a preferred embodiment will now be described with reference to the accompanying figures . a preferred embodiment of the invention comprises molar bands on the upper molars . in fig1 , which shows a plan view of the device in - situ in a patient &# 39 ; s mouth , the molar bands 1 and 1 ′ are shown gripping the upper first molars 2 and 2 ′. the tensioning mechanism of the bands is not illustrated in this figure , for clarity . to these bands 1 and 1 ′ are attached 0 . 9 mm internal diameter stainless steel tubes 3 and 3 ′ palatally , which house free - sliding horizontal arms 4 and 4 ′ as a palatal arch . the arms 4 extend sufficiently from the distal end to allow the required movement of the molars 2 and to prevent trauma , composite can be placed as required although this has not been found to be necessary . the arms 4 occupy the vacant area not intruded to by the tongue adjacent to the second molars 5 and 5 ′. the middle section of this arch carries an acrylic support plate 6 , covering most of the palatal keratinised tissue , free of the incisive papilla . it is much larger than a nance button and contoured to the vertical and horizontal parts of the palate and the rughae to achieve maximum anchorage . the active component is from nickel - titanium open coil springs 7 and 7 ′ of internal diameter 0 . 9 mm ( compression springs 14 mm , medium , such as those sold by forestadent ltd , bernhard forster gmbh , westliche karl - friedrich - straste , 151 , 75172 pforzheim , germany ). a small distally facing hook 8 is attached to the palatal acrylic flange to maintain the bands in the retracted position , with the aid of either dental floss or wire ligatures connected between the hook and the points marked by arrows a and b , during cementation of the bands . a screw lock 9 and 9 ′ is placed on each of the horizontal arms to help activate the coil springs 7 at subsequent appointments . this is not always necessary as sufficient activation can be built into the system for a single activation or 0 . 9 mm internal diameter sleeves can be utilised . fig2 shows an elevation and partial cross - section of the device . the support plate 6 , shaped to fit closely against the keratinised tissue of a user &# 39 ; s palate in use , is connected to side pieces , in the form of arms 4 extending rearwards ( with respect to the user &# 39 ; s mouth , in use ) to lie adjacent a molar to be corrected 2 . a molar band 1 grips the molar to be corrected 2 , and has a tube 3 attached to it . the arm 4 passes through the tube 3 , thus forming a slideable connection allowing the tooth 2 to move . a spring 7 is provided , acting in compression between the tube 3 and an adjustable abutment mechanism 9 , in the form of a ring and screw . fig3 shows an elevation and partial cross - section of the device , further comprising attachment means in the form of an eyelet 8 attached to the support plate 6 to allow restraining means ( such as wire or dental floss ) to temporarily restrain the action of the spring 7 to facilitate fitting of the brace . the appliance system requires very little management . if the level of distal movement has been preselected , by choosing the necessary length distal to the molar band tube , then regular examination is all that is required . on the other hand either activating the springs or reconstructing a new arch can achieve more extensive movement . if only one molar is to be distalised , then the spring means act only upon that molar to be corrected . in order to distribute the resultant forces in this “ unilateral ” mode , the corresponding opposite side piece may be adapted to grip another , opposite , molar , but no spring means are provided on the side that does not require correction . three case reports using this embodiment , referred to as distal moving equipment ( dme ), are presented below . orthodontic treatment was commenced for a 14 year - old patient presenting with a moderately severe class ii / i malocclusion on a moderately severe skeletal ii base with a slightly increased fmp angle . crowding was found in both arches with the lower incisors mildly imbricated and the upper lateral incisors somewhat locked behind the centrals . the upper erupting upper canines were distally tipped and bucally excluded with the deciduous c &# 39 ; s retained . the overjet was increased to 9 mm and the overbite reduced and incomplete . the molar relationship was half a unit class ii on the right and a unit on the left . the treatment plan involved distal movement of both buccal segments using a dme and extractions of four , second premolars . 022 swa mechanics were utilized to retract the canines to a class i relationship with the relief of crowding after the molar relationship had been established at a class i . this latter process took seven months to achieve . the subsequent space closure was completed using sliding mechanics at which stage the dme was removed . the active treatment lasted 25 months and subsequently was on retention for a period of a further 12 months . orthodontic treatment was commenced for a 14 year - old patient presenting with a class ii / ii type malocclusion with crowding in both arches on the left quadrants and mild skeletal ii with an average fmp angle and an increased inter - incisal angle . the lips were competent . the overjet was reduced somewhat and the overbite was quite substantially increased . both the canines on the left were completely excluded bucally . ihe centre lines were not coincident with the lower substantially and the upper somewhat to the left . the buccal segments were mildly post normal on the right and a unit post normal on the left . the centre lines were substantially to the left in the lower and somewhat to the left in the upper . the treatment plan involved a unilateral dme to distally move the left quadrant . the extractions were phased in the lower and upper arches , with the first premolar on the left and the second premolar on the right . 022 swa mechanics were utilized first in the lower , and then in the upper to retract the canines to relieve the crowding and to a class one relationship . buccal anchorage being well maintained , sliding mechanics were used with the removal of the dme and all spaces closed so completing treatment in 27 months . as relapse was likely , upper and lower removable retainer was fitted . orthodontic treatment was commenced for a 12 year old who had been referred by her general dental practitioner . she presented with a class iii malocclusion on a mild skeletal iii base with a average fmp angle and competent lips . the lower arch was well aligned although the upper arch was somewhat crowded with the upper canines unerupted . radiological examination confirmed the clinical impression that both canines were present although with the ur3 impacted and unlikely to erupt on its own . the plan was to limit the treatment to the upper arch if possible , distally move the upper buccal segments to create the necessary space and surgically expose ur3 for an attachment with a gold chain and extract the upper deciduous canines . treatment was commenced with a dme to distalise the buccal segments and create space to align the canines , especially the right . traction was applied to the chain with elastic thread to gradually move the canine into position . 022 swa mechanics were used to complete the treatment with the removal of the dme at space closure . an upper removable retainer was fitted . the active treatment lasted 17 months and the patient was on retention for a further period of 10 months . measurements for each of these cases , before and after treatment , were as follows : case 1 case 2 case 3 measurement * before after before after before after sna 84 . 0 81 . 0 76 . 5 75 . 0 81 . 0 81 . 0 snb 79 . 0 78 . 0 73 . 0 71 . 5 77 . 0 77 . 0 anb 5 . 0 3 . 0 3 . 5 3 . 5 4 . 0 4 . 0 u - incisor / max plane 116 . 0 93 . 5 103 . 0 106 . 0 114 . 0 111 . 0 max / mand plane 28 . 5 26 . 5 25 . 0 23 . 0 31 . 0 32 . 0 l - incisor / mand plane 96 . 0 97 . 5 87 . 0 95 . 0 94 . 0 91 . 0 inter / incisal angle 120 . 0 142 . 5 145 . 0 132 . 0 121 . 0 126 . 0 gonial angle 123 . 5 123 . 0 118 . 5 119 . 5 132 . 0 132 . 0 l - incisor tip / nb line 4 . 0 3 . 0 2 5 6 . 5 6 . 5 ( mm ). * measurements are standard roentgenographic cephalometry indices , after downs , w . b . ( 1948 ), and well - known in the field of orthodontics . the dme can thus achieve the necessary movements in the buccal segments . this is for both traction and anchorage . in a recent audit of head - gear compliance [ 12 ] there was a clinically unacceptable failure rate of head - gear usage . the dme has removed such failures in usage . it has been found that when the palatal tube is sufficiently long and the palatal arch extended adequately for the proposed distal movement and contracted slightly , there appears to be minimum tipping , rotation and expansion of the molars . although during this length of treatment there appears to be some occasional mild palatal tissue changes with some inflammation observed , they are well within acceptable limits and have been contained with satisfactory hygiene methods . given the option , patients prefer the dme to extra - oral headgear . the dme appears to offer excellent distal movement in unilateral usage too . ( case report 2 .) when there is significant crowding and the upper third molars are present and well formed and stacked , the extraction of the second molars as is currently the practice is a useful adjunct . in moderately high fmp angles in the younger subject it appears that there is no further opening of the angle . this may be attributed to the forces used , being less than those generated by the masticatory apparatus . this would have to be confirmed by the necessary cephalometric analysis . in usage , the time taken to achieve a class i , from a class ii molars is considerably less than with extra - oral methods . distal movement of the upper buccal segments can be very satisfactorily achieved utilizing a dme appliance . this has no tooth borne component and therefore none of the disadvantages of the systems as yet described . it has the significant advantage of not requiring the patient compliance as compared with extra - oral methods of usage . 1 . allan , a . t . ; hodgson , e . w . : the use of personality measurements as a determinant of patient co - operation in an orthodontic practice , american journal of orthodontics , 54 : 433 - 440 , 1968 . 2 . clark , j . r . : oral hygiene in orthodontic practice : motivation , responsibilities and concepts , american journal of orthodontics , 69 : 72 - 82 , 1976 . 3 . jarabak , j . r . : management of an orthodontic practice st louis , c . v mosby company , 1965 , chapter 7 , p 150 - 181 . 4 . lewis , h . g . and brown , w . a . b . : attitude of patients wearing removable orthodontic appliances , british dental journal , 134 : 87 - 90 , 1973 . 5 . cucalon , a . s . ; smith , r . j . : relationship between compliance by adolescent orthodontic patients and performance on psychological tests , angle orthod , 60 : 107 - 113 , 1990 . 6 . salzman , j . r . : psychological factors in patient attitudes , american journal of orthodontics , 58 : 295 - 296 , 1970 . 7 . cureton , s . l . ; regennitter , f . j . ; yancey , j . m . : clinical versus quantitative assessment of headgear compliance , american journal of orthodontics and dentofacial orthopedics , 104 : ( 3 ). 277 - 284 , 1993 . 8 . clemmer , j . e . ; hayes , e . w . : patient co - operation in wearing orthodontic headgear , american journal of orthodontics , 75 : ( 5 ). 517 - 524 , 1979 . 9 . lewis , d . h . ; fox , n . a . : distal movement without headgear : the use of an upper removable appliance for the retraction of upper first molars , british journal of orthodontics , 23 : 305 - 312 , 1996 . 10 . webrbein , h . ; merz , b . r . ; diedrich , p . and glatzmaier , j . : the use of palatal implants for orthodontic anchorage , clinical oral implant research , 7 : 410 - 417 , 1996 . 11 . perera , p . s . g . ; patel , s ,: audit of compliance and non - compliance of head - gear usage , the british orthodontic society orthodontic effectiveness working party , newsletter no . 15 , 2002 .
the invention provides a corrective orthodontic brace wherein a spring means acts upon one or more molars to move them towards the back of a user &# 39 ; s mouth . the forces are transmitted to a support plate shaped to fit closely on the keratinised tissue of a user &# 39 ; s mouth .