Description and relationships of the parotid gland levels proposed by the European Salivary Gland Society staging system: an anatomical study.

As traditionally reported, the caudal superficial portion of the gland represents the most voluminous portion of the gland, being labeled in our classification as level II. Levels I and III represent similar amounts of gland, though presenting a significantly different morphological disposition. Level IV is the smallest portion of the body gland and level V, when present represents a scarce 5% of the whole body gland weight. The ESGS levels have a clear anatomical basis and the basic references needed to define them are always present.