Impacted Teeth - Subharti Dental College

Impacted Teeth

INTRODUCTION

The word IMPACTION is derived from latin

word “impactus”.

2 Dr. Apoorva Mowar, Subharti Dental College, SVSU

IMPACTED TEETH

Definition

A tooth which is completely or partially

unerupted & is positioned against another

tooth, bone or soft tissue, so that further eruption

is unlikely, described according to its anatomic

position and its eruption potential has been lost.

Dr. Apoorva Mowar, Subharti Dental College, SVSU

Etiological theories

1. PHYLOGENIC THEORY -- Civilization

has eliminated the human need for large &

powerful jaws which leads to decreases the size

of jaws. Due to this IIIrd molar occupies an

abnormal position & may be consider a vestigial

organ( with out purpose or function).


. 2. MENDELIAN THEORY

HERIDIETRY OR GENETIC INFLUNCE LEADS TO SMALL

JAWS & RESULTING IMPACTED TEETH.

3.ENDOCRINE THEORY

Due to lack of function of anterior lobe of pituitary gland,

leads to hampering the growth of jaws.


5. ORTHODONTIC THEORY • Supported by constricted & narrowed

dental arches of early mouth breathers

• Depend on Position & alignment of

permanent teeth.

4. PATHOLOGICAL THEORY

As a result of early diseases of adjacent

molars leads to existence of osteosclerosis

in IIIrd molar area.


• Mandibular third molar most commonly

impacted tooth, 98% of impacted teeth are

mandibular third molars

• Maxillary canines 1.3%

• Mandibular premolars and other teeth

make up the remainder.

7 Dr. Apoorva Mowar, Subharti Dental College, SVSU

FREQUENCY OF IMPACTION

• Mandibular 3rd molar

• Maxillary 3rd molar

• Maxillary canine

• Mandibular premolar

• Maxillary premolar

• Mandibular canine

• Maxillary central incisor

• Maxillary lateral incisor 8 Dr. Apoorva Mowar, Subharti Dental College, SVSU

Causes of Impaction

LOCAL CAUSES --

1.Irregularity in position & pressure of an

adjacent tooth.

2. Density of overlying or surrounding

bone.

3.Long continued chronic inflammation

with resultant increase in density of

overlying mucous membrane.

4. Premature loss of primary teeth.


Systemic causes • Prenatal Cause :-

Heredity

• Post Natal Cause – Rickets, Anemia

• Congenital Syphilis ,Tuberculosis, Malnutrition,

endocrine dysfunction.

• RARE CONDITION –

Cleidocranial dysostosis

Oxycephaly (Steeple head-pointed head)

Progeria - Premature old age

Achondroplasia (Cartilage fails to develop)

Cleft Palate


INDICATIONS 1 Recurrent pericoronitis – 70 – 80% of

patients are adults with impacted teeth.

2 Root resorption – It may occur due to

pressure effect from 3rd molar to 2nd

molar.


3.Caries or periodontal

problems-It occurs in impacted

teeth


4 Recurrent infection around pericoronal flap may lead to TMJ problems

5 Preventive dentistry- Extraction of impacted tooth can be done as a preventive measure.

6. Paresthesia or Nonspecific pain may sometimes be relieved by removal of impacted teeth.

7.Impacted teeth are sometimes removed when they become foci of infection.

8. Trauma – Impacted teeth are extracted to avoid recurrent cheek bite.

9.Orthodontic problems- Impacted teeth may lead to malocclusion or overcrowding in adolescent period.


10.Cyst or ameloblastic changes – Impacted

teeth are sometimes associated with cysts.


11Autotransplantation – Impacted third

molar can be used to replace the lost 1

molar.

12 Prosthetic consideration- An unerupted

Teeth may cause ulceration under the

denture or later denture failure may occur.


CONTRAINDICATION

• Health consideration – Due to systemic

disorder patient is not fit for minor surgery.

• Prosthetic consideration- Partially erupted

tooth has to be retained sometimes for utilization

as an abutment for fixed partial denture.

• Availability of adequate space – Sometimes if

there is an adequate space between 3 rd molar

and ascending border of ramus operculectomy

can be done.

• Socioeconomic reason -


IMPACTED MANDIBULAR 3RD MOLAR

• One of the most common impaction in all

impacted teeth

– Dense bone

– Last to erupt


CLASSIFICATION

WHY WE HAVE TO STUDY?

• Methodical approach to surgical procedure

• Difficulty assessment in intra – op and post - op

complications

• Type of instrument needed

• Correct information to the patient about likely

complications Dr. Apoorva Mowar, Subharti Dental College, SVSU

Classification is based on:

• Angulation

• of long axis of impacted tooth is compared to

long axis of adjacent erupted tooth.

• importance – to know the path of withdrawal

• to decide – tooth splitting or removal of bone or

both, which obstructs the path of withdrawal of

tooth Dr. Apoorva Mowar, Subharti Dental College, SVSU

RELATIONSHIP TO ANTERIOR BORDER OF

RAMUS

• amount of bone covering the impacted tooth

RELATIONSHIP TO OCCLUSAL PLANE

• depth of impacted tooth in bone when compared to

height of adjacent 2nd molar

• importance - degree of difficulty for removal

assessed by thickness of bone overlying the tooth or

depth of tooth in bone. Dr. Apoorva Mowar, Subharti Dental College, SVSU

George Winter’s classification – 1926

• classified impacted 3rd molar according to

relationship of their long axis to 2nd molar.

• Mesioangular

• Vertical

• Distoangular

• Horizontal

• Transverse

• Buccoangular

• Linguoangular

• Inverted Dr. Apoorva Mowar, Subharti Dental College, SVSU

• Mesioangular – crown of tooth is tilted towards

the 2nd molar mesially

• it is most common and least difficult to remove


MESIOANGULAR IMPACTION


Vertical : long axis of impacted tooth runs in same

direction of 2nd molar.


VERTICAL

IMPACTION


Distoangular: long axis of impacted tooth is

angulated distally or posteriorly away from 2nd molar.

This is most difficult to remove because path of

withdrawal is into the ramus.


DISTOANGULAR IMPACTION


Horizontal : severe mesial inclination of 3rd molar

towards the 2nd molar


HORIZONTAL IMPACTION


Bull’s Eye Sign

TRANSVERSE IMPACTION


Pell’s Gregory Classification

In 1933 Pell’s Gregory classified impacted

mandibular 3rd molar.

• Class I : space between the ramus and the distal

side of 2nd molar is more than mesiodistal diameter

of crown of impacted 3rd molar.


Class II: space is less than mesiodistal diameter of

crown of impacted 3rd molar


Class III: most of the 3rd molar is located within the

ramus, no space between 2nd molar and ascending

border of ramus.


Position: relative depth of 3rd molar in the bone

Position A: Highest portion of impacted tooth is on a

level with or above the occlusal plane of 2nd molar.


Position B: highest portion of impacted tooth is below

the occlusal plane but above the CEJ of 2nd molar.


Position C: highest portion of tooth is below the CEJ

of 2nd molar.


Long axis of impacted tooth in relation to that of

2nd molar:

• Mesioangular

• Vertical

• Distoangular

• Horizontal

• Transverse

• Buccoangular

• Linguoangular

• Inverted


Kay’s Classification:

1.Based on angulation and position:

• Mesioangular

• Vertical

• Distoangular

• Horizontal

2.Based on state of eruption:

• Fully erupted

• Partially erupted

• Embedded Dr. Apoorva Mowar, Subharti Dental College, SVSU

3. Based on number of roots

• Fused roots

• Two roots

• Multiple roots

FUSED ROOTS MULTIPLE ROOTS


4. Based on root pattern:

• Favorable roots

• Unfavorable roots


UNFAVOURABLE ROOTS


Preoperative assessment:

1. History : medical problems must be weighed

against the danger of leaving the tooth.

2. Age: older age group more difficult then younger

age group.


3.Facial form:

1. Tapered facial form: such patient have a high

zygomatic arch and flexible Orbicularis Orris

muscle, therefore access is better.

2. Compact facial form: more challenging,

because such patient have small mouth,

mandibular retrusion, limited opening and

access to operating site is poor. Dr. Apoorva Mowar, Subharti Dental College, SVSU

4. Extraoral:

1. swelling

2. redness of the cheek

3. submandibular lymphadenopathy

4. lower lip tested for anesthesia or

parasthesia


5. Intraoral:

1. mouth opening

2. lateral surface of body of mandible in close

alignment with ramus with little flare makes

procedure difficult

3. relationship of external oblique ridge to 3rd

molar

1. if ridge is posterior to tooth access is good

2. if ridge is alongside the tooth or anterior to

it access is poor Dr. Apoorva Mowar, Subharti Dental College, SVSU

4. General inspection – oral hygiene

5. Adjacent 2nd molar

1. crown

2. Inlay

3. Fillings – which can be dislodged during

elevation

6. Condition of overlying soft tissue

1. fibrosis

2. inclination of upper third molar

3. active pericoronitis

4. pus beneath the flap


RADIOGRAPHIC EVELUATION

IOPA should show entire tooth structure, investing

structures, as well as adjacent tooth

• How to take an ideal IOPA?

• patient is seated such that occlusal plane is

parallel to the floor

• anterior edge of the film should be in line with

mesial surface of 1st permanent molar. Dr. Apoorva Mowar, Subharti Dental College, SVSU

CENTRAL RAY DIRECTION

a. Average case – distal part of 2nd molar

b. Horizontal impaction – through crown of 3rd molar


• X ray tube positioned in such way that central beam

is parallel to occlusal surface of 2nd molar and should

pass through distal cusp of 2nd molar at right angle to

film packet.


•lingual and Buccal cusp of 2nd molar should

superimpose on each other giving an enamel cap

appearance.

• entire length of 2nd molar and impacted 3rd molar

should be visible.


Occlusal films:

•occlusal view provides an alternative to periapical

view in case of horizontally impacted tooth for a

clearer picture of the root pattern.

• Important role in buccolingually placed teeth to

identify which way the crown is pointing.

• helpful in showing the thickness of lingual cortical

plate Dr. Apoorva Mowar, Subharti Dental College, SVSU

• Lateral oblique projection

• provides greater periapical coverage

• shows amount of bone below an

impacted tooth in a thin mandible


•OPG:

• difficult access for positioning of the film or

when patient cannot tolerate IOPA film.

• where the tooth is so far below that it cannot

be projected on to the periapical film.

• when there is associated pathological process

larger than the film to exclude any other

pathology of the jaw.


CBCT


RADIOLOGICAL

ASSESSEMENT


1. TECHNIQUE

2. TYPES OF IMPACTION

3. ACCESS: External Oblique Ridge – position

1. Horizontal – access is good

2. Vertical – access is poor

3. behind the tooth – access is good

4. along or in front of impacted tooth – access is poor


4. EXISTING PATHOLOGY:

1. Dental caries in 2nd or 3rd molar

2. Periodontal disturbances

3. Presence or absence of 1st molar

4. Any fusion of crowns between 2nd and 3rd molars

5. Conical or fused roots of 2nd or third molars

6. Any associated dental pathology like odontome, cyst or

neoplasm.


5. SCORING DETAILS FOR WHARF ASSESSMENT

Contd- Dr. Apoorva Mowar, Subharti Dental College, SVSU

6. POSITION AND DEPTH – George Winter

1. WHITE LINE: - represents the occlusal plane

a) Joining the white enamel caps of the erupted

molars it is extended posteriorly over the 3rd molar.

b) The maximum contour of the impacted tooth and its

relation to the white line will indicate the relative

depth of its location.


2. AMBER LINE: - represents the bone level, distal to the 3rd

molar and extended anteriorly along the crests of

intrdental septum between the molars. Represents the

amount of bone covering the impacted tooth which will

have to be removed

3. RED LINE: indicates depth at which impacted tooth is

located. It is a line drawn perpendicular to the amber line

to point of application of the elevator. If red line is less than

5 mm long – tooth can be conveniently removed under

L.A. for each mm increase in length difficulty increases by

3 times. Length > 9mm and tooth below apices of 2nd

molar then G.A. case


White line

Amber line

Red line


6. BUCCOVERSION AND LINGUOVERSION:

can be identified – more radioopacity of the

tooth overlapped by the 2nd molar and the

portion of tooth nearer to the film.

7. CROWN OF IMPACTED TOOTH: large

bulbous crown with prominent cusps – difficulty

in delivery – tooth division technique indicated.


8. CONFIGURATION OF THE ROOTS OF THE

IMPACTED 3RD MOLAR: point of application of the

elevator and the path of delivery of the tooth vary

greatly with the configuration of the root of the

impacted molar. Radiograph to be examined for

1. Fused or separate roots

2. Number of roots

3. Straight or curved roots

1. if curved – favorable or unfavorable

4. Long and slender or short and stout roots


5. Convergent or divergent

6. Texture and type of investing bone e.g.

hypercementosis

7. Root of the 2nd molar:

a) smaller in relation to 3rd molar

b) fused and conical

8. Absence of 1st molar


8. BONE TEXTURE: texture and density of the

investing bone varies with:

1. Individuals

2. Age

3. Sex

4. Systemic constitution


9. RELATIONSHIP WITH INFERIOR ALVEOLAR

CANAL: if root apices closely related to the canal

then warn patient about possible impairment of

labial sensations, and better to use tooth division

technique.

RELATIONSHIP OF THE ROOT TO THE CANAL

a) Related but not involving the canal

i. Seperated

ii. Adjacent

iii. Superimposed


b) Related to changes in the roots

i. Darkening of the root

ii. Dark and bifid root

iii. Narrowing of the root

iv. Deflected root

c) Related to changes in the canal

a) Interruption (loss) of lines

b) Converging canal (narrowing)

c) Diverted canal Dr. Apoorva Mowar, Subharti Dental College, SVSU

10. OTHER RADIOGRAPHIC TECHNIQUES:

1. IOPA is a 2-dimensional view, another view in

the 3rd dimension can be helpful.

2. Tube shift technique:

a) 2 IOPAs : first at normal position, second at

mesiocentric or distocentric position. The

movement is – same side lingual and

opposite side Buccal (SLOB) ie if the tube

and the object in question both move in the

same direction – object is on lingual side.


TRANS - ALVEOLAR EXTRACTION

Some teeth are unsuitable for removal using

forceps and the technique of intra - alveolar

extraction.

Surgical or trans – alveolar technique gives the

operator a direct access to the alveolar bone and

tooth roots after raising the mucoperiosteal flap,

and bone removal and sectioning of the roots is

under direct vision. Dr. Apoorva Mowar, Subharti Dental College, SVSU

INSTRUMENT TRAY


Principles of flap design

• access : large enough to allow clear access

without stretching or risk of tearing soft tissues.

• blood supply : base of all flaps should be wider

than free margin to maintain unimpeded blood

supply to the tissues of the flap

• avoiding vital structures: the position of the

relieving incision must take into account the

proximity of vital structures. Contd-


• suture over bone: the margins of flap should be

placed away from site of bone removal so that,

incision line is supported by firm bone on suturing

• ease of closure: edges of flap should be

positioned to make their accurate replacement

simple

• extending flaps: when extracting two teeth flap

should be so designed that if needed the flap can be

extended

• oro - antral communication: when removing a

tooth in posterior maxilla then a thought should be

given for inadvertent oro – antral communication and

flap so designed that it can be closed.


FLAP DESIGNS

one sided flap: incision along the gingival margin –

provides restricted access.

Two – sided flap: one incision along the gingival

margin and another relieving incision angled

obliquely across the attached buccal gingiva into lax

vestibular mucosa.

Three – sided flap: have a second relieving

incision at the distal end of the flap, allows greater

mobilization and exposure of the underlying bone

and roots. Dr. Apoorva Mowar, Subharti Dental College, SVSU

ENVELOPE INCISION

• SHORT

• LONG


Ward’s incision

OCCLUSAL VIEW Dr. Apoorva Mowar, Subharti Dental College, SVSU

MODIFIED WARD’S

L – SHAPED INCISION


BONE REMOAVAL

• CHISEL MALLET

• postage stamp method

• lingual split technique

• ROTARY CUTTING INSTRUMENT – buccal

guttering technique. { GILBE MOORE TECHNIQUE }


INDICATIONS OF USE OF BUR

• Old patient – brittle, sclerotic bone

• Position of internal oblique ridge

• Operation under L.A.

INDICATIONS FOR CHISEL & MALLET

• Young patient

• Procedure under G.A.

• Tooth sectioning is not required

• Position of external / internal oblique ridge


INDICATIONS FOR SECTIONING

• Tooth lock

• Unfavourable root pattern

• To protect important structures (nerve, vessel,

adjacent tooth)


ROTARY CUTTING INSTRUMENTS

• 1000 – 30, 000 RPM

• Straight hand piece – optimal control

• Plentiful irrigation- to prevent rise in temperature

as, as little as 10 degrees – lethal to osteocytes

• round burs –

• versatile and efficient

• difficult to control lateral cuts

• once bur head is inside bone difficult to gauge

depth


• fissure burs:

• cut neatly and precisely in lateral direction

• less good at cutting than round bur

• greater feel than round bur

• burs can be used to:

• drilling bone around the tooth or tooth root on

the buccal side – buccal guttering – to make

space for elevator

• bone is shaved off or block of bone outlined

and removed, then tooth or tooth root is

removed (postage stamp method).


BUCCAL GUTTERING


CHISEL AND MALLET

• Postage stamp method : a whole block of bone is

removed to facilitate the removal of the tooth. In

case of mandible a posterior stop cut (vertical) is

given so that the horizontal cut does not extend

beyond that point.


• Lingual approach:{ Introduced by William

Kelsey Fry in 1933 & described in detail

by Warwick james in 1936 & later by

Terence ward in 1956 }

• bone covering Buccal & distal surface of 3rd

molar removed

• chisel at 45° to sagittal plane, bevel placed

lingually, facing parallel to opposite bicuspid &

driven through distal part of molar shelf, twisted to

fracture a part of lingual shelf.


LINGUAL APPROACH

• elevator placed on Buccal side & crown lifted

in lingual & coronal direction.

• after tooth removal, the loosened fragments

on the lingual plate are repositioned by finger

pressure lingually.


LINGUAL SPLIT TECHNIQUE

FRACTURE THE LINGUAL PLATE


REMOVE BONE COVERING THE ROOT ON

DISTAL AND BUCCAL ASPECTS AND ELEVATE

THE TOOTH


LATERAL TREPANATION

{Low Buccal approach}

• INDICATION ---1.unerupted iiird molar in 9-16 years of age group for orthodontic purpose.

• 2. auto transplantation.

• 3.Prophylactic removal in unfavorable pattern-

• [a] vertical axis of 3rd molar is inclined at angle of more than 30 degree to long axis of 2nd molar. [b] space between distal margin of 2nd molar & ramus is less than one-half of crown width of 3rd molar.

• PROCEDURE -- S shape incision from retro molar fossa across external oblique ridge.5 mm. Cuff of attach mucosa at distobuccal region of 2nd molar.

Advocated by BOWDLER HENRY [ 1969] & HOWE [1973]


Tooth splitting TOOTH BELONGS TO DENTIST & BONE

BELONGS TO THE PATIENT


COMPLICATIONS OF IMPACTED MANDIBULAR 3RD

MOLAR EXTRACTION

1. Haemorrhage - intraoperative

a) facial artery

b) Retromolar vessels

c) inferior alveolar vessels

2. Fracture

a) dentoalveolar

b) angle

3. Displaced root / tooth

4. Luxation or damage to adjacent tooth


4. TMJ dislocation

5. Damage to soft tissue

6. Parasthesia / anaesthesia

7. Trismus

8. Alveolar osteitis ( dry socket)

9. Infection

10. Hypersensitivity of 2nd molar or distal pocket

formation

11.Emphysema Dr. Apoorva Mowar, Subharti Dental College, SVSU

Impacted Teeth - Subharti Dental College

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