Management of Impacted Teeth

Question 1

what is an impacted tooth

Answer 1

a tooth that fails to erupt into the dental arch within a specific time frame

Question 2

what is the etiology of impacted teeth

Answer 2

• inadequate arch length
• prolonged deciduous tooth retention
• malposition of impacted tooth
• malposition of adjacent tooth/teeth
• excessive bone and/or soft tissue
• associated pathology

Question 3

what is the order of frequency of impacted teeth

Answer 3

• mandibular third molars
• maxillary third molars
• maxillary canines
• mandibular premolars
• mandibular canines
• maxillary incisors
• supernumeraries

Question 4

what are the classification of impacted teeth

Answer 4

• degree of impacted (depth in bone)
• position of tooth (long axis of tooth in bone)
• pell and gregory

Question 5

what are the classifications of impacted teeth - degree of impaction- depth in bone

Answer 5

• erupted- normal levels of surrounding bone
• soft tissue impaction
• partial bone impaction
• complete bone impaction

Question 6

what are the classifications of impacted teeth - position of tooth

Answer 6

• vertical
• mesioangular
• horizontal
• distoangular
• inverted
• buccal/palatal or lingual

Question 7

what type of position of tooth (long axis of tooth in bone) is most common in the maxilla

Answer 7

vertical

Question 8

what type of position of tooth (long axis of the tooth in bone) is most common in the mandible

Answer 8

mesioangular

Question 9

what is class 1 pell and gregory

Answer 9

-sufficient amount of space between the anterior border of the ramus and the distal of the second molar for the accomodation of the entire crown (mesio-distal diameter) of the third molar
- situated anterior to the anterior border of the ramus and there is adequate room to erupt

Question 10

what is the order of frequency with reference to position of tooth - long axis of the tooth in bone in the mandible

Answer 10

• mesioangular
• vertical
• distoangular
• horizontal
• buccal/lingual
• inverted

Question 11

is the pell and gregory classification commonly used

Answer 11

no

Question 12

what is class 1,2,3 in pell and gregory classification

Answer 12

relation of the mandibular third molar to the anterior border of the ramus

Question 13

what is class A,B, C in pell and gregory classification

Answer 13

depth of the impaction of maxillary or mandibular 3rd molar in bone relative to the adjacent tooth

Question 14

what is pell and gregory class 2

Answer 14

• space between the anterior border of ramus and the distal of the second molar less than the mesio distal diameter of the crown of the third molar
• crown 1/2 covered by the anterior border of the ramus

Question 15

what is the order of frequency with reference to position of tooth in the maxilla

Answer 15

• vertical
• distoangular
• mesioangular
• disto horizontal
• mesio horizontal
• buccal/palatal
• inverted

Question 16

what is pell and gregory class 3

Answer 16

• all of the third molar is within the ramus
• crown fully covered by the anterior border of the ramus

Question 17

what is pell and gregory class A and where is it located

Answer 17

the occlusal plane of the impacted tooth is at the same level as the adjacent tooth
- maxilla

Question 18

what is pell and gregory class B and where is it

Answer 18

• the occlusal plane of the impacted tooth is between the occlusal plane and the cervical line of the adjacent tooth
• mandible and maxilla

Question 19

what is pell and gregory class 3 and where is it

Answer 19

• the occlusal plane of the impacted tooth is apical to the cervical line of the adjacent tooth
• mandible and maxilla

Question 20

all impactions are potentially_____so _____ is important

Answer 20

pathologic, prevention

Question 21

prudent care requires:

Answer 21

removal, exposure, or repositioning

Question 22

pathologic conditions are more common with:

Answer 22

increasing age

Question 23

surgery is more difficult and associated with more complications with:

Answer 23

increased age and oral and systemic compromises

Question 24

surgery is more difficult if _____ such as ______

Answer 24

symptoms present, acute pain and infectionsu

Question 25

surgery in younger patients is associated with:

Answer 25

better healing and less morbidity

Question 26

what age is considered a young patient

Answer 26

less than 25 years old

Question 27

when is third molar surgery ideally performed

Answer 27

when roots are 1/2 to 2/3rds formed

Question 28

what are the indications for removal of impacted teeth

Answer 28

- facilitate the management of or limit progression of periodontal disease - non-restorable caries - non-treatable pulpal lesions - acute or chronic infection - preventive or prophylactic removal - ectopic position - internal or external resorption of tooth of adjacent tooth - facilitate prosthetic rehabilitation - facilitate orthodontic movement and promote dental stability - orthodontic abnormalities - pathology associated with tooth follicle - tooth interfering with orthognathic, reconstructive surgery, trauma or tumor surgery - prophylactic removal in patients with certain medical or surgical conditions or treatments

Question 29

what are examples of orthodontic abnormalities

Answer 29

- arch length/tooth size discrepancies - malposed/impacted second molars

Question 30

what are examples of indications for prophylactic removal in patients with certain medical or surgical conditions or treatments

Answer 30

- organ transplant - alloplastic implants - chemotherapy - radiation therapy

Question 31

what are the contraindications for removal of impacted teeth

Answer 31

- extremes in age - medical condition - surgical morbidity - good outcome with orthodontic eruption

Question 32

what are examples of medical conditions that would be contraindications to removal of impacted teeth

Answer 32

- poor surgical candidate like patient on IV bisphosphonates - head and neck irradiation - significantly compromised cardiac status

Question 33

what are examples of surgical morbidities that would be contraindications to removal of impacted teeth

Answer 33

good outcome with orthodontic eruption

Question 34

the evaluation of the impacted tooth and diagnosis of associated problems are based on:

Answer 34

- history - clinical exam - radigoraphy

Question 35

what history should be evaluated in impacted teeth

Answer 35

- teeth with or without history of pain and swelling of overlying mucosa - inflammation around the crown of the tooth that make more acute symptoms - mouth opening - airway exam - TMJ exam

Question 36

what is pericoronitis and what can it be caused by

Answer 36

- infection of the soft tissue (operculum) around the crown of a partially impacted tooth - caused by normal oral flora - compromised host defenses - trauma (occlusal) - food entrapment

Question 37

what are the treatments for pericoronitis

Answer 37

- removal of offending tooth - removal of opposing tooth - irrigation/debridement - removal of operculum - incision and drainage of infection - antibiotic therapy

Question 38

what needs to be examined in the clinical exam for impacted teeth

Answer 38

- identify caries and periodontal diseases - vitality test of all teeth in doubt - examination for sign of infection - facial asymmetry and jaw bone expansion

Question 39

why is it important to identify caries and periodontal disease in impacted teeth

Answer 39

pain might be from adjacent carious tooth

Question 40

what are the signs of infection

Answer 40

swelling, discharge, trismus, and enlarged lymph nodes

Question 41

what are the possible statuses of tooth in question based on clinical eval

Answer 41

- erupted but non functional (no opposing, tilted, carious) - partially erupted (Covered partially with soft tissue) - partially erupted with signs of recurrent infection - truly impacted (bony or soft) - association with pathological lesions

Question 42

what needs to be done in radiographic assessment

Answer 42

- PA radiograph - orthopantomogram - CBCT

Question 43

what is the radiographic assessment standard of care

Answer 43

orthopantomogram (OPG)

Question 44

what are the purposes of radiographic examination

Answer 44

- to identify the impacted tooth and the density of the surrounding bone - to identify the position of the impacted tooth in the jaw and its relation to adjacent teeth and other vital structures - to disclose the degree and orientation of impaction - to examine the configuration of the roots - to examine the existence of pathological development around the impacted teeth

Question 45

what are the possible configurations of the rooths

Answer 45

- curvature - numbers - hypercementosis - bulbous -fused or diverged

Question 46

what are the vital structures to be concerned with

Answer 46

maxillary sinus and inferior alveolar canal

Question 47

what are the radiogrpahic predictors of nerve injury

Answer 47

- darkening of root - deflection of root - narrowing of root - interruption of the white line of the canal - diverserion of the canal - narrowing of the canal

Question 48

what are the radiographic signs of increased risk of inferior alveolar nerve injury

Answer 48

- deviation of the canal - narrowing of the canal - PA radiolucent area - narrowing of root - darkening of roots - curving of root - interruption of the white line of the canal- loss of lamina dura of canal

Question 49

what can CBCT identify

Answer 49

- number, location, relative position - cystic degeneration - effect on adjacent teeth, nerve, sinus floor