A 65-year-old patient presented with a chronic infection related to an impacted lower third molar. Despite recommendations for removal, the patient refused treatment, resulting in progression of the deep bone infection and a pathologic fracture of the jaw. Factors such as age, medical comorbidities, proximity to adjacent structures, and risk of damage during surgery are considered when determining if an impacted third molar should be removed. Surgical extraction involves raising flaps, removing bone, dividing and extracting the tooth, and closing the wound. Postoperative care may include antibiotics, analgesics, and steroids. Complications can be intraoperative such as nerve injury, fracture, or bleeding, or postoperative like pain, swelling, and infection.

1. impacted lower 3rd
molar
Classification and methods of management of
Ola Mohammed Redha
Abdullah Osama
Abdullah Al-Nasser

2. introduction
An impacted tooth defined as a tooth that is prevented from erupting into
position
Causesof
impaction
lack of space
angulated roots were
more common in
impacted mandibular
third molars
hereditary
factors
lack of sufficient
eruption force for
third molars
regression of the jaw
size

3. lassifications
Classification describes wisdom tooth relation to the adjacent anatomical structures: mandibular
ramus, second molar, alveolar crest, mandibular canal.
Impacted wisdom teeth are classified by the direction and depth of impaction, the amount of
available space for tooth eruption, and the amount of soft tissue or bone (or both) that covers them.
The classification structure helps clinicians estimate the risks for impaction, infections and
complications associated with wisdom teeth removal.
Depth of impaction
Relationship with the mandibular ramus
Angulation of impaction

4. Depth of impaction
According to the Pell and Gregory classification, the relation of the
cementoenamel junction (CEJ) of the third molar with the bone level is
categorized as follows:
Level A:
• Not buried in bone
Level B
• Partially buried in bone if any part of
CEJ was lower than bone level
Level C
• Completely buried in bone

5. Relationship with the mandibular ramus
According to the Pell and Gregory classification, the position of the distal surface of the third molar
crown in relation to the anterior border of the ascending ramus is categorized as follows:
Class I: Anterior to the
anterior border;
Class II: Half of the crown
is covered by the anterior
border
Class III: The crown is
fully covered by the
anterior border

6. Angulation of impaction
Based on Winter's classification, the angle between the
longitudinal axis of the second and third molars
Mesioangular
impaction
Horizontal impaction
Vertical
impaction
Distoangular
impaction

7. Distoangular
Impaction

8. Vertical
Impaction

9. Mesioangular
Impaction

10. Horizontal
Impaction

11. MANAGEMENT OF UNERUPTED AND IMPACTED THIRD MOLAR TEETH
CLINICAL ASSESSMENT
Clinical assessment should be carried out with the aim of assessing the status
of the third molars and excluding other causes of the symptoms. A complete
examination should include assessment of:
• the eruption status of the third molar
• the presence of local infection
• caries in, or resorption of, the third molar and the adjacent tooth
• periodontal status
• orientation and relationship of the tooth to the inferior dental canal (IDC)
• occlusal relationship
• temporomandibular joint function
• regional lymph nodes.
Any associated pathology should also be noted.

12. RADIOLOGICAL EVALUATION
The purpose of a careful radiological evaluation is to complement the clinical examination by providing
additional information about the third molar, the related teeth and anatomical features, and the surrounding
bone. This is necessary in order to make a sound decision about the proposed surgical procedure.
 the type and orientation of impaction and the access to the tooth.
 the crown size and condition
 the root number and morphology
 The alveolar bone level
 the periodontal status
 the relationship or proximity of lower third molars to the inferior dental canal.
ing information should be noted:

13. To remove OR
not
1. Impacted teeth with pericoronitis should be extracted electively because
of their known potential for repetitive infection and morbidity.
ation for extraction

14. 2. tooth in line of fracture

15. 3. dental caries and damage of adjacent lower
second molar

16. 4. cysts and tumors associated with impacted
teeth

17. bone around the impacted teeth

18. 6. preceding dental work with fixed or
removable appliances
7. for chronic facial pain.
wding of the dental arch
ation of the opposing soft tissue

19. 65 year-old with a chronic infection related to an impacted lower third molar. The
patient refused to have her tooth removed. The delay in proper treatment resulted in
progression of the deep bone infection caused by the impacted third molar. This
eventually resulted in a pathologic fracture of the jaw.

21. Extreme
of age
Medical
compromised
patient
Excessive
risk of
damage to
adjacent
structure
Fracture of
mandible
may occur
contraindication

22. Mandibular third molar is situated at the distal end of the body of the mandible where is connection with relatively
thin ramus.
The buccal alveolar bone in this region is thicker than the lingual.
The external oblique ridge forms the buttress that reinforced the buccal plate.
The lingual nerve often lies close to the cortical plate.
panoramic radiographs showed that in most cases the roots of third molars are in close proximity to the mandibular
canal. Furthermore, in some cases third molar roots can contact or penetrate into mandibular canal or they can be
deflected.
atomy of lower 3rd molar region
Inferior alveolar nerve
Mandibular canal

23. prior to surgery, interim measures
may include systemic antibiotic
administration, chlorhexidine mouth
rinses

24. Surgical extraction of impacted
mandibular third molar
Several common steps apply to the removal of all impacted teeth
1. 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
There are two main intraoral approaches for surgical removal of impacted mandibular third
molars: one through the sublingual space and the other buccally through the entire
mandibular thickness.
There is also extraoral method from the submandibular space.

25. 2. Adequate flaps must be reflected for accessibility, Accessibility is a key issue in
removal of impacted teeth.
A full-thickness mucoperiosteal flap must be elevated to allow for visualization and
placement of retractors, drilling equipment, elevators, and forceps.

26. However there are many modifications of flap
techniques including :
1.Triangular flap (L-shaped)

27. 2. Variation of the triangular flap (bayonet)
3. Envelope flap

28. 3. Bone removal
The bone covering the tooth is removed
using a round bur, until
the entire crown is exposed.
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 round bur and the 703
fissure bur

29. 4. Tooth division
After the tooth being cut into smaller pieces, the fragments was removed piece by piece
Sometime the fragments of the separated tooth may still having difficulty to remove due to
curve root or engaged under the bony undercut. In this situation, the surgeon need to do more
grinding of that portion to reduce its size, to facilitate removal of all tooth fragments.
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.

30. 5. finally the wound must be closed.
the surgeon will attempt to achieve haemostatic (stop bleeding) by
applying some direct pressure to help the blood to clot.
The soft tissue flap will be stitched (suture) to immobilize it and help
to stabilize the blood clot.

32. POSTOPERATIVE DRUG THERAPY
Antibiotic
Analgesia
steroid
•Where there is significant
bone removal, prolonged
operation time, or the
patient is at increased risk
of infection
•Normal practice is to
prescribe or advise oral
analgesics such as
paracetamol or ibuprofen.
•Where there is a risk of
significant postoperative
swelling

33. mplications
1.
intraoperati
ve
2.
postoperativ
e
the level of impaction is associated with an increased
risk of inflammatory complications following third
molar surgery.
root number and morphology , tooth position ,
periodontal space and second molar relation were
significant predictors of surgical difficulty
1.
intraoperati
ve
1. Mandibular fracture

34. 2. damage of adjacent teeth,
(In cases if the excessive intraoral force was
applied or/and part of bone was removed, risk
of mandibular fracture or damage of adjacent
teeth is increased)
3. tooth or tooth fragments displacement into soft tissues
can occur in case of wrong operation technique
4. bleeding.

35. The most serious and unpleasant iatrogenic complication that arise from third molar surgery is
inferior alveolar and/or lingual nerve injury and neurosensory function disturbance.
Inferior alveolar nerve injury can cause paresthesia to complete numbness and/or pain in the
region of the skin of the mental area, the lower lip, mucous membranes, and the gingiva as far
posteriorly as the second premolar . Furthermore this commonly interferes with speech, eating,
and drinking.
The injury of the lingual nerve leads to numbness of the ipsilateral anterior two thirds of the
tongue and taste disturbance .
Eruption status of the lower third molar is important risk factor for inferior alveolar
nerve injury. The risk of nerve injury is increasing with the depth of the impacted
mandibular wisdom teeth.
In general the proximity of the mandibular third molar to the mandibular canal is
considered a risk factor for damage to the inferior alveolar nerve.
Studies demonstrated that the most important parameters for inferior alveolar nerve
injury prediction are third molar root apices inside or in contact with the mandibular
canal.
Iatrogenic injury to the lingual nerve may happen during third molar surgery due to the
anatomical proximity of the cortex region of the molar to the nerve, being separated from
it by the periosteum alone.
5. inferior alveolar and/or lingual nerve injury and neurosensory function disturbance

36. 2.
postoperativ
e
are pain, swelling, bruising, trismus , osteitis and
surgical site infection .
Furthermore, the prevalence of post-extraction
complications correlated with the absence of
cortication around the mandibular canal
swelling after wisdom teeth removal

38. Other possible complications will be prolonged pain & discomfort, usually due to dense
socket bone around the wisdom tooth that restrain the blood clot formation ( Dry
Socket )

39. THANK YOU