SURGICAL EXTRACTION OF THE IMPACTED

MANDIBULAR THIRD MOLAR

Presented by: SHALINI THAKUR

GUIDED BY: DR RAMDAS BALAKRISHNA

CONTENTS

INTRODUCTION HISTORY DEFINITIONS WHEN IS A TOOTH CONSIDERED IMPACTED? MOST COMMONLY IMPACTED TEETH WHY DO TEETH GET IMPACTED? ETIOLOGY OF IMPACTION (BERGER) INDICATIONS CONTAINDICATIONS CLASSIFICATIONS SURGICAL ANATOMY PREOPERATIVE ASSESSMENT WINTER’S WAR LINES WHARFE ASSESSMENT PEDERSON SCALE RELATIONSHIP OF THE THIRD MOLAR ROOT TO THE MANDIBULAR CANAL SURGICAL TECHNIQUE TECHNIQUES COMPLICATIONS OF THIRD MOLAR EXTRACTION

INTRODUCTION

The third molar is one of the last teeth to erupt into the oral cavity .

Owing to its time of eruption (17-22 yrs) it is often referred to as the wisdom tooth.

Also because of its late eruption it is the most commonly impacted tooth.

The word impaction is derived from the latin word impactus.

The surgical removal of 3rd molars has been and still is the most common operation performed by the oral and maxillofacial surgeon both in clincal practice as well as in a hospital setting.

HISTORY

Surgical extraction of teeth wasn’t always a safe, routine procedure with a generally predictable outcome as it is today

In the first half of the 20th century- In the second half of the 20th century- Growing interest in preventive dentistry

in 1950’s and 60’s.

DEFINITIONS

According to WHO – An impacted tooth is any tooth that is prevented from reaching its normal position in the mouth by tissue, bone or another tooth.

According to Archer- A tooth which is completely or partially unerupted and is positioned against another tooth, bone or soft tissue so that its further eruption is unlikely, described according to its anatomic Position .

According to Anderson-An impacted tooth is a tooth -which is prevented from completely erupting into a normal functional position due to lack of space, obstruction by another tooth or an abnormal eruption path

Malposed tooth.-A tooth, unerupted or erupted, which is in an abnormal position in the maxilla or mandible.

Unerupted tooth-A tooth which has not perforated the oral mucosa.

WHEN IS A TOOTH CONSIDERED IMPACTED?

A tooth is considered impacted if : It has failed to erupt fully within the

expected time of eruption If the angulation of the tooth is such that

its eruption into the oral cavity is unlikely When the ratio of crown to the space

available for eruption is lesser than 1

MOST COMMONLY IMPACTED TEETH

According to Archer impacted teeth occur in the following order of frequency:

Maxillary 3rd molars. Mandibular 3rd molars. Maxillary cuspids. Mandibular bicuspids. Mandibular cuspids. Maxillary bicuspids. Maxillary central incisors. Maxillary lateral incisors

WHY DO TEETH GET IMPACTED?A number of theories have been put forward to explain

why the third molars get impacted. They are:

PHYLOGENIC THEORY (Nodine)

ORTHODONTIC THEORY (Durbeck)

MENDELIAN THEORY

PATHOLOGIC THEORY

ENDOCRINAL THEORY

ETIOLOGY OF IMPACTION (BERGER)

LOCAL CAUSES Lack of Space in the Dental arch Obstruction for eruption Ankylosis Retained deciduous teeth Non absorbing alveolar bone Bony lesion Ectopic position of tooth bud Habits involving tongue,

finger,cheek,pencil,etc.

SYSTEMIC CAUSES

Prenatal causes Heredity MiscegenationPostnatal causes Rickets Anemia Congenital syphilis T.B Endocrine dysfunctions Malnutrition 

Rare conditions Cleidocranial

dysostosis Oxycephaly Progeria Achondroplasia Cleft palate  

INDICATIONS

Therapeutic indications Recurrent or severe pericoronitis Periodontal disease with a pocket depth

of 5 mm or more distal to the 2nd molar Non restorable caries in the third molar Resorption of adjacent tooth Cysts or tumours associated with the

tooth Removal of third molar in fracture line

Prophylactic indications To prevent caries, periodontitis,periodontal

disease Before orthodontic treatment Prevent cysts or tumours Prevent fracture of jaws in athletes Teeth under dentures To treat unexplained pain in the facial region To prevent systemic diseases  

Medical and surgical indications Prior to orthognathic surgery For autotransplantation of teeth When involved in tumour resection of

jaws Prior to radiation therapy Bisphosphonate therapy

CONTAINDICATIONS

  Asymptomatic and pathology free molars

totally covered in bone Compromised medical condition Extremes of age

Complications associated with retained impacted teeth:

Dental caries Pericoronal infection Pain Fascial space infections Risk of development of cysts and tumors Fractures Trismus

CLASSIFICATIONS

Winter’s classification.1926

BASED ON The position of the long axis of the impacted Mandibular third molar in relation to the long axis of the second molar. 1.      Vertical.2.      Horizontal.3.      Inverted.4.      Mesioangular.5.      Distoangular. 6.      Buccoangular.7.      Linguoangular.

According to Pell and Gregory (1933)

Relation of the tooth to ramus of mandible and 2nd molar : Class I : There is a sufficient

amount of space between the ramus and distal side of 2nd molar for the accommodation of the mesiodistal diameter of the crown of 3rd molar.

Class II : The space between the ramus and the distal side of the 2nd less than the mesiodistal diameter of the crown of 3rd molar.

Class III : All or most of the 3rd molar is located within the ramus.

B. BASED ON Relative depth of the third molar in bone.

Position A-The highest portion of the tooth is on a level with or above the occlusal plane. Position B-The highest portion of the tooth is below the occlusal plane, but above the cervical line of the second molar. Position C-The highest portion of the tooth is below the cervical line of the second molar.

 

The AAOMS published the ADA coding with explanations from the AAOMS procedural terminology, in parentheses, as follows: 07220 : (overlying) soft

tissue impaction. 07230 : partially bony

Impaction 07240 : complete bony

impaction 07241 : complete bony

impaction, with unusual surgical complications.

G.R.OGDEN METHOD

A simple method of determining the type of impaction involves comparing the distance between the roots of 3rd and 2nd molars , with the distance between the roots of the 2nd and 1st molars .

Surgical anatomy

LINGUAL NERVE INFERIOR ALVEOLAR NERVE INFERIOR ALVEOLAR VESSELS RETROMOLAR TRIANGLE RETROMANDIBULAR VESSELS TEMPORALIS TENDON INSERTION FACIAL ARTERY

The Retromolar Triangle

Behind the third molar is a depressed roughened area on the upper surface of the mandible which is bounded by the lingual and buccal crests of the alveolar ridge this is the retromolar triangle.

Lying lateral to the retromolar triangle is a shallow, hollow depression, the retromolar fossa, which is bounded by the anterior border of the ascending ramus.

This is the area into which a third molar would erupt if the usual dental arch were shrunk by abrasive and attritive foods. Spread of acute inflammatory processes may occur in any transverse plane from the retromolar triangle.

The retromolar triangle is the site for initial surgical procedures to remove the usual impacted mandibular third molars.

Retromolar canal and foramen

It is a rare anatomic variation, found In the retromolar triangle through which emerges branches of the mandibular vessels which, according to Schejtman, Devoto and Arias (1967), are distributed over the temporalis tendon, buccinator and adjacent alveolus.

Contents of this canal originates from mandibular neurovascular bundle before it enters the mandibular canal.

Anderson et al. (1991) – innervate and supply temporalis M, part of buccinator M, retromolar trigone.

Although these are small vessels a brisk hemorrhage can occur during the surgical exposure of the third molar region if the distal incision is carried up the ramus and not taken laterally towards the cheek.

Schejtmann et al.(1967) – 27% Narayana et.al – the retromolar

foramen and canal in South Indian dry mandible( Eur J anat 2002)- 24%.

Burak et.al(2006) - 23%

Inferior Alveolar Nerve and Vessels

NORTJÉ et al., 1977The mandibular canal was then

classified in 4 types: Type 1: Bilateral single high mandibular

canals - single canals either touching or within 2 mm of the apices first and second permanent molars.

Type 2: Bilateral single intermediate mandibular canals – single canals

not fulfilling the criteria for either high or low canals.

Type 3: Bilateral single low mandibular canals, single canals either

touching or within 2 mm of the cortical plate of the lower border of the mandible.

Type 4: Variations including: asymmetry, duplications and absence of mandibular canal.

Lingual Nerve

LINGUAL NERVE LIES INFERIOR & LINGUAL TO THE CREST OF LINGUAL PLATE OF MANDIBLE WITH A MEAN 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 LINGUAL PLATE

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

MRI STUDY DEMONSTRATED THAT THE NERVE IS LOCATED AT A MEAN DISTANCE OF 2.53MM MEDIAL TO AND

2.75MM BELOW ALVEOLAR CREST

Temporalis tendon attachment The temporalis muscle is a

broad, thick muscle Originates from the temporal

fossa of the skull and the deep surface of the temporal fascia.

The fibers, divided into anterior, middle, and posterior divisions, join together as they descend, passing deep to the zygomatic arch,

Insert as a tendon into the coronoid process of the mandible

Facial artery and veins

The facial artery crosses the region of 1st mandibular molar at the anterior border of the massetor

The artery can be severed accidentally during surgical procedure

Hence deep incisions in 1st molar area predispose a risk of injuring facial artery

To avoid

Pre operative assessment

Clinical assessment; History Age Mouth opening Size of mouth and tongue Postion of the mandible Flexibility of the oral musculature Physical status of the patient Palpation of external oblique ridge Existing pathology

Radiographic assessment

This can be done by using the following radiographs:

OPG IOPA OCCLUSAL LATERAL SKULL PROJECTIONS IN SPECIAL CASES CT AND MRI CAN

ALSO BE USED

WINTER’S LINES OR WAR LINES.

Wharfe’s Assessment McGregor (1985)

1. Winter’s classification Horizontal 2 Distoangular 2 Mesioangular 1 Vertical 0

2. Height of mandible 1-30mm 0 31-34mm 1 35-39mm 2

3. Angulation of 3rd molar 1-50 deg 0 60-69 1 70-79 2 80-89 3 90+ 4

4. Root shape Complex 1

Favorable curvature 2 Unfavorable curvature 3

5. Follicles Normal 0

Possibly enlarged 1 Enlarged 2

6. Path of exit Space available 0

Distal cusp covered 1 Mesial cusp covered 2 Both cusp covered 3

TOTAL 33

Pederson scale

RADIOGRAPHIC ASSESSMENT Assessment of angulations and depth Access Number and shape of roots Relation of the third molar roots to the

mandibular canal Condition of the second molar Density of the bone Bone loss Follicular size Existing pathology

Relationship to the mandibular canal

Seven radiological signs had been suggested by Howe And Payton as indicative of a close relationship between the 3rd molar and IAN canal.

Four of these signs were seen on the root of the tooth and the other three were related to changes in the appearance of the inferior alveolar canal.

RELATIONSHIP OF INFERIOR ALVEOLAR NERVE TO THE ROOTS OF THE THIRD

MOLAR.

Darkening of root Deflection of root Narrowing of root Dark & Bifid apex

Interruption of white line of canal Diversion of canal Narrowing of canal

FRANK’S TUBE SHIFT

TECHNIQUE.

RP

RP RP

DONOVAN TECHNIQUE IN OCCLUSAL RADIOGRAPHY (1952)

Howes technique to prevent inferior alveolar nerve

damage.

Archer’s technique to prevent inferior alveolar

nerve damage.

Surgical technique

There are 5 basic steps in the surgical removal of mandibular 3rd molar:

Adequate exposure Adequate access Sectioning of tooth if required Elevation of the tooth Debridement irrigation and closure

Adequate exposure

Adequate exposure of the third molar or the bone overlying it is acheived by placing a suitable incision and reflection of a full thickness mucoperiosteal flap.

There are various flaps that have been developed

Parts of incision

The incision having three parts: Limb A: The anterior incision started from

buccal sulcus approximately at the junction of posterior and middle third of the second molar, passes upwards extended upto the distobuccal angle of the second molar at the gingival margin for a distance of 1-2cm.

Limb B: It was carried along the gingival crevice of the third molar extending upto the middle of exposed distal surface of the tooth.

Limb C: Started from a point where intermediate gingival incision ended and was carried laterally towards the cheek at mucosal depth. This arm should be about 2cm long.

In case of unerupted tooth when intermediate gingival incision was not needed. Then limb' A' was extended upto the middle of the distal surface of the second molar.

Wards incision

Sir TG Ward 1968, made some modification of the incision. The anterior line of the incision runs from the distal aspect of the second molar curving ,downward and forward to the level of the apex of the distal root of the first molar. The posterior part of the incision is the same but the anterior part commences as the junction of the anterior and middle thirds of the second molar and runs down to the apex of the distal root of the first molar.

Flap designs

The different types of flaps used are:

L- shaped flap: suits only the buccal approach since it is difficult to raise a lingual flap from this approach. The posterior limb of the incision extends from a point just lateral to the ascending ramus of the mandible into the sulcus. It passes to the disto-lateral periodontium by avoiding or including it -depending upon the proximity of the third molar with the second molar .

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

Bayonet flap: This incision has three parts: distal or posterior, intermediate or gingival, and an anterior part.

Envelop flap: Extends from the mesial papilla of the mandibular first molar and passes around the neck of the teeth to the disto buccal line angle of the second molar. Now the incision line extends posteriorly and laterally upto the anterior border of the mandible. Its anterior extension is directly proportional to the depth at which the impacted tooth is present- deeper the tooth, longer the ant extension

Adv- Easier to close and heal better .

Design of disto lingually based flap by buccal Comma incision

.

-begins at a point below the second molar, smoothly curved up to meet the gingival crest at the distobuccal line angle of the second molar.

The incision is continued as a crevicular incision around the distal aspect of the second molar.

allows reflection of a distolingually based flap adequately exposing the entire third molar area.

The incision and flap design seems best suited to cases in which the third molar is completely covered with soft tissues.

In cases in which part of the impacted tooth is visible in the mouth, a small modification is made. (Joms 2002)

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 the anterior releasing incision is located 0.5 cm apical to the gingival margin of the second and first molars

GROVES AND MOORE

In the year 1970 they designed three flaps

Produced an apparent decrease in pocketing distal to 2nd molar

A collar of tissue was preserved around the 2nd molar hence decreasing pocket formation

A lingual extension of the incision allowed for exposure of the lingual aspect as well

Adequate access

Aim: To expose the crown by removing the bone

overlying it. To remove the bone obstructing the pathway for

removal of the impacted tooth. To prepare a fulcrum for support of an elevator.

This can be achieved by using chisels or bursThe amount of bone removed depends on; The depth of the tooth (amber line) Morphology of the tooth Angulation of the tooth

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

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

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

Old 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 boneCOMPLICATIONSCOMPLICATIONS

Accidental denuding 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

Accidental denuding 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

Bur technique

The size of the bur used for the removal of the bone removal : Ideal length – 7mm; diameter – 1.5mm. The bur should rotate in correct direction and at maximum

speed. Cutting instruments that induce air should’nt be used. Handpiece should not rest on the tissues of the cheek and

lips to avoid burning. The crown of the impacted tooth should be exposed (CEJ) by removal

of surrounding bone: mesially – to create a point of application Buccaly – cutting a trough or gutter around the tooth to the

root furcation. Distolingually – lingual plate should not be breached to

protect the lingual nerve.

Irrigation

The surgeons should apply a handpiece load of approximately 300g and an irrigation rate of 15 mL/min (for intermittent drip) to 24 mL/min (for continuous flow). (Sharon et al Oral Surg Oral Med Oral Pathol Oral Radiol Endod 1999)

The various solutions which can be used as irrigants are: Normal Saline Ringer’s lactate. 1% povidone iodine

The irrigation cools the bur and prevents bone-damaging heat buildup. The irrigation also increases the efficiency of the bur by washing away bone chips from the flutes of the bur and by providing a certain amount of lubrication.

A large plastic syringe with a blunt I8-gauge needle is used for irrigation purposes. The needle should be blunt and smooth so that it does not damage soft tissue, and it should be angled for more efficient direction of the irrigating stream

Chiesel vs bur

Bone belongs to the patient and the tooth belongs to the surgeon.

Pell and Gregory stated the following advantages

of splitting technique: Amount of bone to be removed is reduced. The time of operation is reduced. The field of operation is small and therefore

damage to adjacent teeth and bone is reduced. Risk of jaw fracture is reduced. Risk of damage to the inferior alveolar nerve is

reduced

Sectioning of the tooth

CRITERIA TO DECIDE IF SECTIONING OF TOOTH IS INDICATED

Sectioning of the tooth based on the type of impaction

Horizontal impactions - the crown is separated from its roots and removed first. The roots are themselves divided and removed individually into the space vacated by the crown.

Vertical impactions - the tooth is divided in half along its vertical axis and each half removed individually.

Disto-angular impactions - the tooth may be divided in half along its longitudinal axis or the crown may be sectioned from its roots with the roots being elevated into the space vacated by the crown.

Mesio-angular impactions - the tooth may be divided in half along its longitudinal axis or the crown may be divided obliquely with the distal segment removed first prior to mobilizing the rest of the tooth.

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 IRRIGATIONAFTER REMOVAL OF TOOTHAFTER REMOVAL OF TOOTH

All 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

All 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

SURGICAL TECHNIQUE

VARIOUS SURGICAL TECHNIQUES HAVE BEEN DEVELOPED FOR THE EXTRACTION OF THE THIRD MOLARS

MOORE AND GILBE’S COLLAR TECHNIQUE

SPLIT BONE TECHNIQUE BY SIR WILLIAM LESEY FRY

LATERAL TREPHINATION TECHNIQUE BY BOWDLER HENRY

MOORE/GILLBE COLLAR TECHNIQUE

The collar technique is a modificarion of the split bone rechnique designed to be used with burs (Moore 1965)

fine fissure bur(NO 702) is used to create a ‘gutter’ along the buccal side and distal surface of the tooth.

The lingual soft tissue is protected with a periosteal elevator during the removal of the distolingual spur of bone

A mesial point of application is created with the bur, and a straight elevator is used to deliver the tooth.

LINGUAL SPLIT BONE TECHNIQUE

INCISION VERTICAL STOP CUT

HORIZONTAL CUTDISTAL CUT

REMOVAL OF DISTAL & BUCCAL BONE

REMOVAL OF LINGUAL BONE CLOSURE

ELEVATION

ADVANTAGES

Faster tooth removal. Less risk of inferior alveolar nerve damage.Reduces the size of residual blood clot by means of saucerization of the socket . Decreased risk of damage to the periodontium of the second molar. Decreased risk of socket healing problems.

DRAWBACKS Risk of damage to the lingual nerve. The incidence of lingual nerve and inferior alveolar nerve damage has been reported as 1-6.6% .Increased risk of postoperative infectionPatient discomfort due to the use of a chisel and mallet for lingual bone removal or fracturing.Only suitable for young patients with elastic bone

Modified distolingual bone splitting technique

Davis's technique mentions not to separate the mucoperiosteom from lingual area of bone. The bone was released in segments to allow tactile control of osteotome to prevent penetration of the osteotome into soft tissue. More than one osteotome per impaction was usually used to ensure sharp cutting edge. Wedging the osteotome between tooth and bone should be avoided to prevent fracture of the mandible.

Lewis technique: Lewis (1980) modified the lingual split-bone technique by minimizing periosteal reflection and buccal bone removal and by preserving the fractured lingual plate. He claims that these modifications reduce the possibility of lingual nerve damage, minimize periodontal pocket formation, and improve the chances for primary wound healings.

Lateral trephenation technique

This procedure was first described by Bowdler-Henry to remove any partially formed and unerupted third molar in the age group of 9-16 years.

Modified S-shaped incision is made from retromolar fossa across the external oblique ridge. It then curves down along the reflection of the mucous membrane above the vestibule, extending up to the I molar anteriorly. Such an incision leaves behind a 5-mm cuff of attached mucosa at the distobuccal region of the II molar.

The mucoperiosteal flap is elevated and buccal cortical plate is trephined over the III molar crypt. The same bur is used to make vertical cuts anteriorly and posteriorly.

A chisel or an osteotome is applied in the vertical direction over the bur holes. Then the buccal plate is fractured out, exposing the third molar crypt completely.

Elevator is applied to deliver the tooth out of the crypt. Any follicular remnant present in the crypt is carefully scooped out, avoiding injury to the inferior alveolar (dental) canal at the lower part of the crypt.

Advantages:Partially formed unerupted 3rd molar

can be removed. Can be preformed under general or

regional anesthesia with sedation. Post-op pain is minimal. Bone healing is excellent and there is

no loss of alveolar bone around the 2nd molar.

Disadvantages : Virtually every patient has some post operative

buccal swelling for 2-3 days after surgery

COMPLICATIONS OF THIRD MOLAR SURGERY

Surgical extraction of third molars is often accompanied by pain, swelling, trismus, and general oral dysfunction during the healing phase. Careful surgical technique and scrupulous perioperative care can minimize the frequency of complications and limit their severity.

INTRAOPERATIVEDuring incision Facial or buccal vessel may be cut Lingual nerve injury Bleeding from Retromolar vessels During bone removal Damage to second molar and roots Fracture of mandible Bleeding

DURING ELEVATION Crown fracture root fracture fracture of the jaws slipping of tooth into lingual pouch damage to nerve aspiration of the tooth   DURING DEBRIDEMENT Damage to inferior alveolar nerve

Post operative complications Pain: Swelling/edema Hematoma Excessive Bleeding: Trismus: Infection: Dry socket- Paraesthesia: Sensitivity Loss of vitality Pocket formation

FRACTURE OF THE JAW The incidence of mandibular fracture during or after third molar removal has

been reported to be 0.0049% . Mandibular fracture as an intraoperative or postoperative complication after

surgical removal of the wisdom tooth is rare. HERTEL et al have reported its incidence to be 0.19%.

Injudicious use of force during removal of the tooth, a deeply impacted tooth, and osteoporosis and other metabolic bone disorders or lesions, such as cysts or tumours, increase the likelihood of fracture. The presence of an impacted tooth in a severely atrophic mandible, or infection involving the bone surrounding the tooth, may also predispose to fracture.

DAMAGE TO NERVE The incidence of lingual and IAN injuries reported ranges from 0.4% to 22%. The incidence of neurologic injuries from third molar surgery may be related

to multiple factors, including surgeon experience and proximity of the tooth relative to the IAN canal.

Horizontally impacted teeth are generally more difIicult to remove because of the increased need for bone removal and soft tissue manipulation with a higher incidence of nerve injuries.

PAIN: Pain caused by third molar surgery usually begins after the

anesthesia from the procedure subsides and reaches peak levels 6 to 12 hours postoperatively. Pain is anticipated, and the use of numerous analgesics, including nonsteroidal antiinflammatory drugs and narcotics, has been advocated for management.

SWELLING/EDEMA Surgical edema is an expected sequela of removal of impacted teeth.

Swelling usually reaches a maximum level 2 to 3 days postoperatively and should subside by 4 days and be completely resolved by 7 days . The use of ice and head elevation in the perioperative period may limit postoperative swelling and improve patient comfort . The preoperative use of systemic corticosteroids has been advocated to reduce immediate swelling, but debate still exists as to their efficacy

 

EXCESSIVE BLEEDING:

Excessive bleeding is defined as bleeding beyond that expected from the extraction or continued bleeding beyond the postoperative window for clot formation (6–12 hours).

  Excessive bleeding and hemorrhage have been reported to

occur in the range of 1% to 6% of third molar surgery. Preoperative assessment of intrinsic coagulation disorders and the use of anticoagulant and antiplatelet medications are essential. Of the predisposing risk factors reported, the most important is the level of the impaction and its proximity to the neurovascular bundle

  

TRISMUS: Trismus is often the result of surgical

trauma and is secondary to masticatory muscle and fascial inflammation. As with surgical edema, there is evidence to support the preoperative use of steroids in reducing postoperative trismus.No current agreement exists as to the most beneficial dose, type, or timing of its administration, however.

INFECTION Because of the large variety of indigenous oral flora, postoperative infection is

of concern. Although the use of aseptic technique, hemostasis, meticulous tissue management, and complete and thorough lavage of extraction sites can decrease the likelihood of postoperative infection.

The overall incidence of infection from third molar extraction has been reported to be in the range of 3% to 5%

 

Dry socket- Alveolar osteitis is one of the most common complications associated with third

molar surgery. It is characterized by a severe throbbing pain that usually begins 3 to 5 days postoperatively

According to the article in oral surgery clinics of north America volume 19 -Overall rates of alveolar osteitis vary in the literature from 1% to 30%

According to Francois Blondeau et al about 3.6% of patients reported with alveolar osteitis .1.8% of the males examined and 4.9% of the total number of females were affected showing a female predilection

PARAESTHESIA: Among the most serious and often discussed postoperative

complications that arise from third molar surgery is trigeminal nerve injury, specifically, involvement of either the inferior alveolar or lingual nerve. These nerves can be damaged as the result of direct or indirect forces. Direct injuries include those that result from anesthetic injections, crush injuries sustained during the extraction process or soft tissue management, and damage caused by the use of instruments. Indirect injuries to nerves can be the result of physiologic phenomena, including root infections, pressure from hematomas, and postsurgical edema .

According to Anwar et al in the article sensory nerve impairment following third molar surgery (JOMS 2001) Post operative lingual nerve paresthesia occurred in 2.6% of patients operated with a significant rise in incidence associated with raising of the lingual flap. The incidence of inferior alveolar nerve paresthesia was 3.9%.

Damage to adjacent teeth

The incidence of damage to adjacent tooth has been reported to be 0.3% to 0.4%.

Teeth with large restorations or carious lesions are always at risk of fracture or damage upon elevation. Correct use of surgical elevators and bone removal can help prevent this occurrence.

THERAPEUTIC AGENTS

The removal of impacted third molars involves trauma to soft and bony tissue, resulting in swelling. It is not clear why some of these surgical extractions are followed by considerable swelling, whilst others are affected to a much lesser degree.

Inflammatory response is a pre requisite for the subsequent healing process when present in the degree conducive to stimulate the process of repair. However excessive post operative edema is undesirable as it adversely affects and delays the process of healing. Therefore its control has become a subject of scientific enthusiasm

Several types of medications (antihistamines, enzymes and steroids) have been used to inhibit these post operative sequelae.

Conclusion

Surgical removal of impacted tooth is a stressful experience for many patients.. As each patient and each surgical procedure are unique , surgeons should carefully assess the risk factors of removal of impacted tooth by proper diagnosis and choose correct surgical techniques to avoid surgical complications & minimizing adverse side effects thereby making the surgical experience more favorable for patients .

BIBLIOGRAPHY

Peterson’s Principles of oral and maxillofacial surgery, 2nd edition, vol. 1.

Textbook of oral and maxillofacial surgery, vol. 2, Laskin.

Textbook of oral and maxillofacial surgery-Kruger

Oral and maxillofacial surgery-Archer Surgery of the mouth and jaws-Moore OMFS CLINICS OF NA VOLUME 19 FEB

2007