Presented by :

2nd year PG OMFS

CONTENT Introduction Definition Eruption Chronology Theories of impaction Local & systemic causes Indication and contra indication Classification Difficulty index Radiographic analysis

introduction Removal of impacted teeth is one of the most common surgical

procedures performed by oral and maxillofacial surgeons

Extensive training, skill, and experience are necessary to performthis procedure with minimal trauma.

When the surgeon is untrained and/or inexperienced, the incidenceof complications rises significantly

Definition Latin – “impactus” – an organ or structure which because

of an abnormal mechanical condition has been preventedfrom assuming its normal position.

Webster – “wedging of one part into another”

Rounds (1962)– “the condition in which a tooth is embededin the alveolus so that its further eruption is prevented”

Archer – “ a tooth which is completely or partially unerupted and is positionedagainst another tooth or bone or soft tissue so that its further eruption isunlikely” (1975)

Lytle (1979) – “ one tooth that has failed to erupt into normal functionalposition beyond the time usually expected for such appearance”

Andreasen et al (1997) – “ a cessation of the eruption of a tooth caused by aclinically or radio-graphically detectable physical barrier in the eruption pathor by an ectopic position of the tooth”

Peterson – “ A tooth is considered impacted when it has failed to fully eruptinto the oral cavity within in its expected developmental time period and canno longer reasonably be expected to do so”

Tooth eruption Movement of a tooth from its site of development within

the alveolar bone to its functional position in the oral cavity.

6 stage Pre-eruptive stage

Intra-osseous stage/ Alveolar bone stage

Mucosal penetration/Mucosal stage

Pre-occlusal stage

Occlusal stage

Maturation stage

Eruption stage Eruption mechanism/theory Structures resisting eruption

Pre-eruptive stage

Intra-osseous stage Vascular hydrostatic pressureRoot formationBone formation

BonePrimary predecessors

Mucosal stage Vascular hydrostatic pressureRoot formationBone formation

Mucosa

Pre-occlusal stage Vascular hydrostatic pressureRoot formationBone formation

Periodontal ligamentMastication

Occlusal stage Root elongationBone formation

Periodontal ligamentMasticationOcclusion

Maturation Root elongationBone formation

Periodontal ligamentMastication

UNERUPTED TOOTH- NOT HAVING

PERFORATED ORAL MUCOSA

MALPOSED TOOTH- A TOOTH,ERUPTED OR

UNERUPTED WHICH IS IN ABNORMAL POSITION IN MAXILLA OR MANDIBLE

Partial eruption: A tooth that is

incompletely erupted is a partial eruption. The tooth may be seen clinically but is frequently malposed and always covered with soft tissue to some extent.

Partial bony impaction:

The tooth is partially covered with the bone. The tooth may be a complete soft tissue impaction & a partial bony impaction.

Complete bony impaction: The tooth is completely contained within the bone

Potential impaction: An unerrupted tooth that still retains the potential for

eruption, but which will most likely not erupt into normal position & function because of obstruction, unless surgical intervention occurs.

Ectopic/ displaced teeth: a tooth is ectopic if malposed due to congenital factors or displaced by the presence of pathology.

Chronology of 3rd molar

Tooth germ visible – 9yrs

Cusp mineralization – 11 yrs

Crown formation – 14 yrs

Roots formed (apex open) – 18 yrs

Eruption – 18-24 yrs

Bjork (1956) – 3 factors – significant in developmentof mandible & space for third molar

Vertical direction of condylar growth

Insufficient growth of mandible

Backwardly directed trend of eruption

Hattab (1997) – position changes and eruption of 3rd

molar is an unpredictable phenomenon

Nance (2006) – if third molars are angled mesial/ horizontal – unlikely to erupt-- if third molars are vertical/ distal – a period of follow up – they

might erupt.

Why teeth get impacted?Theories of impaction (Durbeck)

The Phylogenic theory Nature tries to eliminate the disused organs i.e., use makes the organ develop better, disuse causes slow regression of organ. Due to evolution increase in brain size and decrease in jaw size as per node’s hypothesis Evolution of Masticatory habits- leading to Withdrawal / elimination of stimulus.

Softer and refined foods / fibrous food / Uncooked meat

The Mendelian theory Heredity is most common cause. The hereditary transmission of small jaws and large teeth from parents to siblings. This may be

important etiological factor in the occurrence of impaction.

The Endocrine theory Increase or decrease in growth hormone secretion may affect the size of the jaws.

The Pathological theory Chronic infections affecting an individual may bring the condensation of osseous tissue further preventing the growth and development

of the jaws.

The Orthodontic theory Jaws develop in downward and forward direction. Growth of the jaw and movement of teeth occurs in forward direction,so any thing that

interfere with such moment will cause an impaction (small jaw-decreased space).

A dense bone decreases the movement of the teeth in forward direction.

The Skeletal theory

Several studies have demonstrated that when there is inadequate bony length, there is a higher proportion of impacted teeth

The Belfast Study Group They claim that there may be differential root growth between the mesial and distal roots,

which causes the tooth to either remain mesially inclined or rotate to a vertical positiondepending on the amount of root development.

Local causes (Berger)

Lack of space Retained deciduous teeth Premature loss of deciduous teeth Ectopic position of tooth bud Obstruction of eruption path Cyst tumor and supernumery teeth Infection and trauma Abnormality of jaw Dilaceration : abnormal path of eruption of tooth due to traumatic

forces during the eruption period

SYSTEMIC CAUSES (Berger) Prenatal causes

Heredity

Postnatal

Rickets

Anaemia

Congenital Syphillis

Endocrine dysfunction

Malnutrition

Rare conditions

Cleidocranial dysostosis

Oxycephaly

Progeria

Anchondroplasia

Cleft plate

Commonly impacted tooth mandibular third molars

maxillary third molars

maxillary cuspids

mandibular bicuspids

mandibular cuspids

maxillary bicuspids

maxillary central incisior

maxillary lateral incisor

supernumerary teeth mainly mesiodens

INDICATION FOR REMOVAL

prevention of pericoronitis

Dental caries or prevention of dental caries

Periodontal disease or its prevention

Prevention of root resorption

Odontogenic cysts & tumours – dentigerous cyst

Pain of unexplained origin

autogenous transplantation to first molar socket

Fracture of the jaw/tooth in the line of fracture

Prosthetic problems e.g. under prosthesis

Orthodontic relapse/facilitation of orthodontic tooth movement

Tooth interfering with orthognathic and/or reconstructive surgery

Prophylactic removal - Patients with medical or surgical conditions requiring removal of third molar (e.g. organ transplants, alloplastic implants, chemotherapy, radiation therapy)

Pericoronitis There should be a portion of the crown in the oral cavity to actually call it pericoronitis

Patients with pericoronitis at time of extraction have higher potential for dry socket (loss of blood clot, causing excruciating pain post-op)

Partly erupted 3rd molars act as reservoirs of Streptococcus Mutans and Lactobacillus along with anaerobes Peptostreptococcus, Spirochaetes, fusibacterium and bacteroids.

Treatment I&D

place patient on antibiotics, let things calm down.

Removal of 3rd molar tooth

Contraindications for removal Extremes of age Compromised medical status Excessive risk of damage to adjacent structures When there is a question about the future status of

the second molar Uncontrolled active pericoronal infection Socioeconomic status fracture of atrophic mandible may occur

Classification of impacted third molars NATURE OF OVERLYING TISSUE IMPACTION

Soft tissue Partial bony Complete bony

ANGULATION OF TOOTH (Winter,1926) Vertical Mesioangular Horizontal Distoangular Buccolangular Lingoangular Inverted

RELATIONSHIP OF THE IMPACTED TOOTH TO THE ANTERIOR BORDER OF RAMUS (Pell & Gregory, 1933)

Class I -- space available anterior to anterior border of ramus

Class II -- space less than mesiodistal width of 3rd molar

Class III – most of the 3rd molars located with in ramus

DEPTH OF IMPACTION AND THE TYPE OF TISSUE OVERLYING

(Pell & Gregory)

Position A – highest portion of the tooth is on occlusal level or above

Position B – highest portion of tooth below occlusal level but above Cervical line

Position C – highest portion of the tooth is below the cervical line

STATE OF ERUPTION Erupted Partially erupted Unerpted

NUMBER OF ROOTS Fused root / single Two roots Multiple roots

CLASSIFICATION SYSTEM BASED ON DENTAL PROCEDURE CODE D7220 -- removal of impacted tooth - overlying soft tissue D7230 -- removal of impacted tooth - partially bony impacted D7240 -- removal of impacted tooth - completely bony D7241 -- removal impacted tooth - completely bony, with unusual surgical

complications

WHARFE assessment - Macgregor 1985 Winters classification

Horizontal 2 Distoangular 2 Mesioangular 1 Vertical 0

Height of the mandible

1-30 mm 0 31-34 mm 1 35-39 mm 2

Angulation of 3rd molar

1-59 degrees 0 60-69 1 70-79 2 80-89 3 90 + 4

Root shape and development

favourable curvature 1 unfavourable curvature 2 complex 3 < 1/3 complete 2 1/3 to 2/3 complete 1 > 2/3 complete 3

Follicles normal 0 possibly enlarged 1 enlarged 2 impaction relieved 3

path of Exit space available 0 distal cusps covered 1 mesial cusp also covered 2 both covered 3

Difficulty index for removal of third molar (PEDERSON’S SCALE ,1988)

ANGULATION/SPATIAL RELATIONSHIP

Mesioangular 1

Horizontal/Transverse 2

Vertical 3

Distoangular 4

DEPTH

Level A 1

Level B 2

Level C 3

RAMUS RELATIONSHIP

Class I 1

Class II 2

Class III 3

Difficulty index

Very difficult : 7 to 10

Moderately difficult : 5 to 7

Minimally difficult : 3 to 4

PARANT SCALEEASY I EXTRACTION REQUIRING FORCEPS ONLY

EASY II EXTRACTION REQUIRING OSTECTOMY

DIFFICULT III EXTRACTION REQUIRING OSTEOTOMY AND CORONAL SECTION

DIFFICULT IV COMPLEX EXTRACTION ( ROOT RESECTION)

Radiography of impacted mandibular teeth

Radiographic views intraoral periapical occlusal orthopontamograph lateral radiograph Linear cross sectional tomography

A diagnostic technique for determining the buccolingualrelationship of impacted mandibular third molar and inferior alveolar neurovascular bundle

Interpretation of IOPAR Access

By noting inclination of the radio-opaque line – external oblique line If horizontal – access is easy If vertical – access is difficult

Position & depth of impacted tooth

Root pattern of impacted teeth

Shape of crown

Texture of investing bone

Relation to inferior alveolar canal

Position & root pattern of second molar

Position and depth of impacted tooth

White Line

Provide information regarding the depth & inclination

Amber Line

Indicate the margin of the alveolar bone enclosing the teeth

One must differentiate between external oblique ridge and bone lying distal to impacted tooth

Red Line

Provides information about depth at which elevator should be applied

Longer the line difficult to remove/access the tooth

Length : difficulty :: 1 : 3

Importance of interdental septum

Vertical

Disto-angular

Root pattern Root morphology influence the degree

of difficulty of removal

limited root development – ROLLINGtooth – difficult to remove

1/3rd to 2/3rd root formation – easy toremove

Mesiodistal width of root > crown –need sectioning longituidinally.

Sometime multiple root may not bevisible on radiograph due tosuperimposition.

Shape of crown

Large square crown with prominent cusp – difficult to remove

“line of withdrawal” of the tooth – obstructed by 2nd

molar – “locking of crown”

RADIOGRAPHIC CRITERIA TO DECIDE

SECTIONING OF TOOTH

THIS CRITERIA DECIDES WHETHER THE TOOTH IS LOCKED OR NOT

A LINE IS DRAWN FROM THE MESIOLINGUAL CUSP TILL THE DISTAL ROOT

THE DISTANCE IS THEN MEASURED

HALF THE DISTANCE IS TAKEN AS THE RADIUS

AN ARC IS DRAWN

IF THE ARC TOUCHES THE 2ND MOLAR INDICATES LOCKING OF TOOTH

SECTIONING IS MANDATORY

Localization of impacted third molar using radiographs

Horizontal tube shift tech

For seperating superimposed objects with vertical longaxis

For buccal / lingual localisation of impacted third molarfrom roots of erupted teeth

vertical tube shift tech

For seperating horizontally oriented objects

For determining bucco-lingual position of third molarapices that super impose the mand canal

7 radiological signs had been suggested by

HOWE & POYTON (1960) Darkening of the root

Deflected root

Narrowing of the root

Dark & bifid root

Interruption of the white line(s)

Diversion of inferior alveolar canal

Narrowing of the inferior alveolar canal

Related to Root

Related toinferior alveolarcanal

Use of CT scan Helps to show relationship of root apices with inferior dental canal.

Useful to predict the bone density of mandible

Use of CBCT When OPG suggest close relationship

between root apex and ID canal.

Information about distance between IAN &lower tooth root

Prediction for risk of damage of IAN

Advantage : Radiation exposure 10 times less than regular CT

scan

Required less time(10-40 sec) than conventional CT

Price is comparatively less than CT scan (<50%)

Assessment of impaction

Preoperative assessment

Clinical assessment

General

Local

ERUPTION STATUS OF IMPACTED TOOTH

RESORPTION OF SECOND MOLAR

PRESENCE OF LOCAL INFECTION- PERICORONITIS

ORTHODONTIC CONSIDERATION

CARIES IN OR RESORPTION OF THIRD MOLAR OR ADJACENT TEETH

PERIODONTAL STATUS

Local assessment

Mouth opening

Size of tongue

Extensibility of lips and cheeks

Status of dentition

Assessment of teeth in particular

ORIENTATION AND RELATIONSHIP TO IDC

OCCLUSAL RELATIONSHIP

REGIONAL LYMPH NODES

TMJ FUNCTION

If planned under GA, other impacted teeth should also be

considered for removal

FACTORS THAT MAKE REMOVAL EASIER

SOFT

TISSUE

IMPACTION

SEPRTATED

FROM

II MOLAR

LESS

DENSE

BONE

LARGE

FOLLICE

WIDE

PERIODONTAL

SPACE

FUSED CONIC

ROOTS

ROOT 1/3RD

TO

2/3RD

POSITION A

CLASS 1

MESIOANGULAR

FACTORS THAT MAKE REMOVAL DIFFICULT

COMPLETE

BONY

IMPACTION

CONTACT

WITH

IIMOLAR

DENSE

INELASTIC

BONE

THIN

FOLLICLE

NARROW

PERIODONTAL

SPACE

DIVERGENT

CURVED

ROOTS

LONG

THIN

ROOTS

POSITION C

CLASS 3

DISTOANGULAR

Risk of Intervention: Minor transient

Sensory nerve alteration

Dry socket

Trismus

Infection

Hemorrhage

Dentoalveolar fracture

Displacement of tooth

Risk of Intervention: Minor Permanent

Periodontal injury

Adjacent tooth injury

TMJ injury

Risk of Intervention: Major

Altered sensation

Vital organ infection

Fracture of the mandible and maxillary tuberosity

injury

Risk of Non-intervention

Crowding of dentition based on growth prediction

Resorption of adjacent tooth and periodontal status

Development of pathological condition such as caries, infection, cyst, tumor

Surgical anatomy Mandibular third molar Neurovascular bundle Retromolar trigon Facial artery and vein Lingual nerve Mylohyoid nerve Long buccal nerve Bone trajectories of mandible Lingual plate Masticatory musculature

Mandibular third molar

Situated at distal end of the body of the mandiblewhere it meets a relatively thin ramus

At this point if undue force is applied duringremoval – causes fracture.

Tooth is embedded within thick buccal bone andthin lingual bone

Sometime the thickness of lingual cortical plate –<1mm

In such cases fractured root apices may displace tolingual pouch

Lingual plate:

Because of its extreme thinness apices of lower third molar may perforate it

Rarely but it may happen that the whole tooth may be pushed into the lingual pouch

Sir william kelsy Fry popularized the “lingual split bone technique” thin lingual plate joins with thick body of

mandible, when inner plates breaks at junction then the lingual nerve extend forward

But a undue force may extend the breakage till the LINGULA as it is present 25 mm from the 3rd molar

Neurovascular bundle

ID canal positioned apically and slightly buccalto the 3rd molar root

Canal encloses – IA artery, vein and nerve –encloses within fascial sheath

Sometimes root apices may invade the superiorwall of the canal.

Forceful intrusion of root in canal may injurevessels – profound bleeding.

When root of third molar is in direct contactwith ID canal – radiographicaly loss of laminadura may be seen.

Retromolar Triangle Depressed roughened area – bounded by buccal &

lingual crest.

Lateral to this – retromolar fossa

Through this branches of mandibular vesselsemerges and supply temporalis tendon, buccinatormuscle & adjacent alveolus

If the distla incision is extended on ramus insteadof extending over cheek – cause injury to thisvessels – lead to brisk bleeding

Retromolar pad Resist upward displacement of tooth – relieving

incision required through mucoperiosteum

Striping of tendinous insertion of temporalis – lead topostoperative pain

Facial artery & vein

Cross the inferior border of mandible anterior to masseter muscle near to 2nd molar

Injury may occur due to slips of BP blade during buccal cut

It is better to start incision from buccal sulcus then extend upward to the tooth

Lingual nerve LINGUAL NERVE LIES INFERIOR & LINGUAL TO THE

CREST OF LINGUAL PLATE OF MANDIBLE WITH AMEAN POSITION OF 2.28MM(±0.9)BELOW THE CREST &0.58MM(=/-(0.9) MEDIAL TO CREST

- KIESSELBACH & CHAMBERLAIN

15% OF CASES SHOWS IT LIES SUPERIOR TO LINGUALPLATE

CADAVERIC STUDIES SHOWED THAT IT LIES 3.45MMMEDIAL TO ALVEOLAR CREST & 8.32MM BELOW

MRI STUDY DEMONSTRATED THAT THE NERVE ISLOCATED AT A MEAN DISTANCE OF 2.53MM MEDIAL TO

AND 2.75MM BELOW ALVEOLAR CREST

Lingual version of distoangular impacted lower 3rd molar Root of few distoangular 3rd molar directed lingually – lingual version – increase the

vulnerability with lingual nerve

Lingual plate deficiency Root Apices of third molar penetrate the lingual plate – deflected into lingual pouch – injure

the lingual nerve

High lateral position of lingual nerve Lingual nerve can be in full contact with lingual plate / above the lingual plate – increase

vulnerability of lingual nerve

Local chronic inflammatory condition Long standing pericoronal infection lead to scaring of lingual nerve with lingual plate If ligual plate is deficient then its tend to attached with the 3rd molar tooth

Mylohyoid nerve Leaves IAN before entering

mandibular canal

Then penetrate the spheno-mandibular ligamnet

In 16% of cases this nerve present in too close proximity of ID canal

Damage may take place during lingual approach for removing 3rd

molar tooth.

Long Buccal Nerve Emerges through the buccinator

and passes anteriorly on its outer surface

During wide opening of mouth it lies above the retro molar fossa region

Injury is rare but can occur if incision is placed too laterally into the buccal mucosa.

Bone trajectories of mandible:

“Grain” of mandible run longitudinally.

Importance lies in use of chisel for boneremoval.

Buccal horizontal cut may extend from 1st

molar till distal to 3rd molar till ramus & causefracture.

To prevent from such phenomenon verticalstop cut need to be placed mesial and distal tothe 3rd molar

Musculature Buccinator

During surgical removal deeply seated impacted tooth require detachment of this muscle – lead to postoperative swelling,trismus & pain

Temporalis

Ends at anterior border of mandible as tendinous structure

Outer tendon sectioned during buccal approach – facilitate adequate bone removal

Masseter

Rarely involed in third molar surgery

Postoperative edema may involve posteriorly to the muscle leading to trismus and pain

Pre and post operative infection may drain into submasseteric space – lead to sub-masseteric abcess formation

Medial pterygoid

Not directly involved in third molar surgery

But during lingual approach – postoperative edema involve this muscle which can lead to trismus.

Mylohyoid

During lingual approach – this muscle can partly sever – may lead to transient swallowing difficulty

Postoperative infection can spread to sublingual / submandibular space through this muscle breakage.

SURGICAL PROCEDURE

ADEQUATE EXPOSURE

ACCESS TO THE TOOTH

SECTIONING OF THE TOOTH(OPTIONAL)

ELEVATION FROM THE ALVEOLAR PROCESS

DEBRIDMENT & IRRIGATION

FIVE BASIC STEPS

ADEQUATE EXPOSURE

SEVERAL DIFFERENT FLAP TECHNIQUES HAVE BEEN DEVELOPED, AND DISCUSSED TO MINIMIZE POTENTIAL PERIODONTAL COMPLICATIONS TO ADJACENT SECOND MOLAR OR IMPROVE SURGICAL ACCESS.

TYPES OF INCISIONS AND FLAPS

L-SHAPED FLAP

BAYONET FLAP(WARDS INCISION)

THREE CORNERED FLAP(MODIFIED WARDS INCISION)

ENVELOPE FLAP

COMMA SHAPED INCISION/FLAP

VESTIBULAR TONGUE SHAPED FLAP

GROOVES AND MOORE FLAPS

L-SHAPED FLAP THE ANTERIOR LIMB IS THE VESTIBULAR EXTENSION AT THE LEVEL OF 2ND MOLAR

IT CAN BE EXTENDED UPTO 1ST MOLAR

RISK OF DAMAGING FACIAL VESSELS

THE VERTICAL RELIEVING INCISION DIFFERENTIATE IT FROM WARDS INCISION

THIS RELIEVING INCISION IS GIVEN AT 45O ANGLE TO THE LONG AXIS OF THE 2ND MOLAR AND RUNS STRAIGHT ANTERIORLY AND DOWNWARDS

IT TOTALLY COMMITS AN OPERATOR TO A BUCCAL APPROACH

BAYONET FLAP

it has three parts

anterior

intermediate or gingival

distal

Also known as wards incision

Anteriorly it extends around the gingival margin of 2nd molar and even the 1st

molar before turning into the sulcus usually angled forward

over extension of the incision into the sulcus may cause brisk oozing of blood fromvenous plexus

can be avoided by making the anterior part more oblique

intermediate is along the gingiva

distally it is placed more lingually over the impacted tooth but laterally towards theascending ramus.

THREE CORNERED FLAP

MODIFIED WARDS INCISION

LARGER LAYER OF MUCOPERIOSTEAL FLAP

USUALLY FOR DEEPLY IMPACTED MOLARS

THE ANTERIOR PART SHOULD COMMENCE AT THE DISTOBUCCAL CORNER OF 1ST MOLAR INSTEAD OF 2ND

MOLAR

EXTENDS VERTICALLY DOWNWARDS AND THEN CURVED ANTERIORLY

FOLLOWED BY GINGIVAL CREVICULAR INCISION ALONG THE 2ND MOLAR

DISTALLY IT IS SIMILAR TO WARDS INCISION

ENVELOPE FLAP

EXTENDS FROM MESIAL PAPILLA OF THE 1ST

MOLAR AROUND THE NECKS OF THE TEETHTO THE DISTOBUCCAL LINE ANGLE OF THE2ND MOLAR

THEN EXTENDS POSTERIORLY ANDLATERALLY UP TO THE ANTERIOR BORDEROF THE MANDIBLE

IT SHOULD NOT CONTINUE POSTRIORLY INA STRAIGHT LINE BECAUSE THE MANDIBLEDIVERGE LATERALLY

EASIER TO CLOSE AND BEST HEALING

IN 1971, SZMYD DESCRIBED THIS INCISION

COMMA SHAPED INCISION

PROVIDES LAREG ACCESS

INDICATED IN CASE DEEP HORIZONTAL

IMPACTIONS

PERIODONTAL POCKETING DISTAL TO

2ND MOLAR IS LESS

VESTIBULAR TONGUE SHAPED FLAP

BERWICK, IN 1966, DESIGNED A VESTIBULAR TONGUE-SHAPED FLAP

EXTENDED ONTO THE BUCCAL SHELF OF THE MANDIBLE

INCISION LINE DID NOT LIE OVER THE BONY DEFECT CREATED BY THE REMOVAL OF THE IMPACTED TOOTH

ITS BASE AT THE DISTOLINGUAL ASPECT OF THE SECOND MOLAR

MAGNUS ET AL WITH THE SAME AIM,

DESCRIBED A PARAGINGIVAL FLAP IN WHICH THEANTERIOR RELEASING INCISION IS LOCATED 0.5 CM APICALTO THE GINGIVAL MARGIN OF THE SECOND AND FIRSTMOLARS

GROVES AND MOORE

IN THE YEAR 1970 THEY DESIGNED THREE FLAPS

RELATED TO INVOLMENT OF THE GINGIVAL MARGIN OF 2ND MOLAR

THE TWO FLAPS THAT DID NOT INVOLVED THE GINGIVAL MARGIN OF THE 2ND MOLAR

PRODUCED AN APPARENT DECREASE IN POCKETING DISTAL TO 2ND MOLAR

ACCESS TO THE IMPACTED TOOTH

IT IS ACHIEVED BY REMOVAL OF OVERLYING BONE

AMOUNT OF REMOVAL DEPENDS ON

DEPTH OF THE TOOTH

MORPHOLOGY OF ROOT

ANGULATION OF TOOTH

BONE REMOVAL CAN BE DONE BY

CHISELS

DRILLS

Piezo surgical unit

CHISEL AND MALLET

TRADITIONAL TECHNIQUE,

SUPPORT OF MANDIBLE IS MANDATORY

THE CHISEL IS KEPT PARALLEL TO THE LONG AXIS OF BONE

INDICATIONS YOUNG PATIENTS

AN EXTERNAL OBLIQUE RIDGE SLIGHTLY BELOW THE LEVEL OF BONE ENCLOSING THE 3RD MOLAR

AN EXTERNAL OBLIQUE RIDGE THAT IS SLIGHTLY BEHIND THE 3RD MOLAR SO THAT THE DISTOLINGUAL CORNER OF THE TOOTH SITS IN A THIN BALCONY OF BONE

THE CHISEL IS KEPT PARALLEL TO THE LONG AXIS OF BONE

A VERTICAL LIMITING CUT IS MADE AT THE DISTAL ASPECT OF THE 2ND

MOLAR WITH CHISEL BEVEL FACING POSTERIORLY

THE LIMITING CUT IS THEN TURNED INTO A VERTICAL GROOVE

THEN THE CHISEL IS PLACED AT 45O ANGLE TO THE LOWER EDGE OF LIMITING CUT IN AN OBLIQUE DIRECTION

A TRINGULAR PIECE OF BUCCAL PLATE DISTAL TO 2ND MOLAR IS THEN REMOVED

THE DISTAL BONE IS THEN REMOVED IF REQUIRED

THE BONY CUT CAN BE ENLARGED TO UNCOVER THE TOOTH

ELEVATOR IS THEN PLACED AT THE JUCTION OF VERRTICAL LIMITING CUT AND OBLIQUE BONE CUT

LOW SPEED ENGINE DRIVEN DRILLS

INDICATIONSOLD PATIENTS

AN EXTERNAL OBLIQUE RIDGE AND INTERNAL OBLIQUE RIDGE OR BOTH ARE FAR FORMED IN RELATIONSHIP TO THE TOOTH

HENCE GUTTERING IS NECESSARY TO AVOID EXCESS REMOVAL OF BONE

COMPLICATIONSACCIDENTAL DENUDEING OF ROOTS OF 2ND MOLAR

WHILE GUTTERING THE BONE THE MANDIBULAR CANAL MAY BE OPENED AND DAMAGE TO NERVE MAY OCCUR

WHILE CUTTING DISTOLINGUAL SPUR OF BONE HIGH CHANCE OF LINGUAL NERVE DAMAGE HENCE IT SHOULD BE MOVED LINGUAL TO BUCCAL TO PREVENT SUDDEN SLIPPING INTO LINGUAL SIDE

BUCCAL BONE GUTTERING begins at the mesiobuccal line angle of the 3rd molar

initial bone cut is made vertically down to expose the height of covexity of the 3rd molar

the bur is passed distally at this depth to the distobuccalline angle

then lingually around the distal surface

if tooth cannot be delivered then again bur is used to increase the depth of ossisection to the level of bifurcation

INITIALLY HOLES ARE DRILLED AT A DISTANCE OF 4-5MM FROM EACH OTHER AROUND THE BUCCAL ASPECT (FROM THE MESIOBUCCAL LINE ANGLE TO THE DISTOBUCCAL LINE ANGLE OF THE TOOTH)

LARGE ROUND NO-8 BUR IS PREFFERED THESE HOLES ARE THEN JOINED WITH A FLAT FISSURE BUR NO.701,702 DOWN TO

THE CERVICAL MARGIN OF TOOTH THIS PROVIDES ACCESS FOR ELEVATORS TO GAIN PURCHASE POINT AND A

PATHWAY FOR DELIVERY OF TOOTH THE BONE CUTTING SHOULD BE DONE WITH A CONTINOUS JET OF NORMAL

SALINE

SECTIONING OF THE TOOTH

IT ALLOWS PORTIONS OF THE TOOTH TO BE REMOVED SEPERATELY

DEPENDS PRIMARILY ONANGULATION OF THE TOOTH

UNFAVOURABLE ROOT PATTERN

TO PROTECT IMPORTANT STRUCTURES

ADVANTAGESTHE INCISION IS LESS EXTENSIVE

OPERATION FIELD CAN BE KEPT SMALL

LESS POST OPERATIVE SWELLING

LESS BONE REMOVAL

FORCEFUL ELEVATION OF TOOTH IS NOT NEEDFUL

NO DAMAGE TO ADJACENT TOOTH

RISK OF FRACTURE IS MINIMISED

DISADVANTAGES

IT CAN BE ACHIEVED WITHCHISELSDRILLS

TEETH WITH SHALLOW GROOVES DIFFICULT TO SPLIT

DIFFICULT TO CONTROL THE LINE OF SPLITING

WITH CHISEL SPLITING DAMAGE TO SOFT TISSUE MAY BE CAUSED

PATIENT MAY FIND IT INCONVENIENT

REMOVAL OF MESIOANGULAR IMPACTED III MOLAR

TOOTH DIVISION IS NECESSARYIF THE TOOTH IS BISSECTED AT NECK

ENAMEL IS VERY THIN

LOWER POSITION

Distal half of the crown is sectioned off at the buccal groove just below the cervical line

Position of elevator under cemento enamel junction on mesial surface

Tooth is moved upward and backward as far as distal rim of bone will allow

Upward movement of roots

REMOVAL OF DISTOANGULAR IMPACTED III MOLAR

Distoangular position brings the iii molar well under the ascending ramus

frequently distally curved roots are encountered

after sufficient bone removal, the crown is sectioned horizontally from the roots just above the cervical line

the entire crown is first removed

if roots if fused then a elevator can be straight used to elevate the roots into the space previously occupied by the crown

if roots are divergent sectioning of roots is necessary and individual removal

extraction of this type of impaction is difficult,becausemore distal bone has to be removed and the tooth tends to be elevated distally and into the ramusportion of the mandible

REMOVAL OF VERTICALLY IMPACTED III MOLAR

procedure of bone removal and tooth sectioning is similar to mesioangularimpaction

tooth sectioned vertically

distal part removed first,followed by the mesial half

it is more difficult than mesioangularimpaction because the access around 2nd

molar is less and requires more removal of bone on the buccal and distal sides

REMOVAL OF HORIZONTALLY IMPACTED III MOLAR requires maximum bone removal

bone should be removed down to the cervical line to expose the superior aspect of the distal root and the majority of buccal surface of crown

superior(distal) and inferior(mesial) cusp sectioned

superior crown is removed first

followed by bulk of tooth and then the inferior crown fragment

if sufficient space is not available then a split is made near the anatomic neck of tooth

if divergent roots then spitting of roots is necassery

and then each root is delivered individually

REMOVAL OF BUCCOANGULAR OR LINGULAR IMPACTED III MOLARS

NOT SO COMMON

TOOTH IS SECTIONED HORIZONTALLY AT THE CERVICAL REGION

CROWN IS FIRST DELIVERED FOLLOWING ROOTS

IN CASE OF LINGUOANGULAR IMPACTION RETRACTION OF THE LINGUAL MUCOSA IS IMPORTANT

LINGUOANGULAR BUCCOANGULAR

ELEVATION FROM THE ALVEOLAR PROCESS

IT CAN BE DONE WITH DENTAL ELEVATORS

IN MANDIBLE THE MOST FREQUENT ELEVATOR USED IS STRAIGHT ELEVATOR,PAIRED CRYER

CAREFUL APPLICATION OF FORCE SHOULD BE DONE IN ORDER TO AVOID FRACTURE OF BUCCAL BONE,ADJECENT TOOTH AND SOMETIME ENTIRE MANDIBLE

THE ELEVATORS SHOULD BE PROPERLY ENGAGED TO THE TOOTH OR TOOTH-ROOT AND FORCE SHOULD BE DELIVERED IN PROPER DIRECTION

DEBRIDMENT AND IRRIGATION

AFTER REMOVAL OF TOOTHALL PARTICULATE BONE CHIPS AND DEBRIS SHOULD BE DEBRIDED

THOROUGH IRRIGATION WITH STERILE SALINE INCLUDING UNDER THE REFLECTED SOFT TISSUE FLAP

A PERIAPICAL CURETTE CAN BE USED

A BONE FILE CAN BE USED TO SMOOTHEN ANY SHARP,ROUGH EDGE OF BONE

A HEMOSTAT CAN BE USED TO REMOVE ANY REMNANT OF DENTAL FOLLICLE

CLOSURE OF THE FLAP SHOULD BE DONE BY PRIMARY SUTURES

LINGUAL SPLIT-BONE TECHNIQUE DEVELOPED BY -- FRY &DESCRIBED BY -- WARD IN 1956

USED TO REMOVE IMPACTED 3RD MOLARS IN ALL POSITION PROVIDED THEY ARE NOT BUCCOVERSION

USEFUL IN REMOVING DEEPLY POSITIONED HORIZONTAL AND DISTOANGULAR IMPACTED 3RD MOLARS

IT INVOLVES SPLITTING THE LINGUAL CORTEX AND ELEVATING THE TOOTH IN DISTOLINGUAL DIRECTION

THE INCISION STARTS IN THE BUCCAL SULCUS AT ABOUT THE JUNCTION OF MIDDLE AND POSTERIOR 3RD OF THE 2ND

MOLAR AND PASSING UPWARD TO THE GINGIVAL MARGIN AT THE DISTAL ASPECT OF THAT TOOTH

FROM THIS POINT THE INCISION COURSE BEHIND THE 2ND MOLAR TO THE MIDDLE OF ITS POSTERIOR SURFACE AND THEN DISTOBUCCALY UP THE RAMUS TOWARDS THE CHEEK

IF GREATER ACCESS IS NEEDED THE ANTERIOR ND OF THE INCISION CAN BEGIN IMMEDIATELY DISTAL TO THE FIRST MOLAR

Vertical stop cut

Split of Disto

lingual bone

Elevation

Horizontal cut

Removal of distal

& buccal bone

Removal of disto

lingual bone

Incision

Closure

LINGUAL SPLIT BONE TECHNIQUE BY LEWIS

FLAP IS DESIGNED SUCH THAT BONE BODY ATTACHED TO THE FLAP IS PRESERVED

FLAP IS RAISED LINGUAL TO II MOLAR AND NOT THE IIIMOLAR

VERTICAL LINGUAL STEP CUT IS GIVEN JUST DISTAL TO THE II MOLAR

LINGUAL PLATE IS HINGED AS AN OSTEOMUCOPERIOSTEAL FLAP

LESS TISSUE TRAUMA THAN OTHER

ACCEPTED TECHNIQUE

ASSISTS IN PRIMARY WOUND CLOSURE,

OBLITERATION OF DEAD SPACE,

Sagittal split ramus osteotomy Conventionally used for orthognathic surgery. Amin 1995, Toffanin 2003, and Jones 2004 have

advocated this technique for remiving impactionin indicated cases.

Advantages Good access Conserve bony structure Allows nerve to be seen and avoided

Disadvantages Occlusion at risk (risk) Unfavourable split either proximally or distally

Indication: Deeply impacted in close proximity with IAN

Buccal corticotomy Alternative approach to deeply seated

impacted third molar

Advocated by Tay in 2007

Trapezoid mucoperiosteal flap raised

Rectangular bony window made and removed

Mesial and distal cut extended till inferior border.

Tooth removed.

LATERAL TREPHINATION TECHNIQUE

prophylactic removal of developing 3rd molar

age group 10 to 16 yrs

before calcified cusps are united

a modified s-shaped incision is made fromretromolar fossa across the external oblique ridge

then it curves down along the mucous membraneabove the vestibule extending upto 1st molar

leaving behind 5mm cuff of attached mucosa at thedistobuccal region of 2nd molar

the buccal cortical plate is trephined over 3rd molar

then vertical cuts are made anteriorly andposteriorly

these cuts are joined and buccal plate is fracturedout

exposing 3rd molar crypt completely

elevator then applied to deliver the tooth

BUCCAL APPROACH VS LINGUAL APPROACH

BUCCAL APPROACH

ADVANTAGESMORE TRADITIONAL

EASY TO GET THE TOOTH

WHEN PATIENT IS CONCIOUS

NO DAMAGE TO LINGUAL PERIOSTEUM

BOTH CHISEL&BURS CAN BE USED

DISADVANTAGES

THICK BUCCAL PLATE

MORE P.O OEDEMA

INCIDENCE OF DRY SOCKET IS HIGHER

LINGUAL APPROACH

ADVANTAGES

EASIER THAN BUCCAL

LESS TIME CONSUMING

LESS P.O OEDEMA

DRY SOCKET INCIDENCE IS NEGLIGIBLE

DISADVANTAGES

DIFFICULT TECHNIQUE IN CONSIOUS PATIENT

ONLY CHISEL&MALLET TO BE USED

CHANCE OF LINGUAL NERVE INJURY

SLIIPING OF TOOTH INTO LINGUAL POUCH

COMPLICATIONS INTRAOPERATIVE DURING INCISION

facial or buccal vessel may be cutlingual nerve injury retromolar vessels

DURING BONE REMOVALdamage to second molar and roots fracture of mandiblebleeding

DURING ELEVATIONcrown fractureroot fracturefracture of the jaws slipping of tooth into lingual pouch

damage to nerveaspiration of the tooth

DURING DEBRIDEMENTdamage to inferior alveolar nerve

POSTOPERATIVE

PAIN SWELLING/EDEMA HEMATOMA BLEEDING TRISMUS INFECTION DRY SOCKET TMJ PAIN PARAESTHESIA SENSITIVITY LOSS OF VITALITY POCKET FORMATION

INCIDENCE OF NERVE INJURY

LINGUAL NERVE-0-23%

INFERIOR ALVEOLAR NERVE-0.4-8.4%

CLINICAL MANIFESTATIONS OF NERVE INJURYanaesthesia or hypoesthesia for more than 3 months

tongue , lip & cheek biting

altered mastication & taste

triggering,signs(tingling,electric sensation over the injured site that does not extend distally)

no or minimal response to instrumentation

absence in the detection of sharp, dull, moving tactile stimuli & two point discrimination

increase in hot or cold temperature threshold

CAUSES FOR LINGUAL NERVE INJURY

CLUMSY INSTRUMENTATION POOR FLAP DESIGN

FRACTURE OF LINGUAL PLATE

RAISING & RETRACTING MUCOPERIOSTEAL FLAP

VARIATION IN LINGUAL NERVE POSITION

PREVENTION OF LINGUAL NERVE DAMAGE

USE OF BROAD LINGUAL RETRACTOR

BUCCAL APPROACH WITHOUT A LINGUAL RETRACTOR SHOULD BE THE STANDARDAPPROACH

AVOIDING LINGUAL FLAP RETRACTION

USE OF SMALL 10MM MALLEABLE RETRACTOR

SPLITTING WITH BUR RATHER THAN USING LINGUAL SPLIT TECHNIQUE

MANAGEMENT OF LINGUAL NERVE DAMAGE

SURGICAL TREATMENT SHOULD BE UNDERTAKEN AFTER 3MONTHS TOLOCATE & SUTURE THE NERVE

WHILE SUTURING CARE MUST BE TAKEN TO AVOID INTERPOSITION OFNON NERVOUS TISSUE

NONOPERATIVE TREATMENT – CORTICOSTEROID

CHANCES OF NEUROMA.

CAUSES OF INFERIOR ALVEOLAR NERVE INJURY

DEEPLY PLACED IMPACTED MOLAR

MESIOANGULAR & HORIZONTAL IMPACTION

SURGICAL TECHNIQUE USING BUR

CONDITIONS FAVOURING NERVE INJURYINTERUPTION OF WHITE LINE OF CANALDEFLECTION OF ROOTDIVERSION OF CANALDARK &RIGID APEX OF ROOTNARROWING OF CANALNARROWING OF ROOT

MANDIBLE FRACTURE

• RARE

• DEEPLY IMPACTED THIRD MOLAR IN OLDER

INDIVIDUAL WITH DENSE BONE

• USE OF EXCESSIVE PRESSURE WITH ELEVATORS

• SHOULD PERFORM IMMEDIATE REDUCTION AND

FIXATION OF FRACTURE.

INJURY TO ADJACENT TEETH•DAMAGE TO FILLINGS AND ADJACENT TEETH,

• DAMAGE TO BRIDGEWORK OR TO SURROUNDING BONE CAN OCCUR DURING THE REMOVAL OF IMPACTED WISDOM TEETH.

DISPLACEMENT INTO LINGUAL POUCH

INDEX FINGER IN THE LINGUAL ASPECT

MOBILIZE THE TOOTH TOWARDS SOCKET

CAREFULLY ELEVATE THE TOOTH

TMJ PAIN

TMJ DYSFUNCTION FOLLOWING THE REMOVAL OF WISDOM TEETH IS UNUSUAL AND USUALLY TEMPORARY.

IF TREATMENT IS REQUIRED, IT IS USUALLY CONSERVATIVE IN NATURE AND INCLUDES ANTI-INFLAMMATORY MEDICINES, PHYSICAL THERAPY AND IN SOME CASES SHORT TERM BITE SPLINT THERAPY.

PAIN

USUALLY REACHES MAXIMUM DURING FIRST 12 TO

24 HOURS POSTOPERATIVELY.

NSAIDS BEFORE SURGERY MAY OR MAY NOT BE

BENEFICIAL

MOST IMPORTANT DETERMINANT OF AMOUNT OF

POST OPERATIVE PAIN IS THE LENGTH OF OPERATION.

THERE IS A STRONG CORRELATION BETWEEN POST OPERATIVE PAIN AND TRISMUS

EDEMA

USE OF CORTICOSTEROIDS.

ICE – MAY BE COMFORTING BUT HAS LITTLE EFFECT ON SIZE OF SWELLING.

SWELLING REACHES MAXIMUM BY END OF SECOND POST OPERATIVE DAY AND RESOLVED BY 5TH TO 7TH DAY.

TRISMUS

USE OF CORTICOSTEROIDS.

MINIMAL FLAP REFLECTION

CAREFUL PLACEMENT OF MOUTH PROP

LENGTH OF SURGERY

REACHES MAXIMUM BY SECOND POST OPERATIVE DAY AND RESOLVED BY END OF FIRST WEEK.

INFECTION INCIDENCE BETWEEN 2-3% 50% ARE LOCALIZED SUBPERIOSTEAL ABSCESSWHICH OCCUR 2-4 WEEKS AFTER USUALLY CAUSED BECAUSE DEBRIS UNDER THE FLAPDEBRIDEMENT AND ANTIBIOTICS.

BLEEDING

use good surgical technique, minimize trauma, avoid tears of flaps.

most effective measure to achieve hemostasis is via moist gauze pressure over wound.

application of topical thrombin on gelfoam into socket and oversuturing.

other hemostatics: oxidized cellulose (oxycel or surgicel), microfibrillar collagen(avitene).

patients with acquired or congenital coagulopathy may need blood productreplacement.

ALVEOLAR OSTEITIS (DRY SOCKET)

• INCIDENCE BETWEEN 3% AND 25%.

• INCIDENCE APPEARS HIGHER IN SMOKERS AND

FEMALES TAKING ORAL CONTRACEPTIVES.

• PATHOGENESIS NOT ABSOLUTELY DEFINED BUT MOST

LIKELY RESULT OF LYSIS OF FULLY FORMED BLOOD CLOT

BEFORE THE CLOT IS REPLACED WITH GRANULATION

TISSUE.

• THIS FIBRINOLYSIS OCCURS DURING

THE 3RD – 4TH POST OPERATED DAY

•GOAL OF TREATMENT IS RELIEF OF PAIN•IRRIGATION OF EXTRACTION SITE•PLACEMENT OF EUGENOL DRESSING•ANALGESICS•PAIN USUALLY RESOLVES WITHIN3-5 DAYS BUT UP TO 10 TO 14 DAYS

AIR EMBOLISM/ SUBCUTANEOUS EMPHYSEMA

A GAS RELATED EMBOLUS CAN BE CAUSED BY INADVERTENT INJECTION OF A

MIXTURE OF AIR AND WATER UNDER PRESSURE

WHICH THEN PASSES INTO THE MANDIBLE (JAW) TO THE VEINS AND THEN TO THE LARGE VESSELS LEADING TO THE HEART.

LARGE AMOUNTS OF AIR CAN CAUSE SERIOUS PROBLEMS INCLUDING CARDIAC ARREST AND DEATH,

BY TRAVELING TO THE LARGE VEINS LEADING TO THE HEART, AND MECHANICALLY BLOCKING THE FLOW OF BLOOD THROUGH THE HEART.

CORTICOSTERIODS

INHIBITS PROSTAGLADIN SYNTHETASE

HENCE PREVENT THE INFLAMMATORY COMPLICATIONS OF REMOVAL OF 3RD MOLAR

HENCE REDUCES SWELLING AND PAIN

ABSOLUTE CONTRAINDICATED

TUBERCULOSIS

OCULAR HERPEX SIMPLEX

ACUTE PSYCHOSIS

RELATIVE CONTRAINDICATION

EARLY PREGNANCY

NSAID

BLOCKS PROSTAGLANDIN SYNTHESIS

LOKKEN IN 1980 INDICATED PARACETOMOL THOUGH NOT A PROSTAGLANDIN SYNTETASE BLOCKER BUT CAN BE EFFECTIVE IN REDUCING PAIN IN FIRST 24 HRS

IT ACTS BY ACCELERATING THE CONVERSION OF PROSTAGLANDIN G2

A PRIME FACTOR IN OEDEMA AND PAIN

CONCLUSION

EXTRACTION OF IMPACTED THIRD MOLAR NOT ONLY INCLUDES A PROPER TECHNIQUE WITH MAXIMUM CONSIDERATION FOR COMPLICATIONS

BUT ALSO THE EVALUATION OF THE PSHYCOLOGICAL FACT OF THE PATIENT UNCERTAINITY OF THE PROCEDURE

THE COMBINATION OF BOTH PATIENT PSHYCOLOGY AND SURGEON ABILITY WILL ONLY LEAD TO A SUCCESSFUL TREATMENT