Wizzies Flashcards
Types of impaction
Soft tissue impaction
Bony impaction
How to identify soft tissue impaction
Tooth almost erupted but covered partially by a dense fibrous operculum
Crown above alveolar bone level, can probe distally beyond the crown height
Easier to extract as compared to bony impaction
What is bony impaction
Tooth obstructed by overlying alveolar bone
Partial bony impaction: part of tooth will be visible after raising flap
Complete bony impaction: will require bone removal after raising flap before the tooth is visible, more expensive, basically tooth is completely buried
Winter’s Classification
Inclination of impacted tooth wrt to long axis of 2nd molar
Degree of difficulty: Distoangular > mesioangular > vertical
Why distoangular so difficult?
> takes up more space
> mesial root is blocked by 7
> very near the lingual nerve, higher risk of damage
Pell and Gregory’s Classification
Relationship of lower wisdom tooth to occlusal plane and anterior border of descending ramus, shows you how much bone you need to remove
Position
> A: Occlusal plane at same level as 2nd molar
> B: Occlusal plane between occlusal plane and cervical margin of 2nd molar
> C: Occlusal plane below cervical margin of 2nd molar
Class
> 1: Entire mesiodistal width of crown anterior to anterior border of ramus
> 2: Approx half crown is anterior to anterior border of ramus
> 3: Crown totally embedded in the bone of the ramus
How does placement/angulation affect difficulty?
Vertical: conical roots easier to exo than bulbous roots
Horizontal: main factor is depth of tooth
Mesioangular: teeth with bifurcated roots easier to section and easier to remove (unless super bifurcated and therefore lots of bone in between)
Distoangular: generally more difficult as there is higher chance of damaging the 7 or lingual nerve
Buccally placed teeth are easier as you always raise flap from buccal side
Orthognathic surgery link to 3rd molar removal?
Need to wait at least 6 months to do orthognathic surgery after exo of 8s, as in orthognathic surgery you induce iatrogenic fractures
If too soon after exo the fracture may occur at the wrong plane as it follows the weak spot created by the extraction socket
Steps of 3rd molar surgical removal
1) Anesthesia
2) Incise
3) Raise mucoperiosteal flap
4) Gutter bone
5) Section tooth if necessary
6) Elevate tooth
7) Irrigate
8) Suture
9) Post-op instructions
What to anesthetize for surgical removal of mandibular 3rd molars?
IDN: Mand teeth until midline, body of mandible
Mental nerve: Buccal periosteum anterior to mental foramen
Lingual nerve: Anterior 2/3 of tongue, floor of oral cavity, lingual soft tissues, periosteum
Long buccal
Considerations when raising mucoperiosteal flap
Allow for adequate access to underlying tooth and bone
Resist tearing by using a sharp blade and firm, continuous strokes
Should have a broad base with good blood supply
Flap design:
> Not super impt, more impt is operator familiarity
Types of mucoperiosteal flap designs
Envelope flap
> Cut along ascending ramus to distobuccal surface of second molar. Cut more buccal to avoid lingual nerve, and must avoid fracturing the lingual plate and causing compressive nerve injury
> Extend as a sulcular incision, usually to 6 unless there are extenuating factors like crown or brackets on 6
Triangular flap
> Just cut a lil triangle, envelope flap but ends at midbuccal of 7 and goes inferiorly
> Must stop before going below bone of mandible or will cut facial artery
> Used if there are extenuating circumstances preventing the use of the envelope flap
Lingual-based flap
> Impractical as hard to retract flap
Purposes of guttering bone for 3rd molar surgical removal
Dis-impacts the tooth and gains access
Creates space for retrieval
Creates engagement point for elevators
How to gutter bone?
Use a round bur to drill out the distal and buccal aspects (starting distobuccally and moving mesially)
Should have good access to both mesial and distal contact points of the tooth crown
How to do tooth sectioning and considerations
Most impt step! So do carefully and take ur time
Dis-impacts the tooth, removing undercuts and cuts the tooth into smaller pieces
Can either divide longitudinally (parallel to tooth axis) or transversely (perpendicular to tooth axis)
Decoronate first in horizontal and distoangular impactions
Stay within the tooth, cannot go beyond in case the nerve is nearby! After cutting can fracture the tooth with instruments
Be careful not to damage adjacent restorations esp in mesioangular impactions!
What sutures are the most commonly used?
Interrupted sutures, as they are easy, fast, reliable and have less surface contact
