ICP-32 Clinically Relevant Anatomy Flashcards
What are the 12 Cranial Nerves
1 - Olfactory 2 - Optic 3 - Oculomotor 4 - Trochlear 5 - Trigeminal 6 - Abducens 7 - Facial 8 - Vestibulocochlear 9 - Glossopharyngeal 10 - Vagus 11 - Accessory 12 - Hypoglossal
What does the trigeminal nerve innervate
The muscles of mastication, facial expression and the sinuses and teeth
What is the largest cranial nerve
The trigeminal nerve
Is the trigeminal nerve mainly sensory or motor
Sensory
What are the 3 main branches of the trigeminal nerve
Ophthalmic (V1)
Maxillary (V2)
Mandibular (V3)
What do the branches of the Maxillary division of the trigeminal nerve innervate
The upper teeth and their supporting structures
What branches of the Maxillary division of the trigeminal nerve are important in anaesthetics
- Posterior superior alveolar nerve
- Middle superior alveolar nerve
- Anterior superior alveolar nerve
- Nasopalatine nerve
- Greater and lesser palatine nerves
What structures does the posterior superior alveolar nerve innervate
Second and third molars, distobuccal and palatal cusp of the first molar and adjacent gingiva, mucosa, periodontium and buccal alveolar bone
What structures does the middle superior alveolar nerve innervate
Mesiobuccal cusp of the first molar, premolars and adjacent gingiva, mucosa and periodontium and buccal alveolar bone
What structures does the anterior superior alveolar nerve innervate
Canines, incisors and adjacent buccal gingiva, mucosa, periodontium and buccal alveolar nerve
What structures does the greater palatine nerve innervate
Palatal mucosa and bone adjacent to molars and premolars and canines
What structures does the lesser palatine nerve innervate
Soft palate and uvula
What structures does the nasopalatine nerve innervate
Palatal mucosa and bone adjacent to incisors and canines
Where is anaesthesia deposited to anaesthetise maxillary teeth and why
At the buccal side of the maxilla that infiltrates to the pulp of the teeth to produce anaesthesia this is because the cortical plate on the buccal side of the maxilla is thin, by injecting the solution above one tooth you will often get anaesthesia of adjacent teeth as well
Where would we aim to inject the LA and what structures will the needle pass through to get there
The stratified squamous epithelium and keratinised layer, through the lamina propria and aim to deposit the LA in the CT layer above the periosteum and bone, whilst trying to avoid any main vessels
Where does the nasopalatine nerve exit the maxilla
Incisive papillae
Where does the greater and lesser palatine nerves exit the maxilla
At the greater and lesser palatine foramen
What LA administration techniques are there in the palate
Infiltration or block techniques
Infiltration of how much LA deposited where will anaesthetise the palatal tings
0.2 ml into the palatal mucosa just distal to the tooth of interest
What will infiltration of the palatal mucosa anaesthetise
The palatal mucosa and periodontium anterior to the point of infiltration up to the canine region
When carrying out palatal infiltrations what is different about the upper third molar and why
Unlike all other teeth the infiltration of the upper third molar, the solution should be deposited at the anterior aspect of the tooth as the greater palatine foramen lies anterior to the third molar tooth and the nerve supplying this region travels in a posterior region
When anaesthetising the anterior region (canines and beyond i think) what kind of LA admin is preferred
Nasopalatine nerve block
How do you know whether or not to anaesthetise both the palatal mucosa and main nerve supply
Depends on procedure:
Extraction = both buccal and palatal nerve supply
Restorative procedures - usually anaesthesia of the main nerve supply is enough
What structures does the inferior alveolar nerve innervate
Mandibular teeth and alveolus
What structures does the long buccal nerve innervate
Buccal gingiva and mucosa opposite molars and premolars
What structures does the mental nerve innervate
Buccal gingiva and mucosa opposite premolars, canines and incisors, skin and mucosa of the lower lip and chin
What structures does the lingual nerve innervates
Anterior 2/3 of the tongue, gingiva, mucosa and floor of the mouth
What kind of LA administration do we need to use in mandibular teeth and why
Regional nerve block as the cortical bone is too thick so we need to inject the LA near the nerve trunk
What is the conventional method used to anaesthetise teeth in the mandible
Inferior alveolar nerve block (IANB) - Can use infiltration for the mandibular anterior teeth where the cortical plate is thinner
What are the advantages of infiltration LA administration
- Simple
- When successful it anaesthetises all nerve endings in the area
What are the disadvantages of infiltration LA administration
- LA must diffuse through bone
- Localised infection may be spread if an inflamed area is infiltrated
- Only a limited zone of anaesthesia per injection
What are the advantages of regional block techniques
- Anaesthetic delivered to a major nerve
- Blocks sensation downstream of the injection site
- The more proximal the block, the greater the affected area
- Widespread anaesthesia from one injection
- Anaesthetic can be injected away from infected areas
What are the disadvantages of regional block techniques
- Regional blocks require complete knowledge of the anatomy and are harder to perform
- Does not anaesthetise nerve endings from different trunks - in the midline
- Excessive soft tissue anaesthesia
- May cause haemorrhage in patients with bleeding disorders
- Potential for injury to a nerve trunk
What does the mandibular foramen function as
Entrance to the mandibular canal that transmits the inferior alveolar vessels and nerves to the roots of the mandibular teeth
What happens at the mental foramen
Branches of inferior alveolar vessels and mental nerve emerge from the mandibular canal at the mental foramen
What does the lingual do
Thin tongue like projection of bone that overlaps and guards the superior border of the foramen - has some role in IANB techniques?
