METHODS OF GAINING S P A C E

PRESENTED BY – DR. ROKEYA RAHMAN TANI FCPS Part-II Trainee Dept. of Orthodontics Dhaka Dental College & Hospital.

For the resolution of a majority of malocclusions, spaceis required. Like - Alignment of crowded teeth Retraction of proclincd teeth Correction of molar relationship Derotation of anterior teeth Leveling the curve of Spee Correction of ant. and post. cross bite Correction of narrow dental arch Intrusion

Why Space Is Required –

What are the methods of gaining space –

Space can be gained byNon

Extraction Extraction Surgical

Proximal stripping Arch expansion Molar teeth

distalization Uprighting of tilted

teeth Derotation of

posterior teeth Proclination of

anterior teeth

Orthognathig surgery Distraction

osteogenesis

Balancing extractions

Compensating extractions

Phased extractions Enforced

extractions Wilkinson

extractions Therapeutic

extractions

Non Extraction methods

PROXIMAL STRIPPINGProximal stripping involves the selective reduction of the mesiodistal width of certain teeth to create space.The procedure is also called - Proximal slicingReproximationSlenderization

INDICATION FOR PROXIMAL STRIPPING• Done when space requirement is minimal (2.5-3 mm).( Or when Bolton's tooth material excess less than 2.5 mm).• Usually when the excess exists in the mandibularanterior segment. CONTRAINDICATIONS FOR PROXIMAL STRIPPING• Patients who are susceptible to caries.• Avoided in young individual as their teeth may possess large pulp chambers.

The procedure involves three steps –

1. Assessing space requirements.2. Selecting the teeth and amount of enamel to bestripped. Not more than 50% of Enamel thickness to be stripped.

3. Enamel stripping.

Metal abrasive strips

Enamel stripping is generally performed using the following methods -

PROCEDURE

Thin fissure burs

Safe sided corborundum disks

Tungsten carbide or diamond burs

Perforated diamond disc

Air Rotor Stripping method (ARS)

Please note: After Reproximation there will be sensitivity.Artificial remineralization is possible by crystal growth. A low concentration of calcium-fluoride solution produce this growth in a time dependent fasion.

Advantages of proximal stripping To avoid extractions in borderline cases where space

requirements are minimal. To achieve better interdigitation, overbite and overjet To broaden the contacts to add the stability of results Localized malalignments can be corrected without involving too many teeth, especially in adult patients.

Disadvantages of proximal stripping≠ Sensitivity≠ Increases caries susceptibility≠ Difficult to reproduce exact morphology of the tooth. ≠ The shape created may not be as esthetic≠ Food lodgement

Arch expansionRapid maxillary

expansion

Removable

Fixed

RAPID MAXILLARY EXPANSION (RME) DEVICES

First reported at 1860 by Emerson C. Angell These are the kind of Dentofacial Orthpedic appliance Mid palatine suture is mainly used to separate to gain

the space 15- 19 years of age is more Sweetable time post. teeth are used to transmit force to the maxilla Midline diastema seen primarily Open bite is possible

Growing individuals with severely constricted maxillary arches, Involving airway impairment or mouth breathing tendencies.

Posterior cross bites with real or relative maxillary deficiency

Cleft patients Along with facemask therapy Class Ill cases with minor maxillary deficiency As part of interceptive orthodontics

Indications for RME use

Removable RME appliance The appliance basically consists of a screwin the midline with retentive clasps on posteriorTeeth. More effective when used in the early mixed dentition phase. But its efficiency is doubtful.

Fixed RME Appliances I. Tooth Born appliance II. Tooth-tissue born appliance

Tooth Born appliance are -

1. HYRAX APPLIANCES

2. ISAACSON RME APPLIANCES

1. DERICHSWEILER RME APPLIANCES

2. HASS RME APPLIANCE

Tooth-tissue born appliances are -

SLOW EXPANSION DEVICES

Indications of slow expansion Correction of unilateral cross bites Correction of 'V' shaped arches Preparation for bone grafts in cleft cases Minimal crowding in the upper arch (1-2 mm) Elimination of a displacement

1. Screw Appliances (upper & lower)

2. Coffin Spring

Some of them are removable, some are fixed type -

3. Quad/Tri/Bi -Helix

4. Ni-Ti Expanders

5. The Schwarz Appliance

DISTALIZATION OF MOLARS The main purpose of Distalization is to pushthe maxillary and/or mandibular terminal molarsposteriorly.

Usually undertaken before the eruption of the second permanent molars.

There are 2 types – I. Extraoral distalizing appliances II. Intraoral distalizing appliances

Extraoral distalizing appliances

The most frequently used extraoral distalizingappliances are the headgears.

Bilateral as well as unilateral distalization is possibleusing headgears.

Distal tipping of molars helps in - Opening the bite - Incrising the lower facial heigt 18 to 20 hours of wearing is recomanded for orthodontic effect.

Headgear

INTRAORAL METHODS OF DISTALlZING MOLARS

Tooth moving force generators are mainly of – - Screws - Open coil springs - Wire springs with helices

Intra oral distalizing appliances are –

• Schwartz plate• Sagitta1 appliance• First class• Veltribilateral and monolateral sagittal screws• Open coil springs• Jones jig• Oistal jet appliance• Fast back appliance• Pendulum appliance• Intraoral magnets• Jasper jumper• Lip bumper

UPRIGHTING OF TILTED POSTERIOR TEETHUprighting of molars can lead to an arch length gain of 1-1.5 mm.

Fixed appliances are idealIy used.

DEROTATION OF POSTERIOR TEETHDerotation can be best achieved using a couple forceon the lingual and buccal surfaces of the tooth.

Forces should be equal in magnitude but opposite in direction.

Fixed appliance system with a two point contact is useful.

PROCLlNATION OF ANTERIOR TEETH

Proclination of anteriors is indicated if only – - They are retroclined - Soft tissue profile will not be disturbed - Stability will be achived

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