DENTAL GROSS ANATOMY

CASE 4.2

(POSTERIOR SUPERIOR ALVEOLAR NERVE BLOCK)

HISTORY

A 52 yo man, Francis McKean, went to his dentist because of severe pain in his left maxillary molars. The dentist found that the 2nd and 3rd maxillary molars had fractured crowns and thought that the remaining root portions should be extracted. A posterior superior alveolar nerve block was administered. The needle was placed just distal to the maxillary 3rd molar and was advanced superiorly and posteriorly ~ 2cm into the infratemporal region. Immediately after deposition of the anesthetic Mr. McKean felt the left side of his face swell up. The dentist realized what had happened and explained that he had probably penetrated a venous structure causing a hematoma. This complication might have been avoided by using an aspirating technique. No extractions were attempted because of the facial swelling. Mr. McKean was prescribed antibiotics and asked to return in one week to re-attempt extraction.

1. Would a posterior superior alveolar nerve block be suitable for extraction of other upper teeth?

Anterior superior alveolar n.

Mucosa of maxillary sinus

Dental and gingival branches

Middle superior alveolar n.

Posterior superior alveolar n.

INNERVATION OF MAXILLARY TEETH

2. Where does the posterior superior alveolar nerve arise from and where does it enter the maxilla?

V ganglion

V1

V2

V3

Sensory root of V

Infraorbital n.

Anterior superior alveolar n.

Mucosa of maxillary sinus

Dental and gingival branches

Middle superior alveolar n.

Posterior superior alveolar n.

INNERVATION OF MAXILLARY TEETH

3. What venous structure was penetrated by the needle?

POSTERIOR SUPERIOR ALVEOLAR NERVE BLOCK

Maxillary 2nd molar

Pterygoid plexus

Maxillary a.

PSA nerve and foramina

4. Are there any special concerns about infection of this venous structure?

Inferior alveolar v.

Posterior superior alveolar v.

Pterygoid plexus

Emissary vein communicating with cavernous sinus throughforamen ovale

5. What important structure is related to the roots of the maxillary molars and must be taken into consideration when performing their extraction?

Maxillary sinus

Roots of teeth

Opening into middle nasal meatus

END OF CASE 4.2