Who would preform a uvulopalatopharyngoplasty?

Otolaryngologist. These operations are performed by an otolaryngology - head and neck surgeon (ent). The surgeon performs this surgery to help treat obstructive sleep apnea.
Otolaryngology/ENT. This is mostly done by otolaryngologists. There are some specialized maxillofacial surgeons that also do the procedures (especialy maxillo-mandibular advancement.