OS- Wisdom teeth Flashcards
When do wisdom teeth normally erupt
18-24
When does the calcification of the crowns of 8s start?
uppers 7-9. Lowers 8-10 years.
When is root calcification complete in wisdom teeth?
18-25
What is third molar agenesis?
When there is no third molar as it has not formed.
Where is third molar agenesis more common?
Maxilla. and in females
What is the rule of thumb for third molar agenesis?
If the 8 is not visible in a radiograph by 14- 8 will fail to develop.
What is the most common cause of failed eruption of third molars
Impaction
What is impaction?
The blocking of eruption of the tooth by (alveolar bone/other teeth/ surrounding mucosal soft tissue)
Compare unerupted/partially erupted and fully erupted third molars.
Unerupted- contained in the bone.
Partially erupted- some of the tooth has erupted into the oral cavity.
Fully erupted- whole occlusal surface is through the mucosa and exposed.
List the consequences of wisdom tooth impaction?
Caries
Pericoronitis
Cysts.
What nerves are at risk during a third molar surgery.
Lingual nerve
Inferior alveolar nerve
Nerve to mylohyoid.
Long buccal nerve .
Discuss the location of the lingual nerve.
Close to the lingual plate in the mandibular and retromolar region
Name the current guidelines followed for extraction of wisdom teeth
Faculty of dental surgery (FDS) parameters of care.
List indications for extraction of 8s
- infection (caries/pericoronitis/periodontal disease/ local bone infection
- Cysts
- Tumours located close to the molar
- External resorption of 7/8
- in the way of a surgical
- High risk of disease
- Medical indications (e.g. MRONJ)
What 8s would have a higher risk of caries?
A mesial angle or horizontally impacted 8
What is pericoronitis?
Inflammation around the crown of a partially erupted tooth. This causes food and debris to get trapped under the operculum (flap of gum) resulting in inflammation/infection (it is difficult to keep clean)
How can we tell clinically that a tooth is partially erupted?
If we find a communication when Probing distal to the 7
What is the normal age of patients presenting with pericoronitis?
20-40
Give signs and symptoms of pericoronitis?
- Pain
- swelling
- pus (causing bad taste)
- Bad breath
- Trauma to the operculum.
- Cheek biting
- Limited mouth opening
- Regional lymphadenopathy
- Dysphagia
- Pyrexia
How do we treat pericoronitis?
Incise the abcess
LA (dependent on patient and pain)
Irrigate the area with warm saline or chlorhexidine mouthwash (10-20ml syringe with blunt needle – under the operculum).
How does a patient presenting with ulceration of the operculum influence treatment?
The upper 3rd molar should be extracted as it is traumatising the operculum.
What patient instructions do we give to someone with pericoronitis?
Frequent mouthwash (warm saline or chlorohexidine)
Analgesia
Keep fluid levels up and keep eating (soft/liquid diet if neccessary)
When do we prescribe antibiotics for pericoronitis and what do we prescribe?
Extra-oral swelling.
Systemically unwell.
Immunocompromised
Metrondiazole.
How does pericoronitis presentation impact extraction of 8s
You need to wait for the resolution of the pericoronitis before extacting the 8s.