Palatal Expander

The present invention relates to an orthodontic appliance or device and more particularly to an intraoral orthodontic appliance having a coil spring for applying a force to anchor teeth in the human mouth.

In some instances such as where a person may have an unusually small mouth insufficient room exists in the mouth for a normal set of teeth. In situations of this type, certain teeth tend to become twisted or otherwise pushed out of place due to overcrowding spoiling a person's facial appearance and sometimes interferring with proper chewing.

Rather than pull certain teeth in order to avoid overcrowding, the orthodontist may wish to attempt to expand the palate to provide sufficient room. Other situations in which the orthodontist may wish to expand a palate is in certain limited situations where the upper and lower jaw structures are not identical in overall size and configuration. Since it is desirable to have the upper and lower teeth in at least substantial alignment, the orthodontist may wish to expand the palate to obtain this alignment.

Various devices have been proposed in the past for moving and/or aligning teeth in the human mouth. However, insofar as applicant is aware there is not presently available to the orthodontist a relatively simplified and inexpensive mechanical structure which may be inserted into the human mouth to expand the palate, which automatically effects palatal expansion. The present invention provides such a unit in the form of relatively movable and stationary members which may be normally retained in a close, side-by-side configuration by a removable keeper. One of the members is stationarily secured to one side of the palate while the other member telescopically received in and slidable with respect to the stationary member is secured to the other side of the palate. They are urged apart by a coil wound torsion spring. After the two members have been secured to anchor teeth on opposite sides of the plate, the keeper is removed and the mainspring freed to exert an expansion pressure on the palate of the wearer. As the expander gradually clefts the palate, cellular structure grows, filling the cleft as the maxilla is widened. Although the device is primarily constructed for use as a palatal expander and will be so described, it may also be used for palatal contraction by reversing the direction of the coil spring or torsion spring and changing the direction of the applied force.

It is therefore one object of the present invention to provide a simplified and relatively inexpensive palatal expander.

Another object of the present invention is to provide a device which may be used for either expanding or contracting the palate in a human mouth.

Another object of the present invention is to provide a palatal expander which may be simply inserted and applied to anchor teeth in the mouth by an orthodontist.

Another object of the present invention is to provide a palatal expander which applies a substantially constant force to anchor teeth on opposite sides of a human palate.

Another object of the present invention is to provide a palatal expander in which telescoping elements are forced apart by the torsion force of a conventional mechanical wristwatch mainspring.

These and further objects and advantages of the invention will be more apparent upon reference to the following specification, claims and appended drawings wherein:

FIG. 1 is a diagrammatic view of a portion of a human palate and teeth showing the palate expander of the present invention as initially inserted in the mouth;

FIG. 2 is a view similar to FIG. 1 showing the expander after it has clefted the palate;

FIG. 3 is a view of the palate expander by itself with the keeper in place;

FIG. 4 is a plan view of the palatal expander with the movable elements in the retracted or compressed position; and

FIG. 5 is a plan view similar to FIG. 4 with the movable elements in the open or expanded position.

Referring to the drawings, the palate expander of the present invention is generally illustrated at 10 in FIG. 1. It is illustrated as applied to two pair of anchor teeth (two each side) such as 12 and 14 in the form of human molars extending downwardly from a human palate generally outlined by the dashed line 16. A pair of central incisors extending from the same palate are shown at 18 and 20. The expander is shown in FIGS. 1 and 2 as generally comprising a stationary body 22 and movable block 24 attached to respective metal legs 26 and 28. These are in turn connected to the respective bands 30 and 32 surrounding the molars 12 and 14.

FIG. 2 shows the block 24 as having moved away from the body 22. This is done under the urging of a coil spring generally indicated at 34 preferably in the form of a conventional mechanical wristwatch mainspring. As illustrated in FIG. 2, both the anchor teeth 12 and 14 and the central incisors 18 and 20 have separated relative to the position illustrated in FIG. 1 indicating in FIG. 2 that the expander has clefted the palate. It is understood that in treatment of this type cellular structure grows, filling the cleft as the maxilla is widened. The separating force exerted by the spring 34 in FIG. 2 is illustrated by the double ended arrow 36.

FIG. 3 is a view of the palatal expander 10 in the closed or unexpanded position and retained by a substantially U-shaped keeper 38 having ends 40 and 42 which engage and retain the body 22 and movable block 24. The expander is inserted into the mouth in the position illustrated in FIG. 3 and the legs attached to the anchor teeth. When the device has been completely attached, and only then, the keeper 38 is removed so that the force of the spring 34 is exerted on the block 24.

FIG. 4 is a plan view of the expander 10 in the collapsed position with the keeper removed and FIG. 5 is a similar plan view of the device in the expanded position. In addition to the front legs 26 and 28 previously described block 22 is connected to a downwardly and rearwardly extending back leg 44 and block 24 is connected to a similar back leg 46. These are normally connected to the backside of the bands 30 and 32 on the same molars 12 and 14 as the front legs 26 and 28. Attached to movable block 24 and slidably received in suitable apertures in the body 22 are a pair of spaced guide legs 48 and 50 and a force receiver 52. The force receiver carries a push pin 54 slidable in a slot 56 in the body 22.

Spring 34 is of helical coil construction and is wrapped around a post 58. One end of the spring as indicated at 60 is turned over and received in a hole 62 in the body 22. The other end of the spring as indicated at 64 bears against push pin 54. When the keeper 38 is removed, coil spring 34 urges the two members to separate from the position illustrated in FIG. 4 to the completely expanded position illustrated in FIG. 5. Spring 34 acts as a torsion spring and exerts a force approximately in the direction illustrated by the arrow 70 in FIG. 4. Outward movement of block 24 is limited by engagement of the push pin 54 with the other end of slot 56 in body 22. Force receiver 52 carrying push pin 54 is secured to block 24 in a suitable manner such as by a pin 72 passing through the block and receiver. Guide legs 48 and 50 are similarly secured to the movable block in a desired manner such as by soldering, braising or the like. All of the elements illustrated are preferably of metallic construction for strength since the device is of relatively small size so that it may be inserted into and removed from a human mouth.

It is apparent from the above that the present invention provides a simplified and relatively inexpensive palatal expander and in particular one which may be simply applied to and removed from a human mouth. The expander is inserted with the keeper 38 so that attachment to the teeth is easy for the orthodontist. Removal is facilitated in a like manner by simply removing the bands 30 and 32 from the molars 12 and 14.

Although the device is primarily designed as a palatal expander and has been so described, it is understood that it may also be used for palatal contraction. This can be simply accomplished by reversing the direction of force of the torsion spring 34 and moving the long arm 64 of the spring to the other side of pin 54. In this case, suitable removable plus may be inserted in the space between the body and block to keep it in the expanded position illustrated in FIG. 5 until it has been attached to the teeth and then the separating block removed by the orthodontist in the same manner that the keeper 38 is removed when the device is formed as an expander.

The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiment is, therefore, to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are, therefore, intended to be embraced therein.