Simulation of local anaesthetic nerve block of the infraorbital nerve within the pterygopalatine fossa: anatomical landmarks defined by computed tomography.

The research study explores an improved method for administering an anaesthetic block to the infraorbital nerve in the pterygopalatine fossa to numb the maxillary cheek teeth, utilizing computed tomography to define anatomical landmarks and mitigate the risk of puncturing significant structures during injection.

Anatomy of the Pterygopalatine Fossa and Injection Techniques

• The pterygopalatine fossa is an intricate anatomical region housing important nerves, arteries, and veins. Profound understanding of this region is critical to successfully administer an anaesthetic nerve block.
• Anatomical landmarks were thoroughly examined to establish a safe and efficient way to inject an anaesthetic into the pterygopalatine fossa.
• The study employed contrast medium injections and computed tomography (CT) to simulate the infiltration of an anaesthetic. The contrast medium helped visualise the path and distribution of the injected substance, allowing for a better assessment of the injection techniques used.

Palatine Bone Insertion (PBI) and Extraperiorbital Fat Body Insertion (EFBI)

• Two different techniques were used for needle insertion: Palatine Bone Insertion (PBI) and Extraperiorbital Fat Body Insertion (EFBI).
• The aim was to determine which method provided more consistent results with the least risk. Both methods demonstrated consistent contrast medium distribution around the infraorbital nerve during their respective injections.

Prevention of Penetration to the Intraperiorbital Compartment

• The study revealed that the periorbita, a membranous tissue surrounding the eyeball, prevented the contrast medium from penetrating into the intraperiorbital compartment. This observation is significant as it can help avoid possible complications due to unwanted anaesthetic spread.

Appropriate Technique for Infraorbital Nerve Block

• The EFBI technique emerged as the most suitable method for achieving a sufficient infraorbital nerve block. In comparison to the PBI, the EFBI method was associated with minimal risks while effectively providing the desired anaesthesia.
• These findings suggest that with careful positioning guided by anatomical landmarks, a safe and effective infraorbital nerve block can be achieved. Additionally, the use of computed tomography proved to be instrumental in accurately defining these crucial landmarks.