Dental blocks

Question 1

Infraorbital block or rostral maxillary block:
What nerve is the infraorbital nerve a branch of?
What tissues does it innervate?
Which surgeries would you choose this block for?
what do you need to be carful about?
you can apply pressure with the thumb over the infraorbital foramen, why?

Answer 1

What nerve is the infraorbital nerve a branch of?
Is a branch of the maxillary nerve, which is a branch of the trigeminal nerve (CNV)
What tissues does it innervate?
This nerve then separates out into smaller branches that provide afferent innervation to the buccal maxillary soft tissue, rostral to the infraorbital foramen. However, the nerve at this level does not innervate the teeth or bone.
Which surgeries would you choose this block for?
Rostral Maxillary soft tissues (gingiva, mucosa, submucosa and the periosteum.)
Care Inserting the needle into the canal may cause trauma (to the globe!) in cats and brachy dogs – care! only insert partially
Digital pressure - Placing firm digital pressure over the foramen and injection site during and after injection will force local anaesthetic deeper into the foramen minimising the risk of needle trauma.

Question 2

what type of needle is used for dental nerve blocks?

Answer 2

23-25G 5/8 or 3/4 inch needle,

Question 3

Caudal maxillary block:
What is being blocked here?
What tissues does it innervate?
Which surgeries would you choose this block for?
What are the two techniques?

Answer 3

superior alveolar nerve (SAN) innervates the teeth and the bone adjacent to the teeth within the maxilla - surgery of the teeth and bone of the maxilla

It can be blocked intraorally or extra- orally:
** Extra-orally:**
* Needle inserted below the cranioventral border of the zygomatic arch, between caudal border of maxilla and cranial border of mandibular ramus
* Needle advanced parallel to the plane of the hard palate and 1cm caudal to the lateral canthus of the eye
* The needle is advanced until bone is felt, aspirate! ++ risk of venepuncture
* Misses the buccal nerve so need to - local anaesthetic deposited on the buccal aspect of the caudal extent of the maxilla

**Intra oral: **
* Advance the needle in a dorsal direction perpendicular to the plane of the palate, penetrating the mucosa directly behind the palatal and distobuccal roots of the maxillary second molar tooth.
* The needle does not need to be advanced more than 3 to 5 mm beyond the mucosa, depending on the patient’s size

Intraorally

Question 4

mandibular block:
What is being blocked here?
What tissues does it innervate?
Which surgeries would you choose this block for?
What are the two techniques?

Answer 4

The inferior alveolar nerve (IAN) is a branch of the mandibular nerve - whole of the IAN is anaethetised
all mandibular teeth anaethetised and the adjacent bone, rostral lower lip also blocked (might also block the sublingual branch of the lingual nerve (tongue)) - surgery of the lower teeth

Intra or extra oral techniques:
extra-oral
- Pass the needle into the skin on the lingual aspect of the caudal extent of the indentation.
- With the needle parallel to the lingual aspect of the mandible, advance it along the bone until it reaches one-third of the distance from the ventral to the dorsal mandibular body.

**Intra-oral **
Insert the needle intraorally through the gingiva at the location of the distal aspect of the mandibular third molar in the dog or the mandibular first molar in the cat. Then insert the needle on the lingual aspect of the mandible, as opposed to the buccal surface, directed toward the angular process, attempting to palpate and deposit the block at the opening of the mandibular foramen

Question 5

How is the rosteal mandibular block performed?
What does it block?
what is the use?

Answer 5

• The mental nerve block is carried out by either placing local anaesthetic at the opening of the mental foramen (usually middle), or by inserting a needle within the mental foramen.
• Mental nerves only supply the soft tissues of the rostral mandible, these are the only tissues anaesthetised using this technique
• Limited use for dental surgery

Question 6

Palatine blocks are used for palate surgery, are teeth anaesthetized with these blocks?
how is the paletine block performed?

Answer 6

Yes
The palatine nerve block partially anesthetizes the maxillary incisors, canines, and premolars. This block is recommended in cats.
In dogs, the palatine nerve block should be performed simultaneously with the infraorbital nerve block to offer the highest degree of analgesia.

The palatine nerve block. Local anesthetic is injected at a midpoint between the mesial aspect of the maxillary carnassial tooth and the palatal midline (arrows). One or both sides may be blocked simultaneously

Question 7

Local anaesthesia mixtures can be used (lidocaine plus bupivacaine) what are the advantages?
What are the signs of local anaesthetic toxicity under GA?
What is the treatment for local anaesthesia toxicity?

Answer 7

• A lidocaine and bupivacaine combination is thought to provide a rapid onset with a good duration of action
• Studies in cats have demonstrated the combination of lidocaine and bupivacaine to be effective in reducing how much volatile agent is used and improving postoperative pain scores
• Under anaesthesia, signs of LAST are tachycardia, bradycardia and respiratory depression. Treatment should be initiated immediately with intralipid (1.5 ml/kg given intravenously, followed by 0.5 ml/kg/min) and CPR commenced.

Question 8

Which local block would you suggest is used for a dog undergoing a total ear canal ablation?

Answer 8

The great auricular and auriculotemporal nerve