The inferior alveolar nerve block is administered into the region of the pterygomandibular space, which contains the inferior alveolar nerve. This space lies between the medial pterygoid muscle and the mandibular ramus. Introducing a needle into this restricted area can potentially carry oral pathogens directly into the pterygomandibular space, leading to infection. The buccal, submandibular, and sublingual spaces are anatomically distinct and not directly accessed during this nerve block. Therefore, the risk of infection transposition is highest in the pterygomandibular space due to the needle's path during injection.

Reference: Oral and Maxillofacial Pathology, Neville et al., 4th Edition.