4. 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
5. 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
6. 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
7. 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
8. 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
10. 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
13. 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
14. 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
15. 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
16. 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
18. 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
20. INTRODUCTION
Origin Latin - Impactus -
Cessation of eruption
caused by physical
barrier / ectopic eruption.
"IMPINGO", "IN" and
Pingo or strike.
20
21. Heironymous cardus -Dens sensus et sapientia et
intellectus.
Dens serotinus – lateness 21
22. 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
23. Kelsey Fry and Ward- lingual split technique
Hellman (1936)- females were twice as likely to
have impaction as males
23
24. 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
25. 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
26. 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
28. 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
29. 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
30. DEFINITION -
Any tooth that is prevented from reaching its
normal position in the mouth by tissue or bone
or other tooth.
-WHO
30
31. 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
32. 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
33. 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
34. 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
35. 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
36. 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
37. 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
38. 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
39. 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
40. 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
41. 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
43. 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
44. 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
45. 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
46. 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
47. 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
52. PERICORONITIS
• Transient inflammation of gingiva and
periodontal tissues associated with normal
eruption of any tooth.
• Infection/ abscess/ cellulitis
52
54. 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
60. 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
63. 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
64. 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
66. 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
67. 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
69. 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
71. 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
72. 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
73. 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
74. 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
75. CLASSIFICATION BY ARCHER (1975) AND
KRUGER (1984)
Based on angulation of 3rd molar
Mesioangular
Distoangular
Vertical
Horizontal
Buccoangular
Lingoangular
Inverted
75
76. 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
80. 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
81. 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
83. KILLEY & KAY'S CLASSIFICATION
Based on angulation and position
Vertical
Mesioangular
Distoangular
Horizontal
Transverse
Buccoangular
Linguoangular
Inverted
Aberrant positions
83
84. 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
85. 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
88. Intra oral examination
Soft tissues
Size of rima oris
Tongue size
Extensibility of lips & cheeks
Soft tissue trauma
Hard tissues
Dentition status
88
89. 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
90. 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
91. INTRA ORAL RADIOGRAPHS
Intra oral periapical radiographs
Bisecting angle technique
X- ray film stabilized against the teeth and
supporting lingual alveolar mucosa
Principle-
91
92. 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
95. 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
96. 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
98. 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
99. 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
100. 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
102. 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
104. 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
105. 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
106. 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
107. 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
108. 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
110. 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
113. 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
114. 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
115. 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
116. 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
117. 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
118. Basically two types of Incision are used in
third molar surgery
1. Horizontal Incision
2. Vertical incision
118
123. 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).
126. 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.
127. 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
129. 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
131. 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
133. 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
134. 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
135. 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
136. Exposure of the crown of the tooth using a round bur.
a. Diagrammatic illustration. b .Clinical photograph
136
137. 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.
138. 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
139. 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
140. 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
142. 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
143. 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
146. 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
147. 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
149. 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
150. 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
151. 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
152. 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
153. 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
154. 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
155. 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
156. SURGICAL CLOSURE
WEDGE REMOVAL
Remove triangular wedge of soft tissue
immediately posterior to second molar-
surgical drainage
Excess tissue- elliptical incision
156
157. 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
159. Closure of soft tissue flap
Return soft tissue flap to the original position
Stabilize the flap to permit repair
Resecure periodontal/ gingival attachments
159
160. 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
161. ....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
165. 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
166. 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
168. Theories Of Dry Socket
1. Nitzin’s theory
2. Birn’s fibrinolytic theory
3. Bacterial theory
168
169. 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
170. 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
171. Socket
Empty / partially lost blood clot
Exposed bone surface
Extremely sensitive on probing
Clot color- gray- dirty yellow- necrotic clot
Halitosis
171
172. 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
175. 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
180. 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
181. 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
185. 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
186. 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
191. 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
192. 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
193. 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
194. 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
Allen-in the first dental tb- the english vernacular
Winter- ossisector
Primates- brain size increase- at expense of jaw size- no reduction in teeth size
Chief indication
Infection bwn the remnants of follicle and surrounding bone/soft tissues
Initial mangmt- pocket debridement, irrigation, disinfectants, mechanical debridement, xn of opp teeth
Peptostreptococcus, fusobacterium, porphyromonas, bacteroids
Streptococcus-rheumatic fever, pericoronitis glomerulonephritis
Mesio- 43% in mand
63%max
College pliars, bard parker molt9,wodson, spencer wells/kelly/halstead/lucas curette,bluementhal,miller&calburn bone file,adson,mayo hager,fraser suction ,pincher/beckhouse, ferguson/doyen
Cetrimonium bromide
Savlon= cetrimide+chx gluconate
Hibiscrub= chxgluconate in alcohol
Loose free swinging wrist motion- max speed to the head of the mallet without weight of the arm or body
KE= ½ mv2
To plane the bone- bevel towards the bone
To penetrate the bone- bevel away from the bone
First the bur is used in sweeping motion around the occlusal buccal and distal aspect of the crown to expose the ocllusal surface
Second on the buccal aspect till the cervical line- upto the ht of contour buccal trough is created
Initial ditch cut- cancellous bone- loss of resistance- bleeding- full depth of the working length of the bur head