SURGICAL EXTRACTION OF MANDIBULAR THIRD MOLAR

IMPACTION
UNDER GUIDANCE OF –
DR. SANTOSH A. N.

PRESENTER –
KSHITIJA PATIL

CONTENTS
 RELEVANT ANATOMY
 INTRODUCTION
 TERMINOLOGIES
 DEFINITIONS OF IMPACTION
 THEORIES OF IMPACTION
 ETIOLOGY
 INDICATIONS AND CONTRAINDICATIONS OF REMOVAL OF
IMPACTED TOOTH
 CLASSIFICATION OF IMPACTED THIRD MOLARS
 ASSESSMENT OF IMPACTED THIRD MOLARS
 SURGICAL PROCEDURE
 COMPLICATIONS
2

 IMPACTED MAXILLARY THIRD MOLARS
 IMPACTED MAXILLARY CUSPIDS
 REFERENCES
3

RELEVANT ANATOMY
 Unless the operator builds on that
soild foundation, he is no way better
then ‘a hewer of flesh and a drawer
of blood’.
 Hence a discussion of those
anatomic structures with which the
surgeon is concerned in the surgical
removal of mandibular third molar is
pertinent.
 The mandible consists of a
horseshoe shaped body and two flat,
broad rami. Each ramus is
surrounted by two processes,
coronoid process and condylar
process.
 The lower third molar tooth is
situated at the distal end of the body
of the mandible where it meets a
relatively thin ramus
4

 The buccal bone is predominantly
formed by the buccal cortical plate of
mandible and the external oblique ridge,
the latter being the site of insertion of
buccinator muscle.
 Reduction of the buccal plate will not
permit the same ease of surgical access
and its loss tends to weaken the
mandible.
 The external oblique ridge is a bulky
prominence in some patients and it
impedes the buccal surgical approach to
the wisdom tooth.
 The interdental bone between the
second and third molar maybe minimal
or even missing.
 In such case while using elevators
extreme care should be used not to
damage the bony and periodontal
support of second molar, lest it may lead
to periodontal pocket formation in the
post operative period. 5

 Below or alongside the roots of the
third molar is the mandibular canal.
 The canal is usually positioned
apically and slightly buccal to the
third molar roots.
 However a variation from the usual
position is not infrequent.
 The canal encloses the
neurovascular bundle.
 The neurovascular bundle contains
the inferior alveolar artery, vein and
nerve enclosed in a fascial sheath.
 Since the calcification of the
mandibular canal is completed
before formation of the roots of
third molar, the growing roots may
impinge on the canal causing its
deflection.
6

 Occasionally roots are indented by the mandibular canal, and
rarely penetration of the roots of the wisdom tooth by this
structure may occur. In the latter case, the neurovascular bundle
will be torn during extraction of the tooth.
 Sometimes the apices may reach the superior wall of the canal
and protrude into it
 In such cases attempted elevation of a small fractured root tip
may displace it into the mandibular canal.
 Furthermore, penetration of mandibular canal by instruments or
forceful intrusion of third molar roots may injure the artery or the
vein resulting in profuse bleeding.
 From its start at the mandibular foramen, the canal and its
contents are surrounded by a thin layer of bone with a
configuration similar to lamina dura and this is radiographically
detectable.
 In cases where the roots of the third molar are in direct contact
with the neurovascular bundle, the lamina dura may be partially
or totally absent. Hence, the radiographic evaluation of the
relationship of the mandibular canal and roots of the third molar
forms an important part of the preoperative assessment.
7

CLASSIFICATION OF INFERIOR ALVEOLAR NERVE
NORTJE et al.,1977
 Type I:
 Bilaterally single high mandibular canals-single high canals either touching or
within 2 mm of the apices of 1st and 2nd permanent molars.
 Type II:
 Bilaterally single intermediate canals-single canals not fulfilling the criteria for
either high or low canals
 Type III:
 Bilateral single low canals-single canals either touching or within 2mm of the
cortical plate of the lower border of the mandible
 Type IV:
 Variations including- asymmetry, duplications and absence of mandibular canals
8

LINGUAL NERVE
 The lingual nerve (LN) is one of
the two terminal branches of
the posterior division of the
mandibular nerve.
 It supplies the general
sensation to the mucosa of the
anterior two-thirds of the
tongue, the sublingual mucosa,
the mandibular lingual gingiva
and the floor of the mouth
 The chorda tympani nerve, a
branch of the facial nerve joins
this nerve carrying taste fibers
from the anterior two third of
the tongue and
parasympathetic fibers to the
submandibular ganglion 10

RETROMOLAR TRIANGLE
 The retromolar
triangle, retromolar fossa
, retromolar space
or retromolar gap is a
space at the rear of a
mandible, between the
back of the last molar and
the anterior edge of the
ascending ramus where it
crosses the alveolar
margin.
13

Most prevalent types of retromolar triangles,according to Suazo et
al.,2007
A.Drop form 9.16% B. tapering form 10.83%;
C. Triangular form 80%.
14

RETROMOLAR FORAMEN AND CANAL
 The retromolar foramina (RMF)
and the retromolar canal (RMC)
are anatomic variants in the
mandible located distally to the
last molar.
 The RMF is located posteriorly
to the last molar in the
retromolar trigone, which is
bounded
 anteriorly by the third molar,
 medially by the temporal crest,
 laterally by the anterior border
of the ramus
15

The nerve that runs through the RMC
might arise from the early accessory
branches of the inferior alveolar nerve
(IAN) or long buccal nerve.This area is
commonly invaded during
mandibular third molar surgery,
autologous bone harvesting, and
sagittal split osteotomy.
The most common variation of the
RMC is a branch of the mandibular
canal below the third molar.The
nerve travels in a posterosuperior
direction and opens in the retromolar
fossa those posterior to the third
molar
Clinical significance –
Mucoperiosteal flap elevation
Insufficient anesthesia
Autologous bone graft
16

MUSCLES
 TEMPORALIS
 BUCCINATOR
 MASSETER
 MEDIAL
PTERYGOID
 MYLOHYOID
17

 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.
18

INTRODUCTION
Origin Latin - Impactus -
Cessation of eruption
caused by physical
barrier / ectopic eruption.
"IMPINGO", "IN" and
Pingo or strike.
20

 Heironymous cardus -Dens sensus et sapientia et
intellectus.
 Dens serotinus – lateness 21

 Allen (1685) - wisdom tooth
 John Tomes (1848)- extraction of second molar reduced
incidence of impaction
 Steele (1895)- proposed grinding of distal surface of second
molar
 Novitsky (1890)- first to raise the flap and remove bone
 Edmund Kells (1918)- tooth sectioning
 Winter (1926)- introduced the use of chisel
 Killey (1971)- introduced buccal flap approach
 Warwick James (1936)- lingual approach
22

 Kelsey Fry and Ward- lingual split technique
 Hellman (1936)- females were twice as likely to
have impaction as males
23

3 stages of prophylatic removal of 3rd molar
Enucleation and germectomy (Henry &Morant 1936)and (Ricketts 1972)
 Around 9 yrs
 Just before calcification of cusps
Lateral trepanation
 Just before crown is fully formed
 Crown ½ calcified roots 1/3 completed
 Inclination of occlusal surface of 3rd molar > 30 degree long axis of 2nd molar
Adult surgery
 2/3 root developed
 Before roots develop curved apices or inferior dental canal is encroached
24

GERMECTOMY
Germectomy is curettage at the
germ stage of tooth development
or removal at the initial stages
of calcification when it is
possible to predict a deficient
eruption space for mandibular
third molars. Tooth germ- near bone surface- simple
extraction- minimal surgical invasion- 7-11 yrs
25

Can the possibility of mandibular third molar impaction be
diagnosed at the germ stage?
 Dr. R.M Ricketts- possible to predict with a high degree of
accuracy and more than 10 years in advance whether a
third molar will erupt or be impacted at the time growth
has terminated.
 Dr. P. Turley stated that the distance from the xi point to
the distal region of second molar was the most important
key. He showed a probability curve between the predicted
values 10 yrs prior to growth completion 90% reliability
26

TERMINOLOGIES
 ERUPTION- defined as the movement of tooth from its
developmental position within the jaw toward the functional
position within the occlusion.
 PRIMARY RETENTION- defined as a cessation of eruption
before gingival emergence without a recognizable physical
barrier in the eruption path and ectopic position.
 SECONDARY RETENTION- is related to the cessation of
eruption of a tooth after emergence without physical barrier in
its path or ectopic position of a tooth.
28

ANKYLOSED TOOTH- when the cementum of
the tooth is fused to the bone and there is no
periodontal soft tissue in between.
MALPOSED TOOTH- a tooth, unerupted or
erupted that is in abnormal position in the
maxilla or mandible
29

DEFINITION -
Any tooth that is prevented from reaching its
normal position in the mouth by tissue or bone
or other tooth.
-WHO
30

A tooth that has failed to erupt into the oral cavity to
its functional level of occlusion, beyond the time
usually expected for that tooth to erupt and is
prevented by adjacent hard or soft tissue including
overlying teeth or dense soft tissue.
-LYTLE 1979
31

A tooth is considered impacted when it has
failed to fully erupt into the oral cavity
within its expected developmental time
period and can no longer reasonably be
expected to do so.
- PETERSON
32

Impaction is defined as a cessation of the tooth
eruption caused by a clinically or
radiographically detectable physical barrier
in the path or by an ectopic position of tooth.
-ANDERSON
33

A tooth which is completely or partially
unerupted and is positioned against another
tooth ,bone, soft tissue so that its further
eruption is unlikely, described according to
its anatomic position.
-ORAL SURGERY GLOSSARY ,
CHICAGO, AMERICAN SOCIETY OF
ORAL SURGEONS.
34

A tooth which is completely or partially
unerupted and it is positioned against
another tooth,bone or soft tissue, so that its
further eruption is unlikely ,described
according to its anatomic position.
-ARCHER
35

TWO HYPOTHESIS
Nature and Nurture Hypothesis:
John hunter (1771)- stated that as the successive
teeth erupt the jaws grow to make room for
them. If the jaws are not big enough then there
will not be room for all teeth, and last to erupt
will become misplaced.
36

Darwin (1881)-he had previously noted that the posterior dental
portion of the jaws always shortened in more civilized races of
man and Darwin attributed this to “civilized mans habitually
feeding on soft cooked food”
37

THEORIES OF IMPACTION
(DURBECK)
PHYLOGENIC THEORY: Nature tries to eliminate the
disused organs i.e., use makes the organ
develop better, disuse causes slow regression of
organ.
[More-functional masticatory force – better the
development of the jaw]
The changing nutritional habits of our civilization have practically
eliminated need for large powerful jaws, thus, over centuries the mandible
and maxilla decreased in size leaving insufficient room for third molars.
38

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.
Pathological theory:
Chronic infections affecting an individual may bring the condensation of
osseous tissue further preventing the growth and development of the jaws.
Endocrinal theory:
Increase or decrease in growth hormone secretion may affect the size of the
jaws
39

Orthodontic theory :
Jaws develop in downward and forward direction. Growth of the jaw
and movement of teeth occurs in forward direction 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.
Causes for increased density of bone
a) Acute infection b) Local inflammation of PDL c)
Malocclusion d) trauma e) Early loss of primary teeth – arrested
growth of the jaw.
40

DEVELOPMENT OF THIRD
MOLARS
 7-8 yrs: initiation of tooth bud formation
 9 yrs: tooth germ visible in the radiograph
 11 yrs: completion of cusp mineralisation- anterior
border of ramus
 14 yrs: crown development completed
 16 yrs: approx. 50% root developed
 18 yrs: root development completed
 20- 24 yrs: 95% of lower third molars erupt 41

 BELFAST STUDY GROUP proposed that there
may be differential root growth between the
mesial and distal roots of the mandibular third
molar, which causes the tooth to either remain
mesially inclined or rotate to a vertical position
depending on the amount of root development.
 Underdevelopment of mesial root- mesioangular
impaction
 Overdevelopment of mesial root- distoangular
impaction
43

ETIOLOGY OF IMPACTION
(BERGER)
Local causes:
 Irregularity in the position and pressure of an adjacent tooth.
 The density of overlying or surrounding bone.
 Long continued chronic inflammation with the resultant
increase in density of the overlying mucous membrane.
 Lack of space due to under develop jaws.
 Prolong retention of the primary teeth.
 Premature loss of primary teeth.
44

 Acquired diseases – such as necrosis due to infection or
abscess
 Ectopic position
 Inflammatory changes in the bone due to exenthematous
diseases in children
 Abnormal path of eruption
 Inadequate space
 Adverse skeletal growth
 Obstructions- ankylosed tooth, gingival fibromatosis
 Increased crown size of impactus
45

SYSTEMIC CAUSES:
a) Prenatal causes – Hereditary
Miscegenation
b) Post natal causes – All the conditions that may interfere with development
of child.
- Rickets
- Anaemia
- Congenital syphilis
- Tuberculosis
- Endocrinal dysfunction
c) Rare conditions
- Cleidocranial dysostosis -Oxycephaly
- Progeria -Achondroplasia -Cleft palate 46

PATHOLOGY OF IMPACTED
TOOTH
Clinical problems associated with erupting tooth
 Pericoronitis
 Eruption cyst/ hematoma/ sequestrum
 Ankylosed tooth
 Root resorption
Solitary well defined radiolucency (not tooth associated)
 Early developing tooth
 Primordial cyst
 Focal osteoporotic bone defect
47

Small (0.05 cm) unilocular pericoronal radiolucency
 Dental follicle & hyperplastic dental follicle
Larger unilocular pericoronal radiolucency
 Dentigerous cyst
 Unicystic ameloblastoma
Multilocular radiolucency
 OKC
 Ameloblastoma
 Ameloblastic fibroma
 Odontogenic myxoma
48

Pericoronal radiolucency with radioopacities
 Calcifying Odontogenic Cyst (Gorlin cyst)
 Calcifying Epithelial Odontogenic Tumor (CEOT)
 Adenomatoid Odontogenic Tumor (AOT)
 Ameloblastic fibro- odontoma
Radiolucency with malignant features
 Odontogenic cyst malignancy
 Mucoepidermoid carcinoma
 Malignant odontogenic tumor
49

Radiopaque mass
 Condensing osteitis (Chronic Focal
Sclerosing Osteomyelitis)
 Odontoma
 Supernumerary teeth
50

INDICATIONS
PAIN
• Inflammation
• Food lodgement
• Trauma to adjacent mucosa
• Pressure on adjacent tooth
• Rule out MPDS& TMDs
51

PERICORONITIS
• Transient inflammation of gingiva and
periodontal tissues associated with normal
eruption of any tooth.
• Infection/ abscess/ cellulitis
52

UNRESTORABLE DENTAL CARIES
• Inability to effectively clean the area
• Inaccessibility
53

PATHOLOGIES/ PREVENTION OF CYSTS
AND TUMORS
54
RISK OF CYST & TUMOR
DEVELOPMENT:
•Most common age : 20- 25
years.
•Incidence of cyst formation-
2.31% (Guven et al,2000)
•Incidence of dentigerous cyst-
1.6% (Keith,1973)
•Incidence of ameloblastoma –
0.14- 2% (Shear,1978)
•Risk of surgical morbidity
increases with age

ORTHODONTIC CONSIDERATION
 Crowding of mandibular incisors
 Obstruction of orthodontic treatment
 Interference with orthognathic surgery
55

ROOT RESORPTION OF ADJACENT TEETH
56

TEETH UNDER DENTAL PROSTHESIS
58

Autologous tooth transplantation to
replace molars lost in patients with
juvenile periodontitis
 A method is described to replace periodontally destroyed first
molars in patients with juvenile periodontitis by auto-
transplantation of third molars.
 Fifteen molars which had been extracted due to periodontal
destruction were replaced by autologous third molars with
incomplete root formation.
 The patients were then observed for a period up to 7 years. In all
cases complete regeneration of the alveolar bone took place and
radiographically a normal periodontal membrane was established.
 All of the transplanted teeth continued their root formation and
there was no radiographic evidence for root resorption, ankylosis
or necrosis of the pulp.
 None of the transplanted teeth displayed pocket depths over 3
mm and no abnormal mobility was detectable.
 ( Authors - Borring Moller & frandsenA. )
60

Surgical Guidelines for
Extractions Prior to Head & Neck
Radiation Therapy
 Perform adequate alveoloplasty with
extractions to eliminate sharp bony
projections, tori and to make the
patient “denture ready”.
 Achieve primary closure, if possible.
Do not stretch the mucosal tissue
beyond its physiologic limits.
 It may be advisable to place the
patient on prophylactic antibiotics
for one week after extraction to
reduce the risk of infection.
 Allow a minimum of 14-21 days of
healing prior to the initiation of
radiation therapy.
63

 If the radiation dose to the bone of the
mandible and maxilla is less than 5000cGy,
then according to the literature and our
experience, there should be minimal risk of
osteonecrosis after radiotherapy.

 The radiation oncologist must give this
information to the dentist prior to the
initiation of head and neck radiation.
64

TOOTH IN THE LINE OF FRACTURE
65

1. Intact teeth in the fracture line should be left in situ if they
shown no evidence of severe loosening or inflammatory change
2. Impacted molars, especially complete bony impactions,
should be left in place to provide a larger repositioning surface.
Exceptions are partially erupted molars with pericoronitis or
those associated with follicular cyst
3.Teeth that prevent reduction of fractures should be removed
4.Teeth with crown fractures may be retained provided that
emergency endodontic therapy is carried out. All teeth with
fractured roots must be removed
66

5.Teeth with exposed root apices, or where the fracture
line follows the root surface from the apical region to the
gingival margin, should be carefully monitored
6.Teeth that appear nonvital at the time of injury should
be retained
7.The timing of the fracture treatment should be a factor
in the decision to extract the tooth. Complication will be
an exception when fracture reduction and adequate
fixation is instituted as soon as possible
8. Primary extraction is recommended when extensive
damage to the periodontium and supporting alveolus has occurred
67

CONTRAINDICATIONS
1. Extreme of age
2. Compromised medical status
3. Probable excessive damage to adjacent structure
(unfavorable risk /benefit ratio)
4. Third molars needed as abutments
69

Absolute contraindications
 Acute pericoronitis
 Acute necrotising ulcerative gingivitis
 Haemangioma
 Thyrotoxicosis
70

ORDER OF IMPACTED TEETH
(ARCHER)
 Maxillary third molar
 Mandibular third molar
 Maxillary cuspids
 Mandibular bicuspids
 Supernumerary tooth
 Maxillary bicuspids
 Mandibular cuspids
 Maxillary central incisors
 Maxillary lateral incisors
71

CLINICAL FEATURES
 Mobility of adjacent teeth
 Unexplained TMJ pain
 Crowding of lower anterior teeth
 Trismus
 Bulge distal to second molar
 Distal proximal caries on second molar
 Operculitis
 Pericoronitis
72

CLASSIFICATION OF
IMPACTED THIRD MOLAR
WINTER’S CLASSIFICATION (1926)
 According to the position of the impacted third molar to the long
axis of second molar
 Mesioangular
 Horizontal
 Vertical
 Distoangular
 These may occur simultaneously in:
 Buccal version
 Lingual version
 Torsoversion
73

MODIFIED WINTERS CLASSIFICATION
 Vertical impaction (10° to -10°)
 Mesioangular impaction(11° to 79°)
 Horizontal impaction (80° to 100°)
 Distoangular impaction ( -11° to -79°)
 Others (111° to -80°)
 Buccolingual impaction (any tooth oriented in a buccolingual
direction with crown overlapping the roots)
Sadeta Šeèiæ et al. Journal of Health Sciences 2013;3(2):151-
158
74

CLASSIFICATION BY ARCHER (1975) AND
KRUGER (1984)
Based on angulation of 3rd molar
 Mesioangular
 Distoangular
 Vertical
 Horizontal
 Buccoangular
 Lingoangular
 Inverted
75

BASED ON NATURE OF OVER LYING
TISSUE
According to contemporary oral and
maxillofacial surgery-Peterson
The three types of impactions are:
(1) Soft tissue impaction
(2) Partial bony impaction
(3) Full bony impaction
76

PELL & GREGORIES
CLASSIFICATION
78

COMBINED ADA & AAOMS CLASSIFICATION
07220- Soft tissue impaction that requires incision of
overlying soft tissue and the removal of the tooth.
07230- Partially bony impaction that requires
incision of overlying soft tissue, elevation of a flap,
and either removal of bone and the tooth or
sectioning and removal of tooth.
80

07240- Complete bony impaction that requires
incision of overlying soft tissue, elevation of a flap,
removal of bone, and sectioning of tooth for
removal
07241- Complete bony impaction with unusual
surgical complication 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.
81

KILLEY & KAY'S CLASSIFICATION
Based on angulation and position
 Vertical
 Mesioangular
 Distoangular
 Horizontal
 Transverse
 Buccoangular
 Linguoangular
 Inverted
 Aberrant positions
83

Based on state of eruption
Erupted
Partially erupted
Unerupted
Soft tissue impaction
Complete bony impaction
Based on number of roots
Unfavorable impaction-
 Mesial curvature of roots
 Multiple roots
Favorable impaction-
 Fused roots
 Distal curvature of roots
84

Angulation of the third molar according to
MA’AITAAND ALWRIKAT
It refers to the angle formed between dental
long axis and occlusal plane:
Horizontal <20°
 Mesioangular = 20-80°,
Vertical = 80-100°;
Distoangular ≥ 100°
85

PRE- OPERATIVEASSESSMENT
CLINICAL ASSESSMENT
General assessment
 Age/ Gender
 Medical history
 Previous dental history
 General physical examination
86

Extra oral examination
 Head shape
 Facial form & profile
 Ramus flare
 Cheek bulk
 Swelling
 Sinus/ fistula
 Trismus
87

Intra oral examination
 Soft tissues
 Size of rima oris
 Tongue size
 Extensibility of lips & cheeks
 Soft tissue trauma
 Hard tissues
 Dentition status
88

Assessment of impacted teeth
Status of eruption
Periodontal status
External and internal oblique ridge
Relationship with adjacent teeth
Pericoronal tissues
Occlusal relationship with opposing tooth
89

RADIOGRAPHIC INVESTIGATIONS
 A good radiograph helps to plan out the surgical procedure,
rule out and pathologies like cystic changes & also helps to
visualize the proximity of vital structures.
 Routine radiographs include:
1. Intraoral –IOPAR, Bite wing , Occlusal radiograph
2. Extra oral –OPG, Lateral cephelometric
3. Digital imaging –CT, CBCT
90

INTRA ORAL RADIOGRAPHS
Intra oral periapical radiographs
 Bisecting angle technique
 X- ray film stabilized against the teeth and
supporting lingual alveolar mucosa
 Principle-
91

 PARALLELING TECHNIQUE
 Film positioned medial and parallel to long axis of
target tooth
 Impacted teeth can be imaged relative to the apices
of the adjacent teeth, interproximal alveolar crests,
contact areas, surrounding bone
 In the maxilla assess an impacted tooth in the
tuberosity relative to the crown, root and apices of
the first and second molars
 Best anatomical, distortion free radiographs
92

EXTRAORAL RADIOGRAPHS
 Panoramic radiographs
 Lateral cephalometric skull projection
 Lateral oblique view of mandible
Indications
 Restricted mouth opening
 Impacted tooth in aberrant position
 Rule out pathology
 Study the relationship to inferior alveolar nerve, inferior border of mandible 95

Specialized techniques
 COMPUTED
TOMOGRAPHY
 Impacted tooth in ectopic
position – distant from oral
cavity
 Associated with neoplastic or
inflammatory process with
morbidity in contigious tissues
96

Cone beam computed
tomography
97

RADIOGRAPHIC ASSESSMENT
1. State of eruption of level of tooth
2. Angulation of tooth
3. Relationship with second molar
4. Distance between ascending ramus and distal surface of
second molar
5. Condition of second molar and impacted tooth
6. The existing pathology
7. Root shape
8. Bone removal to permit application of elevators
9. Bone density
10. The relationship with inferior alveolar canal
11. WHARFE assessment with OPG
12. WAR lines/winters lines with IOPA 98

RADIOGRAPHIC FEATURES
 Follicular changes- widening of follicular space- cyst
formation.
 Resorption cavities in few affected tooth in the crown region.
 Disappearance of follicle and replacement with the bone-
ankylosis
 Pulpal changes- none
 Mesial and distal inclination of the tooth.
 Buccal placement- tooth is clearly seen without over lapping of
the adjacent tooth
 Lingual placement- crown is overlapped by the adjacent tooth.
99

IDEAL IOPA RADIOGRAPH (WINTER)
 The buccal and lingual cusps of erupted second molar
should be superimposed.
 The area of contact of first and
Second molar must not overlap.
 The film must be kept back in the
mouth that shows only the distal root of the first molar.
 The whole third molar should be seen.
 The objects closest to the film were represented in greater
detail.
100

WHARFE ASSESSMENT by McGregor (1985)
Category Score
1. Winters classification Horizontal
Distoangular
Mesioangular
Vertical
2
2
1
0
2. Height of mandible 1-30mm
31-34mm
35-39mm
0
1
2
3. Angulation of 2nd molar 1° - 59°
60° - 69°
70° -79°
80° - 89°
90°+
0
1
2
3
4
4. Root shape Complex
Favourable curvature
Unfavourable curvature
3
1
2
5. Follicles Normal
Possibly enlarged
Enlarged
Impaction relieved
0
-1
-2
-3
6. Path of exit Space available
Distal cusp covered
Mesial cusp covered
Both cusp covered
0
1
2
3
101

LIMITATIONS
1. Bizarre impactions & Impactions in edentulous
jaws are not considered
2. Complete range of manifestations is not taken into
account , e. g. Follicle can be obliterated by
resorption of crown and would make the tooth
extremely difficult for removal
3. Extremely difficult teeth those with florid root
shapes are extremes, which are not included
4. An appearent short coming of this method is that
details of surgical technique are not related to
radiological features
102

Winter’s war lines
 White line: Line joining the occlusal
surfaces/highest cusps tips of all erupted
molars, extending up to the ramus. It
indicates the difference in occlusal level of
second and third molars.
104

 Amber line: Represents the bone level distal
to the 3rd molar, extended anteriorly along
the crest of interdental septum. This line
denotes the alveolar bone covering the
impacted tooth and the portion of the tooth
not covered.
105

 Red Line: Drawn perpendicular from
Amber line to the imaginary point of
application of elevator on the 3rd molar. It
indicates the amount of bone that will have
to be removed before elevation i.e. the depth
of the tooth in bone and the difficulty
encountered in removing the tooth
106
According to Howe : with 1 mm
increase in length of red line,
difficulty increases by 3 times
By this if red line 5mm  L.A
> 5mm  G.A

Factors that Make Surgery Less Difficult:
1. Mesioangular impaction
2. Class 1 ramus
3. Position A
4. Roots 1/3 – 2/3 formed
5. Fused conical roots
6. Wide periodontal ligament
7. Large follicle
8. Elastic bone
9. Separated from 2nd molar
10. Separated from IDN
11. Soft tissue impaction
107

Factors that Make Surgery More Difficult:
1. Distoangular impaction
2. Class 3 ramus
3. Position C
4. Long thin roots
5. Divergent curved roots
6. Narrow periodontal ligament
7. Thin follicle
8. Dense, inelastic bone
9. Contact with 2nd molar
10. Close to IDN
11. Complete bony impaction
108

Surgical procedure
The surgical procedure for the extraction of impacted teeth
includes the following steps:
1. Asepsis and isolation
2. Local anesthesia/ general anesthesia
3. Incision—flap design
4. Reflection of mucoperiosteal flap
5. Bone removal
6. Sectioning (division) of tooth
7. Elevation and tooth removal
8. Debridement and smoothening of bone
10. Closure—suturing
110

ISOLATIONANDASEPSIS
SCRUBBING
• Cetrimide+ absolute alcohol
• Cetrimide+povidone iodine
• Cetrimide+abs.Alcohol+chlorhexidine
CLEANING
• Normal saline
• Alcohol- spirit
PAINTING
• Povidone iodine (5% skin, 1% oral mucosa)
• Chlorhexidine (7.5% skin, 0.2% oral cavity)
112

ANESTHESIA
Choice of anesthesia
Apprehension level
The patient’s acceptance of the procedure
The length and technical difficulty of the
procedure
Patient’s preference and risk to benefit ratio
113

Indications for general anesthesia
Fear of pain during the procedure
Emotionally unstable patient
Anticipated lengthy procedures
Removal of all four impacted molars in one sitting
Uncooperative patients
Allergy to LA
Tooth in aberrant position
114

INCISIONAND FLAPDESIGN
Incision – A cut or surgical wound deliberately
made over skin or mucosal surface for adequate
surgical access that can be approximated properly.
Flap –According to Peterson the term flap
indicates a section of soft tissue that
 is outlined by a surgical incision,
 carries its own blood supply,
 allows surgical access to underlying tissues,
 can be replaced in the original position,
 maintained with sutures.
115

Principles of incisions:
 Thorough anatomical knowledge
 Parallel to vital structures
 Extra oral incisions parallel to Langer’s lines
 Sharp blade of proper size and shape
 Clean, firm, continuous,single stroke incision
 Place incision on sound bone
 Pen/ table knife grasp
 Stabilize skin/ mucosa with finger pressure
 No sharp angles
116

Incisions in the oral cavity:
Adequate accessibility
Desirable to incise through attached gingiva
Maintain integrity of interdental papilla
Base of flap wider than apex
Full thickness mucoperiostel flap
Avoid placing incisions on bony prominences
In posterior mandible avoid extending incision
too far distally
117

Basically two types of Incision are used in
third molar surgery
1. Horizontal Incision
2. Vertical incision
118

• L- shaped incision
• Bayonet incision
• Ward’s incision and Modified Ward’s
incision.
• Comma shaped incision.
• S -shaped incision
• Szmyd and modified Szmyd incision
• Envelope flap
• Triangular shaped incision
• Groove and Moore’s Flap
• Vestibular Tongue shaped Flap
119

Macgregor:
Envelop incision
L-shaped incision
Bayonet shaped incision
120

Triangular (three-cornered) Flap
121

Ward’s and Modified Ward’s incision
122

COMMA INCISION
123
Starting from a point , posterior to the distal aspect of the preceding second
molar, the incision is made in an anterior direction.
Incision is made to a point below the second molar, from where it is smoothly
curved up to meet the gingival crest at the distobuccal line angle of the second
molar.
The incision is continued as a crevicular incision around the distal aspect of
the second molar (a distolingually based flap).

S SHAPED INCISION
126
Incision was made from the
retromolar fossa across the external
oblique ridge curving down
through the attached
mucoperiosteum to run along the
reflection of the mucous
membrane to the anterior border of
the first permanent molar.

GROOVE AND MOORE’S FLAP
In the year 1970 they designed three flaps
Produced an apparent decrease in pocket
formation distal to 2 nd Molar
A collar of tissue was preserved around the 2
nd molar hence decreasing pocket formation
A lingual extension of the incision allowed for
exposure of the lingual aspect as well
127

VESTIBULAR TONGUE SHAPED FLAP
 Berwick in 1986 designed a vestibular tongue shaped
flap.
 Extended into the buccal shelf of the mandible.
 For the pedicle flap an incision distal to the third molar
was extended approximately 1 cm and then curved
towards the buccal sulcus allowing for rotation of the flap
and primary closure over sound bone.
 Prior to closure, the gingival papilla distal to the second
molar was removed and the apex of the pedicle de-
epithelialised
129

REFLECTION OF
MUCOPERIOSTEALFLAP
 Periosteal elevator or Minnesota or Austin retractors
 Howarth nasal raspator
 Thimble
 Austin retractor
 Ward killner retractor
 Dyson’s Malleable copper
retractor
 Mac gregor periosteal elevator
 Fickling periosteal elevator
 Read periosteal elevator
131

BONE REMOVAL
Aim:
Crown exposure
To remove the bone obstructing the
path for removal of tooth
Adequate removal- chisel or bur
132

Methods of bone removal
133
WITH BUR
1.Buccal guttering
technique
2.Postage stamp technique
3.Collar technique (Moore
and Gillbe)
4.Lateral trepanation
technique [Bowdler Henry]
WITH CHISEL
1.Window technique
2.Shaving technique
3.Lingual split technique
4.Distal lingual split
technique

Criteria Bur Chisel and mallet
Technique Easy Difficult
Patients acceptance Tolerated well under LA Tolerated well under GA
Chance of fracture of
bone
Less More
Healing of bone Compromised Good
Postoperative edema More Less
Dry socket incidence High Low
Postoperative infection More Less
Emphysema More Not present
134

REMOVAL OF OVERLYING BONE
 Soft tissue reflection
 Removal of bone in atraumatic, aseptic, non- heat
producing technique
 The amount of bone that must be removed varies
with the depth of impaction, the morphology of
roots, and the angulation of tooth
 The speed of micromotor should be 12000- 20000
rpm.
135

Exposure of the crown of the tooth using a round bur.
a. Diagrammatic illustration. b .Clinical photograph
136

Buccal guttering technique
137
It involves the removal of bone by creating a groove
on the buccal and distal aspects of the crown of the
tooth, ensuring a pathway for removal that will
facilitate its luxation.

Postage stamp technique
 In this technique a row of small holes is made
with a small bur and then joined together
either with bur or chisel cuts.
138

Moore & Gillbe’s CollarTechnique
 Conventional technique of using bur.
 Rosehead round bur no.3 is used to create a
gutter along the buccal side & distal aspect of
tooth.
 A point of elevation (mesial purchase point) is
created with bur.
 Amount of bone sacrificed is less.
 Can be used in old patient.
 Convenient for patient.
139

Lateral TrepanationTechnique
Bowlder Henry
 Employed to remove any partially formed unerupted 3rd molar that has not
breached the overlying hard & soft tissues.
 Age 9-18 yrs
 GA/LA with sedation.
 Excellent PDL healing on distal surface of 2nd molar.
 Bone healing is excellent as there is no loss of alveolar bone around 2nd
molar.
 Disadvantage – increased buccal swelling
140

CHISEL TECHNIQUE THROUGH BUCCAL
APPROACH
 Elevation of mucoperiosteal flap
 Vertical limiting cut -5-6mm
 Oblique cut -45 deg
 Removal of triangular plate of bone
 Point of application of elevator
 Distolingual bone not fractured parallel to internal oblique
ridge due to the risk of fracture extending upto the coronoid
142

SPLIT BONE TECHNIQUE
Sir William Kelsey Fry in 1933
Quick ,clean technique.
Reduces the size of the residual blood clot
by means of saucerization of the socket.
Suitable in young patients with elastic bone.
Increased incidence of post operative
transient lingual anesthesia.
143

Modified Lingual Split Technique For Removal Of
Mandibular Third Molar (Dr. Davis 1979)
Not to separate the mucoperiosteom from lingual area of
bone
Kamanishi modification:
 Do not raise the lingual flap
 Advance to the lingual side under the bone only to the
extent which is necessary.
Lewis modification:
 Flap was made lingual to second molar instead of third.
 Vertical lingual step cut just distal to second molar.
 Lingual plate was hinged like an osteoplastic flap.
 It is considered as combination of both lingual and
buccal approach
146

TOOTH DIVISION TECHNIQUE
 Kelsey Fry
 To reduce the removal of large amount of bone
 Avoid damage to adjacent structures
 Decreases dead space
 Allows portions of tooth to be removed separately with
elevators
 Direction depends primarily on angulation of impacted
tooth
 With a bur, tooth is sectioned 3/4th toward lingual aspect
147

 A line is drawn from the
mesiolingual cusp till the distal root
of the impacted third molar.
 Half the distance measured is taken
as the radius and an arc is drawn.
 If the arc touches the 2nd molar
indicates locking of tooth.
 Then sectioning is mandatory.
 Mesio distal diameter of crown and
mesiodistal width of roots are more
than the space for exit of the tooth. 149
CRITERIA FOR SECTIONING OF TOOTH

A. Buccal and distal
bone are removed
to expose crown of
tooth to its cervical
line
B.The distal aspect of
the crown is then
sectioned from tooth.
Occasionally it is
necessary to section
the entire tooth into
two portions rather
than to section the
distal portion of
crown only
C . A small straight
elevator is inserted
into the purchase
point on mesial aspect
of 3rd molar, & the
tooth is delivered with
a rotational and level
motion of elevator.
150

A. Removal of mesial
& distal bone. It is
important to
remember that more
distal bone must be
taken off than for a
vertical or
mesioangular
impaction.
B. The crown of
the tooth is
sectioned off with
a bur and is
delivered with
straight
elevator
The purchase point is
put into the remaining
root portion of the
tooth, and the roots are
delivered by a Cryer
elevator with a wheel
and-axle
motion. If the roots
diverge, it may be
necessary in some cases
to split them into
independent portions 151

A. When removing a
vertical impaction, the
bone on the occlusal,
buccal, and distal
aspects of the crown is
removed, and the tooth
is sectioned into
mesial and distal
portions.
B. The posterior
aspect of the crown
is elevated first with
a Cryer elevator
inserted into a small
purchase point in
the distal portion of
the tooth.
C. A small straight
no. 301 elevator is
then used to lift the
mesial aspect of the
tooth with a rotary
and levering motion.
152

A. Removal of distal and
buccal underlying bone
B. The crown is sectioned
from the roots of the tooth and is
delivered from socket
C. The roots are delivered
together or independently with a
Cryer elevator used with a
rotational motion. Saperation of
root into 2 parts - occasionally the
purchase point is made in the
root to allow the Cryer elevator to
engage it.
D. The mesial root of the tooth
is elevated in similar fashion
153

Delivery Of The Sectioned Tooth With Elevator
Once adequate bone has been removed to
expose the tooth and the tooth has been
sectioned in the appropriate fashion, the tooth is
delivered from the alveolar process with
dental elevators.
 In the mandible the most frequently used
elevators are the straight elevator, the paired
Cryer elevators, and the crane pick
154

CRITERIA BUCCAL LINGUAL
Access Easy in conscious patient Difficult in conscious
patient
Instruments Chisel and mallet or bur Only Chisel and mallet
Procedure Tedious Easy
Operating time Time consuming Less time
Technique Tech. easy Tech.difficult
Bone removal Thick buccal plate Thin lingual plate
Post op pain Less More-due to damage to
lingual periosteum
Post op edema More Less
Dry socket Incidence high – due to
damage to ext. oblique
ridge
Negligible-socket
eliminated
Buccal vs. Lingual approach
155

SURGICAL CLOSURE
WEDGE REMOVAL
 Remove triangular wedge of soft tissue
immediately posterior to second molar-
surgical drainage
 Excess tissue- elliptical incision
156

 DEBRIDEMENT AND SMOOTHENING OF
BONE MARGINS
 Socket irrigation-saline, betadine
 Socket curettage
 Check for damage to adjacent tooth
 Smoothen socket margins
 Control heavy bleeding
157

INTRA- ALVEOLAR DRESSING
 Enhance repair process, control pain, reduce
edema
 Medicaments on gauze strips, sponges,
pastes, tablets, dusts
 Preserve coagulum
 Prevent infection
158

Closure of soft tissue flap
 Return soft tissue flap to the original position
 Stabilize the flap to permit repair
 Resecure periodontal/ gingival attachments
159

COMPLICATIONS
160
PRE- OP
Difficulty in access
Difficulty in co-
operation
Difficulty in
anesthesia
OPERATIVE
•Abnormal resistance
•Fracture of tooth
•Displacement of
tooth into spaces
•Fracture of adjacent
tooth
•Jaw fracture
•Soft tissueinjury
•Damage to vital
structures
•Instrument breakage
•TMJ dislocation
POST- OP
•Pain
•Hemorrhage
•Hematoma
•Edema
•Paresthesia
•Trismus
•Sore throat
•Dysphagia
•Fever
•Surgical emphysema
•Wound dehiscence
•Dry socket
•Periodontal defects of
adjacent tooth

....KILLEY AND KAY
1.Soft tissue
injuries
• Tearing of
mucosal
flap
• Puncture
wounds
• Lip injury
7. Complications due to
local anesthesia
Systemic
Overdose
Allergy
Idiosyncrosy
Local
Paresthesia, trismus,
hematoma,facial palsy,
infection, edema,
burning on injection
3. Due to incision
•Extended post.or med-
bleeding
•Injury to facial A, anterior
facial vein
6. Other complications
•Damage to neurovascular
bundle
•Damage to lingual nerve
•TMJ pain
•Needle breakage
2. Complications
with the tooth
being extracted
•Root fracture
•Root
displacement into
spaces
5. Due to elevation
•Fracture of impacted tooth
•Displacement into spaces
•Damage to adjacent tooth
•Fracture of mandible,
alveolar process
•Fracture of adjacent
restoration
4. Due to use of bur
•Slippagge, soft tissue
injury
•Drill into nerve canal
•Thermal necrosis of
bone
•emphysema
161

TREATMENT FLOWCHART FOR IAN INJURY
163

TREATMENT FLOWCHART FOR LINGUAL NERVE INJURY
164

DRY SOCKET (crawford)
DEFINITION
“Postoperative pain in and around the extraction site
which increases in severity at any time between 1 and 3 days after the
extraction accomtepanied by a partially or totally disingrated blood
clot within the alveolar socket with or without halitosis.”
I.R. Blum: Contemporary views on dry socket (alveolar osteitis):
a clinical appraisalof standardization, aetiopathogenesis and management
:a critical review.
Int. J. Oral Maxillofac. Surg. 2002; 31: 309–317
165

Shafer-a focal osteomyelitis in which the blood
clot has disintegrated or been lost, with the
production of a foul odour and severe pain, but
no suppuration
MacGregor 1968- classically occurs after
forceps extraction and the diagnosis is made by
excluding the other causes of pain.
166

Synonyms
Alveolar osteitis(ao)
Alveolitis
Localized osteitis
 Alveolitis sicca dolorosa
Localized alveolar osteitis
Fibrinolytic alveolitis
Septic socket
Necrotic socket
Alveolalgia
167

Theories Of Dry Socket
1. Nitzin’s theory
2. Birn’s fibrinolytic theory
3. Bacterial theory
168

ETIOLOGY
 Early lysis of a fully formed blot clot
 Trauma to bone
 Reduced bleeding- vasoconstrictor
 Generalised debilitation
 Oral contraceptives
 Dense bone
 Vigorous mouthrinse
 Smoking
169

Clinical features
Pain
 2-3 days after extraction
 No usual signs of inflammation
 Dull aching pain
 Radiating to ear
 Moderate- severe pain
 Increases on chewing
 Chemical / thermal irritation of nerve endings
170

Socket
 Empty / partially lost blood clot
 Exposed bone surface
 Extremely sensitive on probing
 Clot color- gray- dirty yellow- necrotic clot
Halitosis
171

MANAGEMENT
 Radiographs- rule out retained tooth fragments,
foreign body
 Socket irrigation- CHX
 Gelatin sponge with tetracycline
 Gentle mechanical debridement
 NO CURETTAGE
 Topical anesthetics
 Intra alveolar medicaments
 Analgesics
 Eugenol obtunds pain+ topical anesthetics 172

IMPACTED MAXILLARY
THIRD MOLARS
173

Clinical examination
Inspection
 Patient opens the mouth 25-30 mm
 Partial eruption of crown
 Pericoronitis
 Periodontitis posterior to second molar
Palpation
 Positioned buccally to second molar
 Rounded bulge / sharp cusps of crown
 Absence of these findings- third molar is directly
posterior, medial or extremely superior to second
molar
175

RADIOGRAPHS
 Panoramic x- ray view
 Periapical views
 Bitewing view
 Occlusal radiographs
176

complications
Maxillary tuberosity fracture
Displacement of maxillary third molar
Aspiration
Oro-antral communications
Alveolar osteitis
Bleeding and hemorrhage
Trismus
178

ETIOLOGY (DEWEL)
1. The hard palatal bone offers more resistance
2. The mucoperiosteum of the hard palate becomes very
dense and resistant due to repeated stress
3. Greater the distance a tooth must travel, greater is the
possibility of deflection
4. Any change in the position or condition of the primary
canine may reflect along the full length of the root of
permanent canine and cause a deviation in its position
180

5. Delayed resorption of primary canine
6. The upper canines are last among
successor teeth to erupt
7. Canines erupt between the teeth already in
occlusion and are competing for space
8.Mesiodistal dimension of deciduous canine is
much smaller
181

DIAGNOSIS
CLINICAL EVALUATION :
– Prolonged retention of deciduous canine
– Delayed eruption of permanent canine
– Presence of palatal bulge
– Absence of labial canine bulge
– Delayed eruption, persistent distal tipping and
migration of lateral incisors.
183

RADIOGRAPHIC EVALUATION
– Intra-oral radiograph
– Tube shift technique or clarke technique
(parallax method)
– Buccal object rule technique
– Occlusal radiograph (true occlusal or vertex
occlusal)
184

INDICATIONS TO THE REMOVALOF
IMPACTED CANINES
 If the impacted canine is ankylosed and cannot be
transplanted
 Internal or external resorption
 Dilacerated roots
 Severe impaction i.e., canine lodged between roots
of central and lateral incisors
 If occlusion is acceptable with the first premolar in
position of canine
 If there are pathological changes
185

CONTRAINDICATIONS
 When the canine can be brought into normal
position either by surgical repositioning or by a
combination of surgery and orthodontia at an
early age; it should not be removed
186

SURGICAL MANAGEMENT
187
PALATALLY IMPACTED CANINE

Surgical removal of impacted canine in class III position
189

Removal Of Impacted
Maxillary Premolars
190

 The technique is dependent upon location, the
formation of the tooth. Its relationship; to the adjacent
teeth to maxillary sinus and the nasal cavity and
whether or not it is involved in a cyst.
 Impacted premolar located buccally or midway
between buccal and lingual surfaces
 Impacted premolar located in the palatal process of
maxilla
191

 Envelop flap is used &
posterior palatine vessel are
elvated with flap
 No. 11 elevated tip is used to
remove tooth
 Provided an adequate
exposure of the crown, a No.
286 forceps can grasp the
crown & luxate it.
Surgical removal of impacted maxillary premolar
192

REFERENCES
 Textbook of oral & maxillofacial surgery-Harry
Archer
 Impacted teeth – Alling and Helfrick
 Textbook of oral & maxillofacial surgery-Daniel M
Laskin
 The impacted lower wisdom tooth –Macgregor
 Expert third molar extractions- Asanami Kasazaki
193

 Killey and Kay's outline of oral surgery
 Principles of oral & maxillofacial surgery-Peterson
 Textbook of oral & maxillofacial surgery-Neelima
Anil Malik
 Textbook of oral & maxillofacial surgery-Gordon w
Pedersen
 Textbook of oral & maxillofacial surgery-
Srinivasan
 Extraction of teeth –Geoffory L Howe
194

SURGICAL EXTRACTION OF MANDIBULAR THIRD MOLAR

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