The superior alveolar artery does not exist.
Rather, the posterior superior alveolar artery is a branch of the maxillary artery that serves the upper teeth and other related structures.
The anterior superior alveolar arteries are branches of the infraorbital artery, also supplying the upper teeth and related structures.
If a middle superior alveolar artery is present, it also arises as a branch of the infraorbital artery.