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(J lnd Orthod Soc 2002 ; 35 :13-1-142):....:...:....:=;.:..:.:..:...;=.:...:..:= REV IE W

Effective Means of Intraoral Molar Distalization- An Overview

D. N . apoor I rvp Razdan OSridhar Kannan O

Correction of Class II malocclusion without extractions requires maxillary molardistalization by means of intraoral or ext raoral forces . Although headgears have provenundoubtly useful in the correction of this skeletal anomaly . the constancy of forcesand the dependence on pat ient co-operation is of concern.

Since the 1980s various intra arch dev ices have been introduced such as the K loopV. Kalra) . NiTi co il springs (G ianelly) . Superelastic NiT wires (Locatelli) . Repell ing

magnets (Gianelly) . Fixed Piston appliance (Green field ). Pendulum appliance (Hilgers) .Lokar Dista lizer (SCOII). Distal Jet (Carano) as well as combination of extraoral andintraoral b rce s (Cetlin and Tenhoeve) . Researchers have bcused on the simplicity andefficiency of Ihe se intraarch devices . which improves the continuity and consta ncyof forces . Oral hygiene is easier to maintain and the need for patient compl iance iseliminated . A modified Nance appliance has olten been applied in conjunction withthese force delivery systems to increase anchorage during distal movement or keepthe molars in position fonowing dista l movement. This pape r presentation is an anemptto update informat ion rega rding various in tra oral dista lizing appliances availablecurrently and discusses patients treated successfully by using NiTi coi l springs (Orthoorganizer) by distalization for correction of class II molar relationship .

Introduction :Correction of Class II malocclusion without

extractions requ ires maxillary molar distalization bymeans of intraoral or extraoral forces. Althoughheadgears have proven useful in the co rrection ofskeletal problems , as well as in providing anchoragefor extraction cases, the dependence on pal ientcoope ration is heavy .

William Kingsley (1892) described for the firsttime headgear apparatus w ith which Class I molarrelationship of the molar could be achievedsuccessfully. Kloehn in 1947 started a long andbeneficial series of investiga tions and clinicalappl ications of occipital anchorage to the maxillary

Professor and Head . Department of Qf thodon tics. Faculty1 Dental Sciences. K.G:s , Medica l College , lucknow

. Po s t Graduate Student , Department of Orthodont ics.Faculty 1 Dent a l Sc iences . K.G . s . Med ic a l Colle ge .lucknow

. . Post Graduate Student. Department of On hod on tics.Faculty of Dental Science s . K.G : s . Med ica l College ,Lucknow

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dentition. The headgears ove r the years have shownto be effective in maxillary molar distalization withmovements in all planes of space . With the recenttrend more towards non extrac tion treatment, severalintra arch devices have been advocated to distalizemolars in the upper arch. Researchers have focusedon the simplicity and efficiency of these intraarchdevices , which improves the continuity andconstancy of forces . Oral hygiene is easier tomaintain and the need for palient compliance iseliminated. Certain principles , as outlined byBurst one' must be borne in mind . when designinga n ideal intraoral molar dis lalization appliance.

Molar distalization is a lechnique that hasadded a new co lumn in the practice of everyonhodonfist to produ ce consistent, predictable andhigh quality results. The goals of practicising w ithefficiency and profitability are positively affected.

Since space is eas ier to gain in the maxillaryarch than in the mandible because of inc reasedtrabecular structure of supporting bone a ndincreased anchorage afforded by pa latal vault . thedistatl:t.ation of maxi llary molar becomes 01

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132 Effective Means of Intraoral Molar Distafization - An Overview - D N. Kapoor/Anup Razdan /Sridhar Kannan

significant value for the treatment of cases w ith mildto mode rate arch dis crepancy and Class II molarrelationship associated with a normal mandible.

Indications: An end on or full Angle 's class II mo lar re lation

ship due to maxillary protrusion. impacted.unerupted and ectopic erup tion o f cuspids .

Situation requir ing distal movement of mo lars Mild to moderate arch discrepancy. Class II molar relationsh ip associated with normal

mandible .

Timing :A favourable time to move molars dis ta lly

appears to be in the mixed dentition , be fore theeruption of the second molars , and an efficientlorcesystem to move molars distally is a conti nuously

acting force .Principles of Appliance Design : Magnitude of forces and moments. Moment to force ratio. Constancy of force and moments . Bracket friction. Minimal loss of an te rior anchorage . Bodily movement of molars to avo id lengthening

of treatment and unstable results. Ease of use. Cost. Minimal chairtime for placement and reactivation.

Limitations: High angle retrognalhic type o f pattern Third molars that have erupted or close to

eruption imp ede dista lization Treatment in vertical growth pattern sho u ld be

done conservatively with extractionThe present study is an attempt to upda te

informat ion regarding va rious intraoral distal izin gappliances available. This article w ill also presentand discuss results obtained in lew patients trea tedin the Department of O rth odontics , Fa culty of

Dental Sciences , King George 's Medical College ,Lucknow after distalization using Nance applia nceand NiTi coil springs.

Intra Oral Methods for Distalizing Molars

1. Ae pelling Magnet sIntra arch repelling magnets (Fig . 1) used to

dist a lize molars were introduced by Gianelly t a1988). These are prefabricated repelling Samarium

Cobalt magnet (SmC05) with a po le face 2 x 5 m .The magnets are attached to headgear tube of

maxillary first molar bands and repelling surfacesare brought into contact by 0.14 ligature wire.Forces measure to 200 225 gms but dropsubstant iall y as space opens beyond 1 mm .Movement of 3 mm is see n in 7 weeks if secondmolars are absent and 0.75- 1 mm per month ifpresent. An chorage is reinforced by Nanceapp liance and Class II elastics against an 0.016 )0 .022 sectiona l arch wi re . The rate of molardislalization using magna orce is less than thatobserved with conventional mechanotherapy. Thisis in ag re ement w ith the findings of Owman t al :