This document provides an overview of impacted teeth. It begins with definitions of impacted teeth and describes the stages of tooth eruption. It then discusses various theories for what causes teeth to become impacted, including lack of space, heredity, and jaw size. Local and systemic causes of impactions are presented. The document outlines indications and contraindications for removal of impacted teeth and classifications of impactions. It also describes scales for assessing the difficulty of removing impacted third molars based on their angulation, depth, and relationship to surrounding structures. The role of radiography in evaluating impacted teeth is discussed.
2. CONTENT
Introduction
Definition
Eruption
Chronology
Theories of impaction
Local & systemic causes
Indication and contra indication
Classification
Difficulty index
Radiographic analysis
3. 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 perform
this procedure with minimal trauma.
When the surgeon is untrained and/or inexperienced, the incidence
of complications rises significantly
4. Definition
Latin – “impactus” – an organ or structure which because
of an abnormal mechanical condition has been prevented
from assuming its normal position.
Webster – “wedging of one part into another”
Rounds (1962)– “the condition in which a tooth is embeded
in the alveolus so that its further eruption is prevented”
5. Archer – “ a tooth which is completely or partially unerupted and is positioned
against another tooth or bone or soft tissue so that its further eruption is
unlikely” (1975)
Lytle (1979) – “ one tooth that has failed to erupt into normal functional
position beyond the time usually expected for such appearance”
Andreasen et al (1997) – “ a cessation of the eruption of a tooth caused by a
clinically or radio-graphically detectable physical barrier in the eruption path
or by an ectopic position of the tooth”
Peterson – “ A tooth is considered impacted when it has failed to fully erupt
into the oral cavity within in its expected developmental time period and can
no longer reasonably be expected to do so”
6. 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
8. 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.
9. 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.
11. Bjork (1956) – 3 factors – significant in development
of 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.
12. 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.
13. 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 position
depending on the amount of root development.
14. 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
17. 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
18. 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)
19. 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
20. 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
21. 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
22. 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
23. 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
24. 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
25. 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
26. Difficulty index
Very difficult : 7 to 10
Moderately difficult : 5 to 7
Minimally difficult : 3 to 4
27. PARANT SCALE
EASY I EXTRACTION REQUIRING FORCEPS ONLY
EASY II EXTRACTION REQUIRING OSTECTOMY
DIFFICULT III EXTRACTION REQUIRING OSTEOTOMY AND CORONAL SECTION
DIFFICULT IV COMPLEX EXTRACTION ( ROOT RESECTION)
28. Radiography of impacted mandibular teeth
Radiographic views
intraoral periapical
occlusal
orthopontamograph
lateral radiograph
Linear cross sectional tomography
A diagnostic technique for determining the buccolingual
relationship of impacted mandibular third molar and inferior
alveolar neurovascular bundle
29. 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
30. 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
31. Importance of interdental septum
Vertical
Disto-angular
32. Root pattern
Root morphology influence the degree
of difficulty of removal
limited root development – ROLLING
tooth – difficult to remove
1/3rd to 2/3rd root formation – easy to
remove
Mesiodistal width of root > crown –
need sectioning longituidinally.
Sometime multiple root may not be
visible on radiograph due to
superimposition.
33. 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”
34. 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
35. Localization of impacted third molar using radiographs
Horizontal tube shift tech
For seperating superimposed objects with vertical long
axis
For buccal / lingual localisation of impacted third molar
from roots of erupted teeth
vertical tube shift tech
For seperating horizontally oriented objects
For determining bucco-lingual position of third molar
apices that super impose the mand canal
36. 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 to
inferior alveolar
canal
37. Use of CT scan
Helps to show relationship of root apices with inferior dental canal.
Useful to predict the bone density of mandible
38. 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%)
39. 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
40. 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
41. 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
42. 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
43. Risk of Intervention: Minor transient
Sensory nerve alteration
Dry socket
Trismus
Infection
Hemorrhage
Dentoalveolar fracture
Displacement of tooth
44. Risk of Intervention: Minor Permanent
Periodontal injury
Adjacent tooth injury
TMJ injury
45. Risk of Intervention: Major
Altered sensation
Vital organ infection
Fracture of the mandible and maxillary
tuberosity
injury
46. 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
47. 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
48. Mandibular third molar
Situated at distal end of the body of the mandible
where it meets a relatively thin ramus
At this point if undue force is applied during
removal – causes fracture.
Tooth is embedded within thick buccal bone and
thin lingual bone
Sometime the thickness of lingual cortical plate –
<1mm
In such cases fractured root apices may displace to
lingual pouch
49. 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
50. Neurovascular bundle
ID canal positioned apically and slightly buccal
to the 3rd molar root
Canal encloses – IA artery, vein and nerve –
encloses within fascial sheath
Sometimes root apices may invade the superior
wall of the canal.
Forceful intrusion of root in canal may injure
vessels – profound bleeding.
When root of third molar is in direct contact
with ID canal – radiographicaly loss of lamina
dura may be seen.
51. Retromolar Triangle
Depressed roughened area – bounded by buccal &
lingual crest.
Lateral to this – retromolar fossa
Through this branches of mandibular vessels
emerges and supply temporalis tendon, buccinator
muscle & adjacent alveolus
If the distla incision is extended on ramus instead
of extending over cheek – cause injury to this
vessels – lead to brisk bleeding
Retromolar pad
Resist upward displacement of tooth – relieving
incision required through mucoperiosteum
Striping of tendinous insertion of temporalis – lead to
postoperative pain
52. 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
53. 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
54. 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
55. 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.
56. 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.
57. Bone trajectories of mandible:
“Grain” of mandible run longitudinally.
Importance lies in use of chisel for bone
removal.
Buccal horizontal cut may extend from 1st
molar till distal to 3rd molar till ramus & cause
fracture.
To prevent from such phenomenon vertical
stop cut need to be placed mesial and distal to
the 3rd molar
58. 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.
61. 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
62. 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
63. 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 from
venous 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 the
ascending ramus.
64. 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
65. ENVELOPE FLAP
EXTENDS FROM MESIAL PAPILLA OF THE 1ST
MOLAR AROUND THE NECKS OF THE TEETH
TO THE DISTOBUCCAL LINE ANGLE OF THE
2ND MOLAR
THEN EXTENDS POSTERIORLY AND
LATERALLY UP TO THE ANTERIOR BORDER
OF THE MANDIBLE
IT SHOULD NOT CONTINUE POSTRIORLY IN
A STRAIGHT LINE BECAUSE THE MANDIBLE
DIVERGE LATERALLY
EASIER TO CLOSE AND BEST HEALING
IN 1971, SZMYD DESCRIBED THIS INCISION
66. COMMA SHAPED INCISION
PROVIDES LAREG ACCESS
INDICATED IN CASE DEEP HORIZONTAL
IMPACTIONS
PERIODONTAL POCKETING DISTAL TO
2ND MOLAR IS LESS
67. 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
68. 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
69. 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
70. 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
71. 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
72. 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
73. LOW SPEED ENGINE DRIVEN DRILLS
INDICATIONS
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 BONE
COMPLICATIONS
ACCIDENTAL 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
74. 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 distobuccal
line 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
75. 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
76. SECTIONING OF THE TOOTH
IT ALLOWS PORTIONS OF THE TOOTH TO BE REMOVED SEPERATELY
DEPENDS PRIMARILY ON
ANGULATION OF THE TOOTH
UNFAVOURABLE ROOT PATTERN
TO PROTECT IMPORTANT STRUCTURES
ADVANTAGES
THE 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
77. DISADVANTAGES
IT CAN BE ACHIEVED WITH
CHISELS
DRILLS
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
78. REMOVAL OF MESIOANGULAR IMPACTED III MOLAR
TOOTH DIVISION IS NECESSARY
IF 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
79. 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,because
more distal bone has to be removed and the tooth
tends to be elevated distally and into the ramus
portion of the mandible
80. REMOVAL OF VERTICALLY IMPACTED III MOLAR
procedure of bone removal and tooth
sectioning is similar to mesioangular
impaction
tooth sectioned vertically
distal part removed first,followed by the
mesial half
it is more difficult than mesioangular
impaction because the access around 2nd
molar is less and requires more removal of
bone on the buccal and distal sides
81. 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
82. 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
83. 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
84. DEBRIDMENT AND IRRIGATION
AFTER 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
85. 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
86. Vertical stop cut
Split of Disto
lingual bone
Elevation
Horizontal cut
Removal of distal
& buccal bone
Removal of disto
lingual bone
Incision
Closure
87. 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,
88. Sagittal split ramus osteotomy
Conventionally used for orthognathic surgery.
Amin 1995, Toffanin 2003, and Jones 2004 have
advocated this technique for remiving impaction
in 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
89. 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.
90. 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 from
retromolar fossa across the external oblique ridge
then it curves down along the mucous membrane
above the vestibule extending upto 1st molar
leaving behind 5mm cuff of attached mucosa at the
distobuccal region of 2nd molar
the buccal cortical plate is trephined over 3rd molar
then vertical cuts are made anteriorly and
posteriorly
these cuts are joined and buccal plate is fractured
out
exposing 3rd molar crypt completely
elevator then applied to deliver the tooth
91. BUCCAL APPROACH VS LINGUAL APPROACH
BUCCAL APPROACH
ADVANTAGES
MORE 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
92. COMPLICATIONS INTRAOPERATIVE
DURING INCISION
facial or buccal vessel may be cut
lingual nerve injury
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
94. INCIDENCE OF NERVE INJURY
LINGUAL NERVE-0-23%
INFERIOR ALVEOLAR NERVE-0.4-8.4%
CLINICAL MANIFESTATIONS OF NERVE INJURY
anaesthesia 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
95. CAUSES FOR LINGUAL NERVE INJURY
CLUMSY INSTRUMENTATION POOR FLAP DESIGN
FRACTURE OF LINGUAL PLATE
RAISING & RETRACTING MUCOPERIOSTEAL FLAP
VARIATION IN LINGUAL NERVE POSITION
96. PREVENTION OF LINGUAL NERVE DAMAGE
USE OF BROAD LINGUAL RETRACTOR
BUCCAL APPROACH WITHOUT A LINGUAL RETRACTOR SHOULD BE THE STANDARD
APPROACH
AVOIDING LINGUAL FLAP RETRACTION
USE OF SMALL 10MM MALLEABLE RETRACTOR
SPLITTING WITH BUR RATHER THAN USING LINGUAL SPLIT TECHNIQUE
97. MANAGEMENT OF LINGUAL NERVE DAMAGE
SURGICAL TREATMENT SHOULD BE UNDERTAKEN AFTER 3MONTHS TO
LOCATE & SUTURE THE NERVE
WHILE SUTURING CARE MUST BE TAKEN TO AVOID INTERPOSITION OF
NON NERVOUS TISSUE
NONOPERATIVE TREATMENT – CORTICOSTEROID
CHANCES OF NEUROMA.
98. CAUSES OF INFERIOR ALVEOLAR NERVE INJURY
DEEPLY PLACED IMPACTED MOLAR
MESIOANGULAR & HORIZONTAL IMPACTION
SURGICAL TECHNIQUE USING BUR
CONDITIONS FAVOURING NERVE INJURY
INTERUPTION OF WHITE LINE OF CANAL
DEFLECTION OF ROOT
DIVERSION OF CANAL
DARK &RIGID APEX OF ROOT
NARROWING OF CANAL
NARROWING OF ROOT
99. 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.
100. DISPLACEMENT INTO LINGUAL POUCH
INDEX FINGER IN THE LINGUAL ASPECT
MOBILIZE THE TOOTH TOWARDS SOCKET
CAREFULLY ELEVATE THE TOOTH
101. 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.
102. 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
103. 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.
104. 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 ABSCESS
WHICH OCCUR 2-4 WEEKS AFTER
USUALLY CAUSED BECAUSE DEBRIS UNDER THE FLAP
DEBRIDEMENT AND ANTIBIOTICS.
105. 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 product
replacement.
106. 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 WITHIN
3-5 DAYS BUT UP TO 10 TO 14 DAYS
107. 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.
108. 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
109. 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
110. 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