third molars Flashcards
What are some indications for extracting third molars?
a) resorption of tooth/ adjacent tooth
b) abscess, osteomyelitis
c) extensive or nonrestorable caries in 7s
d) disease of tooth follicle such as cyst , tumors
e) tooth in line of jaw surgery
F) PERICORONITIS
What is pericoronitis?
soft tissue inflammation related to crown of partially erupted teeth as a result of food, debris and plaque accumulation in gingivae resulting swelling and erythema
What are some bacteria present in pericoronitis?
a) streptococci and anaerobic bacteria
When is pericoronitis worse?
pts. stress and feeling run down.
Also, severity increases in immunocompromised pts.
Describe symptoms of acute pericoronitis.
a) pain and swelling localized to the tooth
b) radiation of pain possibly.
Explain examination findings of acute pericoronitis
a) trismus
b) swollen tender to the operculum
c) EO swelling and lymphadenopathy
Describe symptoms of chronic pericoronitis
a) pus released from beneath operculum
b) radiological sign of enlargement of pericoronal space and sclerosing osteitis.
Note: traumatised operculum from opposing over erupted third molar
What is sclerosing osteitis?
is abnormal bone growth and lesion in the jaw due to infection or inflammation.
How to manage episode of pericoronitis?
a) OH
b) single stuffed brush to clean around the tooth
c) irrigate and prescribe chlorhexidine mouthwash
d) grind or extract opposing third molars.
If systemic involvement : prescribe antibiotics
What antibiotics are given to pts. with pericoronitis?
1st line: metronidazole 400mg orally three times a day for 5 days can be given IV 500mg every 8 hrs given over 20 mins.
children: 200-250mg orally every 8 hours for up to 5 days.
What happens if 1st line antibiotics fail or is not possible?
prescribe 2nd line which is amoxicillin 500mg orally three times a day for 5 days can be given IV 500 mg every 8 hours
for children: 500mg 3 times a day
What are the most frequent reason for removing third molars? (NICE and other)
NCIE: one or more severe episodes of pericoronitis
Other: 1) if pt. having GA for extracting other 8s and is likely to be symptomatic
2) non-functional upper 8
3) lower 7s caries distally consider removing 8.
Is there evidence thast removing third molars reduces anterior crowding and improves anterior open bite?
No, also u need to always eliminate TMD (temporomandibular disorder) and myofascial pain
What do the new FDS guidelines state?
a) post-op with chlorhexidine gel
b) 8s mesioangular between 30-90 degrees may cause caries in 7s.
c) support the use of pre-op steriods
d) CBCT has no effect on outcomes
What are factors that are taken into consideration in extracting third molars?
a) mouth opening (trismus?)
b) bone density (bisphosphonates?)
c) tooth (angulation, crown size, caries)
d) surgical anatomy (id nerve, cystic changes?)
e) adjacent teeth (caries, restorations, periodontal status)
If it’s hard to assess the depth of 3rd molar in the alveolar bone what do you do?
insert and elevator to the roots of lower 7s to assess its depth.
Is all of the third molars close to the ID canal?
No, the main three that are found to mainly related to IDN injury is
a) diversion of canals
b) darkening of the tooth (banding)
c) interruption of tramline of the nerve
Even though CBCT is 10x radiation dose of OPT, when is it indicated?
a) only when conventional radiographs don’t show a relationship of 8s and ID
b) cysts
c) trauma and TMJ
What is coronectomy?
partial odontectomy where u remove the crown at CEJ (as root lies -4mm below crestal bone level) and you don’t leave enamel however if the roots are mobilized you proceed to removal,
When is coronectomy necessary?
high risk 8s which are close to IDC.
Why do you have to remove enamel in coronectomy?
Because gums don’t grow over enamel as enamel pushes through it therefore leaving no soft tissues.
Why do you have to remove enamel in coronectomy?
Because gums don’t grow over enamel as enamel pushes through it therefore leaving no soft tissues.
What are the aims of surgery? (remove 8s)
minimize trauma (sectioning tooth)
remove tooth
better vision of flap/ bone removal
create application point
promote healing (debridement and closure)
What are the types of flap designs for third molars? and what are the principles behind it?
triangular and envelope flaps,
mainly to maintain blood supply, suture over bone, avoid vital structure , preserve papillae and ability to close and extend when necessary.
How do you section the tooth?
a) start furcation , section to remove part by part
b) bur’s depth ONLY if you pass (damage to the lingual nerve)
c) use space for elevation
What do you usually use to debride and curettage the socket?
mitchell’s trimmer
List some complications that could happen intra-op removing third molars.
Tooth/alveolar bone fracture
Fracture of maxillary tuberosity
OAC (oral mantra communication)
Hemorrhage
Tooth/root displacement
Damage to adjacent teeth
Damage to soft tissues
Inhaled/swallowed roots
Lip burn
(Fractured mandible)
List some complications that could happen post-op removing third molars.
Pain
TMJ injury
Abscess/spread to tissue spaces
Dry socket (higher risk with 8s/bone removal)
Bleeding
Reactionary (clot lost <48 hours) Secondary (infection)
Haematoma
Nerve damage
Osteomyelitis is rare (infection of bone post tooth extraction)
What is pain?
unpleasant sensory or emotional experience associated with actual or potential tissue damage.
How is pain when removing third molars and removing bone controlled?
prescribing ibuprofen or paracetamol plus or minus other opiods.
