middle superior alveolar nerve middle superior alveolar nerve the middle superior alveolar nerve or middle superior dental nerve is a nerve that drops from the infraorbital portion of the maxillary nerve to supply the sinus mucosa, the roots of the maxillary premolars, and the mesiobuccal root of the first maxillary molar. it is not always present; in 72% of cases it is non existent with the anterior superior alveolar nerve innervating the premolars and the posterior superior alveolar nerve innervating the molars, including the mesiobuccal root of the first molar. middle superior alveolar nervedistribution of the maxillary and mandibular nerves, and the submaxillary ganglion.alveolar branches of superior maxillary nerve and sphenopalatine ganglion.detailsidentifierslatinramus alveolaris superior medius nervi maxillarista98a14.2.01.051ta26240fma52932anatomical terms of neuroanatomy