Journal Club 2018 MCPS Fam Dent, KCD Peshawar Made By: Dr Fahad Qiam

1. PRESURGICAL ASSESSMENT OF
IMPACTED MOLAR TOOTH
Presented By: DR. JAWAD TARIQ
Postgraduate Resident
MCPS Family Dentistry
1

2. WHAT IS AN IMPACTED TOOTH
 “One which is not fully erupted into the oral cavity,
usually due to a lack of space, poor positioning or the
presence of an associated pathology”
(American Association of Oral and Maxillofacial Surgeons)
2

3. COMMONLY IMPACTED TEETH
 Maxillary 3rd molars
 Mandibular 3rd molars
 Maxillary canines
 Mandibular premolars
3

4. INCIDENCE
 1-2% of the general population
 Female predilection with a 1:2 male to female ratio
 Caucasians are affected 5 times more than Asians
4

5. WHY DOES A TOOTH BECOME IMPACTED?
- Lack of space
- Obstruction by another tooth
- Abnormal path of eruption
- Cyst formation
- Developmental conditions
- Tumors
5

6. INDICATIONS FOR 3RD MOLAR REMOVAL
6
 Recurrent or severe
pericoronitis
 Periodontal disease or
pocket depth of more
than 5mm distal to the 2nd
molar
 Non-restorable caries
 Resorption of 3rd molar or
adjacent tooth
 Caries In the 2nd molar
that can be restored if the
3rd molar is removed
 Apical periodontitis
 Cysts or tumors
associated with the 3rd
molar
 For orthognathic surgery
 Tooth in fracture line
“Guidance on the extraction of wisdom teeth” by NICE 2000 and
NIH consensus Conference 1979

7. THERAPEUTIC VS PROPHYLACTIC
REMOVAL?
WHEN AND WHY TO EXTRACT AN IMPACTED 3RD MOLAR?
7

8. PROPHYLACTIC REMOVAL OF 3RD
MOLARS?
 “Aside from obvious indications for removal of impacted
teeth such as overt pathology, removal is also the preferred
option for teeth if there is insufficient anatomic space to
accommodate normal eruption, and that removal of such
impacted 3rd molar teeth at an early age is a valid and
scientifically sound treatment rationale based on medical
necessity.”
 “The management of impacted 3rd molar teeth”, American Association
of Oral and Maxillofacial Surgeons, 2007
8

9. NICE GUIDELINES MARCH 2014
 The practice of prophylactic removal of pathology-free impacted third molars
should be discontinued in the NHS.
 The standard routine programme of dental care by dental practitioners and/or
paraprofessional staff, need be no different, in general, for pathology free
impacted third molars (those requiring no additional investigations or
procedures).
 Surgical removal of impacted third molars should be limited to patients with
evidence of pathology. Such pathology includes unrestorable caries,
nontreatable pulpal and/or periapical pathology, cellulitis, abcess and
osteomyelitis, internal/external resorption of the tooth or adjacent teeth, fracture
of tooth, disease of follicle including cyst/tumour, tooth/teeth impeding surgery or
reconstructive jaw surgery, and when a tooth is involved in or within the field of
tumour resection.
 Specific attention is drawn to plaque formation and pericoronitis. Plaque
formation is a risk factor but is not in itself an indication for surgery. The degree
to which the severity or recurrence rate of pericoronitis should influence the
decision for surgical removal of a third molar remains unclear. The evidence
suggests that a first episode of pericoronitis, unless particularly severe, should
not be considered an indication for surgery. Second or subsequent episodes
should be considered the appropriate indication for surgery.
9

10. CONDITIONS WARRANTING THE
PROPHYLACTIC REMOVAL OF IMPACTED
3RD MOLARS
 Presence of 3rd molar in a fracture line
 Prior to orthognathic surgery
 Autogenous transplantation in place of 1st molar
 Involved in a tumor bearing area primed for resection
 Area being primed for radiation due to head and neck malignancies
 Chemotherapy
 Bisphosphonate therapy
 Prior to organ transplantation 10

11. HOW TO DETERMINE THE RISK FOR
EXTRACTION OF 3RD MOLAR?
11
- Preoperative Plaque index (distal to 2nd molar)
- Pre-op probing depth
Pre-op intrabony defect
- Sagital inclination of 3rd molar
- Contact area b/w 2nd and 3rd molar
- Resorption of distal root of 2nd molar
- Pathologically widened follicle
- Smoking habits
i- Visible - 0
ii- Not visible - 1
i- ≤6mm - 0
ii- >6mm - 1
i- ≤3mm - 0
ii- >3mm - 1
i- ≤50° - 0
ii- >50° - 1
i- Small contact - 0
ii- Large contact - 1
i- Yes - 0
ii- No - 1
i- No or distal - 0
ii- Mesial ≥2.5mm - 1
Non smoker - 0
Smoker - 1
Kugelberg Risk Index M3 in 1991

12. INTERPRETATION OF RISK INDEX M3
12
RISK INDEX M3
 No risk
 Low risk
 Medium risk
 High risk
INDEX SCORE
≤1
2
3
≥4
A score of 3-4 implies that a tooth is being extracted for
therapeutic purpose rather than a prophylactic one and vice versa

13. CONTRAINDICATIONS OF IMPACTED
3RD MOLAR REMOVAL
13
 3rd molar buds in young
people
 Asymptomatic and pathology
free 3rd molars that are totally
covered by bone
 Routine removal of
asymptomatic pathology free
3rd molars that are totally or
partially covered by soft tissue
 Patients whose medical
history or conditions expose
the patient to an unacceptable
risk to their overall health

14. PRESURGICAL ASSESSMENT
 Patient complaint
 Patient age
 Social history
 A full medical history
 A full dental history
 Extra-oral examination
 Intra-oral examination 14

15. COMPLETE EXAMINATION SHOULD
INCLUDE…
 Willingness and ability of patient to cooperate with care
 Eruption status of 3rd molar
 Caries and resorption in 3rd molar and adjacent teeth
 Periodontal status
 Occlusal relationship
 TMJ function
 Mouth opening
 Regional lymph nodes
 Any associated pathology
15

16. RADIOGRAPHIC EVALUATION
 Bitewing radiographs: limited value
 Periapical X-ray: Useful in localizing the position of the tooth
by the SLOB rule.
 Occlusal radiograph: Useful in confirming the position of
impacted teeth in anterior maxilla or anterior mandible
 Panoramic radiograph: Most useful image available
 3D CT scan: Most recent addition to imaging modalities
available. It can identify the exact location and position of tooth in
all 3 dimensions 16

17. 17

18. RADIOLOGICAL ASSESSMENT
18

19. APPLICATION DEPTH
 Measured as the distance from the alveolar ridge to the point
of application of the elevator on the tooth (red line)
 Length of the red line indicates the necessary vertical bone
removal to reach the application point.
 Application points for each angulation
- Vertical: mid-buccal
- Mesioangular: mesiobuccal
- Distoangular: buccal/disto-buccal
- Horizontal: buccal 19

20. ANGULATION
DISTOANGULAR
(5%)
HORIZONTAL (10%)
MESIOANGULAR
(45%)
VERTICAL (40%)
20

21. CROWN SIZE AND CONDITION
NON VITAL
CARIOUS
OR
HEAVILY
RESTORED
CROWN
WIDTH
21

22. ROOT NUMBER, MORPHOLOGY AND THE
RATIO BETWEEN INTER ROOT DISTANCE AND
CROWN ROOT JUNCTION
 If the inter root distance is greater than the mesiodistal
width of the tooth at the alveolar crest, presence of multiple
roots and if one of the roots are hooked
 The difficulty of removing the tooth will increase
 Tooth sectioning 22

23. ROOT SURFACE AREA
 It is assessed relative to the root surface area of the
adjacent 7
 If the 3rd molar has more and longer roots than the
adjacent 7, there is greater chance of subluxating
the 7 instead of the 3rd molar itself
 This demands a change in the application point on
the 3rd molar
 If the adjacent 7 is sub luxated, apply a figure of 8
suture across the tooth occlusally and give
antibiotic cover
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24. FOLLICULAR WIDTH
24
 Enlarged follicle is
considered noncystic if its
diameter is less than 1cm
 If a follicle is more than 1cm
in diameter and the
mandible is highly atrophic,
there is a predisposition for
a pathological fracture

25. ASSOCIATED PATHOLOGY
DETNIGEROUS
CYST
KERATOCYSTIC
ODONTOGENIC
TUMOR
AMELOBLASTOMA
25

26. PERIODONTAL STATUS
 Poor periodontal status of the 3rd molar will facilitate
removal
 Care must be taken while applying force if the
adjacent 7 is also periodontally compromised
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27. RESTORATIVE CONDITION OF
ADJACENT 7
27
 A heavily restored, non
vital tooth may be more
brittle and at risk for
damage during elevation
of the 3rd molar
 Patient must be warned
of possible outcomes
before hand if such a
situation is encountered.

28. PROXIMITY OF INFERIOR ALVEOLAR CANAL
AND MAXILLARY SINUS
28
 Radiographic features to be
cognizant of:
- Darkening of the root where it is
crossed by the I.D. canal
- Interruption of the white lines of the
canal
- Diversion of the I.D canal
- Distance of 2mm or less between
roots of maxillary 3rd molars and the
sinus floor (Sinus approximated
tooth)

29. 29

30. GRADING OF DIFFICULTY
 Winters classification
 Pell and Gregory classification
 Winters lines
 Pederson’s method of assessing difficulty
 Renton’s factors
 Parant Scale
 Pernambuco Index
30

31. WINTERS CLASSIFICATION
Based on the axial inclination of the impacted 3rd molar
relative to the long axis of the adjacent 7
 Mesioangular (31-60°)
 Distoangular (>90°)
 Vertical (61-90°)
 Horizontal (0-30°)
 Buccal or lingual
 Transverse
31

32. 32

33. PELL AND GREGORY CLASSIFICATION
33
 Position A
 Position B
 Position C
 Position I
 Position II
 Position III
Highest point on impacted 3rd molar is level with the
occlusal plane of the adjacent 7
Highest point on impacted 3rd molar is below the occlusal
level but above the CEJ of the adjacent 7
Highest point on impacted 3rd molar is below the CEJ of
the adjacent 7
None of the crown is in the mandibular ramus
Less than half of the crown is in the mandibular ramus
More than half of the crown is in the mandibular ramus

34. 34

35. WINTERS LINES
 Drawn on a standard radiograph with the following colours
- White line: drawn horizontally onto the occlusal surface of the
erupted molars
- Amber line: drawn from the surface of the bone on the distal
aspect of the 3rd molar to the crest of the interdental septum
b/w the 2nd and 3rd molar
- Red line: drawn perpendicularly from the amber line to the
point of applying the elevator. The length of the red line gives
an indication of the difficulty of the impaction 35

36. 36

37. LENGTH OF RED LINE VS DIFFICULTY
OF IMPACTION
37
 Less than 5mm
 More than 5mm
 9mm or more
 Tooth below the
apices of the 2nd molar
Tooth removed under L.A.
Tooth removed under
endotracheal intubation
Tooth removed under
endotracheal intubation
Tooth removed under
endotracheal intubation
With every 1mm increase in the length of the red line, the difficulty of
extracting the impaction increases 3 times

38. PEDERSON’S DIFFICULTY INDEX
(SCORING CRITERIA)
38
 Mesioangular
 Horizontal/transverse
 Vertical
 Distoangular
 Level A
 Level B
 Level C
 Class I
 Class II
 Class III
1
2
3
4
1
2
3
1
2
3
SAGITAL
RELATIONSHIP
OCCLUSAL
LEVEL
RAMUS
RELATIONSHIP

39. INTERPRETATION OF THE
PEDERSON’S INDEX
 Combined score of 3-4 Slightly difficult
 Combined score of 5-6 Moderately difficult
 Combined score of 7-10 Very difficult
39

40. RENTON’S FACTORS FOR PROLONGED
OPERATING TIME
 Depth of impaction
 Density of bone
 Age and ethnicity of patient
 Proximity to I.D canal
 Skill of the surgeon
40

41. PARANT SCALE (MODIFIED BY GARCIA ET AL)
41

42. PERNAMBUCO INDEX (DE CARVALHO AND VACONCELOS 2017)
42

43. 43