Mandibular Motion in Chewing

We are all very concerned about our pets or chinchillas if it is eating well, putting on weight and pooing well.  Eating is what wears teeth down and how they actually chew affect the wearing down of their front/back teeth and molar?  Beanie, my dental problem chinchilla who was fully on extruded food and routine teeth filing was able to eat Alfafa, timothy hay and apple stick now.  We hope to see she could eat and chew for a longer period before she need another filing.

yeah…now we see her digging on her hay bowl everyday!

Some good thoughts after I read this…….

The mechanics of eating pellets to eating hay are different. Eating a pellet involves an up and down jaw motion. Eating hay involves side to side movements and causes full occlusion of the teeth surfaces and thus making the grinding action more effective.

If we observe while they are eating, we will find tat Chewing Hay takes longer time and we see differences in the jaw motion when chewing a pellets and hay.

Based on Equine Veterinary Medicine research ( and it can be extrapolated across to chinchillas:


Reasons for performing study: Previous studies have suggested that temporomandibular joint (TMJ) kinematics depend on the type of food being masticated, but accurate measurements of TMJ motion in horses chewing different feeds have not been published.

Hypothesis: The temporomandibular joint has a larger range of motion when horses chew hay compared to pellets.

Methods: An optical motion capture system was used to track skin markers on the skull and mandible of 7 horses as they chewed hay and pellets. A virtual marker was created on the midline between the mandibles at the level of the 4th premolar teeth to represent the overall motion of the mandible relative to the skull during the chewing cycle.

Results: Frequency of the chewing cycles was lower for hay than for pellets. Excursions of the virtual mandibular marker were significantly larger in all 3 directions when chewing hay compared to pellets. The mean velocity of the virtual mandibular marker during the chewing cycle was the same when chewing the 2 feeds.

Conclusions: The range of mediolateral displacement of the mandible was sufficient to give full occlusal contact of the upper and lower dental arcades when chewing hay but not when chewing pellets.

Potential relevance: These findings support the suggestion that horses receiving a diet high in concentrate feeds may require more frequent dental prophylactic examinations and treatments to avoid the development of dental irregularities associated with smaller mandibular excursions during chewing.


Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s