Wisdom Tooth Impaction

Wisdom Tooth Impaction
Copyright by Oral & Maxillofacial Surgery Department
UDM

1. IMPACTION

2. •Impacted teeth are those prevented from erupting by
some physical barrier in the eruption path (Shafer,1964)
•A tooth that is completely or partially un-erupted and is
positioned against another tooth, bone or soft tissue, so
that its further eruption is unlikely, described according
to its anatomical position. ( Archer, 1975)
•One that fails to erupt into the dental arch within the
expected time ( Peterson, 1993)(18-25yrs for 8s)
•A tooth that fails to erupt, for whatever reason , into the
dental arch within the expected time (Dimitroulis,1997)

3. Causes
•Local causes
-irregularity in the position and pressure of an adjacent
tooth
-density of the overlying and surrounding bone
-long continued chronic inflammation with resultant
increase in density of overlying mucous membrane
-lack of space due to under developed jaws
-unduly retention of the primary teeth
-acquired diseases such as necrosis due to infection or
abscess
- inflammatory changes in bone due to exanthomatous
diseases in children

4. Systemic causes
•Prenatal causes – heredity
•Postnatal causes – Ricket, Anemia , Congenital Syphilis ,
Tuberculosis ,
•Endocrine dysfunction , Malnutrition
•Other rare conditions – Cleidocraiodysostosis ,
Oycephaly , Progeria , Achondroplasia , Cleft palate

5. Frequency of impaction
•upper 8s
•lower 8s
•upper 3s
•lower 4s & 5s
•lower 3s
•upper 4s & 5s
•upper 1s
•upper 2s

6. •"Wisdom tooth" is a nickname for Third Molar. These are
the teeth that come into the mouth last, at age 16-21
(average 18)

7. Lower last molar
Mesioangular 43 %
Vertical 38 %
Distoangular 6 %
Horizontal 3 %

8. Indications for removal of impacted teeth
Local ;
•- Prevention of pericoronitis (operculitis)-,Ac. pericoronitis
•- Prevention of periodontal diseases
•- Prevention of infection- cellulitis , osteomyelitis
•- Prevention of dental caries
•- Prevention of damage to adjacent tooth
•- Impacted teeth under dental prosthesis
•- Prevention of odontogenic cyst & tumour -
•- Prevention of pain of unexplained origin
•- Prevention of fracture of jaw
•- Facilitation of orthodontic treatment
•- Lack of function / occlusion
General ;
•- Young – bone elasticity
•- Difficult to get treatment - Traveler to the remote area , soldier
at frontier , seamen

9. Prevention of pericoronitis
trismus, cellulitis

10. Prevention of infection , such tooth will be
problematic under the denture

11. Prevention of caries

12. Prevention of damage to adjacent tooth

13. -Removal of embedded supernumerary tooth to facilitate the
orthodontic treatment

14. - Prevention of fracture of jaw – impacted last molar weaken the
angle of the mandible

15. Contraindication
•Extreme of age - highly calcified & less flexible, post-op
sequelae, greater recovery period
•Compromised medical status – systemic diseases
•Pregnancy
•Probable excessive damage to adjacent structures – nerves ,
teeth, prosthesis of precious metal (consent)

16. Various Preoperative Difficulty Assessment Various Preoperative Difficulty Assessment
Indices Indices
WAR lines or Winter’s lines (1926)
Winter’s classification (1926)
Pell-Gregory classification (1933)
WHARFE’s scale (1985)
Pederson scale (1988)
New index by Yuasa et.al (2002)
New index by Gbotolorun et.al. (2007)
9/6/2012 16

17. Classification
•Classifying results from analysis of radiograph .
Panoramic X ray shows a more accurate picture of the
total anatomy of the region .
•Pell & Gregory - Classes I, II & III Relationship to anterior
border of the ramus
•Pell & Gregory - Classes A ,B & C Relationship to
occlusal plane of second molar , Thickness of overlying
bone

18. •Class 1 - Mesiodistal diameter of the crown is
completely anterior to anterior border of the ramus.
Mandibular third molar has sufficient room to erupt

19. •Class 2 - About half is covered by anterior portion of
ramus

20. •Class 3 - Completely within the mandibular ramus

21. •Class A - Occlusal surface of impacted tooth is at same
level as or nearly level with occlusal plane of second
molar

22. •Class B - It is between occlusal plane & cervical line of
second molar.

23. •Class C - It is below cervical line of second molar

27. Pell-Gregory Classification (1933)
27

28. Winter’s Classification (1926)
•Angulation ; the third molar could be
Vertical – long axis of the third molar parallel to the second
molar
Horizontal - long axis of the third molar perpendicular to the
second molar
Mesio-angular - long axis of the third molar inclined in mesial
direction to the second molar
Disto- angular - long axis of the third molar inclined in distal
direction to the second molar

29. Angulation assess by long axis of the teeth
•The long axis of impacted third
molar with respect to the long
axis of second molar .
•Mesioangular
•tooth is tilted toward the
second molar in mesial
direction

30. •Distoangular ; long
axis of the third
molar is distally
inclined

31. •Vertical ; long axis
of the impacted
tooth runs in the
same direction as
the long axis of the
second molar

32. •Horizontal ; horizontal
position

38. Winter's Classification
- angulation and level
•Angulation
Mesio angular
Disto angular
Horizontal
Vertical
Inverted
Buccoangular / Buccoversion
Distoangular / Distoversion
•Level
Low
High

39. •Buccal / Lingual version ; tooth angled in
buccal / lingual direction
•Transvers ; tooth absolutely horizontal position
in buccolingual direction . the occclusal surface
face either the buccal / lingual
•

41. Shiller 1979
•Angle b/t occlusal
surfaces of impacted 8s
and 2nd molar.
• Vertical
<10 degree, Horizontal >
70 degree
•
Mesiangular and
Distalangular 10 to 70
degree

42. Angulation assess by Curve of Spee
•Assessed by comparing the line
joining the mesial and distal
images of the cusps of the
wisdom tooth with the curve of
Spee formed by joining the
cusps of the premolar and
molar teeth
•If the wisdom tooth line, when
extended posteriorly would
meet the Spee line then the
tooth is mesio-obliquely
•Conversely , if the wisdom
tooth line never meet the Spee
line , then it is disto-obliquely

43. Killey, Kay Classification (1975)
•Angulation & Position
Mesio, Disto, Horiz., Vert.
Transverse displacement
Aberrant position
• State of eruption – Erupted
Partially erupted
Un erupted
• Number of root – Fused, multirooted

45. Pederson scale
(1988)
45

46. Frequency ;
•mesioangular43%
•vertical38%
•distoangular6%
•horizontal3%
•

47. Radiographic assessment of mandibular
third molars
•Diagnosis , Localisation , Treatment Plan
•Intraoral
•Periapical – Detail, less distortion
•Winter's view – Modified periapical
•Occlusal view – Oblique occlusal of R/L side of
mandible (lingual / buccal )
•Extraoral
•for lower 8s-Oblique lateral view of L + R side of mandible
•for upper 8s- Occipito mental 0· / 10· / 15· / 30· , True
lateral
•for both-Orthopantomogram (Panoramic view)
•CBCT

48. •Radiographic interpretation
The specific features that need to be identified
can be divided into those related to:
• lower third molar itself
• lower second molar
• surrounding bone
• relationship of the apices with the inferior
dental canal

49. •Lower last molar in bony crypt , crown formation only is completed

50. •Lower third molar assessment
• Pell& Gregory classification
• Angulation
• buccal or lingual obliquity
• crown
• root
.

51. •The crown
•The size
•The shape
•The presence and extent of caries
•The presence and severity of resorption
•The roots
•The number
•The shape
•Curvatures, whether they are favourable or unfavourable
•The stage of development

52. •The Lower Second molar assessment
The crown
The condition and extent of existing restorations
The presence of caries
The presence and severity of resorption.
The roots
The number
The shape, and if it is conical
The periodontal status
The condition of the apical tissues.

53. •Assessment of the surrounding bone
• Depth of the tooth
• Distal alveolar bone crest
• Bone between lower second and last molar
• Texture and density of the bone

54. •The depth of the tooth in the alveolar bone
Two main methods are used commonly to assess tooth
depth:
•Winter’s lines
•Using the roots of the second molar as a guide.

55. Winter’s Lines or WAR Lines (1926)
•(White, Amber and Red) that indicate depth of tooth in bone.

56. •Winter’s lines, in this method, three imaginary lines
( traditionally described by number or colour) are drawn on
a geometrically accurate periapical radiograph,as follows:
•The first is drawn along the occlusal surfaces of the
erupted first and second molars
•The second or amber line is drawn along the crest of the
interdental bone between the first and second molars,
extending distally along the internal oblique ridge, NOT the
external oblique ridge. This line indicates the margin of the
alveolar bone surrounding the tooth

57. •The third or red line is a perpendicular dropped from the
white line to the point of application for an elevator, but
is measured from the amber line to this point of
application. This line measures the depth of the third
molar within the mandible.
As a general rule, if the red line is 5mm or more in
length the extraction is considered sufficiently difficult
for the tooth to be removed under general anaesthetic
or using local anaesthetic and sedation

62. Using the roots of the second molar as a guide
•The roots of the adjacent second molar are divided
horizontally into thirds
•A horizontal line is then drawn from the point of application
for an elevator to the second molar
•If the point of application lies opposite the coronal , middle
or apical third the extraction is assessed as being easy ,
moderate or difficulty , respectively

64. •Depth assessment of
the impacted wisdom
tooth
•(a) superficial
•(b) intermediate
•(c) deep

65. Relationship of the apices to the ID
canal
* often appear close to the ID canal
* superimposed / intimate relationship

67. •The normal radiographic appearance of the ID canal (two
thin, parallel radioopaque lines - the so- called Tram
lines)and the variations that indicate a possible intimate
relationship.These variations include:
•Loss of the tramlines
•Narrowing of the tramlines
•A sudden change in direction of the tramlines
•A radiolucent band evident across the root if the tooth is
grooved or tunnelled through by the ID bundle.

71. Assessment of the patient –
Indication/ contraindication , Choice of
anesthesia , Treatment plan - one visit, two visit
•Age – Health condition , surgical stress,
High calcified, thick overlying bone , ankylosed ,
Recovery / healing
•Sex - Male / Female
•Occupation – Traveler, soldier, sailor – all 8s
clearance
•Type – Nervous, apprehensive, Co-operative,
Handicapped
•Others – Small mouth , fat cheek , TMJ
problem , angular stomatitis
•General conditions – Host defense (medically
compromised , immunocompromised ) , Pregnancy
(reproductive age) , R/T – ORN , unable to lie (cervical
spondilosis)

72. Clinical assessment - Treatment plan ,
Operative procedure , Timing
•History – First attack of pericoronitis , Repeated attack ,
Attempted removal , Failure of opeculectomy , Pain of unknown
etiology
•Examination –
- General – febrile/ ill
- Local - intraoral examination
No S/S
With S/S – Pain, Tenderness, Trismus, Swelling ,
Lymphadenitis, Dysphagia , Consequences of untreated
infection
•8 – condition, portion visible intra-oral , position (tally with x ray ),
function
•adjacent tooth (7) condition, caries , periodontal problem
•Opposing 8. Impinging, Buccally erupt
•Site of Injection – Pus - L.A become ionized , cannot diffuse
- Spread of infection
•Oral hygiene status – pre-op prophylaxis

73. Condition of the 8 - caries

74. Cl I , Cl A vertical impaction , soft tissue
impaction only , half of the crown can be
seen intraorally

75. Condition of adjacent tooth – cervical
caries with pulp exposure
Mesioangular last molar can be easily
removed after removal of the the poor
quality adjacent tooth

76. Extracted badly carious 7 and horizontal 8

77. Buccally erupted upper 8 traumatize the buccal soft tissue

78. Treatment Plan
- Treat Ac. condition – ? Hospitalization
- antibiotics –Emperical , mixed gm (+)& (-) and anaerobic
organisms
- analgesic
- anti inflammatory
- mouth wash antiseptic(chlorohexidine) , (hypertonic
hot saline)
- Abscess – I & D, pus for C+ S
- Trismus - mouth opening exercise
- Removal of opposing 8 impinging
- Plan for removal of lower 8 ( focal of infection )only when
Ac. condition are subsided

80. Miscellaneous assessment

•Armamentarium – Light, suction , proper instruments –
chisel , mallet , elevator etc.
•Operator – Skill, condition, time
•Assistant

81. Choice of anaesthesia
•L.A ( Bilateral Block – safe,anesthetize only sensory not motor)
•L.A + Sedation D/Z , Medazolam
- Close monitoring – BP , ECG, Pulse oximeter
- Air way protection – sedated case has reduced gag reflex
- Flumerzenil – reversal agent for D/Z
•L.A + relative analgesia ( O2 + N2O )
•G.A. (Emotional status, competence of patient ,convenience of
surgeon) , Anesthetia assessment

82. Flap
Objective;
•for adequate exposure
•reflected soft t/s (retract of mucoperiosteal flap) provides
accessible surgery
•to access the need for bone removal, create fulcrum by
window , guttering make into hollow) , ditching( trench cut).
NB; stop cut is mandatory when chiseling
•to divide tooth either by bur or chisel without excessive
bone removal
•appropriate elevation
•wound cleansed and irrigated under vision

83. Flap design for removal of wisdom tooth

86. Tooth removal
•Elective surgery – wound prophylaxis
•Simple elevation Cl. I, A, vertical , ¾ crown
•Surgical removal - open
Sectioning - bone ( widening of exit)/ tooth(reducing of
object) , bur and/ or chisel
•Germectomy – removal of developmental buds before
anchoring of the roots in the jaw ( 12-19yrs for lower 8s )

87. Tooth sectioning

88. Chisel
•Advantages – less damages to adjacent structures(buccal
approach)
•Disadvantages – tooth with shallow groove
- disturbing , only perform under GA, premadicated
- cannot perform on elderly , only in young due to high
elasticity
- chisel in line with long axis of tooth, no transverse section
- force not control(bone/ tooth – need experience)
- necessary of jaw support during tapping

89. Bur
•Advantages- familial with bur
- controlled bone removal
- transverse section possible
- fewer assistant
- no sedation
- no physical blow
- continuous wash surgical field
- less swelling & pain
•Disadvantages-emphysema
- continuous water syringing is necessary
- damage to adjacent tissue( friction)
- reassembling of tooth impossible
- bur slip

91. Bone removal by bur

93. Tooth sectioning

94. Bone removal and distal aspect of the crown
sectioning

96. Curvature of the root
Point of elevation on the convex surface

98. Wound Toilet
•saline , chlorohexdine
- inside socket , under flap
•soft tissue ( residual tooth sac , granulation tissue) inside
socket , ? biopsy –if in doubt
•tooth fragment
•bone fragment
•dislodged filling
•sharp bony edge – squeeze , file especially on lingual side

99. Closure (reposition of flap)
•reassemble all tooth pieces
before closure
•absorbable suture ( 3/0 for
oral ) is more convenient for
patient, no STO
•watertight suture is un-
necessary
•socket kept open
•no tension
•no medicated cone inside
socket

100. Flap closure

102. Maxillary Third Molar

103. Vertical impaction of the maxillary third molar

104. Distoangular impaction of the maxillary third molar

105. Mesioangular impaction of the maxillary third molar

106. A – Vertical , B – Distoangular , C – Mesioangular
impaction of maxillary third molar

107. Pell & Gregory class A,B and C of the maxillary third
molar

108. Pell & Gregory Class A

109. Pell & Gregory Class B

110. Pell & Gregory Class C

111. •Envelop flap is most commonly used flap
•When three cornered flap is reflected the bones more
apical portions become more visible

112. Canine Impaction

114. Supernumerary impaction

115. Supernumerary tooth - mesiodens

116. Embedded mesiodens + high labial frenum attachment – treatment plan
includes of removal of the mesiodens and frenectomy

117. Impacted lower 7 s

118. Complications (Mobidity)
•addition to all local complications of simple exodontia
Intraoperative;
•Haemorrhage – local inflammation
- cutting of vessel- severing of facial vessel along vertical
incision at lower first molar region upto the lower border of
mandible
•Displaced tooth – lingual pouch/periosteum, lateral pharyngeal
space, air way , antrum, infratemporal pouch in upper
•Adjacent second molar –subluxation, dislodgement of filling , prosthesis
• Subluxation / dislocation of TMJ
• Jaw fracture

119. Displaced into the lingual pouch

120. Postoperative
•Haemorrhage – Inferior alveolar , facial, buccal , usually
primary bleeding not controlled , FB (tooth fragment,
filling)
•Pain – excessive trauma , scald, abrasion , hematoma
under tight suture
•Dry socket(alveolar osteitis)
•Swelling – directly proportionate to operation time ,
hematoma , infection
• Neuroprexia, Axontemesis, Neurotemesis – lingual ,
inferior alveolar , due to hematoma, odema
• Trimus – infection , trauma
• Dysphagia
• Airway obstruction
• Pyrexia- infection

121. Factors that make the impaction surgery
•Less difficult More difficult
1. Mesioangular positionDistoangular
2. Class 1 ramus Class 3 ramus
3. Class A Depth Class C Depth
4. Roots 1/3 to 2/3 formed Long, thin roots
5. Fused conical roots Divergent curved root
6. Wide periodontal ligamentNarrow periodontal
7. Large Follicle Thin Follicle
8. Elastic Bone Dense, inelastic bone
9. Separated from second molarContact with
10. Separated from IAN Close to
11. Soft tissue impactionComplete bone impaction

122. Benefits of Difficulty Assessment
Treatment
Suitable anaesthesia
Surgical instruments
Surgical technique
Morbidity
Operation time
Referral
122

123. WHARFE's scale
(1985)
Winter’s classification →
expanded by Macgregor to
WHARFE's scale .
Based on six dental factors
Winter's classification
height of mandible
angulation of second molar
root shape and development
follicle morphology
exit path
.
123
Category Score
1. Winter's classification Vertical 0
Mesial 1
Horizontal 2
Distal 2
2. Height of mandible (mm) 01-30 mm 0
31-34 mm 1
35-39 mm 2
3. Angle of second molar (degrees) 1-59
•
0
60-69
•
1
70-79
•
2
80-89
•
3
>90
•
4
4. Root Shape and development
a)Less than 1/3 complete 2
b)1/3 to 2/3 complete 1
c)More than 2/3 complete 3
Complex 3
Unfavourable curve 2
Favourable curve 1
Normal 0
5. Follicle Normal 0
Possibly enlarged --1
Enlarged -2
Impaction relieved -3
6. Exit path Space 0
Distal cusp Covered 1
Mesial cusp Covered 2
Both covered 3
Total score

124. During operation
Operation time
Parant scale
Intraoperative findings related to radiographic variables
Surgeon’s comment
124

125. Intra-operative Assessment
Operation time
-from bone removal to tooth out or if without bone
removal from use of forceps/elevator to tooth out
-
125

126. Operative procedure (Parant scale)
•
•
126
1. Easy - I
2. Moderate- II, III
3. Difficult- IV
(Sulieman et. al, 2006)

127. Consent for the surgical removal of lower
last molar
•Discussion
•Written consent
•Documentation in the chart

128. Seven areas ;
•Specific problem
•Proposed treatment
•Anticipated or common side effects
•Possible complications and frequency of occurence
•Anaesthesia
•Treatment alternatives
•Uncertainities of the outcome