Coronectomy Flashcards
There is an associated risk of “dry socket” associated with coronectomies. True or false
True
A loss of lamina dura of the canal is linked to …
contact of M3M with the canal
What is the additional dose is associated with CBCT ?
60-120 uSv
In cases where CBCT has shown no significant association with the IAN canal, it is beneficial to proceed with the M3M removal. Why is this?
- removes additional risk of future infection and resultant need for additional surgery of root removal
What must you include when consenting patients for coronectomies?
- “it is intended for coronectomy to be undertaken, however, if the roots are mobilised during surgery then they will require removal with heightened risk of nerve injury”
- risk of infection which will necessitate removal of roots
What risks are associated with retained roots following coronectomies that require removal?
although some of the roots erupt away from the IAN canal, the nerve may perforate the root and thus it drags the nerve superiorly as it erupts
What LA is appropriate to deliver for M3M coronectomy?
Long buccal infiltration and anterior buccal infiltration using 4 ml of 4% articaine
Inferior dental block using 2% lidocaine may be used if necessary
What flap is used to expose the M3M ?
buccal triangular mucoperiosteal flap
What surgical technique can be used to prevent mobilisation of the root? What risk is associated with this technique?
extending sectioning of the crown from the roots
associated with increased risk to the lingual nerve
What are the additional indications for elective coronectomy provided by the CBCT?
- loss of lingual cortex and buccally placed mandibular canal with M3M root sandwiched them
reduced lingual cortex-M3M root- buccal IAN canal
Where is the gutter placed ?
on the bone adjacent and buccal to the tooth (NOT distal!)
What is used to create the gutter ?
fissure bur
What is the aim of the creation of a gutter?
expose the EDJ so that we can cut into the pulp
Briefly describe how the fissure bur is used to drill directly into the pulp
- lateral cut is used to create a horizontal groove in the tooth, just below the EDJ
- depth of the cut should be into the pulp
- depth of the cut should be no longer than the length of the fissure bur avoid lingual perforation of the lingual cortical plate
Following the horizontal groove creation, how is the crown seperated from the root ?
small elevator instrument such as coupland No.1 or straight warwick james is used to fracture off the crown from the roots
Whilst fracturing off the crown from the roots, what must you take care not to do?
- must take care not to apply too much torque to the tooth as it may increase the risk of mobilisation of the root
How would you manage a coronectomy for a mesioangular or horizontally impacted tooth?
- further sectioning to avoid damage to lower 2nd molar tooth
What is used to remove any enamel spurs remaining on the root?
rose head bur
What is an acceptable guidance for the amount of root that should be left behind?
- should be a few millimetres below the crestal bone level
Ideally, where should alveolar bone be present following coronectomy?
should be above the root edges but this is not always possible (e.g. missing lingual plate)
What type of suture is appropriate for closure following coronectomy ?
- resorbable
- single 4-0 vicryl
How would you treat “dry socket” symptoms associated with a coronectomy?
- irrigation using chlorhexidine solution
- placement of resorbable dressing alvogyl
