Third Molars - L1

Question 1

what age do third molars roughly erupt at in the mouth?

Answer 1

18-24Y

Question 2

when does crown calcification start, & end by? (for 8’s)

Answer 2

starts: 7-10y
ends: 18y

Question 3

when is root calcification completed in 8s?

Answer 3

18-25Y

Question 4

what is the incidence of impacted lower 8s?

Answer 4

36-59%

Question 5

what are the consequences of impaction of 8s?

Answer 5

caries, pericoronitis, cyst formation

Question 6

what are the nerves at risk in third molar surgery?

Answer 6

• inferior alveolar nerve
• lingual nerve
• nerve to mylohyoid (branch of CN V3)
• long buccal nerve

Question 7

where is rough location of lingual nerve?

Answer 7

• close relationship to lingual plate in mandibular & retromolar area
• between 0-3.5mm medial to mandible

Question 8

what are the guidelines we have on wisdom teeth?

Answer 8

• NICE Guidelines
• SIGN
• FDS (Faculty Dental Surgery)

Question 9

what are indications for XLA of 8s?

Answer 9

• infection (caries, pericoronitis, perio, bone infection) [MOST COMMON]
• cysts
• tumours
• external resorption of 7 or 8

Question 10

what is pericoronitis?

Answer 10

• inflammation around the crown of a partially erupted tooth. Debris trapped under operculum resulting in inflammation/infection

(anaerobic microbes)

Question 11

what are the signs & symptoms of pericoronitis?

Answer 11

• pain
• swelling
• bad taste
• pus discharge
• occlusal trauma & ulceration of operculum
• discomfort
• limited mouth opening

Question 12

what is the tx options for pericoronitis?

Answer 12

• incision of localised pericoronal abscess (IF REQUIRED) [IDB if needed]
• Irrigation with saline/CHX under operculum
• analgesic advice
• ANTIBIOTICS - ONLY - If systemic symptoms, swellings, immunocompromised, or severe

Question 13

what are PREDISPOSING FACTORS for pericoronitis?

Answer 13

• partial eruption & vertical/distoangular impaction
• poor OHI
• full dentition
• white ethnicity