Method of Gaining Space : Proximal Stripping and Extraction

  
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CONTENTS

INTRODUCTION

       For the resolution of majority of malocclusion space is required and For achieving majority of the treatment objectives space has to be created within the jaws. space is required for correction of crowding ,retraction of proclined teeth, leveling a steep curve of teeth , derotation of anterior teeth and for correction of unstable  molar relation

   

  VARIOUS METHODS OF CREATING SPACE ARE

1.      Proximal stripping

2.      Arch expansion

3.      Distalization of molars

4.      Uprighting of tilted tooth

5.      Derotation of posterior teeth

6.      Proclination of anterior teeth

7.      extraction

PROXIMAL STRIPPING

—  Proximal stripping involves the selective reduction of mesiodistal width of certain teeth to create space

—  Also called slenderization,reproximation,disking.

—  It is routinely done in mandibular anteriors

—  It can also be carried out in upper anteriors as well as buccal segments of upper and lower arch.

            PRE REQUISTIES

·        If space requirement is less than 2-3mm.

·        Mostly done if space requirement is only in mandibular anterior region.

·        Adequate enamel thickness is essential to allow proximal stripping.

·         Generally undertaken where there exists a Bolton's tooth material excess.

  

CONTRAINDICATIONS

—  Patients  who are susceptible to caries

—  Proximal stripping is avoided in young individual as their teeth may possess large pulp chamber.

ADVANTAGES

—  It may be possible to avoid extractions in borderline cases where space requirements are minimal.

—  Broad contacts may add to stability of results.

—  Localized malalignments can be corrected without involving too many teeth especially in adults.

—  Tooth material excess can be reduced for achieving better interdigitation, overbite and overjet

DISADVANTAGES

—  Roughens proximal surface attracts plaque and the teeth became caries prone

—  Maintenance of oral hygiene will be poor due to lack of contact between adjacent teeth

—  Sensitivity of teeth

—  Improper procedure  cause alteration in the morphology of tooth

     PROCEDURE

1)     Assessing space requirements

2)     Selecting the teeth and amount of enamel to be stripped

3)  Enamel stripping

ASSESSING SPACE REQUIREMENTS

—  Bolton’s analysis to find the excess tooth material and for locating the area in which the fault lies.

—  Carey’s analysis also used for assessing space requirements in two arches.

—  Tooth material excess of less than 2.5cm per arch is an ideal candidate for proximal stripping.

SELECTING THE TEETH AND THE AMOUNT OF ENAMEL TO BE STRIPPED.

—  Most frequently stripped teeth are the mandibular incisors.

—  Maxilary anterior teeth can stripped if there is an excess tooth material and sufficient enamel thickness.

—  To assess the thickness of enamel, intraoral Periapical views are done.

—  No more than half the thickness of enamel can be removed.

METHODS OF PROXIMAL STRIPPPING

1.       Use of metallic abrasive strips

2.       Diamond abrasives

3.       Thin tapered fissure   burs

4.       Carborundum disc

       METAL ABRASIVE STRIPS

Metal strips with abrasive particles stuck to them are available. Depending upon the the size of the particles coated the strips can be coarse, medium or fine. Special holders are available to aid their use.

PERFORATED DIAMOND DISKS-

            .perforated diamond disks are extensively used for the purpose. They are relatively flexible and  strip both the adjacent teeth.

       SAFE SIDED CORBORUNDUM DISKS

- They were used extensively .but have the inherent problem of being rigid and brittle. The chances of being breaking and causing injury to the patient and clinician are maximum.

THIN FISSURE BUR-

Thin straight or tapered burs can be used for proximal striping. They usually leave deep scars on the enamel.

EXTRACTION

—  Painless removal of teeth from its socket

—  In 1771. Hunter first advised extraction for gaining space in the book of natural history of tooth.

GREAT EXTRACTION CONTROVERSY

—  Based on 2 school of thought by EH ANGLE and CALVIN CASE in 1920

—  Angles believed the full retention of the teeth for the correction of the malocclusion.

—  According to him if crowded teeth were aligned in correct relation to each other, improved function of masticatory apparatus will result in growth of the jaws, creating adequate space for dentition.

—  Calvin case believed in that tooth may be extracted occasionally to produce long lasting results. this leads to the great extraction controversy in 1920s

—  By the late 1940s Charles tweed reintroduced extraction into the orthodontics.

INDICATION

1.      Tooth size arch length discrepancy

2.      Saggital inter arch relationship

3.      To relieve crowding

4.      Abnormal size and form of teeth

5.      Skeletal jaw malrelations

TOOTH SIZE ARCH LENGTH DESCREPANCY

Evaluated by arch perimeter and careys analysis. Extraction choice depends on amount of discrepancy

—  Less than 2mm discrepancy –proximal stripping

—  2-5mm discrepancy –second premolar extraction

—  Greater then 5mm discrepancy =first premolar extraction.

SAGITAL INTER ARCH RELATIONSHIP

CAMOUFLAGE TREATMENT

—  Extraction of teeth in class 2 and class 3 malocclusions improves saggital relationship not only by tooth movement but also by selective impairment of forward growth of corresponding dental arch.

—  This increases the esthetic appearance and functional efficiency.

Angles class1

 –in angles class1 bimaxilary cases, it is preferable to extract tooth in both arches.

Angles class2-

 In class 2 cases if tooth in lower arch is normally aligned it advisable to extract tooth in upper arch alone.

•       if there is severe crowding present in lower arch it is advisable to extract tooth in both arches.

Angles class3

- it  is corrected by extraction of tooth only in lower arch or both.

Extraction of tooth in upper arch alone should be avoided as it causes forward development of maxilla

EXTRACTION FOR THE RELIEF OF CROWDING

TO RELIEVE CROWDING

Extraction pattern also depends on

1)    Site of crowding

                                 Extract the teeth close to the teeth to be retracted.

                                To retract anterior – extract first premolars

                                 To retract posteriors =extract second premolars

2)    Position of tooth

                                 if 2^nd pm is lingualy  tilted extract it

3)          Condition of teeth

                                in case of grossly decayed tooth extract it.

ABNORMAL SIZE AND FORM OF TEETH

Sometimes variation in size, shape and form of individual teeth is so typical that it may necessitate their extraction in order to achieve satisfactory occlusion.

Eg:peg laterls,macrodontia

SKELETAL JAW MALRELATIONS

Orthognathic resective surgeries require the extraction of certain teeth to achieve proper alignment of the jaws.

DIFFERENT EXTRACTION PROCEDURES

 Six types

1)     Balanced extraction

2)     Compensatory extraction

3)     Phased extraction

4)     Enforced extraction

5)     Wilkinson's extraction

6)     Therapeutic extraction

BALANCED EXTRACTION

—  It is defined as the removal of teeth in the opposite side of the same arch to preserve symmetry of the arch.

—  If a tooth is removed only from one side of the arch with tight tooth contacts, it may result in drifting of the rest of the teeth towards extraction site.

COMPENSATORY EXTRACTION

—  Extraction of teeth from opposite arch

—  It is carried out to maintain buccal occlusion.

—  In Class I bimaxillary cases it is usually advised to extract tooth in both arches to preserve molar relationship.

     PHASED EXTRACTION

—  These are the extractions of different teeth carried out in a phased manner at different times in different quadrants.

—  This is mainly done to effect a change in molar relationship

—  It may be possible to  effect a change in molar relationship by extracting in one arch only, or few month earlier than in the others

—  The effect is particularly marked after the premature loss of deciduous tooth.

ENFORCED EXTRACTION

—  If prognosis of tooth is very poor , extraction of that tooth is mandatory.

WILKINSONS EXTRACTION

—  Wilkinson advocated extraction of all the 4 first permanent molars between the age of  8.5 and 9.5 yrs.

 ADVANTAGES

—  Provides additional space for eruption of 3rd molar.

—  Crowding of arch is minimized

—  They are more caries prone tooth.

DISADVANTAGE

·        Offer minimum space to relieve crowding in anterior region

·        Mesial tipping of 2^nd molar

·        Rotation of 2^nd premolar and 2^nd molar

·        Adequate anchorage for tooth movement by orthodontic appliance is lost on removing first permanent molar.

 THERAPEUTIC EXTRACTION

·        Extraction for orthodontic correction

SPECIFIC INDICATIONS FOR EXTRACTION OF TEETH

Maxilary incisors

·        Grossly decayed

·        Compromised periodontal ligament.

·        Abnormally impacted teeth.

·        Trauma

·        Severe crowding in the incisor area with unfavorable buccal or lingual  displacement of one of the lateral incisor.

·        Abnormal transposition between lateral and canine.

·        Congenital absence of lateral incisor on one side  alone, to maintain arch symmetry the lateral incisor on opposite side need to be extracted.

Mandibular incisors

·        Totally blocked out

·        Poor prognosis in trauma caries , bone loss

·        Compromised periodontal ligament

·        When one of the incisors is completely out of the arch with good alignment of other incisors.

·        Lower incisors are extracted in cases basal arch length discrepancy.

Contraindications

·        Deep bite cases with horizontal growth pattern

·        Bimaxillary crowding cases with no tooth size discrepancy in the incisor area

·        Reappearance of crowding

·        Retroclination of lower incisors and deep bite leading to  collapse of  the lower arch.

Canines

·        Unfavorably impacted canine (due to long eruptive path and long root)

·        Ectopic eruption

·        When maxillary canine is completely excluded from arch and approximal contact between lateral incisor and first premolar is good.

·        Premature shedding of a deciduous canine often in the lower arch indicates the arch length discrepancy and fellow teeth in opposite arch should be extracted to preserve symmetry.

·         Deciduous canine may be extracted   as a part of serial extraction procedure.

First premolar

The reasons for their extraction  are

·         Their location in the arch is such that the space gained by their extraction can be utilized for correction both in the anterior as well as posterior region.

·        Favorable contact between 2^nd premolar and canine is obtained.

·        The extraction of the first premolar leaves behind one premolar and molars which forms the posterior segment, which gives adequate anchorage for the retraction of the 6 anterior teeth.

Indicated in

·        Moderate to severe crowding in the arch.

·         Bimaxillary protrusion.

·        Tooth size discrepancy greater than 5mm

·         Never extract both 1^st and 2^nd premolar together as canine  has sharp contact with molar.

First molar

indications

·        Minimum space requirement for correction of anterior crowding or mild proclination

·        Grossly decayed /periodontaly compromised molar with poor prognosis\impacted molar

contraindication

·        It does not give adequate space to relieve anterior crowding

·        Deepening of bite

·        Masticatory efficiency is reduced.

·        Acceptable proximal contact between second premolar and second molar cannot be obtained.

·        Second premolar and second molar may tip into extraction space

Second molar

·        To relieve impaction of second premolar

·        To enable distalization of first molar

·        Grossly decayed

·        Malformed teeth

Bibliography

Contemporary orthodontics- WILLIAM R PROFFIT

Textbook of orthodontics – s GOWRI SANKAR

Textbook of orthodontics –GURKEERAT SINGH