Intraoral injection site point of mucosal penetration for an inferior alveolar nerve block. When a patient’s mouth is held wide open, the pterygomandibular raphe tenses and usually becomes a visible reference line. The injection point should be just lateral to that line so the needle does not penetrate the raphe itself. At the time of first needle penetration the barrel of the syringe should be over the contralateral lower incisors