Infraorbital nerve block is an elegant technique for achieving anesthesia of the mid face region for laceration repair. The infraorbital nerve is a branch of the maxillary nerve (Trigeminal V2) which enters the face through the infraorbital canal. This point of exit is the target for an effective block.
I especially like this one for repair of upper lip lacerations, as seen in the video below.
A few notes on the technique:
There is also an extra-oral approach which is quite effective, but it involves injecting through the skin of the cheek. This is intimidating to most patients.
If a laceration crosses (or even approaches) the midline of the upper lip, your best bet is to anesthetize both sides, as some cross innervation may occur.
Another use for this block is for fractures of the alveolar ridge along the maxillary teeth, or painful dental conditions in the same area. We don’t always think about this, but the branches of the infraorbital nerve also supply sensation to the maxillary alveolar ridge, gingivae, and periodontal tissues of the maxillary premolar area, all the way to the central incisor on the ipsilateral side. I’ve personally found bilateral infra-orbital nerve block to be exceedingly effective for anesthesia when I need to stabilize loose teeth or cement exposed dentin/pulp.
The common reference point for intra-oral injection uses the teeth. Above the lateral incisor is the commonly cited point of injection. In your edentulous patient, one article recommends the superior lateral labial frenum as an alternative landmark. To see this landmark, you must elevate the lip to separate the buccal and gingival mucosa.