Mandibular and Maxillary Arch Ander

This invention relates generally to orthodontic devices and, more specifically, to fixed mandibular arch and maxillary arch expanders.

Orthodontists treating children often need to gain space of unerupted mandibular incisors and increase intercanine distance for narrow archforms as well as distalize mandibular first molars so that a total increase of archlength is available in the lower dental arch from first molar to first molar. Furthermore, the orthodontist also may want to expand the palate correspondingly. Often there is a need for tooth extraction of permanent teeth due to crowding.

Mandibular and maxillary arch expanders are known to the art. However, such mandibular arch expanders are rather bulky in design, impede tongue mobility, are uncomfortable to wear and interfere with good oral hygiene. The devices must be substantial in design to resist torquing or leverage mechanics during chewing.

It is among the objects of the present invention to provide a mandibular arch expander to develop narrow forming mandibular arches in growing children.

Another object of the present invention is to provide a mandibular arch expander that prevents the need for extraction of permanent teeth due to crowding.

It is another object of the invention to provide a maxillary arch expander to expand the maxillary arch and palate in growing children.

Still another object of the present invention is to provide a mandibular expander that can be preset at the desired tension prior to cementing the appliance into place.

Another object of the present invention is to provide a mandibular expander that is lean in design, comfortable, and allows good oral hygiene.

Yet another object of the present invention is to provide a mandibular expander that resists torquing or leverage mechanics against teeth during chewing.

A further object of the present invention is to provide a mandibular expander that has no tissue supported components, does not impinge on gum tissue, and does not impede tongue mobility.

In accordance with the principles of the present invention, a mandibular expander is provided having a midarch expansion screw complex for intercanine archlength development and bilateral spring-loaded rod and tube assemblies for molar distalization and added archlength development in the mandibular bicuspid areas. The appliance has four orthodontic bands, one at each corner, to attached to selected teeth to stabilize and secure the appliance in place. The appliance is fixed to the lower arch by first molar orthodontic bands and to the mandibular deciduous first molars with bicuspid bands. The midarch expansion screw complex is positioned between the front bands. The lateral development of the mandibular arch results from timely activation of the midarch screw. A spring-loaded rod and tube assembly extends between the front band and rear band on each side. The spring loaded rod and tube design allows the orthodontist to preset the desired tension by measuring spring compression. The spring-loaded rod and tube assemblies increase mesial distal archlength. There are occlusal rests on each tube to provide extra support to the rod and tube assembly.

In an alternative embodiment, the midarch expansion screw complex is replaced with a third spring-loaded rod and tube assembly which extends between the two front bands. The third spring-loaded rod and tube assembly has a preset spring tension.

A novel maxillary palatal expander employing a pair of spring loaded rods and tubes is also provided for use with the mandibular arch expander.

The mandibular appliance is used to gain space for unerupted mandibular incisors and increase intercanine distance for narrow archforms and to distalize mandibular first molars so that the total increase in archlength becomes available in the lower dental arch from first molar to first molar. The device is used in conjunction with the novel maxillary palatal expander when the maxilla is being developed and the mandibular arch needs to be expanded to maintain coordinated archforms. The appliance allows for simultaneous alignment of the mandibular incisors by allowing bonded brackets to be added and archwires placed during the expansion.

The mandibular appliances are totally tooth supported and, due to the four band, four comer design, are stable and resists torquing.

FIG. 1 is a perspective view of the orthodontic appliance of the present invention attached to a mold of the mandibular arch;

FIG. 2 is a front plan of the orthodontic appliance of the present invention attached to the mandibular arch;

FIG. 3 is a bottom plan of the orthodontic appliance of the present invention;

FIG. 4 is a top plan of the orthodontic appliance of the present invention;

FIG. 5 is another bottom plan of the orthodontic appliance, the left spring-loaded tube assembly disassembled;

FIG. 6 is another bottom plan of the orthodontic appliance, the right spring-loaded tube assembly disassembled;

FIG. 7 is a perspective view of an alternative embodiment of the orthodontic appliance of the present invention attached to a dental mold;

FIG. 8 is a bottom plan of the orthodontic appliance shown in FIG.7;

FIG. 9 is an exploded view thereof;

FIG. 10 is a bottom plan of an maxillary palatal expander of the present invention shown attached to a mold of the maxillary arch to demonstrate environment; and

FIG. 11 is another bottom plan of the maxillary palatal expander, disassembled.

The mandibular expander appliance of the present invention is indicated generally in the drawings by reference numeral 1. Appliance 1 is shown, in FIG. 1, attached to a conventional dental mold M of the lower teeth. Appliance 1 is shown, in FIG. 2, attached to the lower teeth T of a human subject. Appliance 1 has a pair of space apart forward orthodontic bands 3 and 5. Bands 3 and 5 generally are conventional bicuspid bands and adapted to attach to the mandibular first primary molars. Band 3 has a boss 6 and band 5 has a boss 7, both positioned on the lingual side of the bands. The respective bosses are integrally formed on the respective bands to provide a substantial metallic body for the attachment of other elements to be described hereinafter.

The bands 3 and 5 are interconnected by an expansion screw complex 8. The expansion screw complex 8 has a first metal block 9 and a second metal block 11. First block has three bores 13,15 and 17 formed laterally therethrough and second block 11 has three bores 13', 15' and 17' formed laterally therethrough. Bores 13, 15 and are in substantial horizontal alignment with bores 13', 15' and 17'. The middle bores 15 and 15' are threaded. A first aligning pin 19 extends through bore 13 and a second aligning pin 21 extends through bore 17. The respective aligning pins are slightly undersized relative to the respective bores so that the blocks 9 and 11 can slide on the pins as will be described below.

A threaded screw 23 is threadedly engaged in bores 15 and 15'. It will be appreciated that threaded screw 23 has oppositely threaded ends. That is to say, the end of the screw that engages bore 15 is threaded opposite to the end that engages threaded bore 15'. There is at least one hole 25 formed through the middle of screw 23 between the oppositely threaded ends. Hole 25 accommodates the insertion of a small tool to turn screw 23. Therefore, when screw 23 is rotated in one direction, the blocks 9 and 11 are moved away from each other and when screw 23 is rotated in the opposite direction, the blocks 9 and 11 are drawn toward each other. The blocks 9 and 11 slide on the aligning pins 13 and 17 and the aligning pins serve to stabilize the expansion screw complex.

There is a first curved arm 27 extending between boss 6 and block 9 and a second curved arm 29 extending between boss 7 and block 11. The curved arms can be of any appropriate length and curvature to suitably engage the patient's teeth. The mold M is made following conventional procedures and the arms 27 and 29 are fabricated to be the appropriate length and curvature. The arms 27 and 29 then are soldered to the appropriate boss and to the expansion screw complex.

There is a first rod 31 attached to boss 6. Rod 31 can be a small hollow tube, to reduce weight, or can be a solid rod. A second rod 33 is attached to boss 7. A stated above, the exact position on the respective bosses where the rods are attached and the angle at which the rod extends from the boss depends upon the patient and the patient's needs. It will be appreciated that arm 27 and rod 31 can be one integral piece appropriately bent to form the arm and the rod or the arm and rod can be separate pieces. The same is true for arm 29 and rod 33.

Appliance 1 has a pair of spaced apart rear orthodontic bands, 40 and 42. Bands 40 and 42 generally are molar bands and, in use, are attached to the permanent first molars. Band 40 has an integral boss 44 and band 42 has an integral boss 46, with both bosses being positioned on the lingual side of the bands. There is a first hollow tube 48 attached to boss 44 and a second hollow tube 50 attached to boss 46. Each hollow tube has an internal bore sized to accommodate the sliding insertion of a rod, as will be explained in detail below,

There is a first short wire 52 perpendicular to tube 48 and a second short wire 54 perpendicular to tube 50. The respective short wires extend buccally and serve as occlusal rests and are soldered on the respective tubs at a position corresponding to the lingual occlusal groove of the deciduous second molars bilaterally to provide extra support and stability to the tubes.

The forward pair of orthodontic bands are connected to the rear pair of orthodontic bands to promote molar distalization and added archlength development by a pair of spring-loaded rod and tube assemblies, as will now be described in detail. Rod 29 is slidingly engaged in tube 48. Rod 31 is slidingly engaged in tube 51. There is a first coil spring 55 positioned around rod 31 and fixed between boss 6 and the end of tube 48. Likewise, a second coil spring 57 is positioned around rod 33 and fixed between boss 7 and the end of tube 51. The coils springs are sized so they abut the ends of the tubes and do not slide over the tubes. The respective coil springs, therefore, urge the forward bands away from the tubes.

The respective coil springs have a preset tension. The preset tension of the spring is selected by the orthodontist to effect the appropriate mesial distal archlength development in the bicuspid area.

An alternative embodiment of the orthodontic appliance of the present invention is indicated in FIGS. 7-9 by reference numeral 60. Appliance 60 has a pair of spaced apart forward orthodontic bands 62 and 64. Band 62 and band 64 have bosses 66 and 68 integrally formed thereon. The bosses are positioned on the lingual side of the bands. There is a hollow tube 70 extending from boss 66 and a rod 72 extending from boss 68. The angles at which tube 70 and rod 72 extend from the respective bosses depends upon the shape of the patient's mouth. Rod 72 is slidingly engaged in tube 70. There is a coil spring 74 around rod 72 and fixed between boss 68 and the end of tube 70. Spring 74 is sized to engage the end of the tube and not slip over the tube. Therefore, spring 74 urges band 62 away from band 64. Spring 74 has a predetermined force to be delivered between the molars to widen the anterior canine width.

There is a first lateral rod 76 attached to boss 66 and second lateral rod 78 attached to boss 68. There is a first coil spring 79 around rod 76 and a second coil spring 80 around rod 78, abutting the respective bosses. The respective coil springs have a preset tension, as determined by the orthodontist to effect appropriate mesial distal archlength development.

It will be appreciated that rod 72 and rod 78 can be an integral L-shaped wire, appropriately bent and soldered to boss 68. The angles at which the respective lateral rods extend away from the respective bosses is dependent upon the corrective needs of the patient.

Appliance 60 has a pair of spaced apart rear orthodontic bands 81 and 82. Bands 81 and 82 have integrally bosses 84 and 86 respectively. There is a first hollow tube 88 attached to boss 84 and a second hollow tube 90 attached to boss 86. Each hollow tube has an internal bore sized to accommodate the sliding insertion of a rod, as previously explained. The hollow tubes are sized to allow the coil springs to abut the ends of the tubes without sliding over the tube, as previously described.

There is a first short wire 92 perpendicular to tube 88 and a second short wire perpendicular to tube 90. The respective short wires serve as occlusal rests and are soldered on the respective tubes at a position corresponding to the lingual occlusal groove of the deciduous second molars bilaterally to provide extra support and stability to the tubes.

The forward pair of orthodontic bands are connected to the rear pair of orthodontic bands in the same manner as previously described in reference to appliance 1.

The maxillary palatal expander of the present invention is indicated generally by reference numeral 100 in FIGS. 10 and 11. Expander 100 is shown, in FIG. 10, attached to a conventional dental mold M of the upper teeth. Appliance 100 has a pair of spaced apart forward orthodontic bands 103 and 105. Bands 103 and 105 can be conventional bicuspid bands adapted to attach to the maxillary molars. Band 103 has a boss 106 and band 105 has a boss 107 both positioned on the lingual side of the bands. The respective bosses are integrally formed on the respective bands. There is an integral curved member or hook 109 on boss 106 and an integral curved member or hook 111 on boss 107.

Appliance 100 has a pair of spaced apart rear orthodontic bands 113 and 115. Band 113 has an integral boss 117 and band 115 has an integral boss 119, both on the lingual side of the respective bands. Boss 117 has an integral curved member or hook 121 and boss 119 has an integral curved member or hook 123.

The forward orthodontic bands are connected to the rear orthodontic bands as follows: a first rod 125 extends between boss 106 and boss 117. A second rod 127 extends between boss 107 and boss 119. Furthermore. Hooks 109 and 121 are embedded in a plastic plate 130. Hook 111 and 123 are embedded in a plastic plate 132.

The respective plastic plates are molded to fit the patient's palate. Each plate, with the associated forward and rearward bands, comprises half of the appliance. The halves of the appliance is biased away from each other to widen the maxillary arch. There is a substantially U-shaped rod 135 imbedded in plate 130. Legs 136 and 137 of rod 135 extend out from, and at substantially right angles to, the plastic plate. There are coil springs 138 and 140 around legs 136 and 137 respectively. There is a first short tube 142 and a second short tube 144 embedded in plate 132. The tubes extend out of the palate plate at substantially right angles to the palate plate. The tubes 142 and 144 are on complementary alignment with the legs 136 and 137. The tubes 142 and 144 are slightly oversized so that the legs 136 and 137 can slide into the tubes. The springs 138 and 140 abut the ends of the tubes and exert tension force to urge the halves of the appliance apart. The appropriate tension can be exerted by selecting springs with the appropriate tension.

It will be appreciated that various changes and modifications may be made in the orthodontic appliance of the present invention without departing from the scope of the appended claims. Therefore, the foregoing description and accompanying drawings are intended to be illustrative only and should not be construed in a limiting sense.