serial extraction (2)

SERIAL EXTRACTION

UNDERGUIDENCE-DR.D.K.JAIPURIA

DR.JAIDEEP SINGHDR.NEHA AGARWAL

PRESENTED BY –PRIYANKA YADAV

HISTORYRATIONALEINDICATIONSCONTRAINDICATIONSADVANTAGESDISADVANTAGESDIAGNOSITC PROCEDUREPROBLEMS IN SERIAL EXTRACTION

INTRODUCTION

CONTENTS-

INTRODUCTION:Serial Extraction is an interceptive orthodontic procedure usually initiated in the early mixed dentition.

It is a procedure that includes the planned extraction of certain deciduous teeth & later specific permenent teeth in an orderly sequence & pre-determined pattern to guide the erupting permenent teeth into a more favourable position.

HISTORY:-

Kjellgren (1929) used the term “Serial extraction” to describe a procedure where some deciduous teeth followed by permanent teeth were extracted to guide the rest of the teeth in to normal occlusion.

Nance during 1940’ s popularized this technique in united states of America ,term edit “planned & progressive extraction ”& has been called the ‘father’ of Serial extraction philosophy in united states.Hotz in 1970 called such a procedure “active supervision” of teeth by extraction.

Serial extraction is based on 2 basic principles:-

Arch Length tooth material discrepancy:

When ever there is an excess of tooth material as compared to the arch length a selective extraction of some teeth is done so that rest of the teeth can be guided to normal occlusion..

RATIONALE

Physiologic tooth movement-

Human dentition shows a physiologic tendency to move towards an extraction space. Thus by selective removal of some teeth the rest of the teeth which are in the process of eruption are guided by the natural forces into the extraction spaces.

INDICATIONS FOR SERIAL EXTRACTION-

1.Class I malocclusion showing harmony between skeletal & muscular system.

2.Arch length deficiency as compared to the tooth material is the most important indication for serial extraction.

Arch length deficiency is indicated by the presence of one or more of the following features:-

Absence of physiologic spacing.Unilateral or bilateral premature loss of deciduous canines with midline shift.

Malpositioned or impacted lateral incisors.

Irregular or crowded upper & lower incisors.

Localized gingival recession in the lower anterior region.

Abnormal eruption pattern & sequence.Lower anterior flaring.

Ankylosis of one or more teeth.

Ectopic eruption of teeth.

Mesial migration of buccal segment.

3.Where growth is not enough to over come the discrepancy between tooth material & basal bone.

4.Patients with straight profile & pleasing appearance.

Contraindications of Serial Extraction-

1.ClassII & III malocclusion with skeletal abnormalities.

2.Space dentition.

3.Anodontia /oligodontia.

4.Openbite & deep bite.

5.Midline diastema.

6.ClassI malocclusion with minimal space deficiency.

7.Unerupted malformed teeth. Eg.Dilacerations.

8.Extensive caries or heavily filled I permenent molars.

9.Mild disproportion between arch length and tooth can be treated by proximal stripping.

Advantages of Serial Extraction-

Treatment is more physiologic as it involves guidance of teeth in to normal positions.

Psychological trauma associated with malocclusion can be avoided by treatment of the malocclusion at a nearly stage.

It eliminates the duration of multi-banded fixed treatment.

Better oral hygiene is possible there by reducing the risk of caries.

Health of investing tissue is preserved.

Lesser retention period is indicated at the completion of treatment.

More stable results are achieved as the tooth material & arch length are in harmony.

Disadvantages of Serial Extraction:

It cannot be universally applied to all patients.

Treatment time is prolonged as the treatment is carried out in stages spread over 2-3 years.

It requires the patient to visit the dentist thus patient co-operation is needed.

As the extraction spaces are created that close gradually the patient has a tendency of developing tongue thrust.Extraction of buccal teeth can result in deepening of the bite.

If the procedure are not carried out properly there is a risk of arch length reducing by mesial migration of the buccal segment.

Ditching or space can exist b/w the canine & 2nd premolar.

The axial inclination of teeth at the termination of the serial extraction procedure may require correction.

Selection Of Suitable Extraction Procedure

Extracting the primary canines only – it produces rapid self-improvement in incisor crowding and alignment intercepting the development of lingual cross bite of the lateral incisors.

Extracting the first primary molars only – this approach produces the earlier eruption of first premolars but reduces the rapidity and amount of incisor alignment. This is the result of retention of primary caninesEnucleation of first premolar buds – it is advocated when first premolar eruption is behind that of canines and second premolars. This allows maximal distal translation of the erupting canines. It is rarely indicated in the maxillary arch

Growth and development analysis-

Periodic growth assessment records should be made in all patients where growth is still going on i.e. made until 14 to 16 year old in girls and 18 to 19 year old in boys

Morphologic assessment-

It includes assessment of tooth mass, arch form, arch length, skeletal pattern, skeletal growth potential, orofacial musculature, facial aesthetics, oral habits and hereditary assessment of parents and siblings. The most favorable morphologic factors for serial extraction include class 1 malocclusion, a favorable morphogenetic pattern – one that does not change, a flush terminal plane or a mesial step relationship of the primary second molars, minimum overjet and minimum overbite

The 1st step is to assess that a malocclusion exist in a clinical examination and the need for investigation and collection of diagnostic records . Comprehensive assessment of the dental , skeletal and soft tissue is required. The investigation required are as follows;-study model-radiograph-photograph

DIAGNOSTIC PROCEDURE

STUDY MODEL Assess the dental anatomy of the teethAssess the intercuspation of teethAssess the arch form and curve of occlusionEvaluate the occlusionUndertake model analysis i.e. arch perimeter analysis , Carrey's analysis , mixed dentition analysis using tanaka and Johnston e.t.c.Also used between and after treatment.

RADIOGRAPHS

Intra oral x-rays e.g. periapicals , occlusal views.Extra oral x-rays e.g. cephalometric , panoramic views e.t.c.The above provide the following information;1. Detection of congenitally missing

teeth , supernumerary e.t.c.2. Detection of any bony pathosis.3. To assess the stages of root

development and the possible eruption pattern.

4. To determine the dental age of the patient.

To assess the different relationship between craniofacial structures using cephalometric analysis.6. To assess facial patterns7. To assess soft tissue matrix8. To assess changes in mid and post tx relationship cephalometrically to monitor treatment progress

According to most authors, an arch length deficiency of not <5-7mm should exist for serial extraction.

There are mainly three methods:-

•Dewel’s Method •Tweed’s Method•Nance method

Procedure

DEWEL’S METHOD –

Dewel has proposed a 3 step serial extraction procedure.

In the 1st Step , the deciduous canines are extracted to create a space for alignment of the incisors.

This step is carried out at 8-9 years of age.

After 1 years , the deciduous 1st molars are extracted so that the eruption of 1st premolars is accelerated.

This is followed by the extraction of the erupting 1st premolar to permit the permanent canines to erupt in their place.

In some cases ,a Modified Dewel’s Technique is followed where in the 1st premolar are enucleated at the time of extraction of the 1st deciduous molars.

This is frequently necessary in the mandibular arch where the canines of ten erupt before the 1st PM.

TWEED’SMETHOD:

This method involves the extraction of the deciduous 1st molars around 8 years of age.

This is followed by the extraction of the 1st premolar & the deciduous canines

TWEED METHODEXTRACTION OF DECIDUOUS FIRST MOLAR

EXTRACTION OF DECIDUOUS CANINE AND PREMOLAR

Nance Method:

This is similar to the Tweed’s technique & involves the extraction of the deciduous 1st molars followed by the extraction of the 1st Premolars & the deciduous canines.

Anterior Cross bite in which 1 or more maxillary teeth are in lingual relation to the mandibular anterior is termed as “Dentoalveolar anterior Cross bites”.

This is manifested as single tooth cross bite & usually occurs due to over retained deciduous teeth.

Problems in the serial extraction-Anterior cross bites

References:

Text book of orthodontics:GRABERText book of orthodontics:S.I.BHALAJHI