English to Spanish Medical Psychology mental diseases

Buenas!

Está hablando de un experimento hecho con ratas para comprobar el efecto de un fármaco en el control de la esquizofrenia...

"Microdialysis probes were implanted in the prefrontal cortex; coordinates were: AP +2.0 mm, ML +0.7 mm
(under an 8° angle) from bregma, DV -3.3 mm from the dura, with the tooth-bar also set at 0 mm. The active dialysis
surface length of the membrane was 2 mm. Microdialysis experiments started 48 h (prefrontal cortex) after surgery.
Ringer solution was perfused through the microdialysis probe at a flow at..."

No tengo ni idea de lo que es la tooth-bar? Como habla de las partes del cráneo, se refiere al hueso de la mandíbula superior que sujeta los dientes? Es que no me imagino otra cosa... XD

Gracias!!