*GOAL: THE CORRECTION OF DIFFERENT TYPES OF MALOCCLUSIONS REQUIRES SPACE IN ORDER TO MOVE TEETH INTO MORE IDEAL LOCATIONS.

To treat CrowdingRetraction of proclined teethLeveling of steep curvature of speeDerotation of anterior teethCorrection of unstable molar relation

[D2-E2-P2-U]Proximal strippingExpansionExtractionDistalizationUprighting of molarsDerotation of posterior teethProclination of anterior teeth

Proximal surfaces of the teeth are sliced in order to reduce mesio -distal width of teeth.

WHEN?Space required is minimum;i.e.0-2.5mm If Bolton’s analysis show mild tooth material excess To aid retention in lower anterior region

WHEN NOT? In young patients Patient susceptible to caries or having high caries index

DIAGNOSTIC AIDS Arch perimeter analysis Bolton’s analysis IOPA

AMOUNT Not more than 50% of enamel thickness

ADVANTAGES: Avoid extraction in borderline cases More favourable overbite & overjet relation More stable results can be established

DISADVANTAGES: Roughened proximal surfaces attracts plaque Caries susceptibility is increased Patient may experience sensitivity of teeth Improper procedure creating unnatural appearance of teeth Loss of contact may result in food impaction

PROCEDURE1. Use of metallic abrasive strips2. Safe sided carborundum discs3. Long thin tapered fissure burs

FLUORIDE APPLICATION To manage in increased caries susceptibility.

Premolars are most frequently extracted as a part of therapeutic extraction. Extraction of One premolar from each quadrant of jaw provides sufficient space to correct

the crowding & proclination without unduly hampering function & esthetic. It is not uncommon to extract molars or lower incisors during therapy. Extractions of canines & upper incisors usually avoided.

NEED1.Arch length –tooth material discrepancy2.Correction of sagittal inter-arch relationship3.Abnormal size & form of teeth4.Skeletal jaw malrelations BALANCING EXTRACTION Removal of another tooth on the opposite side of same arch.

COMPENSATING EXTRACTION Extraction of teeth in opposite jaws to preserve buccal occlusal relationship.

AIM Moving the molars in a distal direction to gain space.IDEAL TIMING: In mixed dentition period prior to second molar eruption. METHODS 1. Extra-oral method Head gears deriving anchorage from cervical or cranial regions. Disadvantage; Patient co-operation is essential for timely wear of the appliance. Usually not worn continuously so intermittent in action so prolonged

treatment time.2. INTRA ORAL METHOD Fixed on to the teeth and therefore produce a continuous effect

Contd…

Sagittal Appliance By the removable appliance incorporating jack

screw E.g. Split acrylic plate joined by a jack screw used for distalization of only one tooth at a time

Distalization using intraoral magnet Repelling magnet placed on the molars to be

distalized and the tooth anterior and anterior anchorage can be reinforced using Nance holding arch.

Use of open coil spring to distalize molars Open coil NICKEL TITENIUM spring compressed

between the molar & the anterior segment. Anterior segment is reinforced by use of a Nance button

PENDULUM APPLIANCE

It consists of a stainless steel wire with a helix ,the distal end of which is inserted in to a sleeve on palatal aspect of molars to be distalized

Distaliation is produced by opening the helix & forcefully engaging the distal ends in to sleeves

EXPANSION

Classified as 1.Rapid arch expansion 2.Slow arch expansion Rapid maxillary arch expansion• A skeletal type of expansion which involves separation of mid palatal suture• Initiated prior to ossification of mid-palatal suture.

WHY WE NEED EXPANSION ? Posterior cross bite associated with real or

relative maxillary deficiencies. Class 3 mal-occlusion of dental or skeletal cause. Cleft palate with collapsed maxillary arch. In cases requiring face mask therapy. Medical indication. i.e. Nasal stenosis, septal

defect, recurrent nasal & ear defects, poor nasal airway, allergic rhinitis & DNS

DIAGNOSTIC AIDS Case historyClinical examinationStudy modelsOcclusal view radiographCephalogram

EFFECTS

• Amount of expansion-0.2 to 0.5mm per day •On alveolar bone—is bends adjacent to anchor teeth•On max. ant. teeth—midline spacing between max. central incisors•On max. post. teeth—anchors teeth show buccal tipping•On mand.—downward & backward rotation of mand.•On nasal cavity—increase intra-nasal space

TYPES

1.Removable 2.Fixed

Tooth born 1.Isaacson type. 2.Hyrax type.

Tooth & tissue born 1.Derichsweiler type.

2.Hass type.

ACTIVATION SCHEDULE --Schedule by Timms For patients up to 15yrs of age,90*rotation in

morning & evening For patients over 15yrs of age,45*activation 4 times

a day. --Schedule by Zimring & Isaacson For young patients, two turns each day for 4-5 days

& later one turn per day. For non growing adult, two turns each day for first

two days, & later one turn per day for 5-7 days and one turn every alternative day.

Noticeable Feature During expansion•Appearance of mid-line diastema •Maxillary occlusal radiograph & PA•P.A.Cephalogram –more reliable in estimating max. expansion

?WHEN NOT USE? Single tooth cross-biteIn unco -operative patientAfter ossification of the mid-palatal suture Skeletal asymmetry of max. & mand.Vertical growers with steep mandibular plane angleIn periodontally weak dentition

*Retention Following R.M.E.• Retention period is not less than 3-6 months ,by screw immobilization with •cold cure acrylic or removable or fixed retainer

*Requirement of surgery Unusual resistance to separation of the palatal bone•usually occur in female over 16yrs age & in male over 18yrs age

*Surgical procedure palatal osteotomylateral max. osteotomy Anterior max. osteotomy

CLINICAL TIPS FOR R.M.E.

•Oral hygiene instructions

•Orthodontic movement of anchor teeth should be avoided prior to R.M.E.

•Patient should be trained to use the key

•Occlusal radiographs should be taken at regular interval to monitor

expansion

•Possible immediate effects of premature removal of appliance

i.e.dizziness ,pressure at the bridge of nose , pressure under eyes,

so that keep patient seated & not to stand immediately after appliance

removal .

SLOW EXPANSION Also termed as Dento -Alveolar expansion

•Rate of expansion – 0.5-1mm per week

•Forces generated—2-4 pounds against 10-20 pounds by

rapid maxillary expansion.

•Time require –2-5 months

Advantages•More physiologic adjustment to max. expansion

•Producing greater stability

•Less relapse potential

TYPES OF APLIANCES FOR SLOW

EXPANSION Jack screw Coffin spring Quad helix Arch expansion using fixed appliances (NITI

expander)

Premature loss of a second deciduous molar or extraction of second premolar can cause mesial tipping of the first permanent molar.

Mesially tipped molars occupied more space than upright molar.

Certain amount of space can be recovered by using molar uprighting spring or

some form of space regainer.

Rotated posterior teeth occupies more space than normally placed posterior Rotated posterior teeth occupies more space than normally placed posterior

Derotation provides some amount of arch length ACHIEVED BY Fixed appliances incorporating springs or elastics

using a force of couple Derotation provides some amount of arch length

Proclination of retruded anterior teeth results in gaining of arch length

INDICATED IN Teeth are retroclined or where teeth are Protracting the anterior teeth will not affect the soft tissue profile of the patient

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