100
46TH
ANNUAL
CONGRESS
OF
THE
SAEVA
SKUKUZA
16-‐20
FEBRUARY
2014
Figure 3: Anatomy of the pterigopalatine fossa (Campoy 2012 WCVA 2012)
Procedure:
The maxillary nerve is blocked as close to the maxillary foramen as possible. There
are two approaches described: the infraorbital foramen block and the maxillary
foramen block.
The infraorbital foramen block:
The spinal needle is premeasured from the infraorbital foramen to the medial
canthus of the eye. The infraorbital foramen is located by palpating the facial crest
and the nasoincisive notch. An imaginary line is drawn between these two points and
2 cm cranial and perpendicular to the midpoint of this line, the foramen is located.
The needle is placed in the infraorbital foramen and advanced the premeasured
length before aspiration and then injection of the local anaesthetic.
The maxillary foramen block:
The caudal lateral border of the bony orbit and the zygomatic arch is palpated. The
needle is inserted at the angle created by the orbit and zygomatic arch. The needle is
advanced in the direction of the 6th contra lateral maxillary molar until bone is felt.
The needle is retracted, the syringe aspirated and the local anaesthetic injected.
There has been two techniques described to further classify the technique: the
palatine bone insertion technique (PBI) and the periorbital fat body insertion
technique (PFBI). The fundamental difference is the length of advancement of the
needle. The PBI required complete advancement onto the palatine bone, where the
PFBI technique advances the needle no further than 20mm.
Complications:
Both techniques may cause inadvertent intravascular penetration and thus aspiration
is required. The maxillary foramen technique has been documented to penetrate the
palatine artery in cadavers. The infraorbital foramen technique presents potential
complication through haemorrhage due to trauma of the infraorbital artery and
nerve within the canal.
Efficacy:
The maxillary foramen block has been associated with incidental trauma to the
periorbita and blood vessels within the ptreygopalatine fossa. The advancement of
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