The Mouth Jack
A speculum is a device that holds open a body cavity. The types used in equine dentistry vary.
A full mouth speculum places two metal plates between the incisor (nipper) teeth, and a lever with a locking mechanism is used to hold open the mouth against the hinges of the device located on either side of the cheek. I have one horse in my practice whose lower jaw was fractured by another equine dentist’s prolonged use of this type of speculum.
At an AAEP meeting where speculum use was being discussed, a vendor of full mouth speculum stated that “it is not if a speculum breaks, but when,” further recommending replacement every three years. I wonder how much force a horse is applying to these devices that it causes aircraft-grade aluminum and stainless steel bolts to break?
Another type is the wedge speculum. This style places a solid object (metal or rubber) between the cheek teeth on one side of the mouth. These can be difficult to leave in place, and some styles can cause tooth fractures.
The Hand And Arm Is A Speculum By Definition
For some reason, the use of my hand and arm as a speculum is not looked upon by other dentists as a valid speculum. Here, I give the reasons why I find it perfect. Plus, I’ve never left my speculum behind in a barn.