Lecture 8: Management of Impacted Teeth

tooth impaction

A tooth that fails to erupt into the dental arch within the expected time

What is a common cause of tooth impaction?

inadequate dental alveolar bone arch length

What are the three most commonly impacted teeth?

1)maxillary/mandibular third molars (most)

2)maxillary canine (11-12 age)

3)mandibular premolars (10-13 age)

What are the indications for the removal of impacted teeth?

1)prevention of periodontal disease

2)prevention of dental caries

3)prevention of pericoronitis

4)prevention of root resorption

5)impaction under dental prosthesis

6)odontogenic cyst

7)fractured jaw

8)orthodontic treatment

How does the removal of an impacted tooth prevent periodontal disease?

adjacent teeth to the impacted tooth are predisposed to periodontal disease, so removal prevents

How does the removal of an impacted tooth prevent dental caries?

Bacteria that cause caries may gain access to the distal aspect of the 2nd or 3rd molar without removal

How does the removal of an impacted tooth prevent pericoronitis?

The infected/inflamed soft tissue around the crown will reduce with irrigation, antibiotics, and extraction of the tooth

How does the removal of an impacted tooth prevent root resorption?

The impacted tooth applies pressure on the roots of adjacent teeth, and without its removal, the adjacent tooth will require endodontic treatment or extraction.

How does the impaction of a tooth affect dental prosthesis?

Gradual resorption of the alveolar process and compression of the overlying soft tissue by a denture may cause exposure of the tooth with subsequent infection

How does the removal of an impacted tooth help with management of a fractured jaw?

The lower 3rd molar can weaken the bone at the angle of the jaw, making it more predisposed to fracture

How does the removal of an impacted tooth facilitate orthodontic treatment?

The removal of an impacted tooth can help alleviate the tendency toward crowding of mandibular anterior teeth

How does the removal of an impacted tooth help with an odontogenic cyst?

Helps treat an odontogenic cyst by eliminating the source of the cyst and allowing for complete surgical removal or healing of the surrounding tissue.

periocoronitis

Inflammation of the gingiva around a partially erupted tooth

odontoma

odontogenic tumor that abnormally proliferates (tiny teeth)

What are the contradictions for asymptomatic impacted teeth?

1)extremes of age (child<12 years or adult>50 years)

2)compromised medical status

3)probable damage to adjacent structures

What is the ideal time for the removal of impacted third molars?

between the ages of 16-18 when rots are usually 1/3 formed

What is the preferred radiograph for analysis of impacted teeth?

panoramic radiograph

What is the classification for impacted teeth acording to angulation?

1)mesioangular (53%)

2)horizontal (3%)

3)vertical (38%)

4)distoangular (6%)

mesioangular impacted tooth

crown of 3rd molar points in mesial direction and in contact with 2nd molar preventing eruption

horizontal impacted tooth

crown of 3rd molar is seen in horizontal position relative to the inferior border of mandible

vertical impacted tooth

normal position but prevented by distal aspect of 2nd molar or by anterior border of ramus

distoangular impacted tooth

crown of 3rd molar points in distal direction toward ramus and roots are adjacent to 2nd molar

Why is a distoangular impacted tooth so difficult to remove?

1)path of withdrawal is leaning into ramus

2)roots are in contact with the adjacent tooth

What is the order of difficulty for impacted molars based on angulation?

1)mesioangular (least)

2)vertical

3)horizontal

4)distoangular (most)

Pell and Gregory classification

Class 1, 2, 3: relationship to anterior border of ramus

Class A, B, C: relationship to occlusal plane

Class 1

entire crown is anterior to the anterior border of ramus

Class 2

crown is partially anterior to the anterior border of ramus

Class 3

crown is posterior to the anterior border of ramus (harder)

Class A

occlusal table of 3rd molar at level of occlusal table of 2nd molar

Class B

occlusal table of 3rd molar is between occlusal table and cervical margin of 2nd molar

Class C

occlusal table of 3rd molar is below cervical margin of 2nd molar (harder)

What factors influence the degree of difficulty of extraction for third molars?

1)root morphology

2)size of follicular sac

3)density of surrounding bone

4)contact with mandibular 2nd molar

5)relationship to IAN

6)relationship to maxillary sinus

7)relationship to maxillary tuberosity

8)nature of overlying tissue (soft, partial bone, or full bone)

How does root morphology affect extraction of third molars?

easy: partially developed, fused, and straight

hard: fully developed, separated, and curved

How does the size of the follicular sac affect the extraction of the third molars?

large: easier extraction (more space)

small: harder extraction (less space)

How does bone density affect extraction of third molars?

18 years or less: bone is less dense and more pliable for easier extraction

35 years or greater: bone is denser and less pliable for harder extraction

How does contact with the second molar affect extraction of third molars?

If contacted, to 2nd molar extraction is more difficult because you have to be aware of injury to the adjacent 2nd molar

How does the relationship to IAN or lingual nerve affect extraction of third molars?

IAN: risk of lip, chin, gum, and teeth paresthesia or anesthesia

lingual nerve: risk of tongue paresthesia or anesthesia

How does the overlying tissue affect extraction of third molars?

soft tissue: least difficult

partially bone: intermediate

full bone: most difficult

soft tissue impaction

The height of the tooth's contour is above the level of the alveolar bone

partial bone impaction

The superficial portion of the tooth is covered by soft tissue, but the height of the tooth's contour is below the level of the adjacent alveolar bone

complete bone impaction

The impacted tooth is completely encased in bone (most difficult to remove)

What are the basic steps of extraction for an impacted tooth?

1)reflection of an adequate thickness mucoperiosteal flap for accessibility

2)removal of overlying bone

3)section of tooth

4)removal of the sectioned tooth

5)debridement and closure of the wound

How do you perform an envelope flap for a mandibular 3rd molar?

Diverge laterally on posterior extension to avoid the lingual nerve and reflect tissue laterally to expose the underlying bone

How do you perform a three-cornered flap for a mandibular 3rd molar?

Create a releasing incision at the mesial aspect of the 2nd molar and reflect laterally to expose the underlying bone

How do you perform an envelope flap for a maxillary 3rd molar?

soft tissue reflected laterally to expose the underlying bone and should not be used for deep impacted teeth

How do you perform a three-cornered flap for a maxillary 3rd molar?

Create a releasing incision at the mesial aspect of the 2nd molar and reflect laterally to expose the underlying bone (use for deep impacted teeth)

How do you remove a slightly mesioangular mandibular 3rd molar?

1)buccodistal bone removed to expose crown of tooth to cervical line

2)distal aspect of crown section from tooth (just crown)

3)small straight elevator inserted into the purchase point along mesial aspect of 3rd molar (rotational and lever removal)

How do you remove a mesioangular impacted 3rd molar?

1)buccodistal bone removed to expose crown of tooth to cervical line

2)molar section in half vertically

3)distal half of the tooth is removed (crown and root)

4)mesial half of the tooth is removed (crown and root)

How do you remove a horizontal mandibular 3rd molar?

1)2/3 to 3/4 of buccodistal bone removed to expose tooth

2)crown section from roots and removed

3)innsuficient space then second horizontal (T) cut

4)superior half removed

5)inferior half removed

6)roots removed via purchase point on furcation with elevator

7)roots might need to be separated with aid of an elevator

8)superior root removed

9)inferior root removed

How do you remove a distoangular mandibular 3rd molar?

1)occlusal, buccal, and distal bone removed with a fissure bur

2)crown of sectioned off and removed with a straight elevator

3)purchase point in furcation is used to remove roots with pick elevator or triangular elevator

4)might need sectioning if roots are divergent

How do you remove an impacted maxillary 3rd molar?

1)small amount of buccal bone is removed with a bur or mallet, and a chisel

2)tooth is delivered with a small straight elevator or Potts elevator

What are patient management tools for extractions?

1)intraoperative anxiety and pain control (local anesthesia, IV sedation, light general anesthesia)

2)post-operative antibiotics

3)antibiotics

4)ice pack

5)gauze pack

6)reassurance (trismus, swelling, eating