Table 2.

Definitions of bit size and bit fit.

Variable	Definition
Bit mouthpiece length	Distance between inner border of bit ring hole measured along caudal curve of bit mouthpiece
Bit mouthpiece thickness	Thickness/diameter (height) of bit mouthpiece between upper and lower jaw measured next to inner bit ring hole
Bit mouthpiece center link length	Length of bit mouthpiece center link in double-jointed or barrel bit
Bit space	Difference in distance between upper and lower jaw and tongue thickness
Tongue space	Difference in distance between upper and lower jaw and thickness of the bit
Bit length fit	Difference in bit mouthpiece length and mouth width—bit length fits, if bit mouthpiece length equal to or 1–10 mm longer than mouth width
Bit thickness fit	Difference in bit space and bit mouthpiece thickness – bit thickness fits, if bit mouthpiece thickness equal to or smaller than bit space
Bit center link length fit	Difference in bit center link length and lower jaw width—bit center link length fits, if center link length shorter or longer than lower jaw width