Impacted Teeth Flashcards
What are 2 common types of impacted teeth?
- Mandibular 3rd molars
2. Maxillary canines
Describe a possible history during the clinical assessment of a patient with impacted mandibular 3rd molars
- Pain / Swelling
- Bad taste
- Number of episodes
- Severity of the pain
- Antibiotic treatment
Describe 3 clinical issues in the mouth which impacted mandibular 3rd molars do not cause
- Facial pain
- Lower incisor crowding
- Movement of other teeth
Describe the intra oral examination for a suspected impacted mandibular 3rd molar
- Access to the impacted tooth
- Degree of eruption if any
- Decay in the impacted tooth or adjacent 7
- Any evidence of food packing
Describe the radiological assessment of an impacted mandibular 3rd molars
- IOPA usually not sufficient to show inferior boarder of mandible
- OPT is most commonly used
- CBCT use where increased risk or surgical difficulty as precise interpretation of relationship between tooth and IDN
What are essential components of the radiological assessment of impacted mandibular 3rd molars?
Allow assessment of:
- all of third molar
- type and orientation of impaction
- crown size and condition
- root morphology
- bone level / periodontal status
- relationship between ID canal and lower boarder of mandible
Name 2 types of impaction of impacted mandibular 3rd molars
- Soft tissue
2. Boney
Describe 4 types of boney impaction of mandibular 3rd molars
- Mesioangular (crown towards 7 and roots distal)
- Distoangular (crown towards ramus of mandible and roots mesial)
- Vertical
- Horizontal
What are Winters Lines (WAR Lines) used for?
Imaginary lines on a radiographs used to estimate depth and angle of impaction
What 3 lines make up Winters Lines?
- White line
- Amber line
- Red line
Describe the white line in Winters Lines
- Drawn along the occlusal surface or erupted mandibular molars
- Extended over the 3rd molar posteriorly
- Indicates difference in occlusal level of 1st + 2nd molars and third molar
Describe the amber line in Winters Lines
- Drawn from the surface of the bone on distal aspect of 3rd molar to crest of interdental septum between 1st and 2nd molar
- Denotes margin of alveolar bone covering 3rd molar and gives indication of amount of bone which will need removed
Describe the red line in Winters Lines
- Imaginary line drawn perpendicular from amber line to point of application
- Usually cemento-enamel junction on the mesial aspect of the tooth
Which type of boney impaction tends to be the hardest to extract?
Distoangular as the path of withdrawal for these teeth tends to be straight into the angle of the mandible
What are 4 signs that the IDN is in close proximity to the tooth?
- Deviation of the nerve canal
- Narrowing of the nerve canal
- Loss of tram lines
- Change in radiodensity of the tooth
Describe perforation of the tooth by IDN
- Uncommon
- Difficult to tell from an OPT if this is the case
- Need to obtain CBCT to verify perforation
- Difficult to extract the tooth if perforation occurs
Describe perforation of the tooth by IDN
- Uncommon
- Difficult to tell from an OPT if this is the case
- Need to obtain CBCT to verify perforation
- Difficult to extract the tooth if perforation occurs
Describe the treatment options for impacted mandibular 3rd molars
- Surgical removal
- Coronectomy
- Operculectomy
- Remove opposing tooth
- Surgical exposure
- Monitor
Describe coronectomy as a treatment option for impacted mandibular 3rd molars
- Reserved for teeth which are bigger risk
- Remove the crown of the tooth and leave the roots
- Risk of infection especially if the roots are mobile
Describe operculectomy as a treatment option for impacted mandibular 3rd molars
- Flap of the gum is removed from over the tooth
- Not carried out often as does not work particularly well
Describe removal of the opposing tooth as a treatment option for impacted mandibular 3rd molars
- Encourage lower wisdom tooth to erupt further
- Less risks associated with the upper wisdom tooth extraction
Describe surgical exposure as a treatment option for impacted mandibular 3rd molars
Not very commonly carried out for a wisdom tooth
Describe 6 indications not to remove an impacted mandibular 3rd molar
- No / minimal symptoms
- Lower incisor crowding
- Treatment for TMD
- Contralateral tooth removal
- Patient wishes
- Close proximity to IDN
Describe 7 indications for removal of impacted mandibular 3rd molar
- Pericoronitis (2 or more episodes)
- Unrestorable caries
- Non-treatable pulpal or periapical disease
- Fracture of tooth
- Disease of follicle e.g. cyst / tumour
- Tooth impeding surgery
- Resorption of tooth or adjacent tooth
Describe extraction of impacted mandibular 3rd molar with regards to proximity to IDN
- Does not preclude surgery
- Indications for surgery must be clear
- Appropriate imaging (CBCT if indicated)
- Discuss all option and implications with patient
- Informed consent
Describe the risk assessment of surgical extraction of impacted mandibular 3rd molar
- Balance risks v benefit to patient
- Is the treatment required?
- Are there risks involved in leaving the tooth?
- Can the patient tolerate the procedure?
- Have I the relevant expertise to carry out the procedure?
Describe informed consent with regards to surgical extraction of impacted mandibular 3rd molar
- Written informed consent must be obtained
- Risks of surgery and leaving tooth in situ
- General surgical risks
- Specify risks to ID and lingual nerves
- Cooling off period following explanation
- Written advice sheets reinforcing verbal discussion
What is the acronym for describing risks with regards to impacted mandibular 3rd molar?
STALL
- Swelling
- Trismus
- Anaesthesia
- Labial
- Lingual
Where are most ectopic canines found?
80% of impacted canines are found in the palate
Describe the clinical assessment of ectopic canines
- Aim to assess position of tooth and damage to adjacent ones
- Bulge palpable buccally or labially
- Proclination of upper incisors
- Vitality of upper lateral incisors
- Mobility of lateral upper incisors
- Retention / mobility of deciduous canines
What is the parallax technique?
- 2 radiographs taken at different angles
- Canine position relative to other teeth compared on both films
- If tooth moves in same direction of beam it is palatally ectopic
- If tooth moves in opposite direction of beam it is labially ectopic
What 3 pairs of radiographs can be taken to parallax?
- IOPAs x2
- IOPA and Anterior Occlusal
- OPT and Anterior Occlusal
Describe 4 treatment options for ectopic maxillary canines
- Leave and monitor
- Open exposure
- Closed exposure with bracket and chain
- Surgical removal
What are the 2 main risks of ectopic maxillary canines?
- Movement in the maxilla can destroy other teeth, however risk drops off after around 14 years old
- Any unerupted tooth can form cysts
What are the risks of extraction of ectopic canines?
- General risks, (post-op pain, bleeding, swelling)
- Risk of damage to surrounding teeth
Describe open exposure as a treatment option for ectopic maxillary canines
- Gum has been peeled back and tooth uncovered
- Cut taken out of the gum overlying the tooth
- Palatal flap put back into place
- Put bandage over the teeth to prevent gingiva overgrowing the tooth
Describe closed exposure as a treatment option for ectopic maxillary canines
- Flap lifted up overlying the tooth and gold chain and orthodontic bracket attached to tooth
- Eventually attached to orthodontic brace
- Main risk is chain falling off which means replacement procedure
- Aesthetic purposes usually the reason for closed exposure
Describe 2 risks of no surgery on ectopic maxillary canines
- Root resorption
2. Cyst formation
Describe 2 risks of exposure on ectopic maxillary canines
- Failure of eruption
- Small risk of damage to adjacent teeth
- Gold chain risk of debond and repeat surgery
Describe the main risk of removal of ectopic maxillary canines
Damage to adjacent teeth
Name 3 examples of impacted teeth which are not mandibular 3rd molars or maxillary canines
- Mesiodens
- Supernumaries
- Lower canines
How is an impacted tooth defined?
Any tooth with 2/3 or more root formed that is unlikely to erupt
What is a mesioden?
A supernumerary tooth which grows between the upper central incisors
