all different assessment techniques of impacted teeth

1. Presented by:
Dr. Neha Umakant
Chodankar
PG OMFS
Pre operative assessment
of Impacted teeth

2. Contents
• Introduction
• Pre operative assessment
oHistory
oClinical examination
oRadiological assessment and interpretation
• Classifications
• Difficulty index
• Basic steps in planning the surgical procedure
• Conclusion
• References

3. Introduction
Impacted tooth is 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 anatomical
position.
The goal of the surgical procedure should be removal of an impacted
tooth, with minimum or no interference with adjacent anatomic
structures and an optimal chance of uncomplicated socket healing.
To attain this a detailed preoperative assessment of the patient is
crucial.

4. Pre-operative Assessment
• HISTORY
Chief complaint
History of presenting complaint
Medical history
• EXAMINATION
Clinical
Radiographic
• DECISION
Diagnosis
Treatment planning

5. History
• Compliant : Pain, swelling, reduced mouth opening
• Previous medical history.
• Dental history.
• Pain and infection associated with partially erupted teeth.
• Incidental finding of impacted teeth following radiographic
examination.
• Occasionally, unerupted wisdom teeth, in the absence of any obvious
infection, can give rise to discomfort .
• Other possible causes of pain.

6. Extraoral:
• Signs of swelling & redness of the cheek
• Anesthesia or paresthesia of lower lip.
• Wide face/ narrow face
• Patient with massive mandible - difficult
• Small mouth / restricted mouth opening
• Mandibular retrusion / protrusion
• TMJ if hinge mainly - difficult/ gliding – easy
Clinical Examination

7. Intraoral:
• Mouth opening & any evidence of trismus
• State of eruption of tooth, signs of pericoronitis
• Condition of 1st & 2nd molars
• Elasticity of oral tissues
• Visible 3rd M crown / palpate if not visible

8. • Explore occlusal and distal surface with
a probe
• Distance between distal surface of 2nd
molar & ramus of mandible
• Palpation –
External oblique ridge

9. Palpation –
Internal oblique ridge

10. Radiographic evaluation
1. Periapical Radiographs
2. Bite wing radiography
3. Occlussal films
4. Lateral view of the mandible
5. Orthopantamogram
6. Cone Beam Computed Tomography

11. 11
Periapical radiograph
According to Winter (1926)
An ideal periapical X-ray should include
1. the whole third molar,
2. its investing bone,
3. the anterior border of ramus,
4. the inferior alveolar canal and
5. the adjacent second molar tooth.

12. 12
The specifications for an ideal IOPA radiograph (Mac GREGOR)
• The buccal and lingual cusps of the erupted second molar must be
superimposed
• The area of contact of first and second molar must not show overlap.
• The film must be far enough back in the mouth to show only the distal
root of the first molar.
• The whole third molar should be seen.
According to G.L.Howe the standard IOPA must have typical ‘enamel cap’
appearance of second molar.

13. Points to notice on radiograph –
1. Type of angulation or displacement
2. Root shape, size, pattern, number, dilaceration
3. Root pattern of 2nd molar
4. Depth of 3rd molar in bone
5. Relationship of roots to inferior dental canal
6. Density of surrounding bone
7. Amount of bone destruction distal to 3rd molar
8. Relationship to adjacent tooth

14. PERIAPICAL X-RAYS
FRANK’S TUBE SHIFT TECHNIQUE

15. Occlusal Radiography
1.To study the relation with adjoining tooth.
2.To study the configuration of the roots & status
of the crown.
3.To know the buccoversion or linguoversion of
the impacted tooth.
4.Shadow of the external oblique ridge.
If vertical & anterior to the Impacted tooth –
Poor access.
If oblique & posterior to the Impacted tooth—
Good access.

16. Evaluation of impacted canines
Parallax Technique: Two radiographs taken at different horizontal angles with
the same vertical angle.
Locates canine positioned buccally or palatally to other teeth in the arch

17. Orthopantomographs
• Identify the presence of third molars
• Locate unusual position
• Facilitate establishing their angulation
• Show the vertical relationship to the second molar
• Identify caries and dentoalveolar bone loss
• Detect the location of the IA canal
• Detect bone pathology

18. • Establish the height of the mandible
• Show the relationship of upper third molars and the maxillary sinus
• Identify the structural stability of the second molar
• Locate the relationship of root apices with dense bone
• Detect dilacerated roots

23. CBCT:
• Identifies and locates the position of impacted tooth accurately.
• We can assess any damage to adjacent tooth roots and amount of bone
surrounding each tooth.
• Exact amount of bone encasing tooth can be noted

24. Interpretation of Radiographs
A. Root morphology
a) Length of the root
b) Single/conical, separate/distinct roots are noted.
c) Curvature of roots
d) Total width of the roots in mesiodistal direction should be compared with
the width of the tooth at the cervical line.
e) Assess the periodontal ligament space.

25. B. Size of follicular sac
C. Density of the surrounding bone
D. Contact with the 2nd molar
E. Nature of overlying tissues
F. Inferior Alveolar Nerve and Vessels

26. Classification of impacted
teeth

27. ADA Classification:
Based on amount of hard & soft tissues covering coronal surface of
impacted tooth.
• Soft tissue impactions.
• Partial bony impactions
• Complete bony impactions.
• Complete bony impactions with surgical difficulties.

28. Combined ADA and AAOMS classifications :
The AAOMS published the ADA coding with explanations from the AAOMS
procedural terminology, as follows:
• 07220 : Removal of impacted tooth – (overlying) soft tissue (Impaction
that requires incision of overlying soft tissue and the removal of the
tooth).
• 07230 : Removal of impacted tooth – partially bony impacted (Impaction
that requires incision of overlying soft tissue, elevation of a flap, and
either removal of bone and tooth or sectioning and removal of tooth.

29. • 07240 : Removal of impacted tooth – completely bony (Impaction that
requires incision of overlying soft tissue, elevation of a flap, removal of
bone, and sectioning of tooth for removal).
• 07241 : Removal of impacted tooth – completely bony, with unusual
surgical complications (Impaction that requires incision of overlying soft
tissue, elevation of a flap, removal of bone, sectioning of the tooth for
removal, and/or presents unusual difficulties and circumstances.

30. Pell & Gregory’s Classification
A.Relation of the tooth to the ramus of the mandible and the second molar
CLASS I
Sufficient amount of space present between ramus and distal surface of 2nd
molar to accommodate the mesio-distal width of 3rd molar

31. CLASS II
Space between ramus and distal surface of 2nd molar less than the mesio-
distal width of the 3rd molar

32. CLASS III
All or most of the third molar is located within the ramus of the mandible.

33. B. Relative depth of the third molar in the bone.
POSITION A
Highest portion of tooth is on a level with or above occlusal line

34. POSITION B
Highest portion of 3rd molar below occlusal line but above cervical line of
2nd molar

35. POSITION C
Highest portion of 3rd molar below cervical line of 2nd molar

36. C. The position of the long axis of the impacted mandibular third molar in
relation to the long axis of the second molar (Winter’s classification)

37. • a>b : mesioangular
• a=b: vertical
• a<b: distoangular
G.R. Ogden Method

38. Superior-inferior Position Of The 3rd Molar:
• Crown to crown
• Crown to cervix
• Crown to root

39. Killey & Kay’s Classification:
a) Based on angulation and position:
b) Based on the state of eruption:
• Completely erupted
• Partially erupted
• Unerupted
• Mesioangular
• Distoangular
• Vertical
• Horizontal
• Inverted
• Buccoangular
• Linguoangular

40. c) Based on pattern of roots:
1)They may be
- Fused roots.
- Two roots.
- Multiple roots
2) Root pattern may be –
- Surgically favorable
- Surgically unfavorable

41. According To Nature Of Overlying Tissue
• Soft tissue impaction
• Partial bony impaction
• Fully bony impaction

42. Angulation classification by Quek et al (2003) :
-vertical impaction
10 to -10
-mesioangular impaction
11 to 79
-horizontal impaction
80 to 100
-distoangular impaction
-11 to -79
-others
111 to -80

43. Classification of maxillary impacted third molars
1.According to angulation

44. 2.According to depth of impaction

45. 3.The relationship of tooth to maxillary sinus :
• Sinus approximation (s.a) :

46. • No sinus approximation (n.s.a) :

47. Classification Of Impacted Canine
Class I: Palatally placed maxillary canines
a)Vertical
b)Horizontal
c)Semivertical
Class II: Labialy placed maxillary canines
Class III: Impacted cuspid located both in the palatal and labial bone
Class IV: Impacted in the alveolar process between the incisors and first premolars
Class V:impacted cuspid that are present in an edentulous maxilla

48. Radiographic assessment of impacted canines
1. Angulation of the canine long axis to the upper midline
Grade I: 0-15 degree
Grade II: 16-30 degree
Grade III: >31 degree

49. 2.Position of the canine apex relative to the adjacent teeth
Grade I: Above the region of the canine position
Grade II: Above the first premolar region
Grade III: Above the upper second premolar region

50. 3. Depth of impaction of canine relative to root of lateral incisor
• Grade 1: Below the level of the cemento-enamel junction (CEJ).
• Grade 2: Above the CEJ, but less than halfway up the root.
• Grade 3: More than half way up the root, but less than the full root length.
• Grade 4: Above the full length of the root.

51. 4. Mesiodistal position of the canine tip.
Grade 1: No horizontal overlap
Grade 2: Less than half the root width
Grade 3: More than half, but less than the whole root width
Grade 4: Complete overlap of root width or more.

52. 5.Root resorption of adjacent incisor
6.Labio-palatal position of the canine crown

53. Relationship To The Inferior Alveolar Canal
1.Related but not involving the canal
• Separated
• Adjacent
• Superimposed
2. Related to changes in the canal
• Darkening of the root
• Dark & bifid root
• Narrowing of the root
• Deflected root

54. 3. Related with changes in the canal
• Interruption of lines
• Converging canal
• Diverted canals

55. 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

56. Darkening of Root:

57. Deflected Roots:

58. Narrowing of the Root: Seward(1963)

59. Dark & Bifid root:

60. Interruption of the White Line:

61. Diversion of the Inferior Alveolar Canal:

62. Narrowing of the Inferior Alveolar Canal:

63. Radiological signs significantly related to inferior alveolar nerve injury are:
1.Darkening of the tooth root
2.Narrowing of the tooth root
3.Diversion of the canal
4.Interruption of the white line

64. Radiological signs significantly related to inferior alveolar nerve injury are:
1.Darkening of the tooth root
2.Narrowing of the tooth root
3.Diversion of the canal
4.Interruption of the white line

65. GW Bell classification
• Root of tooth more than 1mm distance from the neurovascular
bundle.
• Root of tooth just touching the upper outline of the neurovascular
bundle.
• Root of tooth superimposed on the neurovascular bundle.

66. Difficulty index

67. Factors increasing the difficulty score for removal of impacted 3rdmolars
1. Difficult access to the operative field because of
a. Small orbicularis oris muscle.
b. Inability to open mouth wide enough.
c. Trismus due to infection.
d. Oral submucous fibrosis.
e. A large tongue.
f. External oblique ridge vertical and ahead of impacted tooth.

68. 2. As per the angulation.
3. As per the depth.
4. As per the space available for the eruption.
5. Dilacerated roots.
6. Hypercementosis.
7. Extremely dense bone.
8. Proximity to mandibular canal.
9. Ankylosed impacted tooth.
10. Large bulbous crown.
11. Long slender roots.

69. Winters WAR lines
WHITE LINE: -
A line drawn along the occlusal surfaces of the 1st, 2nd & the highest point of
the third molar.

70. AMBER LINE: -
A line drawn from the bone distal to the third molar to the Interdental septum
(crest) between the 1st and the 2nd molar.

71. RED LINE: -
A line drawn from the amber line to an imaginary point of application of an
elevator.

72. 72

74. • It has been noted that for every 1 mm increase in the length of 'red' line,
extraction becomes about three times more difficult.
• As a general rule, any tooth with a 'red' line 5 mm or more is better
removed under general anaesthesia.
• If the 'red' line is 9 mm or more, the inferior surface of the crown of the
impacted third molar will be either at the level or below the apex of the
second molar.

75. Pedersons Difficulty Index
Spatial Relationship Classification Value
• Mesioangular 1
• Horizontal/transverse 2
• Vertical 3
• Distoangular 4
• Depth
• Level A: high occlusal level 1
• Level B: medium occlusal level 2
• Level C: low occlusal level 3

76. Ramus relationship / space available
• Class 1: sufficient space 1
• Class 2: reduced space 2
• Class 3: no space 3
Difficulty index
• Very difficult 7–10
• Moderately difficult 5–6
• Slightly difficult 3–4

77. WHARFE’s Assessment
1.WINTERS CLASSIFICTION
2.HEIGHT OF MANDIBLE
3.ANGULATION OF THIRD MOLAR
4.ROOT SHAPE
5.FOLLICLE
6.PATH OF EXIT
Horizontal
Distoangular
Mesioangular
Vertical
2
2
1
0
1-30mm
31-34mm
35-39mm
0
1
2
1° - 50°
60° - 69°
70° -79°
80° - 89°
90°+
0
1
2
3
4
Complex
Favourable curvature
Unfavourable curvature
1
2
3
Normal
Possibly enlarged
Enlarged
0
1
2
Space available
Distal cusp covered
Mesial cusp covered
Both cusp covered
0
1
2
3

78. Evaluation of factors: relatively easy or difficult
Factors Relatively easy Relatively difficult
1. Pell and Gregory’s classification
• Horizontal plane
• Vertical plane
Class I
Position I
Class III
Position III
2. Overlying impediment Soft tissue Bone
3. Crown Small Large
4. Roots
• Formation
• Curvature
Incomplete
Favourable
Complete
Unfavourable
5. Follicular space Large Thin and small
6. Surrounding bone Elastic and cancellous Dense or cortical
7. Relationship
• 2nd molar
• Inferior alveolar canal
Distal space
Not related
No distal space
related
8. Oral sphincter Large Small
9. Health status Satisfactory Medically compromised

79. Classification according to surgical difficulty
Carvalho et al JOMS 2011
79
Definition Classification Difficulty
Surgical
technique
1. Use of Elevator
alone
2. Ostectomy
3. Ostectomy and
tooth sectioning
Low
Moderate
High
Surgery (time
elapsed between
incision and
suturing)
1. < 15min
2. 15-30min
3. > 30min
Low
Moderate
High

80. 80
Class
Easy I Extraction requiring forceps only
Easy II Extraction requiring osteotomy
Difficult III Extraction requiring osteotomy and
coronal section
Difficult IV Complex extractions (root section)
Criteria of the modified Parant scale

81. Yuasa et al. (BJOMS 2002) difficulty scale
• Relative depth
• Relation with the ramus of the mandible
• Width of the root
Thin width of the middle of the root is thinner than the width of the neck
– removal easy.
Bulbous width of the middle root is thicker than the width of the neck-
difficult.

82. 82
Basic steps in planning operative procedure
Study the radiograph carefully
1. Classify the impaction
2. Determine that your radiograph exactly the full size, not elongated or
shortened, and actual form of tooth; also the number, size and curvature
of roots and the proximity of the roots or crown to adjacent vital structure.
3. Study the occlusal view to ascertain buccal lingual position of the tooth.
4. Carefully note the relationship of the roots to inferior alveolar canal
Assemble all the information gained from the preceding thorough
examination and then plan the operative procedure.

83. 83
5. Outline the extent of the soft tissue flaps to be used
6. Decide whether or not this impacted tooth could be removed by
a. Sectioning of the tooth
b. Combination of some bone removal and the sectioning technique.
c. Solely by the removal of surrounding bone.
7. Estimate the amount of surrounding osseous structure to be removed in
order to give adequate exposure and create space into which the
impaction can be moved into to facilitate its removal.

98. Conclusion
• Extraction of an impacted tooth will be successful only if a thorough
preoperative assessment is carried out and if the surgical protocol is
adapted to the clinical situation, ensuring that the tooth is correctly
sectioned and bone removal is minimal; this will reduce the likelihood
of infection and postoperative pain.

99. References
• Harry Archer – Oral & Maxillofacial Surg. Vol.I
• Geoffery Howe – Minor Oral Surgery.
• Peterson – Contemporary Oral & Maxillofacial Surg, 4th edi.
• Killey & Kay – The Impacted Wisdom tooth,2nd edition.
• Impacted teeth- Alling & Alling.
• Textbook of Oral & Maxillofacial surgery- Nilima Malik.
• Impaction – Korbendau and Korbendau
• Slideshare

100. Predicting degree of difficulty
• Anterior border of ramus
• Crest of alveolar bone distal to 3rd M
• Alveolar compact bone
• Pulp chamber
• Distance to mandibular canal
• Length and number of roots,
condition of root tips
• Depth of impaction
• Direction and angle of inclination
• Bone resorption in the distal region