This document discusses impacted teeth, specifically impacted third molars (wisdom teeth). It begins by defining impacted teeth and listing common causes, including local factors like lack of space and systemic factors like rickets. It then discusses methods for assessing impacted teeth, including the Pell-Gregory and Winter's classifications which examine location, angulation, and depth of impaction. Common angulation types like mesioangular, vertical, and horizontal are defined. Diagnostic imaging tools for evaluating impacted teeth are also outlined. The document concludes by noting that radiographic assessment of impacted third molars is important for diagnosis, treatment planning, and identifying any relationship between the tooth roots and the inferior dental canal. Depth of impaction

1. IMPACTION
HTAY HTAY YI
UDM (Mdy.)

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
Maxillary and mandibular third molars
Maxillary canine
Mandibular premolars

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 DifficultyVarious Preoperative Difficulty
Assessment IndicesAssessment 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. 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

29. 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

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

33. Pederson scale
(1988)
33

34. Frequency ;
mesioangular 43%
vertical 38%
distoangular 6%
horizontal 3%

35. 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

36. 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
Angulation assess by Curve of Spee

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

38. 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

40. 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

42. 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)

43. 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

44. (a) Lower last molar in bony crypt , crown formation only is completed
(b) Lower last molar tooth bud before calcification
Not a Cyst
(a) (b)

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

46. 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

47. 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.

48. 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

49. 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.

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

51. 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 or white line 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

52. •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

57. 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

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

60. Distal alveolar bone crest

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

63. 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.

65. a - interruption of canal
b - diversion of the canal
(a) (b)

67. Assessment of the patient –
Indication/ contraindication , Choice of
anesthesia , Treatment plan - one visit, two
visit
Age – Health condition , surgical
stress, inconvenience ½ visit , High calcified, thick
overlying bone , ankylosed , atrophied periodontal
lig. , 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)

68. 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

69. Condition of the 8 - caries

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

71. 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

72. Extracted badly carious 7 and horizontal 8

73. Buccally erupted upper 8 traumatize the buccal soft tissue

74. Treatment Plan
- Treat Ac. condition – ? Hospitalization
- antibiotics –Emperical , mixed gm (+)& (-) and
anaerobic organisms
- analgesic
- anti inflammatory
- mouth wash antiseptic(chlorohexidine) , bland
(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

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

77. Choice of anaesthesia
L.A ( Bilateral Block – safe,anesthetize only sensory not
motor)
L.A + Sedation D/Z , Medazolam ( twice as potent as D/Z)
- Sedation; provided that standard safe guards are
applied
- 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

78. 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

79. Flap design for removal of wisdom tooth

82. 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 )

83. Tooth sectioning

84. Chisel
Advantages – less damages to adjacent
structures(buccal approach)
Disadvantages – tooth with shallow groove
- sectioning of tooth before elevation
- 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

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

87. Bone removal by bur

89. Tooth sectioning

90. Bone removal and distal aspect of the crown
sectioning

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

94. 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

95. 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

96. Flap closure

99. Maxillary Third Molar

100. Vertical impaction of the maxillary third molar

101. Distoangular impaction of the maxillary third molar

102. Mesioangular impaction of the maxillary third molar

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

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

105. Pell & Gregory Class A

106. Pell & Gregory Class B

107. Pell & Gregory Class C

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

110. Canine Impaction

112. Supernumerary impaction

113. Supernumerary tooth - mesiodens

114. 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 , GI( 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 , chorda tympani , 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 position Distoangular
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 ligament Narrow periodontal
7. Large Follicle Thin Follicle
8. Elastic Bone Dense, inelastic bone
9. Separated from second molar Contact with
10. Separated from IAN Close to
11. Soft tissue impaction Complete bone impaction

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

123. New Indices
Yuasa et al (2002) proposed a new index
 a combination of Pederson index &
measurement of width of root
Gbotolorun et al (2007) also proposed a new
index with variables of
 age
 body mass index
 depth from point of elevation
 curvature of roots.
123

124. Variables
Previous assessments - based exclusively on
radiographic variables (MacGregor,1976).
root number and morphology
tooth position
periodontal space
depth from point of elevation
second molar relation
124

125. Variables in 21st
Century
nonradiographic variables with difficulty assessment of
impacted third molar surgery (Renton et.al, 2001,
Susurla and Dodson, 2004, Akadiri and Obiechina,
2009, Cavalho and Vasconcelos, 2011).
age
gender
body mass index
mouth opening
cheek flexibility
experience of surgeon
procedure type
number of teeth extracted 125

126. Width of root
Thin - width of middle root →
thinner than width of neck
Thick - (multiple roots), width
of middle root is thicker than
width of neck & roots
separately
Bulbous - width of middle root
is thicker than width of neck
& roots do not separate
Bulbous root. A<B: the width of middle
root (B) is thicker than width of neck (A)
and roots do not separate.

127. 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
.
127
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

128. During operation
Operation time
Parant scale
Intraoperative findings related to radiographic
variables
Surgeon’s comment
128

129. Intra-operative Assessment
Operation time
- from bone removal to tooth out or if without bone
removal from use of forceps/elevator to tooth out
-
129

130. Operative procedure (Parant scale)
130
1. Easy - I
2. Moderate - II, III
3. Difficult - IV
(Sulieman et. al, 2006)

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

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