If tooth 15 has a periodontal abscess and the PSA has been given, what other injection is needed to numb the lingual?

If tooth 15 has a periodontal abscess and the PSA has been given, what other injection is needed to numb the lingual?

• A. Greater Palatine
• B. Nasopalatine
• C. Infraorbital
• D. Mental

Answer: (A)

The key idea is that a PSA block covers the maxillary molars and their buccal tissues, but it does not numb the palatal (lingual) side of those teeth. To numb the lingual aspect and the palatal gingiva behind the molars, you need to block the nerve that supplies the posterior hard palate—the greater palatine nerve. Blocking the greater palatine nerve at its foramen anesthetizes the palatal mucosa and gingiva over the posterior maxillary teeth, including the area around tooth 15, which the PSA alone would not reach. The other injections serve different regions: the nasopalatine block targets the anterior palate; the infraorbital block covers the maxillary anterior teeth and may affect some midface regions but not specifically the lingual palatal tissues of the molars; the mental block anesthetizes the mandible’s anterior region. Hence, the greater palatine injection is the appropriate addition to numb the lingual side.

The key idea is that a PSA block covers the maxillary molars and their buccal tissues, but it does not numb the palatal (lingual) side of those teeth. To numb the lingual aspect and the palatal gingiva behind the molars, you need to block the nerve that supplies the posterior hard palate—the greater palatine nerve. Blocking the greater palatine nerve at its foramen anesthetizes the palatal mucosa and gingiva over the posterior maxillary teeth, including the area around tooth 15, which the PSA alone would not reach. The other injections serve different regions: the nasopalatine block targets the anterior palate; the infraorbital block covers the maxillary anterior teeth and may affect some midface regions but not specifically the lingual palatal tissues of the molars; the mental block anesthetizes the mandible’s anterior region. Hence, the greater palatine injection is the appropriate addition to numb the lingual side.