Middle superior alveolar nerve supplies upper premolar teeth. It is a branch of:

While running forward in the floor of the orbit, the infraorbital nerve lies in the roof of the maxillary sinus and gives branches that carry sensation from the roots of the upper premolar teeth, the middle superior alveolar nerve, and the roots of the upper canines and incisors, the anterior superior alveolar nerve. Once it reaches the face, the infraorbital nerve carries sensation from an area of skin that extends from the lower eyelid to the upper lip. Ref: Dhillon N. (2012). Chapter 1. Anatomy. In A.K. Lalwani (Ed), CURRENT Diagnosis & Treatment in Otolaryngology--Head & Neck Surgery, 3e.