing a precision fit between wire 120 and brackets 140. The 0.022 dimension of arch wire 120 will face the posterior teeth due to twists 172 and will also completely fill the 0.022 slots of buccal brackets 142 thereby also providing a precision fit between wire 120 and brackets 142. Two-way buccal tubes 190 will also hold wire 120 securely and prevent rotation relative thereto. Thus the orthodontist has resiliency for the anterior teeth and strength and rigidity for the posterior teeth and yet has complete control of all the teeth.

FIGS. 13-17 describe a new headgear hook 220 for use with a headgear (not shown) to apply pressure to arch wire 120. FIGS. 13-14 illustrate the preferred embodiment. Eyes or loops 222 are formed in the front portion of arch wire 120 and comprise circular or omega-shaped loops made in wire 120.

FIG. 15 illustrates headgear hook 220. Hook 220 is generally in the form of a large hook which extends from loops 222 on wire 120 out of the mouth and around the cheek where the end 224 of hook 220 is attached to an elastic band (not shown). End 224 may be in the form of a circular loop for attachment to the elastic band. A notch or groove 226 is ground into the other end of hook 220 for engagement with loop 222 having approximately the same diameter as the diameter of arch wire 120. Groove 226 acts as a lock preventing disengagement once inserted into and engaged with loop 222. The closer that end 224 is brought to the cheek the better the locking engagement.

FIGS. 16 and 17 illustrate a second embodiment of the headgear hook 230. As shown in FIG. 17 eyes 232 are made into a small semi-circle or into a complete loop as illustrated in FIG. 17 and soldered or brazed to arch wire 120. Headgear hook 230 has a small hook 234 secured to one end 236 which engages eye 232 as illustrated in FIG. 16. Hook 234 has an arcuate diameter the same size as the diameter of arch wire 120. Again as end 238 moves towards the patient's cheek, the headgear hook 230 becomes locked into engagement with eye 232. It must be understood that headgear hooks 220 and 230 may be made of either metal or plastic.

In the method of orthodontic treatment labial brackets 140 having a 0.016 slot are secured to the anterior teeth and buccal brackets 142 having a 0.022 slot are secured to the posterior teeth. Two-way buccal tubes 190 are anchored to the second molars 26. The preliminary round arch wire is installed on dental arch 10 by means of brackets 140, 142 and tubes 190 to rotate the irregular teeth into position and to place the teeth in general alignment for the application of rectangular arch wire 120. The round arch wire must be removed prior to installation of the rectangular arch wire 120.

A 0.016 by 0.022 rectangular arch wire 120 is then installed to close any voids, to level the teeth, and to produce good arch form. The rectangular arch 120 has its 0.016 side vertical thereby filling the slots of the labial brackets 140 and leaving a gap in the slots of the buccal brackets 142. Wire 120 is anchored to two-way buccal tubes 190 and prevented from rotation relative thereto. In closing the voids the antifriction spring 110 is used to maintain the tooth to be shifted substantially vertically during its movement. The rectangular wire 120 is then removed.

Caliper 150 is used to measure the dental arch for a preformed arch wire 120. By virtue of these measurements, two 90° twists 172 have been placed in wire 120 at the juncture 168 of the anterior and posterior teeth. The preformed arch wire 120 is then installed with its 0.016 side facing the anterior teeth filling the 0.016 slots of labial brackets 140 and with its 0.022 side facing the posterior teeth filling the slots of buccal brackets 142 due to 90° twists 172. Two-way buccal tube 190 again secures preformed arch wire 120 and prevents relative rotation therewith.

Each time after the rectangular arch wire 120 and the preformed rectangular arch wire 120 is installed, headgear hook 220 is lockingly engaged to the wires to apply pressure to move teeth posteriorly and/or prevent their movement anteriorly.

While a preferred embodiment of the invention has been shown and described, modifications thereof can be made by one skilled in the art without departing from the spirit of the invention.