In DGS, non-manuals may be an obligatory, inherent part of certain signs. Non-manuals which are part of the internal structure of a sign are synchronized with the manual parts of the respective sign. Non-manuals can be split up into the following four components: (i) facial expressions on the lower face, (ii) facial expressions on the upper face, (iii) head actions, (iv) and torso actions. Regarding the lexical level in DGS, the lower face seems to be the most productive non-manual component. But, all the four non-manual components carry essential phonological functions. In addition, mouthings have to be considered [Phonology 1.5.2.]).
With respect to the articulation of non-manuals, they appear in two different action types: (i) constant (no change in configuration of non-manuals) and (ii) dynamic (change in configuration of non-manuals). An example of constant non-manuals is the sign tease.
tease
The sign bite_off is an example of dynamic non-manuals.
bite_off
A further interesting characteristic of non-manuals is the lateral alignment between the dominant hand and unilateral non-manuals. An example of this lateral alignment regarding the lower face is the sign super which is articulated with puffed cheek with air output.
super