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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