Figure 2

The alveolar portion of the upper gum pad is separated from the palate by a groove. The alveolar portion itself is again divided into buccal and lingual portions which are also separated by grooves. The former is the larger, participates in the formation of the sheath and socket of the teeth, and is further divided by transverse grooves or sulci into segments corresponding to the developing tooth germs. For nomenclature of palatal structures, see Table 2 (Additional file 2). Interestingly, the 'Terminologia Anatomica' contains for discription of palatal structures only the following terms: Frenulum labii superioris (Frenulum of upper lip); Palatum (Palate); Palatum durum (Hard palate); Palatum molle, Velum palatinum (Soft palate); Raphe palati (Palatine raphe); Plicae palatinae transversae, Rugae palatinae (Transverse palatine folds; Palatine rugae); Papilla incisiva (Incisive papilla).