US3332150A

US3332150A - Method of loosening teeth with high-frequency vibrations

Info

Publication number: US3332150A
Application number: US524999A
Authority: US
Inventors: Everett D Mumaw
Original assignee: Individual
Current assignee: Individual
Priority date: 1966-01-24
Filing date: 1966-01-24
Publication date: 1967-07-25
Anticipated expiration: 1984-07-25

Description

July 25, 1967 E. D. MUMAW 3,332,150

METHOD OF LOOSENING TEE TH WITH HIGB'FREQUENCY VIBRATIONS Filed Jan. 24, 1966 3 Sheets-Sheet, 1

INVENTOR. EVERETT D. MUMAW ATTORNEY July 25, 1967 E. o. MUMAW METHOD OF LOOSENING TEETH WITH HIGH-FREQUENCY VIBRATIONS Filed Jan. 24, 1966 .3 Sheetsheet 2 FIG.-- 9

FIG-8 FIG. l2

FIG-ll INVENTOR EVERETT D. MUMAW 3,332,150 METHOD OF LOOSENING TEETH WITH HIGH-FREQUENCY VIBRATIONS F'iled Jan. 24, 1966 E- D. MUMAW July 25 1967 3 Sheets-Sheet 5 mTQE on g m m :1 R. M E 7 WW MW 9 E D. I O! ..J E o2 m I J B V 5 M NH m2 31 y E Y B 8. SW. 3. N. h N2 N2 ATTORNEYS United States Patent 3,332,150 METHOD OF LOOSENING TEETH WITH HIGH-FREQUENCY VIBRATIONS Everett D. Mumaw, 2717 Edgehill Road, Cleveland Heights, Ohio 44118 Filed Jan. 24, 1966, Ser. No. 524,999 18 Claims. (CI. 32-14) The present application is a continuation-in-part of application Ser. No. 261,399, filed Feb. 27, 1963, now abandoned, and entitled Stomatological Method and Device.

The present invention relates generally to stomatology and more particularly to methods of moving a tooth in its alveolar socket for orthodontia, oral surgery, re-implantation and other dental purposes.

Prior orthodontic or re-alignment procedures and methods are slow, painful and always in the case of surgery, accompanied by traumatic as well as neurological and psychological disturbances. In orthodontia the mechanical aids used to correct irregularities of the dental arch are uncomfortable and unsightly to the wearer and must be worn for several years to sustain tooth re-alignment. In oral surgery the various forceps used to twist, push and pull teeth cause a great deal of injury to the surrounding alveolar structure by both tearing the periodontal membrane connecting the tooth to the surrounding alveolar bone and by causing traumatic destruction of portions of the alveolar bone itself. This leaves an unnecessarily dis turbed wound which is susceptible to infection, and, frequently requires a great deal of time as well as several post operative surgical and/or medical treatments before healing occurs.

Oftentimes, a substantial portion of the alveolar bone itself is lost during tooth extraction, such that the normal contours of he alveolar bone can never be restored. In these instances, irreparable damage is done to the external facial contours of the patient and therefore to his appearance because the tissues recede and shrink, such that the external covering musculature assumes a drawn and haggard look.

A rocking motion utilized in these prior methods of tooth removal can be visualized as a see-saw movement in that the tooth rocks about a fulcrum area approximately at the center of the longitudinal axis of the tooth. Such rocking motions damage the unyielding surrounding alveolar bone in generally direct relation to its rigidity of tooth retention. Further, only opposing apical and coronal ends of a tooth are moved by such rocking motions, not the fulcrum area at the center of the longitudinal axis of the tooth. It is generally impossible, therefore, to loosen a tooth in its socket by a rocking method without damaging the alveolar bone socket.

In addition, the trauma and bone damage done by the prior methods is heightened in view of the marked variance in lengths of the various teeth of a single person as well as between different persons. There may be over 30% difference in length of the various teeth of one person and an even more marked difference between the teeth of different persons. When rocking a tooth, the damage done to the surrounding alveolar wall is the direct function of the amplification of the vibrations produced which in turn is dependent solely upon the length of the tooth. The longer the tooth, the greater the amplification necessary and the greater will be the damage done. Large and intense amounts of trauma will be attendant the tooth removal because of the crushing of the root of the tooth against either wall as it is vibrated. The bone damage and trauma attendant the prior methods is not eliminated by increased speeds of operation, for example, ultrasonic frequencies, alone as the rocking tooth is still being crushed against the alveolar walls. Thus, in those prior instruments utiliz- 3,332,150 Patented July 25, 1967 ing high frequencies to vibrate the tooth, trauma and bone damage is not eliminated.

In these prior instruments, it is necessary generally to vary the amount of the amplification of the vibration in relation to the length of the tooth to achieve any degree of success in removing the tooth. It is therefore necessary to determine the exact length of the tooth. As the motive power used to vibrate the tooth increases in speed, the information as to exact length of the tooth must be even more precise. However, it is presently impossible to accurately predetermine the exact length of a tooth while it is in its socket.

In these prior tooth removal methods, or procedures, lifting of the tooth is equally as indiscriminate and uncontrollable as the rocking motion and is applied during the rocking motion. In these prior methods, a lifting force is applied during and even before the connecting fibers are severed and increase the trauma and tooth damage.

The present invention provides a method of relatively instantaneously and painlessly disconnecting the tooth from its periodontal membrane either for realignment, such as for orthodontic purposes, or for extracting it from its alveolar socket for surgery. The present method comprises rotating, reciprocating or otherwise moving the tooth in situ in an oscillating manner at an ultrasonic frequency without lifting the tooth entirely from its alveolar socket. By the term oscillating it is meant that the tooth is moved in a controlled manner back and forth repeatedly in at least one direction of movement between fixed limits. The back and forth ultrasonic oscillations are substantially equidistant and are sufficient in distance to cause the periodontal membrane to sever, principally at the pericemental of the tooths root rather than from the surrounding alveolar bone structure. In addition, only the periodontal membrane is'detached from the tooth and not the vital apical circulatory and nervous attachments so that the tooth retains its vitality and may be realigned in its alveolar socket for other dental purposes. This movement occurs with minimal trauma to the tooth as well as to the socket and with no apparent sensation to the patient. Moreover, with the tooth disconnected from the periodontal membrane, it may be easily lifted from its socket either at the same time or immediately afterwards by a minimum of elfort.

An instrument is provided for effecting the above stomatological method. In a preferred form' the instrument includes a clamping head which securely fastens to the tooth, a transducer device connected to the clamping head, and suitable electrical circuitry connected to the transducer device to cause it to alternately elongate and retract at an ultrasonic frequency which elongation and retraction imparts a controlled, oscillating movement to the clamping head and to the tooth attached to it. The instrument is shaped and sized to be conveniently held in one hand of an operator. The operator thus using the present instrument can provide precise but free control as may be stomatologically desirable and/or necessary.

Accordingly, an object of the present invention is to provide a new and improved method of dental treatment wherein the tooth is disconnected from the periorontal membrane with minimal trauma to the tooth or the alveolar socket as well as without any apparent sensation to the patient.

Another object of the present invention is to provide a new and improved method of dental treatment wherein the tooth is disconnected from its periodontal membrane but not from its vital apical circulatory and nervous attachments so that it may be moved or repositioned in its alveolar socket for orthodontic purposes.

Still another object of the present invention is to provide a new and improved stomatological method of treatment which loosens the tooth within its alveolar socket without severing the vital apical circulatory and nervous attachments.

An yet another object of the present invention is to provide a new and improved stomatological method of treatment which permits or aids in relatively instantaneous removal of a tooth from its socket with a minimum of traumatic disturbance to the tooth or the socket and without apparent sensation to the patient.

Other objects and a fuller understanding of the invention may be had by referring to the following description and claims taken in conjunction with the accompanying drawings in which:

FIGURE 1 is a top longitudinal view, with portions removed, of one preferred form of a stomatological instrument which can be used in the stomatological method of the present invention;

FIGURE 2 is a side longitudinal view of the instrument of FIGURE 1;

FIGURE 3 is an enlarged, top view of part of the stomatological instrument of FIGURE 1 as taken along line 33 of FIGURE 2;

FIGURE 4 is an enlarged, section view taken along line 44 of FIGURE 2;

FIGURE 5 is a section view taken along line 5-5 of FIGURE 3;

FIGURE 6 is a transverse sectional view of a typical tooth situated in its alveolar socket;

FIGURE 7 is a sectional view in a longitudinal plane of two teeth as situated in their alveolar sockets;

FIGURE 8 is an elevational view of an alternate form of a tooth attaching device for use with the instrument of FIGURE 1;

FIGURE 9 is a cross-sectional view in a longitudinal plane of another alternate form of a tooth attaching device;

FIGURE 10 is a top view of a second preferred form of a stomatological instrument;

FIGURE 11 is a section end view taken along line 1111 of FIGURE 10;

FIGURE 12 is an exploded side view of the instrument of FIGURE 10;

FIGURE 13 is a top longitudinal view, with portions removed, of another form of a stomatological instrument;

FIGURE 14 is a side longitudinal view of the instrument of FIGURE 13;

FIGURE 15 is a cross-sectional view in a longitudinal plane of an attachment mechanism for attaching or mechanically connecting a tooth attaching device to the stomatological instrument of the FIGURES 13, 14; and,

FIGURE 16 is a view similar to FIGURE 15 showing the mechanism in a second, disconnected state as compared to the connected state of FIGURE 15.

Referring now to the drawing, wherein like reference characters indicate like or corresponding parts throughout the several views, a preferred form of a stomatological instrument is indicated generally by the reference character 11. The instrument 11 includes a handpiece 12 and a tooth attachment member 13. The handpiece 12 includes a handle 14 which houses a suitable switch mechanism operated by a push button 15. A pair of

transducers

16, 17 are arranged in a spaced, parallel arrangement and extend longitudinally within the handle 14.

The

transducers

16, 17 are magnetostrictive and are made of a ferromagnetic material or other suitable material which will change its dimension when placed in a magnetic field. Wire coils 18, 19 are wound longitudinally around the

transducers

16, 17 respectively to simultaneously induce alternating magnetic fields in the transducers. The ends of the wire coils 18, 19 are silver soldered, or otherwise electrically connected, at 18a, 19a to the

transducers

16, 17 respectively. The wire coils 18, 19 are connected by the switch 15 and a conductor 22 to the output of an ultrasonic generator 23. The ultrasonic generator 23 provides an alternating voltage output and includes a control knob 24 to select the frequency of the output from a frequency range of approximately 20 kc. to 200 kc. or

more.

The polarity of the

transducers

16, 17 and the arrangement of the

coils

18, 19 on the

transducers

16, 17 is such that as one transducer elongates the other transducer contracts. When the switch 15 is closed to connect the

coils

18, 19 to the ultrasonic generator 23, the

transducers

16, 17 alternately and simultaneously elongate and contract at such ultrasonic frequency.

The outermost ends of the

transducers

16, 17 are connected by exponentially tapered

horns

20, 21 to diametrically opposite sides of an annular driving head 25. The

horns

20, 21 amplify the movements of the

transducers

16, 17 and transmit this movement to the sides of the driving head 25. As one transducer retracts and the other elongates, the driving head 25 is caused to rotate about a vertical center axis. When such retraction and elongation takes place at the ultrasonic frequency of the source 23 the driving head is caused to rotatably oscillate at the ultrasonic frequency. The total rotational movement of the driving head 25 depends upon the total length differential of the

transducers

16, 17 during elongation and retraction and the characteristics of the tapered

horns

20, 21.

The drving head 25 includes a protruding portion 26 which snugly fits within a mating socket 27 in the top of the attachment member 13. The protruding portion 26 and the mating socket 27 are triangular with curved sides and circular apexes to eliminate any free play between the driving head 25 and the attachhment member 13.

A preferred attachment member 13 is the tooth clamping head 13 shown in FIGURES 2-5. The tooth clamping head 13 includes an internal cavity 33 defined on its sides by an upper cylindrical wall 34 and three small claws 35-37. The internal cavity 33 is sized to receive the exposed portion of a tooth 38. When the clamping head is disposed over the tooth 38 the three small claws 35-37 grip the tooth at its neck which is located below the height of contour of the coronal portion of the exposed crown of the tooth.

When a transverse section is taken through a tooth its curvature on the outside surface of the tooth facing to the outside of the mouth is greater than its curvature on the surface or side of the tooth facing to the inside of the mouth. The outside surface of the tooth is termed the buccal surface and the inside surface of the tooth is termed the lingual surface. The claws 35-37 are arranged approximately two on the buccal side and one on the lingual side. As shown in FIGURE 4, the claw 35 is positioned near the center of the lingual surface of the tooth 38 shown in the phantom. The

claws

36, 37 are positioned closer to the proximal surfaces of the tooth than to its buccal surface. The claws 35-37 are locked in their gripping position about the tooth by a locking sleeve 39.

The locking sleeve 39 is slidably mounted on the outside of the clamping head 13. The locking sleeve 39 in cludes an inclined camming slot 40 which receives a camming pin 41 protruding fromthe side of the clamping head 13. Manual rotation of the locking sleeve moves it from a release position shown in FIGURE 2 to a tooth locked position shown in FIGURE 5 through the coaction of the inclined slot 40 and the pin 41. As the locking sleeve 39 is moved from the release position toward the locking position the claws 35-37 are forced radially inward and securely grip the tooth when the locking sleeve 39 is in the locking position shown in FIGURE 5. The interior surface of the locking sleeve 39 may be tapered to additionally force the claws 35-37 inwardly as the sleeve moves towards its locking position.

In some instances it is preferable to fill the space remaining between the tooth and the inside surface defining the internal cavity 33 with a putty-like substance to aid in transmitting the movement of the tooth clamping head to the tooth. One substance which has been found suitable for this purpose is silica gel.

Since the incisors, cuspids, bicuspids, and the molars all vary in their general shape within a single mouth as well as between human beings, several different tooth clamping heads will necessarily be provided. Each such tooth clamping head will have the same socket 27 to receive the protruding portion 26 of a single handpiece.

Where a tooth is to be extracted and its crown is missing or damaged, an internal securement member 42 is provided to rigidly connect the tooth to the driving head 25 of the handpiece 12. As shown in FIGURE 8 the securement member 42 is preferably a tapered dowel 44 with suitable means for securing it to the tooth, such as the screw threads as shown, or the like. The tapered dowel is driven, as by threading, into the pulp canal of the tooth. A socket plate 43 is provided at a large end of the dowel 44 and includes the triangularly shaped socket 27 for rigid driving connection with the driving head 25.

Another device for connecting a tooth to the driving head 25 is shown in FIGURE 9. This device comprises an oval shaped, continuous metal band 45 which fits around the exposed portion of a tooth 46 as an impression form. A quick-setting substance 48 is placed around the tooth within the cavity defined by the metal band 45. A metal socket plate 49 having the triangularly shaped socket 27 is set on top of the substance 48. The socket plate 49 has an oval shaped groove 50 which receives the end of the band 45. After the substance 48 sets, rigidly securing the socket plate 49 and the band 45 to the tooth, the driving head 25 may be attached to the socket plate 49 for disconnecting the tooth from its periodental membrane in the manner described above. After the tooth is removed the socket plate 49 is separated from the band 45. The band 45 is then discarded with the tooth and the socket plate 49 is retained for resterilization and reuse.

The substance 48 sets quickly within a matter of minutes with a minimum of discomfort to the patient. In addition, the substance 48, when set, has the strength to transmit the mechanical oscillating motion of the driving head to the tooth without breaking. One substance found suitable for this purpose is a quick-setting acrylic resin.

A second stomatological instrument is indicated generally by the reference character 51 in FIGURES 12. The instrument 51 is similar to the instrument 11 of FIG- URES 1 and 2 and includes a driving head 52 which attaches to the toot-h attachment members 13. The instrument 51 further includes a pair of cylindrical,

piezoelectric transducers

54, 55 which are connected by short, exponentially tapered

horns

56, 57 to diametrically opposite sides of the driving head 42. The

piezoelectric transducers

54, 55 are electrically energized by

conductors

58, 59, 60, 61 which connect the

transducers

54, 55 in parallel. The

transducers

54, 55 are identically tuned and arranged adjacent one another in the end of the handle with the exposed ends of the

transducers

54, 55 in an oppositely poled relation so that energization of the transducers causes one to retract when the other elongates. Energization of the

transducers

54, 55 is by an electrical signal of an ultrasonic frequency so that the transducers elongate and retract at such ultrasonic frequency. The

tapered horns

56, 57 amplify the alternate elongation and retraction of the transducers '54, 55 and transmit this mechanical motion to the opposite sides of the driving head 52. The operation of the piezoelectric instrument 51 is thus very similar to that of the magnetostrictive instrument 11.

While both forms of the stomatological instrument of the present invention include two transducers for imparting a rotatable oscillating driving force, it will be recognized that other transducer arrangements, such as circular transducers, may also be employed.

Referring to FIGURES 13, 14 another form of the st-omatological instrument is indicated generally by the reference character 111. The instrument 111 includes a handpiece 112 and a tooth attachment member 113. The handpiece 112 includes a handle 114, a suitable switch mechanism embedded within the handle 114 and operated by a pushbutton 115, a transducer 116 extending longitudinally within the handle 114, a wire coil 118 wound longitudinally around the transducer 116 and having an end 119 silver soldered or otherwise electrically connected to the transducer 116, an exponential horn 120 extending longitudinally forward from the end of the transducer 116, and a driving head 125 attached to the end of the exponential horn 120.

Although the present instrument is generally straight, it is to be understood that the transducer 116 and/or the horn 120 may be curved to facilitate its use in the oral cavity. The wire coil 118 is connected by the switch and a conductor 22 to the output of the voltage generator 23. When the switch 115 is closed and the alternating voltage output of the generator 23 is applied to the coil 118 to induce alternating magnetic fields in the transducer 116 the transducer 116 alternately elongates and contracts at the frequency of the voltage output of the generator 23. The exponential horn amplifies the movements of the transducers 116 and transmits this amplified movement to the driving head 125. As the transducer retracts and elongates, the driving head is caused to reciprocate at the frequency of the source 23.

The driving head includes an attachment mechanism 126 which fits within and connects to a mating socket 127 in the tooth attachment member 113. The attachment mechanism includes a plunger 128, locking

pins

129, 130 and a pushbutton release 131. The plunger 138 includes a cylindrical shaft portion 132 disposed within a longitudinally extending cylindrical cavity in the end of the driving head 125, and a head portion 133 having an outer frustoconical surface. A circular flange 134 extends radially from around a mid-portion of the shaft portion 132 and is disposed within an enlarged cylindrical cavity or recess 135.

The locking pins 129, 130 are disposed in aligned locking

passages

137, 138 disposed transversely to the longitudinal axis of the plunger 128. The locking pins 129, 130 include angled camming end surfaces 139, 140 respectively which engage the frustoconical surface of the plunger head 133.

Limit projections

141, 142 project from the side of the locking pins 129, 130 and are disposed within

recesses

144, 145 to limit outward radial movement of the locking pins 129, 130. The pushbutton release mechanism 131 includes a pushbutton head 148, a pushbutton camming shaft 149 having a tapered end 150 and a spring 151 interposed between the pushbutton head 148 and a surface on the driving head 125 to normally bias the pushbutton so that its camming surface 150 is out of engagement with a rearward end of the plunger shaft 132.

When the driving head 125 is placed within the socket cavity 127, the forward end of the plunger 12 8 abuts against a bottom surface of the socket cavity causing the plunger to move rearwardly within the longitudinally extending cylindrical cavity or bore in the driving head 125 until the flange 134 abuts against a radially extending, rearward surface defining part of the enlarged annular recess 135. At this point, the outwardmost ends of the locking pins 129, 130 enter locking pin recesses 152, 153 as their

camming surfaces

139, 140 slide along the frustoconical surface on the head 133 of the plunger 128. The driving head 125 is thus securely fastened to the tooth attachment device 113. Forward movement of the transducer 116 as amplified through the exponential horn 120 is transmitted from the driving head 125 to the tooth attachment device 113 through the annular flange 134, the shaft portion 132 of the plunger, and the plunger head 133 which abuts against the bottom surface of the socket 127. To remove or detach the driving head from the tooth attachment device 113, the pushbutton head 148 is pressed causing its camming surface 150 to push the plunger shaft 132 forwardly, forcing the driving head 125 rearwardly and at the same time permitting the locking pins 129, 130 to withdraw radially inward out of the locking recesses 152, 153. Rearward movement of the driving head 125 during retraction of the transducer device 116 is transmitted from the driving head 125 to the locking pins 129, 130 and thence to the tooth attachment device 113.

Stomatological method A principal use of the stomatological instrument 11 is as a realignment instrument, as for example in orthodontia. The present stomatological method can best be explained in connection with FIGURES 6 and 7 which illustrate transverse and longitudinal sections of human teeth 71, 72. As shown in FIGURE 6, the tooth 71 includes a dentin portion 73 surrounding a central pulp cavity 74. Apical blood vessels and nerves 75 run longitudinally through the pulp cavity 74. The outer surface of the dentin 73 is covered by cementum '76 and a periodontal membrane 77 connects the cementum to an alveolar bone 78. The alveolar bone 78 is enclosed by overlying gingival tissue on the buccal and

lingual sides

79, 80 respectively of the tooth 51.

As shown in FIGURE 7 an interdental ligament 82 connects the teeth 71, 72 immediately above the alveolar bone 78 and the periodontal membrane 77. A circular dental ligament 83 runs transversely immediately above the interdental ligament 82. The interdental and the circular dental ligaments are two of three classes of ligaments which make up the periodontal ligament or membrane.

The third class of ligaments in the periodontal membrane comprise a plurality of tiny fiber bundles 85 which criss-cross in the space between the cementum 76 and the alveolar bone 78. These tiny fiber bundles 85 have very little, if any elasticity, but are coiled to provide a resilient connection of the tooth to the alveolar bone 7 8. When the tooth is caused to oscillate at the ultrasonic frequency these tiny fiber bundles are stretched beyond their limits and are ruptured. Thi rupturing or severing of the fiber bundles takes place substantially instantaneously upon application of an oscillating movement to the tooth 71. Where the oscillatory motion is a rotating motion about the longitudinal axis of the tooth, the periodontal fibers surrounding the sides of the root of the tooth are caused to rupture by direct extension and those attached to the apical end of the root are caused to rupture by means of a twisting over-extension. Where the oscillatory motion is a reciprocal motion along the longitudinal axis of the tooth the periodontal fibers surrounding the sides of the root as well as those attached to the apical end of the root are caused to rupture by simple over-extension. The oscillation of the tooth in its alveolar bone socket thus effectively produces a knife-like action which ruptures or severs the tiny fiber bundles. Any heat produced by the oscillation of the tooth causes the fiber bundles 85 to shrink and lose what elasticity they have and thereby aids in causing them to rupture or be severed. Since the whole operation is relatively instantaneous, any heat produced causes the patient only a momentary pain sensation of very low intensity and no permanent damage.

The above described oscillating or reciprocating movement of the tooth does not sever the apical blood vessels and nerves 75 extending longitudinally through the tooth and its pulp cavity. Where the oscillating motion is oscillatory rotation about the longitudinal axis of the tooth, the apical blood vessels and nerves are stretched slightly by a slight twist. In a similar manner, where the motion is a reciprocal movement along the longitudinal axis of the tooth, the apical blood vessels and nerves are stretched only by a slight extension. The slight stretching occurring in both of these oscillatory motions does not break or permanently damage the vital connections. The periodontal membrane is primarily a collagen with very little, if any, elasticity and which contracts upon the application of heat. The apical blood vessels and the nerves are comprised primarily of elastic muscular tissue and are not adversely affected by slight movements of the teeth. The modulus of elasticity of elastic muscular tissue is many times greater than that of collagenous fibers such as those comprising the tissue commonly known as the periodontal membrane. Thus, relative to their own normal lengthwise dimensions it is possible to temporarily stretch the apical blood vessel and nerves to a much greater extent than it is possible to stretch the fibers comprising the periodontal membrane either individually or collectively. It is important to note in this relation that both the rotating and the reciprocal movements herein described are very highly controlled, not only in relation to the limited distance traversed but also with relation to a predetermined number of movements automatically accomplished during an on cycle. It is to be further understood that mammalian nerve tissue, such as the apical nerves, has very high powers of regeneration. Thus, a limited stretching movement of the nerves occurring while rupturing the periodontal membrance does not stretch the nerve to its ultimate extent and it will repair itself relatively easily. The smaller blood vessels also have certain regenerative powers, substantially more than the periodontal membrane. Still further, the oscillations used to disassociate a tooth from a periodontal membrane are very closely controlled and limited in duration. The oscillatory movements described herein occur only for a predetermined minimal time, and a controlled distance traversed, necessary to accomplish relatively instantaneous rupturing of the periodontal membranes which are inelastic tissue, not a substantially greater time and distance necessary to rupture the blood vessels and nerves which are elastic tissue. Thus the vitality of the tooth is relatively unimpaired. Of equal importance, both the tooth and the alveolar bone are physically likewise relatively uninjured.

The tooth as thus disconnected from the surrounding alveolar bone may be moved in its socket for whatever stomatological purposes are deemed necessary at the time. Where the tooth is to be permitted to remain in the socket, as for orthodontia, the tooth may be moved, and then fastened in its new position by conventional mechanical contrivances. Because minimal damage has occurred to all of the tissue involved, the tooth will be refastened to the alveolar bone. Of course, where the tooth is to be removed from the socket it is academic whether or not the apical vessels and nerves are injured simultaneously with the rupturing of the periodontal membrane. In this case the tooth is completely separated from all of its attachments.

With the present method, removal of the tooth is accomplished with little damage to the surrounding tissues which are to remain. Very little if any alveolar bone is lost during a tooth extraction, so that the normal contours of the alveolar bone are not destroyed. No irreparable damage is done to the external facial contours of the patient, thereby avoiding a drawn and haggard look. With the present method of complete tooth removal, a lifting force to accomplish removal can be applied after the periodontal membrane has been severed and the lifting force does not have to be extreme. After the periodontal membrane is severed by the present method, a slight twist of the present instrument by the operator removes the tooth relatively instantaneously and cleanly from its socket with comparatively little damage to the surrounding alveolar bone. Thereafter, the socket area is replaced with new bone tissue by the usual reparative processes with comparatively no loss of the surrounding alveolar bone.

When an ultrasonic oscillation is used, the physical characteristics of the tooth are such that the tooth becomes flaccid and looses its rigidity for the duration of those moments when the ultrasonic waves are moving through the tooth. The tooth may be withdrawn from its socket during this flaccid stage with practically no damage to the surrounding tissues. This withdrawal action is accomplished by the application of sufficient on cycles by the operator while applying a very slight lifting force to the tooth until the tooth is released from the socket. The use of ultrasonic frequencies permits very short on cycle times and very little, if any, bone damage.

When a tooth is oscillated as taught by the present invention at a frequency below the ultrasonic range, for example a subsonic or near subsonic range as low as 100 to 600 cycles per second, the tooth fiaccidity does not occur and there is minimal stretching or expanding of the alveolar socket. In these frequency ranges, the control oscillatory movement of the tooth in equidistant directions while maintaining the longitudinal axis of the tooth substantially in line and holding it from rocking as taught by the present invention, provides a temporary minimal stretching of the socket and a clean rupture or severing of the periodontal membrane.

A preferred number of controlled oscillations of both the reciprocal and rotational applications of the stomatological method for on cycle periods is between 10 and 20 oscillations for the ultrasonic ranges and between 50 and 100 oscillations for frequencies below ultrasonic ranges. The predetermined number of on cycles are automatically provided by the source generator 23 and a connected conventional digital counter (not shown) such that activation of pushbutton produces only the predetermined number of oscillations desired.

In an average human the thickness of the periodontal membrane is approximately .3 mm. and the tiny fiber bundles of the periodontal membrane have a breaking limit approximately 17% greater than their origin-a1 length. An .08 mm. movement of the tooth is required to stretch the fiber bundles to their limits. In the preferred stomatological method of the present invention a tooth movement of approximately .10 mm. is provided to assure stretching the fiber bundles beyond their limits. This .10 mm. movement of the tooth is not perceptible and little if any sensation is felt by the patient when the movement is at a high frequency, particularly an ultrasonic frequency.

Another principal advantage of the present invention is the microsecond operation required to disconnect the tooth from the periodontal membrane. Such disconnection from the periodontal membrane permits the tooth to be moved about its periodontal socket or to be extracted from the jaw, all with a minimum apparent sensation to the patient. The knife-like cutting action caused by the ultrasonically oscillating tooth causes little damage, either to the tooth or to the alveolar bone. Moreover, the present method, especially where employed to extract teeth, does not break the interdental gingival or the alveolodental ligaments, or cause laceration of the soft gingival tissue surrounding the tooth as often happens with conventional traumatic methods of extracting teeth. Thus, there is less chance of infection and a shorter time is required for complete healing of any wound.

A very distince possible use of the present invention is in transplanting of teeth. The present method provides a clean separation of the tooth from the periodontal ligament without severing the vital apical circulatory blood vessels and the nerves. Thus the surgery required for transplanting need concern itself primarily with cutting and reconnecting the apical blood vessels and nerves.

In conclusion, the present invention may be briefly described as essentially a stomatological method involving controllably oscillating a tooth at a high frequency within the alveolar socket between fixed limits sufiicient to stretch the fiber bundles of the periodontal membrane be yond their elastic limits while maintaining the longitudinal axis of the tooth in line and holding it from rocking.

Although the invention has been described in its preferred form with a certain degree of particularity, it is understood that the present disclosure of the preferred 10 form has been made only by way of example and that numerous changes in the details of construction and the combination and arrangement of parts may be resorted to without departing from the spirit and the scope of the invention as hereinafter claimed.

What is claimed is:

1. The method of disassociating a tooth from connecting membranes and ligaments comprising controllably oscillating the tooth at a high frequency in situ either along the longitudinal axis of the tooth or rotatably about the longitudinal axis of the tooth or with a combination of such oscillations between limits just sufiicient to stretch the membranes and ligaments beyond their elastic limits while maintaining a longitudinal axis of the tooth substantially in line, and holding the longitudinal axis from substantially rocking during oscillation of the tooth and then moving the toooth after the connecting membranes have been disassociated therefrom.

2. The method of claim 1 wherein the toot-h is oscillated at a frequency of at least cycles per second.

3. The method of claim 1 wherein the oscillations are reciprocal and along the longitudinal axis of the tooth.

4. The method of claim 1 wherein the tooth is moved generally .10 mm. during each oscillation.

5. The method of claim 1 wherein the moving of the tooth includes applying a lifting force to the tooth after oscillating the tooth to sever the membranes and ligaments.

6. The method of claim 1 wherein the oscillations are rotatable about the longitudinal axis of the tooth.

7. The method of claim 6 wherein the oscillations are at an ultrasonic frequency.

8. The method of stomatology wherein a tooth is disassociated from the membranes connecting the tooth to the alveolar bone without severing the apical blood vessels and nerves comprising:

( a) fixedly gripping the tooth by -a driving head;

(b) oscillating the driving .head and the attached tooth in situ in a controlled manner at a high frequency either along the longitudinal axis of the tooth or rotaitably about the longitudinal axis of the tooth or with a combination of such oscillations so as to stress the connecting membranes beyond their elastic limits without stretching the apical blood vessels and nerves beyond their elastic limits whereby the tooth is substantially disassociated from the membranes and can be moved in its bone socket, and

(c) thereafter moving the tooth relative to its bone socket.

9. The method of claim 8 wherein the driving head and attached tooth are oscillated while maintaining a longitudinal axis of the tooth substantially in its original line so there is essentially no rocking of the tooth about a transverse axis during oscillation.

10. The method of claim 8 wherein the tooth is oscillated rotatably about the longitudinal axis.

11. The method of claim 8 wherein the driving head and attached tooth are oscillated along the longitudinal axis of the tooth.

12. The method of orthodontia treatment comprising:

(a) disassociating a tooth from membranes and ligaments connecting the tooth to the alveolar bone socket and other teeth by causing the tooth to rotatably oscillate at an ultrasonic frequency in situ;

(b) aligning the tooth with adjacent teeth by moving the tooth laterally in the bone socket after it is dis associated from the connecting membranes and ligaments; and,

(c) temporarily fixing the tooth in the alignment p0sition until the bone socket has sufficiently healed to fix the tooth in alignment with the adjacent teeth.

13. A stomatological method comprising:

(a) rotatably oscillating a tooth at an ultrasonic frequency and in a controlled manner between fixed 11 limits in its alveolar bone socket so as to stretch membranes connecting the tooth to the bone without stretching the apical blood vessels and nerves beyond their elastic limits and without appreciably 12 (b) rotatably oscillating the driving head and the attached tooth in situ in a controlled manner at a high frequency so as to stress the connecting membranes beyond their elastic limits without stretching the distorting the bone to thereby loosen the tooth sufapical blood vessels and nerves beyond their elastic ficiently to move the tooth in its socket relative to limits whereby the tooth is substantially disassocithe alveolar bone; ated from the membranes and can be moved in its (b) moving the tooth relative to the alveolar bone sufbone socket;

ficiently to withdraw the tooth from its bone socket (c) moving the disassociated tooth relative to the also as to be clear of the bone; and, veolar bone to a new position in the bone socket;

(c) removing the tooth from the oral cavity. and,

14. The method of orthodontia treatment comprising: (d) fixing the moved tooth in its new position at least (a) disassociating a tooth from membranes and ligauntil the bone socket has healed sufficiently to rements connecting the tooth to the alveolar bone tain the tooth in the new position.

socket and other teeth by causing the tooth to oscil- 15 17. The method of stomatology wherein a tooth is dislate at -a high frequency in situ either along the associated from the membranes connecting the tooth to longitudinal axis of the tooth or rotatably about the alveolar bone comprising:

the longitudinal axis of the tooth, or with a combina- (a) fixedly gripping the tooth by a driving head;

tion of such oscillations while maintaining a longi- (b) tet bly oscillating the driving head and the attudinal axis of the tooth substantially in its original tached tooth in situ in a controlled manner at a high line; frequency so as to stress the connecting membranes (b) aligning the tooth with adjacent teeth by moving beyond their elastic limits without appreciably disthe tooth laterally in the bone socket after it is distorting th b whereby the tooth is ubstantially associated from the connecting membranes and ligadi i t d f th mb n a d n be rements; and, moved from its bone socket; and,

(c) temporarily fixing the tooth in the alignment posivremoving the di n oei-ated tooth from the bone tion until the bone socket has sufficiently healed to k t fix the tooth in alignment with the adjacent teeth. 18 A t m t 1 i a1 m thod comprising: 15. The method of stomatology wherein a tooth is dis- (a) oscillating a tooth at a high frequency either along associated from the membranes Connecting the tooth to the longitudinal axis of the tooth or rotatably about the alveolar bone without severing the apical blood vesh l i di l i f h tooth h a combina- S615 and n rv s comprisi g: tion of such oscillations and in a controlled manner fiXedlY pp g The tooth y a driving head; between fixed limits in its alveolar bone socket while Causing the driving head the tooth fixed theremaintaining a longitudinal axis of the tooth substanto to oscillate at an ultrasonic frequency either along i ll i li so as to stretch membranes connect. the longitudinal axis of the tooth or rotatably about ing the tooth to h b i h tretching th the longitudinal axis of the tooth or with a combina' apical blood vessels and nerves beyond their elastic tion of such oscillations between predetermined limlimits and Without appreciably distorting the bone its spaced sufficiently to stretch the mfimbranes to thereby loosen the tooth sufiiciently to move the yond their elastic limits without Stretching h p q 40 tooth in its socket relative to the alveolar bone; blopd ves.sels.a.nd p their elastlc hmlts (b) moving the tooth relative to the alveolar bone Whlle m t h a lprigltudinal axis of the {90th sufiiciently to withdraw the tooth from its bone substantially in its original line and thereby disask t t b 1 f th b0 d sociating the tooth from the membranes while main- Soc 6 as 0 e c ear 0 6 taining the blood vessels and nerves intact; (c) 'removmg the tooth from the Oral cavlty to) moving the disassociated tooth relative to the alveolar bone; and, References Cted (d) fixing the tooth in its moved place in the alveolar UNITED STATES PATENTS bone at least until the tOOth iS Ieattach 0 e 2 777 19 1 1957 Wallace 32 1 membrane.

16. The method of stomatology wherein a tooth is dis- Eggs: 1

associated from the membranes connecting the tooth to the alveolar bone without severing the apical blood vessels and nerves comprising:

(a) fixedly gripping the tooth by a driving head;

RICHARD A. GAUDET, Primary Examiner.

J. W. HINEY, Assistant Examiner.

Claims

1. THE METHOD OF DISASSOCIATING A TOOTH FROM CONNECTING MEMBRANES AND LIGAMENTS COMPRISING CONTROLLABLY OSCILLATING THE TOOTH AT A HIGH FREQUENCY IN SITU EITHER ALONG THE LONGITUDINAL AXIS OF THE TOOTH OR ROTATABLY ABOUT THE LONGITUDINAL AXIS OF THE TOOTH OR WITH A COMBINATION OF SUCH OSCILLATIONS BETWEEN LIMITS JUST SUFFICIENT TO STRETCH THE MEMBRANES AND LIGAMEMNTS BEYOND THEIR ELASTIC LIMITS WHILE MAINTAINING A LONGITUDINAL AXIS OF THE TOOTH SUBSTANTIALLY IN LINE, AND HOLDING THE LONGITUDINAL AXIS FROM SUBSTANTIALLY ROCKING DURING OSCILLATION OF THE TOOTH AND THEN MOVING THE TOOTH AFTER THE CONNECTING MEMBRANES HAVE BEEN DISASSOCIATED THEREFROM.