Cureus. 2018 Jan 28;10(1):e2120. doi: 10.7759/cureus.2120.

Iwanaga J, Tubbs RS.

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Abstract

The superior alveolar nerves course lateral to the maxillary sinus and the greater palatine nerve travels through the hard palate. This difficult three-dimensional anatomy has led some dentists and oral surgeons to a critical misunderstanding in developing the anterior and middle superior alveolar (AMSA) nerve block and the palatal approach anterior superior alveolar (P-ASA) nerve block. In this review, the anatomy of the posterior, middle and anterior superior alveolar nerves, greater palatine nerve, and nasopalatine nerve are revisited in order to clarify the anatomy of these blocks so that the perpetuated anatomical misunderstanding is rectified. We conclude that the AMSA and P-ASA nerve blockades, as currently described, are not based on accurate anatomy.

KEYWORDS:

anatomy; innervation; local anesthesia; maxillary nerve; nerve block; tooth

Figure 1

The PSA, MSA and ASA as depicted by Friedman and Hochman (1998) as if they innervate the teeth through the hard palate. The ASA is drawn as if it is the terminal branch of the infraorbital nerve.

ASA: Anterior superior alveolar branch of the infraorbital nerve; MSA: Middle superior alveolar branch of the infraorbital nerve; PSA: Posterior superior alveolar branch of the maxillary nerve.

Figure 2

The proposed drawing of the P-ASA by Friedman and Hochman (1999).

P-ASA: Palatal approach anterior superior alveolar.

Figure 3

Neither AMSA nor P-ASA nerve blockade is close to the main nerve trunk of the superior alveolar nerves. (A) Relationship of the superior alveolar nerves and GPN. (B) Relationship of the superior alveolar nerves and NPN.

AMSA: Anterior and middle superior alveolar; ASA: Anterior superior alveolar branch of the infraorbital nerve; GPN: Greater palatine nerve; ION: Infraorbital nerve; MSA: Middle superior alveolar branch of the infraorbital nerve; NPN: Nasopalatine nerve; PSA: Posterior superior alveolar branch of the maxillary nerve.