Rapid Molar Intrusion Device / orthodontic courses by Indian dental academy

Treatment of skeletal open bite with a device for rapid molar intrusion

ANGLE ORTHODONTIST-sept 2005; vol 75

www.indiandentalacademy.com

INDIAN DENTAL ACADEMY

Leader in continuing dental education www.indiandentalacademy.com

A rapid molar intruder for ‘non-compliance’ treatment

JCO March 2002 ;volume 36

Aldo Carano DO,MS William C Machata DDS


Various modalities for intrusion-

Coronal reduction Subapical osteotomy Full coverage splints with fixed appliances High pull headgear with functional appliances Magnets Miniplates and screws


it has been shown that 25gm of force is sufficient for intrusion of a single tooth along with significant gain of attachment and the max sinus is not an obstacle to intrusion.


Appliance design

modification of jasper jumper

flexible fixed appliance that delivers light continous forces and can be used to move single teeth,units of teeth,or an entire arch

Delivers functional;bite jumping;headgear like and elastic like forces or a combination of these


Modules

L shaped pinsGuide the modules into positions

parallel to the occlusal plane


During occlusion the modules flex and deliver a force upto 900gms against the molars.

Adverse movt-buccal crown tippingControl-use upper and lower lingual arches


Case report 11yr old male Chief complaint-anterior open bite

difficulty to close lip

Clinically- long face open bite 5mm bilateral posterior crossbite

Cephalometric analysis- straight profile vertical growth pattern mand rotated clockwise



Upper arch - Spring Jet palatal expander Lower arch –soldered lingual arch RMI


Post Rx-


M-B inclination of molars - controlled by palatal/lingual arches

Molar intrusion and counter clockwise rotation of mandible achieved -6months


Discussion-

Although promising a more long term research project needs to be done

Relapse ?

Periodontal status and pseudo pockets ?


Treatment of skeletal open bite with a device for rapid molar intrusion

ANGLE ORTHODONTIST-sept 2005; vol 75

Aldo Carno Giuseppe Siciliani S.Jay Bowman


Open bite is one of the most difficult malocclusions to treat

Features-Vertical max excessBackward rotation of mandibleSupra eruption of post teeth

Vertical control - directed against posterior maxilla corrections obtained here are

relatively stablewww.indiandentalacademy.com

Design

Elastic modules –attached to bands

End caps- Straight-maxillary tube Angulated-mandibular tube

L shaped annealed ball pins- placed into buccal tubes

Force - 600 – 900 gms Buccal tipping-always use TPA

or lingual archwww.indiandentalacademy.com

Clinical application

Attach modules to TPA/lingual arch while in attached to plaster models

Modifications- with tongue crib with expansion screw


Construction-place pin into hole of angulated end of elastic

module of lower archInsert pin through convex side of metal cap with

ball end directed buccogingivallyThen insert it in the mesial opening of buccal

tube.the annealed portion is bent gingivally. Terminal 2mm is bent mesially.


Put other ball pin through the hole in flat end of force module

Then insert pin into mesial of buccal tube of the maxillary band

Ball end of pin at mesial side is bent gingivally


Class II-attach max end of force module to distal of buccal tube

Class III- mand end of force module to distal of buccal tube


Appliance is most suitable for growing patients showing excessive vertical growth

More intrusion in maxillary molars Deciduous molars if hypererupt-serial extraction

If 2nd molars erupt-include using sectional rectangular wire

Avg Rx time-5 – 7 months


Case report-

12 yr old female Chief complaint – lack of contact bet upper and lower incisors

and diff in closing lips Clinical examination-class Imalocclusion open bite – 3.6mm moderate posterior contraction Ceph analysis- obtuse mand plane angle vert excess of maxilla and lower 1/3 of face



Rx time- 4monthsOpen bite reduced to 0mm



Results –Moderate intrusion of 1st molarsAnterior rotation of mandible Anterior facial heightCounter rotation of occlusal plane

relapse of skeletal correction was seen-Cause

Normal growth Return to excessive vertical pattern




adult patients

skeletal open bites with class I and II patterns are treated better

Additional anchorage-TPA/lingual arches

Modules need to be replaced as they deform with time causing decay in force level


Case report

22yr female Chief complaint-lack of contact bet anterior teeth and

poor esthetic appearance of smile

Clinical examination- class II malocclusion 1.9mm openbite posterior cross bite


Ceph analysis-obtuse mand plane angle excess vert dev of maxilla


4months- levelling and alignment Molar rotation and counter clockwise rotation

of mandible -5months




Conclusions

Force – 600 – 900 gms on each side Rx time – 4 – 6 months

Adverse buccal tipping Incisor position appears stable TMD’s ?

during growth -limits normal eruption of molar and induces change of mand plane

Adults-molar intrusion and anterotation of mandible


Noncompliant treatment of skeletal open bite

AJODO December 2005 • Volume 128 • Number 6

Aldo Carano William MachataGiuseppe Siciliani


AIM

to illustrate the effects of the rapid molar intrusion appliance, a treatment alternative that does not require patient compliance, for counteracting excessive vertical dimensions in growing patients and adults.


Anterior dental open bite –backward-rotation mandibleOvereruption of molars

passive system -relative intrusion potential of molar eruption during growth

active system -physically intrude the molars into their bony support


Appliance design

intrusive force - 800 g each side 450 g - end of 1st week 250 g - end of 2nd week


Material and methods – 19 patients

11 - mixed dentition; 7 girls, 4 boys; avg age, 11.9 yrs, SD 1.8 years

8 - permanent dentition; 5 women, 3 men; avg age, 19.9 years, SD 3.9 year

criteria – S-N Go-Gn > 37° palatal plane Go-Gn > 32° UFH/LFH < 0.70 ODI < 68 1-mm opening when the incisal edges were projected

perpendicularly the facial plane (N-Me).


growing patients maxillary and mandibular soldered

stabilization arches were used8 pts-spring jet appliance -maxillary

expansion with a force of 470 g 9 pts,deciduous teeth interfered-the teeth

were extracted If 2nd molars erupted- banded and connected

with the 1st molars by a full-size rectangular wire

Rx time -4 to 5 months


adult patients –No anterior vertical elastics 6 pts-RMI + stabilization arches +fixed

appliances variation -some pts,1st and 2nd molars - only

contacting teeth, other patients, when the premolars were also

in contact


guidelines in the clinical management of patients

1stmolars were stabilized with soldered palatal and lingual arches (1 mm diameter).

ball stops of the pins did not impinge on the gingival tissues.

Patients were recalled at 4-week intervals.


The RMI intruded only the molars to which it was attached.

Occlusal contacts, other than the first molars, were eliminated to allow for the intrusive effects of the RMI deciduous tooth extraction, leveling of the occlusal plane extraction of the maxillary 2nd molars in

difficult adult cases, extraction of the 3rd molars when erupted


Lingual arches were adjusted every 2 months to compensate for compression of the gingival tissue as the molars intruded.

After the intrusion was completed and the open bite closed, the palatal and lingual stabilization arches were left in place for retention.


Results –

Mean closure at the incisors - 5.15 mm

range 3.1-6.21 mm Rx time- 5.45 months

Avg rate of 0.94 mm/month of open-bite correction

Measurement T1 SD T2 SD T2-T1 SD

Skeletal

SNA 79.60 2.20 80.02 2.35 0.41 0.64

SNB 75.08 2.23 77.25 2.16 2.16 1.13

SNÂNS-PNS 2.06 7.84 2.28 7.52 0.22 1.84

S-N-Pg (angle) 75.40 2.66 77.44 2.26 2.04 0.26

SN^Go-Gn 40.48 4.09 38.14 4.23 −2.34 1.04

ANS-Me 75.22 8.15 71.97 7.96 −3.15 1.98

Dental

SNôccl plane 20.60 2.70 18.75 2.58 −1.85 0.82

Upper1^lower 1 123.52 5.95 124.88 6.88 1.36 1.89

Lower1^GoGn 87.75 5.26 89.66 7.31 1.83 1.24

Open bite −3.98 1.05 1.17 1.35 5.15 0.56

Max 6-palat plane 18.32 1.70 15.89 1.11 −2.42 0.37

Max 7-palat plane Not erupted Not erupted

Mand 6-mandible 26.12 1.62 24.60 1.43 −1.52 0.31

Mand 7-mandible Not erupted Not erupted

T1, Pretreatment; T2, posttreatment; T2-T1, treatment changes (Mann-Whitney U test for independent samples).

*P < .01.

Table I. Pre- and posttreatment measurement of growing group with skeletal open bite


Table II. Pre- and posttreatment measurements of adult group with skeletal open bite

Measurement T1 SD T2 SD T2-T1 SD

Skeletal

SNA 76.61 6.46 76.68 6.17 0.08 0.66

SNB 70.60 4.14 72.92 3.80 2.02 0.62

SNÂNS-PNS 10.96 6.27 10.31 6.23 −0.65 0.62

S-N-Pg (angle) 72.71 2.13 74.95 2.26 2.22 0.48

SN^Go-Gn 47.07 8.55 44.71 8.04 −2.36 0.92

ANS-Me 84.02 4.69 81.26 4.50 −2.65 0.57

Dental

SNôccl plane 26.82 10.01 27.30 10.34 0.39 1.01

Upper1^lower 1 123.54 10.26 125.15 7.38 1.60 0.66

Lower1^GoGn 89.59 10.43 92.41 8.95 2.82 0.94

Open bite −3.44 1.36 0.47 0.53 −2.86 0.21

Max 6-palat plane 25.07 3.37 22.63 3.19 −2.40 0.45

Max 7-palat plane 21.37 3.66 19.49 3.91 −1.43 0.38

Mand 6-mandible 32.42 2.75 29.50 3.64 −2.92 0.36

Mand 7-mandible 28.21 2.46 26.14 3.45 −2.01* 0.32

T1, Pretreatment; T2, posttreatment; T2-T1, treatment changes (Mann-Whitney U test for independent samples).

*P < .01.

Mean closure -3.80mm range 3.11-7.00 mm

Rx time-5.01 months

average rate of 0.75 mm/month of open-bite correction


Case study 18-year-old man anterior open-bite and occlusal

disturbance


mandibular 2nd molars - extracted

RMI modules attached

maxillary 2nd molars - banded and consolidated

utility arch was used to disocclude the incisors and allow the mandible to autorotate

Molar intrusion - 5 months


occlusion -Class III

lip bumper - move teeth into the extraction sites of the mandibular 2nd molars.

Class III elastics - maxillary 1st molars to lip bumper



counterclockwise rotation of mandible and decrease in anterior facial height.

more mandibular molar intrusion than maxillary


Discussion

intrusive force simultaneously to the maxillary and mandibular molars

No patient compliance buccal crown tipping

skeletal vertical dimension is accompanied with advancement of the chin; suited for treating Class I and Class II skeletal open bites


Conclusions

Initial experiences with the RMI are promising, but a more structured research project is needed to demonstrate the long-term stability of the results



Thank you

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Rapid Molar Intrusion Device / orthodontic courses by Indian dental academy

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