LEC OF ORAL SURGERY

1. Oral Surgery
L1: 18/5/2015 Dr Amera Alkaisi
Impacted tooth: A tooth that failed to fully erupt into the oral cavity within its
expected developmental time period and can no longer reasonably be expected to
do so.
The most common impacted teeth:
Third molars are the largest group of impacted teeth. Lower third molars are the most
common teeth to be impacted followed by maxillary canines, then upper third molars.
Development of the Mandibular Third Molar
• The development and movement of the third molar between the ages of 7 and
25 years
• The mandibular third molar tooth germ is usually visible radiographically
by age 9 years
• Cusp mineralization is completed approximately 2 years later
• At age11 years, the tooth is located within the anterior border of the ramus
with its occlusal surface facing almost directly anteriorly.
• The level of the tooth germ is approximately at the occlusal plane of the
erupted dentition.
• Crown formation is usually complete by age 14 years, and the roots are
approximately 50% formed by age 16 years.
• During this time the body of the mandible grows in length at the expense of
resorbtion of the anterior border of the ramus
• Usually the roots are completely formed with an open apex by age 18 years.
• By age 24 years 95% of all third molars that will erupt have completed their
eruption.
• The change in orientation of the occlusal surface from a straight anterior
inclination to a straight vertical inclination occurs primarily during root
formation.
• During this time the tooth rotates from horizontal to mesioangular to vertical.
• Therefore, the normal development and eruption pattern, assuming the tooth
has sufficient room to erupt, brings the tooth into its final position by age 20
years.
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2. • Underdevelopment of the mesial root results in a mesioangular impaction.
Overdevelopment of the same root results in over-rotation of the third
molar into a distoangular
• Overdevelopment of the distal root, commonly with a mesial curve, is
responsible for severe mesioangular or horizontal impaction.
Chronology (Mandibular 3rd
Molar)
Mand 3rd
MolarMax 3rd
Molar
7and 25 yearsDevelopment and
movement
7yearsStart development
14 yearsCrown formation
complete
18yearsRoots formation
complete
95%24yearscompleted Eruption
Causes of Impaction
1. Lack or loss of the space in overlying alveolar arch.
2. Discrepancy between tooth size & jaw size due to combination of both
genetic & environmental factors.
3. Premature extraction of deciduous teeth which lead to drifting of
neighboring teeth to the space leave insufficient space for permanent teeth to erupt.
4. Retained roots of deciduous teeth prevent of permanent from eruption.
5. Presence of supernumerary teeth.
6. Trauma which cause displacement of teeth germ.
7. Presence of tumors or cyst which prevent eruption.
8. Systemic causes due to hypothyroidism cleidocranial dystosis.
9. Radiotherapy
Diagnosis of impaction
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3. Need a clear understanding of the usual chronology of eruption, as well factors
that influence eruption potential.
1. Eruption of lower third molars
 Complete at the average age of 20 years but that it can occur up to age
24 years.
 A tooth that appears impacted at age 18 years may have as much as a
30 to 50% chance of erupting fully by age 25 years.
 The position of retained third molars does not change substantially
after age 25 years.
 By age 18 to 20 years, lower third molars that are horizontal or
strongly mesioangular have much less eruption potential than do
those that are oriented more vertically.
 Distoangular teeth are intermediate in their likelihood to erupt
fully.
 The strongest hope of future eruption lies with those third molars that
can be seen radiographically to have space at least as wide as their
crown between the distal of the second molar and the ascending
mandibular ramus.
 At age 20 years, unerupted lower third molars that are nearly
vertical and have adequate horizontal space are more likely to erupt
than to remain impacted. However, if the crown to-space ratio is > 1
or if the tooth orientation diverges substantially from vertical, the
tooth is unlikely ever to erupt fully.
Indications for the removal of impacted teeth
1. Infection: Recurrent periodontitis is commonest cause for removal of impacted
mandibular third molars. Pericoronitis is an acute infection of the soft tissues
covering the semi-impacted tooth and the associated follicle. It occur when food
&debris collect under mucosal covering or operculum of impacted tooth or due to
injury of the operculum by the antagonist third molar or because of entrapment of
food under the operculum, resulting in bacterial invasion and infection of the area.
After inflammation occurs, it remains permanent and causes acute episodes from
time to time. The infection should be controlled before the tooth is removed.
Clinical presentation
• Severe pain in the region of the affected tooth, which radiates to the ear,
temporomandibular joint, and posterior submandibular region.
• Trismus
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4. • Difficulty in swallowing
• Submandibular lymphadenitis
• Rubor, and edema of the operculum area
• Acharacteristic of pericoronitis is that when pressure is applied to the
operculum, severe pain and discharge of pus are observed.
Acute pericoronitis is often responsible for the spread of infection to various regions
of the neck and facial area.
Treatment
Initial treatment of pericoronitis is usually aimed at:
• Débridement of the periodontal pocket by irrigation or by mechanical
means
• Disinfection of the pocket with an irrigation solution such as
hydrogen peroxide or chlorhexidine
• Surgical management by extraction of the opposing maxillary third
molar (source of irritation)
• Severe cases of pericoronitis with systemic symptoms may need
appropriate antibiotic therapy & incision & drainage if necessary.
Uncontrolled pericoronitis can lead to more serious infection.
• Recurrent, removal of the offending mandibular third molar.
Complications
 Pericoronal abscess
 Spread posteriorly to the oropharyngeal area and medialy to the base of
the tongue causing difficulty in swallowung
 In frequently causes peritonsillar abscess , Cellulitis. Ledwege angina
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5. 2. Pathologic conditions: if the tooth clinically or radiographically associated
with pathological lesion or condition such as cyst, fracture line it is usually
better to removed or associated with malignant lesions or the patient need
radiotherapy.
3. Pain: caries, inflammation & infection may cause pain or obscure facial pain
all these indications for removal.
4. Effect on adjacent teeth: third molars that contribute to infection of
adjacent teeth (caries & periodontal disease) or root resorption of adjacent tooth,
should be removed.
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6. 5. Orthodontic consideration: The presence of the impacted third molar,
especially in the mandible, may be responsible for several orthodontic
problems.
• Crowding of Mandibular Incisors: In fact, anterior incisor crowding is
associated with deficient arch length rather than the mere presence of
impacted teeth.
Prophylactic removal of mandibular third molar germ in whole marked
disproportion between tooth size jaw size or when the formation of the crown is
completed. Removal of unerupted lower third molar in which as much as one third
of the root have been formed called lateral trepanation.
• Obstruction of Orthodontic Treatment In some situations the
orthodontist attempts to move the molar teeth distally, but the presence of
an impacted third molar may inhibit or even prevent this procedure
• Interference with Orthognathic Surgery: When maxillary or
mandibular osteotomies are planned, presurgical removal of the impacted
teeth may facilitate the orthognathic procedure.
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7. 6. Prosthodontic consideration: as resorption of the mandibular progresses
some retained teeth become more superficial & may either interfere with the fit
of a full lower denture or cause pain due to either caries or a germ infection.
This tooth should be removed as soon as inflammation is treated.
7. Prevention of Jaw Fracture: An impacted third molar presents an area of
lowered resistance to fracture in the mandible and is therefore a common site
for fracture, Patients who engage in contact sports, such as football and
basketball, should consider having their impacted third molars removed to
prevent jaw fracture during competition. Additionally, the presence of an
impacted third molar in the line of fracture may cause increased complications
in the treatment of the fracture.
Contradictions for Removal of Impacted Teeth
 Extremes of Age:
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8.  Surgical removal of unerupted third molars in the very young is
contraindicated. Accurate growth predictions could be made, whether a given
tooth would be impacted.
 As a patient becomes older there is decreased healing response. the surgical
procedure grows more and more difficult as the patient ages owing to more
densely calcified bone, which is less flexible and more likely to fracture.
 As a general rule, if a patient has a fully impacted third molar that is
completely covered with bone, has no obvious potential source of
communication with the oral cavity, and has no signs of pathology such as
anenlarged follicular sac, and if the patient is over age 40, the tooth probably
should not be removed. Long-term follow-up by the patient’s dentist should be
performed periodically, with radiography performed every several years to
ensure that no adverse sequelae are occurring. If signs of pathology develop,
the tooth should be removed. If the overlying bone is very thin and a removable
denture is to be placed over that tooth, the tooth should probably be removed
before the final prosthesis is constructed.
 Compromised Medical Status
Patients who have impacted teeth may have some compromise in their health sta
tus, especially if they are elderly. As age increases, so does the incidence of
moderate to severe cardiovascular disease, pulmonary disease, and other health
problems, may contraindicate the removal of impacted teeth.
 Surgical Damage to Adjacent Structures: Occasionally an
impacted tooth is positioned such that its removal may seriously
compromise adjacent nerves, teeth, and other vital structures (eg, sinus),
making it prudent to leave the impacted tooth in situ.
Time of age of extraction:
It is usual to avoid doing oral surgery at extremes of age, so it is better to remove
impacted tooth between 15& 35 years.
Determining Surgical Difficulty
Preoperative evaluation of the third molar, both
 Clinically
 Radiographically, is a critical step in the surgical procedure for removal of
impacted teeth. The surgeon pays particular attention to the variety of factors
known to make the impaction surgery more or less difficult.
 Classification systems: A variety of classification systems have been developed
to aid in the determination of difficulty.
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9. The three most widely used are:
 Angulation of the impacted tooth
 The relationship of the impacted tooth to the anterior border
of the ramus and the second molar
 The depth of the impaction and the type of tissue overlying the impacted
tooth.
Factors determine the difficulty of surgery
1. The root morphology may have little influence on the time that surgery
requires.
 Roots can be either conical and fused roots or
 Separate and divergent, with more difficult to manage.
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10. 2. A large follicular sac around the crown of the tooth provides more
room for access to the tooth, making it less difficult to extract than one
with essentially no space around the crown of the tooth.
3. The age of the patient. When impacted teeth are removed before age
20 years, the surgery is almost always less difficult to perform.
 The roots are usually incompletely formed and thus less bone
removal is required for tooth extraction
 There is usually a broader pericoronal space formed by the
follicle of the tooth, which provides additional access for tooth
extraction without bone removal
 Because the roots of the impacted teeth are incompletely formed,
they are usually separated from the inferior alveolar nerve
 There is increasing density and decreasing elasticity in the
bone, necessitating greater bone removal to
deliver the tooth from its socket.
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11. Oral Surgery
L2 Impaction Contin--- Dr Amera Alkaisi
• Classification of mandibular impaction according to their
anatomic position:
1. Verticle. The vertical impaction (40% of all impactions) is intermediate in
difficulty
2. Mesioangular. The mesioangular impaction, which account for
approximately 45% of all impacted mandibular third molars, is the least difficult
to remove.
3. Distoangular. the distoangular impaction (5%) is the most difficult.
4. Horizontal. the horizontal impaction (10%) is intermediate in difficulty
5. Ectopic.
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12. • The relationship of the impacted tooth to the anterior border
of the ramus : is a reflection of the amount of room available for the
tooth eruption as well as the planned extraction:
Class 1: The distance between the second molar and the anterior border of the
ramus is greater than the mesiodistal diameter of the crown of the impacted tooth,
so that its extraction does not require bone removal from the region of the ramus
(Fig 1).
Class 2: The distance is less and the existing space is less than the mesiodistal
diameter of the crown of the impacted tooth (Fig 2).
Class 3: There is no room between the second molar and the anterior border of
the ramus, so that the entire impacted tooth or part of it is em-
bedded in the ramus(Fig 3). present more difficulty during the surgical procedure,
because the extraction of the tooth requires removal of a relatively large amount of
bone and there is a risk of fracturing the mandible and damaging the inferior
alveolar nerve.
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13. • The depth of the impaction under the hard and soft tissues: is an
important consideration in determining the degree of difficulty.
Class A: The occlusal surface of the impacted tooth is at the same level as, or a
little below that of, the second molar (Fig 1).
Class B: The occlusal surface of the impacted tooth is at the middle of the crown
of the second molar or at the same level as the cervical line
(Fig 2).
Class C: The occlusal surface of the impacted tooth is below the cervical line of
the second molar (Fig 3).
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14. Pre operative preparation
1. Patient preparation: explain clinical finding & radiographic &the surgical
procedures. Complications should be explained without frightening the patient, this
include
• Possible labial & lingual parasthesia.
• Possible mandibular fracture with deep mandibular impaction.
• Anaesthetic complication.
• Damage to the adjacent teeth.
• Possible sinus involvement with high maxillary impactions.
Postoperative course should be discussed. The patient must know how much pain to
expect or how long swelling remains.
2. Clinical examination: It is essential in every case thorough examination be
done before surgery.
 Be sure that any pericoronal or other infection is resolve. The presence of
facial swelling & enlarged, tender, lymph nodes indicate the presence of
active infection.
 Surgical access must be determined, size of oral cavity, size of tongue,
degree of the patient mouth opening. When the patient cannot open his or her
mouth, because of trismus that is mainly due to inflammation, the trismus is
treated first, and extraction of the third molar is performed at a later date
 Patient oral hygiene habit must be checked.
 The health of the first & second molars may affect the decision to remove of
the wisdom teeth
 Large crowns inlays or amalgam in second molars can be dislodged during
elevation of wisdom tooth.
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15.  The tooth itself should be observe how much crown is visible palpable if it is
unerupted, partially erupted tooth should be explored with a prob to
determine tooth surfaces.
 Distal surface of the molar , the gingival crevice should be explore with
periodontal probe to see if there is pocket in partially erupted third molar
 The depth of any visible crown below the occlusal planes & it is relation to
alveolar crest is noted & the distance between distal surface of the second
molar & the anterior border of ascending ramus.
 The external & the internal oblique ridge of the mandible are palpated. If the
external oblique ridge is low, relatively vertical & relatively posterior to the
tooth there will be thin alveolar bone buccal to the third molar. If it is high &
forward relative to the tooth thick alveolar bone buccal to third molar will be
the same for the internal oblique ridge.
 The position & condition of upper third molar is checked & its occlusal
relationship to the lower third & second molar noted. If it over erupted it
should extracted or if it bites on the gum flap of lower third molar.
3. Radiographic examination:
 Periapical radiographs gives better details than any other technique.
 Occlusal film should be taken for difficult teeth to complete the two views at
right angle.
 Rotational tomographic films(OPG)
Feature that should be considered that shown in radiograph:
 Orientation of the tooth it may be verticle mesioangular ,distoangular
horizantal or ectopic. Most are oriented in line with the dental arch with
the crown forward but some lies transverse to the arch (the crown buccal
or lingually ) ectopic may be seen in usual situation from coronid notch to
the lower border of the mandible
 The depth of the tooth to determine the bone to be removed.
 Root pattern of the third molar to see the shape & curvature of the root.
 Bone density.
 The relationship to inferior dental canal.
Steps of Surgical Procedure
The surgical procedure for the extraction of impacted
teeth includes the following steps:
1. Incision and reflection of the mucoperiosteal flap
2. Removal of bone to expose the impacted tooth
3. Luxation of the tooth
4. Care of the postsurgical socket and suturing of the wound
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16. Removal of mandibular third molar
Surgical technique
• Anesthesia
Anesthesia in cases of impacted mandibular third molars is achieved by:
inferior alveolar nerve block, buccal nerve block,lingual nerve block,
and local infiltration for hemostasis in the surgical field.
• Mucoperiosteal flap
Adequate size mucoperiosteal flap should be reflected to permit access.
1. A. Envelope flap: Is the most commonly used flap, which extends
from just posterior to the position of the impacted tooth, anteriorly to
approximately the level of the first molar. Used when impaction is:
 Relatively superficial& little bone needs to be removed anterior.
2. Two sided flap(Triangular flap) If the surgeon requires greater
access to remove a deeply impacted tooth, the envelope flap
may not be sufficient. In that case, a release incision is done on the
anterior aspect of the incision. The buccal artery is sometimes
encountered when creating the releasing incision, and this may
be bothersome during the early portion of the surgery. The incision
for this type of flap begins at the anterior border of the ramus
(external oblique ridge)with special care for the lingual nerve and
extends as far as the distal aspect of the second molar, while the
vertical releasing incision is made obliquely downwards and
forward, ending in the vestibular fold.
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17. The incision then carried forward to the second molar over the crown of
the wisdom tooth & through the gum flap. The interdental papilla distal to
the second molar is divided then the anterior incision curves forwards from
the distobuccal corner of the crowns of second molar & end along side the
mesiobuccal cusp of that tooth, or the incision is carried around the gingival
margin of second molar up to the mesial cusp on buccal side & down
toward the sulcus through attached gingiva only. For deeply buried tooth
the papilla mesial to the second also is included in the flap periosteal
elevator is inserted in the mesial relieving incision down to the bone the
flap reflected distally we reflect the flap.
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18. • Bone removal
The bone covering the tooth is removed using a round bur, until the entire
crown is exposed. pathway for removal must b ensured, by removing
sufficient bone from the occlusal, buccal and distal aspects of the crown of
the tooth down to the cervical line(guttering technique). After exposing the
impacted tooth sufficiently, the straight elevator is placed in the mesial
region and the tooth is elevated with a rotational movement distally. The
amount of bone that must be removed varies with the depth of the
impaction. It is advisable not to remove any bone on the lingual aspect
because of the likelihood of damage to the lingual nerve. A variety of burs
can be used to remove bone, but the most commonly used are the no. 8 or
10 rose round bur and the 703 fissure bur. The guttering technique involves
the removal of bone by crown of the tooth, ensuring a pathway for removal
that will facilitate its luxation. Extensive bone removal is thus avoided.
Bone removal is continued on the buccal side to create a gutter. with bur. A
straight elevator is used to deliver the tooth, or bone removal is continued A
mesial point of application is created on buccal side & deepened with
number 6 rose head down to the bifurcation of the roots laterally & mesially
to provide point of application for an elevator.
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20. • Tooth division
The crown is separated from the root mass using bur (Tungsten carbide
tapering fissure bur). The cut should be made through the thin cervical
enamel until two thirds of the cut has been made then an osteotome placed
against the buccal aspect of the transverse fissure & splitting off the half of
sectioned crown. This technique is used when the degree of impaction is
sever or the tooth roots are curved unfavorably. Dividing the tooth in its
long axis between the roots will disimpact a mild mesioangular or
horizontal impacted wisdom.
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