Ppt on Impaction

8/11/2019 Ppt on Impaction

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Impaction

resented by

Binod adhikary

Bds 2004

Rolll no 214


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Contents:

1. Introduction2. Etiology

3. Classifications

4. Indications for removal5. clinical and radiographic assessment

6. Management

7. Complications


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Defini t ion :-

The word impaction comes from the Latin wordimpactus

Impacted tooth is the tooth that fails to erupt to its

normal position due to obstruction by a physical barrier

(adjacent tooth, bone or soft tissue overlying it) ORectopic positioning of the tooth itself .

A tooth should be termed as impacted only if the root

formation is complete & yet it has not erupted fully up

to the final position.

Also known as the embedded tooth

Its the one that is erupted, partially erupted or unerupted & will not eventually assume a normal archrelationship with the other teeth & the tissues.


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Order of frequency:

1. Mandibular 3rd

molars2. Maxillary 3rdmolars

3. Maxillary canine

4. Mandibular premolars5. Maxillary premolars

6. Mandibular canine

7. Maxillary central incisors

8. Mandibular lateral incisors


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Etiology: Multifactorial etiology (local & systemic)

Two theories impaction are:1. Phylogenetic theory

2. Mendalian theory

o Local causes:

1. Obstruction for eruption2. irregularity in position & presence of adjacent tooth

3. density of the overlying bone

4. Lack of space in the archcrowding, supernumeraryteeth

5. Ankylosis of primary or the permanent tooth6. Non resorbing or over retained deciduous tooth.

7. Non absorbing alveolar bone

8. Ectopic position of the tooth bud

9. Dilacerated roots10. Ton ue thrustin or thumb suckin habits


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o Systemic causes:

1. Prenatalhereditary

2. Postnatalrickets, anemia, TB, malaria,

congenital syphilis

3. Endocrine disorders: hypothyroidism,

achondroplasia4. Hereditary disorders : downs syndrome,

hurlers syndrome, cleidocranial

dysostosis, cleft lip and palate etc.


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Classification :

1. Classification of impacted mandibular third

molars

a)Based on angulationa) mesioangular

b) distoangular

c) vertical

d) horizontal

e) buccoangular

f) linguoangular

g) Inverted.


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B) Based on depth :

as per relation to the occlusal surface of the adjacent

2ndmolar

1. Position A: highest position of the tooth is on a level or

below the occlusal plane

2. Position B: highest position is below the occlusal plane ,but

above the cervical level of the 2ndmolar.

3. Position C: highest position of the tooth is below the

cervical level of the 2ndmolar.


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C) Pell & Gregorys classification:

based on the space available distal to the 2ndmolar

1. Class1: sufficient space is available between the anteriorborder of the ascending ramus & distal side of the 2ndmolar

for the eruption of 3rdmolar.

2. Class2: the space available between the anterior border of

ramus & the distal side of the 2ndmolar is less than the MDwidth of the crown of the 3rdmolar

3. Class 3: the third molar is totally embedded in the bone on

the ascending ramus, because of absolute lack of space .


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Classification of impacted maxillary 3rd

molar

1. Angulation and depth classification:

mesioangular, distoangular, vertical, horizontal,

buccoversion ,linguoversion inverted

..position A,B, C


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2) Classification in relation to the floor of

maxillary sinus :

a) Sinus approximation (SA):

no bone or a thin bony portion is present

between the impacted maxillary 3rdmolar and

floor of the maxillary sinusb) No sinus approximation (NSA):

2mm or more bone is present between the sinus floor

& the impacted maxillary 3rdmolar.


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Classification of impacted maxillary canine

Class1:

palatally placed horizontal, vertical,semivertical

Class2:

labially/bucally placed horizontal, vertical,semivertical

Class3:

involving both buccal and palatal bone eg

crown is placed in the palatal aspect & theroot is towards the buccal alveolar process.


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Class4:

vertically impacted canine between the roots of

lateral incisor and the 1st

premolar.Class5:

canine impacted in the edentulous maxilla

Class6:

maxillary canine in unusual position eg. nasoantral

wall or infraorbital margin


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When to remove impacted too th?

1. All impacted teeth should be removed as soon as the

diagnosis is made.2. Early removal reduces the postoperative morbidity &

allows for best healing

3. Younger patients tolerate the procedure better &

recover more quickly because of the more completeregeneration of the periodontal tissues.

4. Ideal time for the removal of impacted 3rdmolar is

when the roots of the teeth are 1/3rdformed and before

they are 2/3rd

formed, usually between the age of 17-20 years.


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Ind icat ions for the removal of impacted

teeth:

1. Prevention of periodontal disease

2. Prevention of dental caries

3. Prevention of pericoronitis

4. Prevention of root resorption

5. Impacted tooth under a denture or prosthesis

6. Prevention of odontogenic cyst and tumors

7. Treatment of pain of unknown origin

8. Facilitation of orthodontic treatment9. Optimal periodontal healing

10. If involved To prevent crowding of dentition

11. in a fracture

12. Preparation for orthognathic surgery.


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Clinical and radiograph ic assessment o f

impacted teeth

Purpose:

I. possible difficulties and

complications.

II. facilities availableIII. necessary surgical skills

IV. to decide whether to remove or not .


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CLINICAL EXAMINATION :

A conscious assessment of the general condition of the pt

including his attitude. Age of the patient

Size of the oral cavity , size of the tongue, the degree ofmouth opening & the extensibility of the lips and cheeks allcontribute to the surgical access.

Large crowns , inlays or amalgam restorations in the secondmolar can dislodge during elevation of the third molar

The amount of crown visible clinically.

If no part of 3rdmolar is visible clinically ,the gingival

crevice distal to the 2nd

molar should be probed for pockets . Note the condition of the soft tissue above the impacted

molar

Palpate the related lymph nodes to determine the extent ofany infection.


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RADIOGRAPHIC ASSESSMENT :

A) Intraoral radiographs possible if the tooth is in the

alveolus and not in the ramus

if the oral opening is adequate

if no gagging

useful to study the relation to the adjoining structure

like the IAN canal.

useful to study the status of the crown &

configuration of the roots


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The position and depth of the tooth canbe assessed using three imaginary

lines (winters lines), they are: White line:

corresponds to the occlusal plane

a line touching the occlusal plane of the 1st& 2ndmolar &

extended posteriorly over the third molar. indicates the difference in the occlusal level of the 2nd& 3rd

molars

Amber line:

represents the bone level a line is drawn from the crest of the interdental septum between the

molars & extend posteriorly distal to the 3rdmolar

it denotes the amount of alveolar bone covering the impacted tooth .


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Red line:

is drawn perpendicular to the amber line

indicates the amount of bone to be removed before

elevation.

if length>5mm .extraction is difficult

every additional mm renders the extraction 3 times

more difficult .

if >9the 3rd molar is below the apices of 2ndmolar

extraction under GA indicated.


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Very difficult: 7-10

Moderately difficult: 5-7

Minimal difficult: 3-4.


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Extraoral radiographs :1. OPG

2. lateral oblique for mandible

3. Waters (PA)view for maxilla.


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Radiographic prediction for the proximityof inferior alveolar nerve canal.

o Darkening of rooto Deflection of root

o Narrowing of root

o Interruption of the white line of the canalo Narrowing of canal

o Divergence of canal


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Management :1. Asepsis and isolation

2. Anesthesia3. Incision-flap design

4. Reflection of mucoperiosteal flap

5. Bone removal

6. Sectioning of tooth

7. Elevation, extraction

8. Debridement & smoothening the bone .

9. Control of bleeding10. Closuresuturing

11. Medications-antibiotics, analgesics etc..

12. Follow up


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Isolation of surgical site:

Scrubbing +painting the skin & oral mucosa

with cetrimide+ povidone +iodine/absolutealcohol. OR cetrimide + abs alcohol

+CHX(providone iodine 5% for skin & 1% for

oral mucosa , CHX 0.2% for oral mucosa &7.5%

for skin.

Drape the patient with sterile drape to cover

upper part of face to isolate the oral cavity .


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Local anesthetic: IAN + lingual+long buccal nerve block for

mandibular molars PSA nerve block + greater palatine nerve block

for maxillary molars

Infraorbital +nasopalatine nerve block for

maxary canines. Local infiltration for homeostasis.


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Incision (mucoperiosteal flap design):

For adequate access

Incision for flap has an anterior limb , a posterior limb, connected with/out a intermediate limb .

Incision for mandibular 3rdmolar extends anteriorly to

midway of CEJ of 2ndmolar at an angle & posteriorly

to distal most point of the 3rd

molar.-incision shouldnt extend too far upward distally.


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Bone removal

Aimto expose the crown & to create a path for the

removal of the tooth .

Adequate amount of bone should be removed ,but can be

minimized by sectioning the tooth

2 ways of bone removal;

-high speed hand piece & bur technique-chisel and mallet technique.


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Lingual split bone technique:

Described by Sir William Kelsey fry

Quick and clean technique

Causes saucerization of the socket thereby reduces the

size of the residual blood clot.

Used for lingually impacted mandibular 3

rd

molars Incidence of transient lingual anesthesia post

operatively .


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Tooth sectioning : Reduces the amount of bone removal

Reduces the risk of damage to the adjacent teeth Planned sectioning permits the parts to be removed

separately in an atraumatic way.

The direction in which the impacted tooth should besectioned depends upon the angulation of impaction ,based

on line of withdraw of the segment. Can be done with bur/chisel ,bur is preferred.


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Elevation & extraction:

1. Coupland elevator :

placed at the base of the crown2. Winter cryer :

may be used for wedging action /buccal elevation.

buccal elevation can be done in molars & canineby creating a purchase point in the roots just

below the CEJ.

support inferior border +lingual alveolar bone

during elevation.


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Debridement & smoothening of bone :1. Irrigate the socket

2. Curette the socket to remove any remaining dentalfollicle and epithelium.

3. Check for pieces of coronal portion ,remnants ofbone ,granulation tissue &bleeding points .

4. Check for caries (crown/root) ,erosion damage ofthe adjacent tooth.

5. Round off the margins of the socket with largevulcanite round bur or bone file .

6. Irrigate the socket again and control bleeding beforesuturing .


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Closure:

3-0 black silk suture used

Interrupted sutures placed & maintained for 7days

In case of 3rdmolars sutures distal to 2ndmolar

should be placed first & should be water tight toprevent pocket formation.


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o Factors making impaction surgery more

difficult:

1. Distoangular

2. Class3 ramus

3. Class C depth

4. Long thin roots5. Divergent curved roots

6. Narrow pdl

7. Thin follicle

8. Dense inelastic bone

9. Contact with 2ndmolar

10. Close to IAN canal

11. Complete bony impaction.


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o Factors making impaction surgery lessdifficult

1. Mesioangular position2. Class1 ramus

3. Class A depth

4. Roots 1/3-2/3rdformed

5. Fused conical roots

6. Wide periodontal ligament

7. Large follicle

8. Elastic bone9. Separated from 2ndmolar, IAN canal

10. Soft tissue impaction


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COMPLICATIONS :

Hemorrhage

Injury to the inferior alveolar nerve . During bone removal:

damage to 2ndmolar

damage to the root of the overlying tooth

slipping of the bur into the soft tissue

fracture of mandible when chisel & mallet are used.

During elevation:

luxation of the neighboring/overlying tooth

fracture of adjoining bone

displacement of the bone into the nearby space.

injury to the IAN ,lingual nerve etc.


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Post operative complications:

pain,

swelling, trismus,

hypoesthesia,

sensitivity,

loss of vitality of the nearby tooth,

pocket formation etc.


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References

1. Textbook of oral and maxillofacial surgery-

Neelima Anil Malik

2. Contemporary oral &maxillofacial surgery-

Peterson.3. Oral & maxillofacial surgeryLaskin

4. www.google.com
http://www.google.com/http://www.google.com/


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