Final answer:
The infraorbital nerve block does not typically affect the posterior superior alveolar nerve, which innervates the maxillary molars. It is meant to anesthetize the anterior superior alveolar nerve and middle superior alveolar nerve that supply the front teeth and premolars.
Step-by-step explanation:
The infraorbital nerve block is a procedure used in dentistry to anesthetize certain areas of the maxilla (upper jaw), teeth, and associated facial structures. The infraorbital nerve, just inferior to the superior orbital fissure, serves as the exit point for major sensory nerves affecting the cheek, nose, and upper teeth. Specifically, the infraorbital nerve block typically affects the anterior superior alveolar nerve and the middle superior alveolar nerve, which innervate the maxillary central, lateral incisors, canine teeth, and the premolars, as well as the associated periodontal structures and the maxillary sinus.
The posterior superior alveolar nerve is not typically affected by the infraorbital nerve block. This nerve gives sensation to the maxillary molars (excluding the maxillary third molar or wisdom tooth sometimes) and part of the maxillary sinus. While the question mentions the infraorbital nerve itself (D), this can be a misconception because while the block is named after this nerve since the injection is administered in its area, it does not affect the nerve outside the zone of its terminal branches –which are actually anesthetized.
Therefore, the correct answer is C. Posterior superior alveolar nerve, as the infraorbital nerve block does not typically anesthetize this nerve.