AU2013205854A1

AU2013205854A1 - An orthodontic appliance

Info

Publication number: AU2013205854A1
Application number: AU2013205854A
Authority: AU
Inventors: Christopher John Farrell
Original assignee: Individual
Current assignee: Individual
Priority date: 2012-08-31
Filing date: 2013-05-15
Publication date: 2014-03-20
Anticipated expiration: 2033-05-15
Also published as: RU2013138149A; FR2994826A1; CN203576668U; AU2013205854B2; RU2636196C2; FR2994826B1; DE102013108291B4; DE102013108291A1

Abstract

An orthodontic appliance (10) including: an appliance body (12) for mounting over the upper arch, the appliance body including an inner wall (14) that is positioned 5 on a lingual side of the upper arch and an outer wall (16) that is positioned on a buccal side of the patient's upper arch, a web (18) interconnecting the inner wall and the outer wall, the inner and outer walls each have an upper portion that projects above the web so as to define an upper dental arch receiving channel and the inner and outer walls each have a lower portion that depends below the 10 web that defines a lower dental arch receiving channel; wherein the upper portion of the inner wall defines a tongue opening (40) for consciously receiving the tip of patient's tongue, the upper portion of the inner wall being configured such that when the tip of the patient's tongue is received, the tip will be located adjacent the anterior palate. -~ 14' (K // \xN U ~ ',>~' " 7' 2(4 7/' 'I FigA

Description

1 AN ORTHODONTIC APPLIANCE FIELD OF THE INVENTION 5 This invention relates to an orthodontic appliance. The invention also extends to a system of appliances for treating a patient and a method of treating a patient with the orthodontic appliance and a method of treatment involving the set of appliances. 10 This invention relates particularly but not exclusively to an orthodontic appliance for promoting beneficial myofunctional habits by a patient to assist in creating the most suitable intra-oral environment for achieving correct dental occlusion. It will therefore be convenient to hereinafter describe the invention with reference to this 15 example application. However at the same time it must be recognized that the invention is capable of broader application. For example the invention could be used for all other types of orthodontic appliances including those promoting arch expansion and dental alignment. 20 DEFINITIONS In the specification the term "comprising" shall be understood to have a broad meaning similar to the term "including" and will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the 25 exclusion of any other integer or step or group of integers or steps. This definition also applies to variations on the term "comprising" such as "comprise" and "comprises". In the specification the term "orthodontic appliance" shall be interpreted broadly 30 and shall be understood to include all manner of contrivances that are used to 2 treat malocclusions in a patient. It shall include wire and band fasteners merely as one example of such an appliance but shall not be limited to these devices. It also includes trainer appliances for promoting good myofunctional habits. 5 BACKGROUND TO THE INVENTION Humans have an upper jaw called a maxilla forming an upper arch and a hinged lower jaw called a mandible forming a lower arch. A patient has correct dental occlusion when the upper arch matches the size and shape of the lower arch such 10 that the teeth of the upper and lower jaw come together when the jaws are closed. Further individual teeth of the upper and lower arch are correctly positioned along the length of the arch relative to each other such that they match each other correctly. However while the upper and lower arches are broadly of the same size they are subtly offset relative to each other. Specifically the teeth of the upper 15 arch are off set relative to the teeth of the lower arch so that at least part of each tooth of the upper arch is positioned outward of the corresponding tooth on the lower arch. The incisors of the lower arch are positioned behind the incisors of the upper arch. However malocclusions which involve a mismatch in the sizes of the upper and lower jaw are a relatively common condition in human populations 20 around the world. At birth, all persons possess a normal tongue position in which the tongue rests naturally in the maxilla and the person breathes through the nose. In an infant, the movements of the tongue are undifferentiated and change to differentiated 25 movements as the person grows. Tongue based position is associated with maxillary position and vertical mandibular rotation and so influences maxilio mandibular growth. Therefore tongue activity defines the position of the teeth and also determines the position of the mandible. Thus a balance between tongue pressure from the inside and labio-buccal pressure from the outside must exist, 30 associated to a correct position of the tongue-base in order to develop correct patterns during the dento-maxillo-mandibular growth.

3 However, in many cases, the normal developmental process of tongue movements does not occur and abnormal position and movement of the tongue may affect the craniofacial morphology. 5 One example of abnormal movement of the tongue is known as tongue thrusting. Tongue thrusting refers to a pattern of swallowing in which the tongue pushes forward and/or sideways against and/or between the teeth during swallowing. Swallowing may occur up to 2000 per day. When the tongue presses against the 10 teeth during swallowing, the pressure can have adverse effects on the position of the teeth, oral bony growth, soft tissue condition and mouth functioning. By way of example only 1.7g of force is required to move an anterior tooth. The tongue is capable of exerting a force of up to 500g. 15 Since tongue thrusting was first identified as being associated with malocclusion and other oral defects, there have been a plethora of appliances designed to discourage or prevent tongue thrusting. These generally involve some sort of physical barrier to physically restrain the tongue from thrusting when swallowing. Others use spikes or other sensory devices to discourage the tongue from 20 thrusting. However, such devices are only effective when worn. When removed, the tongue reverts to its original bad habits. Other oral appliances have been proposed that guide the tongue to the correct swallowing pattern. Again these are only effective when being worn. Further, the functional performance of the tongue is highly complex and is determined by its size, strength, movement patterns and 25 resting positions. Thus it will be appreciated that simply providing a barrier to tongue movement will do little, if anything, to correct the underlying problems. It is also very important that the tongue adopts a proper resting position. When the tongue is in the natural resting position, its tip positions on the incisal papilla at the 30 anterior part of the palate. With the tip of the tongue in this position, the dorsum of the tongue runs at the cervical third of the crowns and roots of the upper 4 premolars. The base of the tongue goes downward at the molars, leading to insert at the hyoid bone. When the tip of the tongue is at its physiological position, its dorsum and base tend to reposition at their physiological positions as well, with the base descending at the molar area. 5 Whilst the pressure of a resting tongue tip may be light, it is continuous and only a small pressure is required to move teeth. When the tongue is in the proper resting position the tongue produces the lowest pressure on the surrounding structures, whereas during movement, the pressure increases or reduces at different sites at 10 different times. An abnormal tongue resting position is a major cause of malocclusions. Poor oral posture and habits in a growing child can cause a number of problems such as malocclusion, crowing of the teeth, an open bite and narrow arch 15 formations. These problems can adversely affect facial growth patterns. Failure to treat these problems at an early age in a growing child will generally require physical intervention such as braces and/or surgery at a later date. This is a most undesirable outcome for a patient. 20 Re-locating the tongue so that it adopts a desired natural resting position is a complex process. An appliance which intends to modify tongue posture may act differently on the various muscles that control the tongue and must balance these forces. Still further, the muscular activity of the cheeks and lips must also be considered when treating malocclusions with functional orthopaedic devices. It is 25 also important to control the pressure of the cheeks and lips on the buccal side of the teeth, reduce the activity of the muscles at the chin to a minimum as well as correcting tongue posture. In order to design functional orthodontic devices and to treat patients accordingly it is important to understand the physiology of the tongue and the complex relationship between the tongue, muscular activity and 30 mandible. Research in this complex area is ongoing.

5 It will therefore be appreciated that in designing oral appliances for myofunctional therapy, it is important to consider all the various factors and their complex interactions. Concentrating on correcting one defect without taking other features into consideration may at best allow the untreated defect to continue or at worst 5 create or exacerbate other defects. Neither situation will provide a satisfactory outcome for the patient. It will be appreciated that there is a constant desire in the field of orthodontics to provide new appliances and treatment methods that can provide patients with 10 alternatives to existing appliances and treatments and that may provide a different or better outcome for a patient. SUMMARY OF THE INVENTION 15 According to one aspect of the invention there is provided an orthodontic appliance for being fitted within in a mouth of a patient having an upper and lower arch and a tongue, the orthodontic appliance including: an appliance body for mounting over the upper arch, the appliance body including an inner wall that is positioned on a lingual side of the upper arch and an 20 outer wall that is positioned on a buccal side of the patient's upper arch, a web interconnecting the inner wall and the outer wall, the inner and outer walls each have an upper portion that projects above the web so as to define an upper dental arch receiving channel and the inner and outer walls each have a lower portion that depends below the 25 web that defines a lower dental arch receiving channel; wherein the upper portion of the inner wall defines a tongue opening for consciously receiving the tip of patient's tongue, the upper portion of the inner wall being configured such that when the tip of the patient's tongue is received, the tip will be located adjacent the anterior palate. 30 6 The appliance includes a web interconnecting the inner wall and the outer wall which is positioned between the dentition on the upper and the lower arches when the orthodontic appliance is fitted within the patient's mouth. Thus the web lies broadly in the occlusal plane between the dentition of the upper and the lower 5 arches in use. The inner wall include an upper portion which projects up above the web and a lower portion which depends down below the web, when the appliance is fitted in the patient's mouth. 10 The tongue opening is formed in the upper portion of the inner wall, e.g. substantially centrally on the inner wall, or substantially midway along the inner wall, corresponding to the midline of the patient's dentition. 15 The inner wall may have two major surfaces, namely a lingual surface which faces inward towards the tongue, and a channel surface which faces outward into the arch receiving channels. The outer wall may also have two major surfaces, namely a buccal surface which 20 faces outward towards the buccal mucosa, and a channel surface which faces into the arch receiving channels. The tongue opening may have a substantially circular configuration. The tongue opening may have a diameter of 1 to 12 mm. In one form the tongue opening has 25 a diameter of 5 to 10mm, e.g. about 6 to 9mm. The tongue opening is for consciously receiving the tip of the tongue. By conscious receipt, it is meant that the patient must actively and consciously place the tongue in position. This conscious placement is important to the training 30 process for the tongue. Eventually, the tongue will be trained to naturally rest in 7 the proper position. This may be compared with devices that provide guidance or force the tongue into position, in which case there is little, if any training effect. The tongue opening may have a different diameter for different appliances 5 depending on the stage and type of treatment which the patient is undergoing. The type of treatment may reflect the dentition stage of the patient and/or the nature and extent of the malocclusion. The dentition stages are typically, primary dentition for ages between 3 and 5 years, mixed dentition for ages between 5 and 8 years, developing permanent dentition for ages 12 to 15 years and for adults. 10 The extent of malocclusion may require different degrees of arch development in addition to retraining the tongue. The stage of treatment relates to whether a patient has just begun treatment or any stage up to completion of treatment. It will be appreciated that during early 15 treatment, the tongue is virtually untrained with respect to correct resting position and/or correct swallowing, whereas towards the end of treatment, the tongue is in its final training stages and will tend to automatically locate to the correct resting position when the appliance is removed from the mouth. 20 In early stages of treatment when the tongue is untrained and has an incorrect resting position, it is desirable to provide an accurate guide to assist a patient in finding the correct position for the tip of the tongue that is in the area of the incisal papilla. Accordingly, where the appliance is to be used in the early stages of treatment, the tongue opening typically has a diameter of no more than about 25 1 mm to 2mm. The small hole provides for proprioceptive positioning of the tongue tip at the correct resting position, or in other words it provides a "target" for a young patient to aim the tip of the tongue. Young children, whose tongue does not rest naturally, often have little idea where 30 the tip of the tongue actually is. The patient is told to keep the tip of the tongue in this position when the appliance is in place. Upon removal, the child is told to 8 keep the tongue in that same position. This enables the patient to "educate" the tongue to the correct position. Some prior art appliances, have a tab or tag that indicates the correct resting 5 position of the tongue. However, the present inventor has surprisingly discovered that there is a very small degree of tolerance in the force generated by the tongue if the tongue tip moves from the correct spot. By having the tab or tag "in the spot", this actually prevents the tongue from adopting the most optimal position. Providing an opening allows the tip of the tongue to be more closely in the correct 10 spot. Whilst such a very small difference in position is considered by many in the art to be negligible, the present inventor has surprisingly observed improved results with the appliance of the present invention. A still further advantage of the opening is that it allows the tip of the tongue to 15 touch the palate, thereby allowing the tongue tip to feel where it should go, rather than feeling an artificial tag. Thus, the patient can better feel how the tongue should be when in the correct position when the appliance is in place. The present inventor has surpisingly discovered that the provision of a small hole 20 for the tongue is particularly effective for use with small children between about 3 to 5 years of age. As the treatment progresses and the patient begins to automatically place the tip of the tongue in the desired position, the diameter of the hole may be increased to 25 allow more of the tip of the tongue to at least partially protrude through the hole so as to contact the palate. This will be discussed further below. The inner wall may form a circumferential edge around the tongue opening and the circumferential edge may be rounded. In particular the circumferential edge 30 may be rounded where the tongue opening transitions from a position inside the opening onto the lingual and channel surfaces of the inner wall.

9 As the walls define upper and lower channels for receiving a dental arch, the inner and outer walls include a frontal portion and two arm portions extending away from the frontal portion. 5 The frontal portion of the inner wall may incline rearward away from the outer wall as it extends up from the web. This angle of inclination is suitably selected to adopt the natural curvature of the palate so as to provide comfort when wearing the appliance. 10 The frontal portion may include a tongue opening zone adjacent the tongue opening and surrounding the tongue opening and the tongue opening zone may be inclined at an angle of 25 to 50 degrees, e.g. 30 to 40 degrees, to horizontal. 15 The lower portion of the inner wall may include a tongue elevator. The inner wall may have a lower terminal edge region that is thickened and that defines a substantially horizontally extending support surface that forms the tongue elevator. The tongue elevator assists in discouraging tongue thrusting. 20 The upper portion of the outer wall may have a protrusion projecting out from the channel surface of the outer wall that extends along part of the outer wall. The protrusion may extend substantially horizontally along the outer wall, i.e. substantially parallel to the web. 25 The protrusion may be a rib formation that assists in fitting the appliance and alignment of the incisor teeth on the upper arch. The rib formation may project out from the channel surface with a height of 1 to 2 mm. The rib formation may have a linear length of 20 to 50 mm, e.g. 30-40mm.

10 The outer wall has a front buccal surface and two arm buccal surfaces. The upper and lower parts of the front buccal surface are suitably dimensioned so that they cover the buccal aspect of the anterior teeth or in other words provide a surface upon which the lips may rest. This may counteract force applied to the teeth by 5 abnormal or overactive movement of the mentalis muscle that control the lower lip. For example, the lower lip can apply a force of between 100 - 300gm. The lower front buccal surface may have a lip trainer. The lip trainer is suitably in the form of one or more projections that touch the mucosa of the lip and inhibits 10 overactivity of the mentalis muscle. The lip trainer may comprise a plurality of dimple like protrusions on the buccal surface, e.g. arranged in the form of an array. The buccal surfaces of the side arms can also operate to resist force exerted by 15 the muscles of the cheeks (buccinators). The appliance body may be formed from a polymeric material. In particular the appliance body is formed from a polymeric material that is polyurethane or silicone, e.g. by injection moulding. 20 The appliance body may be made in a number of different sizes and the sizes may be selected so that a majority of the population can select an appliance that can be fitted over their upper arch with a reasonable fit. Typically there may three to four different sizes of the appliance body. 25 According to another aspect of the invention there is provided a method of treating a patient, the method including: fitting an appliance as defined in the preceding aspect of the invention in the patient's mouth and placing the tip of the patient's tongue within the tongue 30 opening of the appliance.

11 The method may further include getting the patient to wear the appliance in this manner on a regular basis. Wearing the appliance on a regular basis may include wearing the appliance on a daily basis, e.g. for 8 to 12 hours each day. Preferably 5 the appliance is worn overnight and for at least one hour during the day. Wearing during the day is important as this requires conscious placement of the tip of the tongue in the tongue opening. The appliance may have any one or more of the features of the appliance defined 10 in the preceding aspects of the invention. According to another aspect of the invention there is provided an orthodontic system for treating a patient including a set of appliances comprising : a first orthodontic appliance as defined in the preceding aspect of the 15 invention and at least a second orthodontic appliance as defined in the preceding aspect of the invention wherein the appliances have different sized tongue openings. The system may have at least three different appliances and the three appliances 20 may have tongue openings of progressively increasing size. In other embodiments, there may be two or four appliances. The different appliances may be used in different stages of treatment, in which case the first appliance will be used in a first stage of treatment and the at least 25 second appliance will be used in a second stage or further stages of treatment. Further the first stage appliance may have a tongue opening of 1 to 3 mm, second stage appliance may have a tongue opening of 4 to 6mm and a third stage appliance may have a tongue opening of 7 to 10mm. 30 12 The appliance may have any one or more of the features of the appliance defined in the preceding aspects of the invention. The method also extends to method for treating a patient including: 5 providing a set of appliances as defined in the preceding aspect of the invention comprising respectively a first stage appliance having a small tongue opening, at least a second stage appliance wherein the second stage appliance has a larger tongue opening than the first stage appliance; wearing the first stage appliance and placing the patient's tongue within the 10 tongue opening of the appliance; repeating the wearing of the first stage appliance on a regular basis for a first period of time; wearing the second stage appliance and placing the patient's tongue within the tongue opening of the appliance; and 15 repeating the wearing of the second stage appliance on a regular basis for a further period of time. The method may further include providing a third stage appliance in which the tongue opening is larger than the second stage appliance and wearing the third 20 stage appliance and placing the patient's tongue within the tongue opening of the appliance; and repeating the wearing third stage appliance on a regular basis for a further period of time. The method may also include providing a fourth stage appliance in which the 25 tongue opening is substantially the same size of larger than the third stage appliance and wearing the fourth stage appliance and placing the patient's tongue within the tongue opening of the appliance; and repeating the wearing forth stage appliance on a regular basis for a further period of time.

13 The further period of time may be similar to said first period of time. The time may be at least two months, at least 4 months and suitably between about 6 to about 12 months. The method may include wearing the final stage appliance on an ongoing basis into the future for the duration of the treatment. 5 The appliance may have any one or more of the features of the appliance defined in the preceding aspects of the invention. The present invention also relates to an orthodontic system for treating a patient, 10 including a_set of appliances as defined in the preceding aspect of the invention comprising respectively a first stage appliance having a small tongue opening, at least a second stage appliance having wherein the second stage appliance has a larger tongue opening than the first stage appliance. 15 The set may further include third stage appliance in which the tongue opening is larger than the second appliance. The set may further include fourth stage appliance in which the tongue opening is substantially the same or larger than the third appliance. 20 DETAILED DESCRIPTION OF THE INVENTION An orthodontic appliance in accordance with this invention may manifest itself in a variety of forms. It will be convenient to hereinafter describe several embodiments 25 of the invention in detail with reference to the accompanying drawings. The purpose of providing this detailed description is to instruct persons having an interest in the subject matter of the invention how to carry the invention into practical effect. However it is to be clearly understood that the specific nature of this detailed description does not supersede the generality of the preceding broad 30 description. In the drawings: 14 Fig 1 is an upper perspective view of an orthodontic appliance in accordance with one embodiment of this invention; Fig 2 is a lower perspective view of the orthodontic appliance of Figure 1; 5 Fig 3 is a front view of the orthodontic appliance of Fig 1; Fig 4 is a rear view of the appliance of Fig 1; Fig 5 is a top plan view of the appliance of Fig 1; Fig 6 is a bottom plan view of the appliance of Fig 1; Fig 7 is a side view of the appliance of Fig 1; 10 Fig 8 is a sectional side view of the appliance of Fig 1, the section being through the midline of the appliance; Fig 9 is a sectional side view of the appliance of Fig 1 showing a longitudinal section of the web of the appliance, the section being through the midline of the appliance; 15 Fig 10 is a top plan view of an appliance that is a variation on the appliance of Fig 1 that has a much smaller tongue opening; Fig 11 is a top plan view of an appliance that is a variation on the appliance of Fig 1 that has a tongue opening that is intermediate the size of the tongue openings in Fig 1 and Fig 10. 20 Fig 12 is a top plan view of part of the appliance of Fig 10 showing a tip of a tongue received in the tongue opening; Fig 13 is a top plan view of part of the appliance of Fig 11 showing a tip of a tongue received in the tongue opening; Fig 14 is an upper perspective view of part of the appliance of Fig 1 showing a tip 25 of a tongue received in the tongue opening; and Fig 15 is a top plan view of part of the appliance of Fig 1 showing a tip of a tongue received in the tongue opening.

15 In Fig 1 reference numeral 10 refers generally to an orthodontic appliance in accordance with one embodiment of the invention. The orthodontic appliance 10 includes an appliance body 12 for mounting over the 5 upper arch of a user. The appliance body includes an inner wall 14 that is positioned on a lingual side of the patient's upper arch and an outer wall 16 that is positioned on the buccal side thereof. The appliance body 12 also includes a web 18 interconnecting the inner wall 14 and the outer wall 16 which lies in the occlusal plane between the dentition of the upper and the lower arches in use. 10 The inner and outer wall 14 and 16 and web 18 define upper and lower arch receiving channels 20 and 22 within which respectively the upper arch and associated dentition and the lower arch and associated dentition can be received. The inner wall 14 includes an upper portion 15 which projects up from the web 18 15 when the appliance 10 is mounted on the upper arch and a lower portion 17 which projects down from the web 18. Similarly the outer wall 16 comprises an upper portion 19 above the web 18 and a lower portion 21 below the web 18. Further the inner wall 14 has a lingual surface 26 and a channel surface 28. The outer wall 16 similarly has a buccal surface 30 and a channel surface 32. 20 The inner wall 14 defines a tongue opening 40 for receiving the tip of a patient's tongue. The tongue opening 40 is formed substantially centrally in the upper portion 15 of the inner wall 14 corresponding to the midline of the patient's dentition. In the Fig 1 embodiment the tongue opening 40 has a diameter of 6 to 25 9mm. However it needs to be appreciated that this embodiment is part of a set of appliances and different appliances 10 in the set have different sized tongue openings 40. The lingual and channel surfaces 26 and 28 of the inner wall 14 each define a circumferential edge 42 around the tongue opening 40 and the circumferential edges on both the lingual and channel surfaces 26 and 28 are 30 rounded. In particular the circumferential edges may be curved with a radius of curvature where the tongue opening transitions onto each of the lingual and channel surfaces 26 and 28 of the inner wall 14.

16 The inner and outer walls include a frontal portion 31 and two arm portions 33, 35 extending away from the frontal portion. The frontal portion 31 of the inner wall 14 inclines rearward away from the outer wall 16 as it extends up from the web 18 at 5 an angle of about 30 to 40 degrees. In particular a region of the inner wall, indicated by numeral 46 in the drawings within which the tongue opening 40 is formed may incline rearward at an angle of 30 to 40 degrees. The channel surface of the upper portion 19 of the outer wall 16 has a protrusion 10 in the form of a rib 48 projecting out from the channel surface 32 that extends linearly along the outer wall 16 (shown in Fig 1 only). The rib 48 is centrally positioned and projects a distance of 1 to 2 mm away from the channel surface 32 of the outer wall 16. The rib 48 assists with fitting and with dental alignment. The rib 48 is an optional feature that is only present in some embodiments. 15 The lower portion of the inner wall 14 includes a tongue elevator 50. The inner wall 14 has a lower terminal edge region 52 and the lower terminal edge region is thickened to form the tongue elevator 50. 20 The outer wall 16 has a front buccal surface 52 that is dimensioned so that it substantially covers the buccal aspects of the upper and lower posterior teeth when the mouth is closed. In this way any force from overactive lip muscles can be dispersed over the surface 52 rather than applied to the teeth. 25 The outer wall 16 has a lip trainer 56 on the buccal surface 30 thereof that is positioned below the web 18. The lip trainer 56 comprises an array of dimple like protrusions on the buccal surface 30 that inactivate an overactive mentalis muscle.

17 The arm portions 33, 35 of the buccal surface 30 serve to move the cheeks away from the buccal aspect of the posterior teeth. This releases any force produced by the buccinators. 5 In use as shown in Figs 14 and 15, a treating practitioner such as an orthodontist selects a size of appliance 10 from a range of different sizes that best matches and fits the arch of the patient. Typically there might be three different sizes of appliance configured to file three different arch sizes in patients. The appliance 10 is inserted into the mouth of the patient and is fitted in the mouth of the patient. 10 This is done by mounting the appliance over the upper arch of the patient with the upper arch and dentition received within the upper arch receiving channel. The patient positions their tongue 60 so that the tip 62 thereof projects through the tongue opening 40. The tongue opening 40 locates and positions the tongue 60 in an ideal or most preferred position within the mouth which creates a beneficial 15 myofunctional environment. In particular it promotes correct swallowing action with the tongue 60 and this in turn promotes favourable arch development and teeth alignment. The tongue opening is positioned at the preferred height within the intra-oral cavity for the tongue 60 to rest in. 20 The appliance is kept in place by being held between the teeth with the mouth closed and the patient is told to keep the mouth closed and breathe through the nose. Keeping the mouth closed is important for a number of reasons. The correct resting position of the tongue requires the mouth to be closed. Further, closing the mouth encourages nasal breathing. Open mouth breathing is an oral 25 habit resulting from or contributing to a number of oral defects. Still further if the mouth is open, the the lip trainer and the side buccal surfaces cannot carry out their intended function in an optimal manner. The appliance can be fitted in the mouth and removed from the mouth at will by a 30 patient. It is not permanently fitted to the upper arch. It can therefore be fitted in a patient's mouth and removed from the mouth by a patient at will depending on lifestyle needs and considerations. For example it can be removed from the 18 mouth to attend school or a workplace. Typically the appliance is worn for one to two hours each day and overnight, e.g. 8 to 14 hours total. In particular the appliance can be worn while the patient is sleeping at night. 5 Fig 10 is a top plan view of an appliance that is a variation on the appliance shown in Fig 1. In Fig 9 the same reference numerals will be used to refer to the same components as in Fig 1 unless otherwise indicated. The following description will focus on the differences between this appliance and the Fig 1 appliance. 10 The tongue opening on this embodiment is very small and can receive only a tip of patient's tongue therein. It only receives a sufficient amount of the tip of the tongue so as to be able to locate the tongue and hold it in position. Fig 11 is a top plan view of an appliance that is a variation on the appliance shown 15 in Fig 1. In Fig 11 the same reference numerals will be used to refer to the same components as in Fig 1 unless otherwise indicated. The following description will focus on the differences between this appliance and the Fig 1 appliance. The tongue opening on this embodiment is of intermediate size. It can receive 20 more of the tongue than the tongue opening in Fig 10. The tongue opening is large enough to receive a tip of the tongue so to speak. However it is still significantly smaller than the tongue opening in Fig 10. It receives a portion of the tongue and permits the tip of the tongue to be positioned forward of the inner wall. 25 In use, the three appliances illustrated in Figures 10, 11 and Fig 5 are used in a treatment program. In a first stage of treatment, a first stage appliance illustrated in Fig 10 with a small tongue opening is used first. This appliance is used first to train the patient to 30 position their tongue in the correct position with the tongue tip received within the 19 small tongue opening. The tip of the tongue does not project through the tongue opening to any appreciable extent. Myofunctional training of the tongue requires a patient to positively locate the tip of 5 the tongue in the correct resting position towards the palate. When the tongue is placed with the tip in the hole, it helps to train the tongue to position it in the correct position. The presence of the hole assists in correctly position the tip of the tongue more easily than conventional tongue thrust appliances and further invites a higher level of compliance in keeping the tongue in this position. Such 10 compliance is important for the training of the tongue and especially so when it is taken into consideration that the patients are children with short attention spans. The first appliance whilst providing habit correction may also assist in providing some initial dental alignment. 15 After a period of time of treatment that is typically at least several months and the habit correction has been partially achieved, the orthodontist can start using the second stage appliance on the patient. The second stage appliance has a larger tongue opening and this opening receives a larger region of the tongue therein. 20 Patients who have received a period of training have already progressed in relation to being able to locate their tongue in the correct resting position. With this appliance the tip of the tongue projects fully through the tongue opening. It is also important for the tongue not to press against or protrude between the teeth when swallowing. As the larger hole allows more of the tongue to protrude 25 therethrough it offers a further advantage in that it offers some assistance to guide the tongue to the correct position and/or movement when swallowing. Depending upon the extent of malocclusion, the second stage may also further correct dental alignment. In this case, the appliance may be made of a harder 30 material than the first stage.

20 Once again after a period of training of several months the patient can be transferred onto the third stage appliance with the large tongue opening. At this stage, the tongue is generally at its final stages of training and the patient does not require the "target" of the smaller openings. As the opening is larger, the tongue 5 may make further contact with the pallet in a more natural manner. With this appliance the entire tip region of the tongue can project fully though the tongue opening and bear up against the upper arch. This is a most desired position for the tongue. 10 One advantage of the orthodontic appliance in accordance with the invention is that it can be used to stepwise train a patient's tongue to adopt a correct position within the intra-oral environment, together with training the tongue to be in the correct position when swallowing. Further once trained the tongue can adopt a relaxed and desired longitudinal position within the patient's mouth. 15 Another advantage is that a system, of appliances having progressively increasing sizes of tongue openings can be used to train a patient to accept the appliance and develop a behaviour where the tongue naturally and instinctively locates within the tongue opening with the tip of tongue forward of the inner wall and 20 adjacent to the lingual wall of the upper arch. Another advantage of this invention is that it utilises the proprioceptive nature of a patient's tongue. 25 Applicant has discovered that forming a tongue opening in the inner wall elicits a physiological response that causes a patient to project their tongue forward through the opening. This leads to a more favourable tongue positioning that has previously been achieved and this leads to positive tongue habits and the benefits that flow therefrom. 30 21 It will of course be realized that the above has been given only by way of illustrative example of the invention and that all such modifications and variations thereto, as would be apparent to persons skilled in the art, are deemed to fall within the broad scope and ambit of the invention as is herein set forth. 5

Claims

1. An orthodontic appliance including: an appliance body for mounting over the upper arch, the appliance 5 body including an inner wall that is positioned on a lingual side of the upper arch and an outer wall that is positioned on a buccal side of the patient's upper arch, a web interconnecting the inner wall and the outer wall, the inner and outer walls each have an upper portion that projects above the web so as to define an upper dental arch receiving channel and 10 the inner and outer walls each have a lower portion that depends below the web that defines a lower dental arch receiving channel; wherein the upper portion of the inner wall defines a tongue opening for consciously receiving the tip of patient's tongue, the upper portion of the inner wall being configured such that when the tip of the patient's tongue is 15 received, the tip will be located adjacent the anterior palate.

2. The orthodontic appliance according to claim 1, wherein the tongue opening has a substantially circular configuration having a diameter of 1 to 12 mm. 20

3. The orthodontic appliance according to claim 1, wherein the tongue opening has a substantially circular configuration having a diameter of 1 to 3 mm. 25

4. The orthodontic appliance according to claim 1, wherein the tongue opening has a substantially circular configuration having a diameter of 4 to 6 mm. 23

5. The orthodontic appliance according to claim 1, wherein the tongue opening has a substantially circular configuration having a diameter of 7 to 10 mm 5

6. The orthodontic appliance of any one of claims 1 to 5, wherein the inner and outer walls each include a frontal portion and two arm portions extending away from the frontal portion.

7. The orthodontic appliance of claim 6, wherein the frontal portion of the 10 inner wall inclines rearward away from the outer wall as it extends up from the web.

8. The orthodontic appliance of claim 7, wherein the frontal portion includes a tongue opening zone adjacent the tongue opening and surrounding the 15 tongue opening and the tongue opening zone may be inclined at an angle of 25 to 50 degrees to horizontal.

9. The orthodontic appliance of claim 7, wherein the angle is 30-40degrees. 20

10. The orthodontic appliance of any one of claims 1 to 9, wherein the lower portion of the inner wall has a lower terminal edge region that is thickened and that defines a substantially horizontally extending support surface that forms a tongue elevator. 25

11. The orthodontic appliance of any one of claims 6 to 10, wherein the outer wall has a front buccal surface and two arm buccal surfaces, the upper and lower parts of the front buccal surface are suitably dimensioned so that they cover the buccal aspect of the anterior teeth. 24

12. The orthodontic appliance of any one of claims 1 to 11, wherein the lower front buccal surface includes a lip trainer in the form of one or more projections that when worn by a patient, touches the mucosa of the lip. 5

13. A method of treating a patient, the method including fitting the appliance of any one of claims 1 to 12 placing the patient's tongue within the tongue opening of the appliance.

14. A method according to claim 13, wherein the method further includes 10 getting the patient to wear the appliance on a daily basis for 8 to 12 hours each day.

15. An orthodontic system for treating a patient including: a set of orthodontic appliances, each appliance including: 15 a first appliance according to any one of claims 1 to 12 and at least a second appliance according to any one of claims 1 to 12, wherein the tongue opening of the second appliance is larger than the tongue opening of the first appliance. 20

16. The orthodontic system according to claim 15, wherein the set of appliances includes a third appliance and the tongue opening of the third appliance is larger than the tongue opening of the second appliance.

17. The orthodontic system according to claim 15, wherein the set of 25 appliances includes a fourth appliance and the tongue opening of the fourth appliance is substantially the same or larger than the tongue opening of the third appliance.

18. A method for treating a patient including: 25 providing a set of appliances comprising respectively a first appliance according to any one of claims 1 to 12 and at least a second stage appliance according to any one of claims 1 to 12 wherein the tongue opening of the second stage appliance is larger than the opening of the first 5 stage appliance; wearing the first stage appliance and placing the patient's tongue within the tongue opening of the appliance; repeating the wearing of the first stage appliance on a regular basis for a first period of time; 10 wearing the at least second stage appliance and placing the patient's tongue within the tongue opening of the appliance; repeating the wearing of the at least second stage appliance on a regular basis for a further period of time. 15

19. The method of claim 18, which further comprises providing a third appliance according to any one of claims 1 to 12, wherein the tongue opening is larger than that of the second appliance; wearing the third stage appliance and placing the patient's tongue within the tongue opening of the appliance; 20 repeating the wearing of the at least third stage appliance on a regular basis for a further period of time.

20. The method of claim 18, which further comprises providing a fourth appliance according to any one of claims 1 to 12, wherein the tongue 25 opening is substantially the same or larger than that of the second appliance; wearing the fourth stage appliance and placing the patient's tongue within the tongue opening of the appliance; repeating the wearing of the at least third stage appliance on a 30 regular basis for a further period of time.