gagging during dental treatment

[OnUrNerv]

I believe from my recent studies in neurology and its functional applications
 noninvasively the answer is not one with a simple answer...this is because you
 are discussing something that occurs as a result of its being in a multimodal
 system....gagging is as a consequence of metabolic neurological threshold
 being met in the pontomedular brainstem where the 9th and 10th cranial nerves
 exit. When you fire other receptors whose 3rd order neurons also meet and fire
 in the thalamus (a primary cite of neuronal integration )hence the sqeezing of
 a fist elicits joint mechanoreceptors, stretch receptors possibly even
 nociceptors which all integrate in the thalamus changing its central
 integrative state and thereby causing an inhibition to the cranial nerves and
 alteration of the gag reflex which now requires a different excitation threshold  .