Ergonomics is understood as the science dealing with designing and arranging things so people can use them easily and safely. Dental procedures are often long, physically demanding sessions in which efficiency and fatigue can play a role with outcomes.
When performing dental procedures on a daily basis, attention to ergonomics may not only save time and allow you to see more patients, but ergonomics may also extend careers by avoiding or minimizing chronic pain. This column will discuss important considerations that will hopefully improve your working environment, as well as your enjoyment of these challenging procedures.
What to consider
The first consideration is the decision of whether to stand or sit during the procedure. Since dentistry and oral surgery procedures often involve assessment and treatment of 42 individual “patients” in a dog’s mouth and 30 patients in a cat’s, these procedures can be rather long.
Most veterinary dentists sit while doing procedures. Whether sitting or standing, proper posture is a must. An adjustable chair is very helpful to ensure this. We use mostly saddle chairs in our practice, which encourage an upright sitting position. There are also other chairs that can prevent poor upper body posture, such as a kneeling chair. The adjustability of a chair should ideally have a wide range of heights, especially if your table is not adjustable.
Speaking of adjustable tables, they are wonderful! I’ve spent the second half of my career using adjustable tables and would not go back. Adjustable tables are expensive, but they are worth saving up for. Even if you have an adjustable chair, the ability to adjust both the table and the position of the patient on the table is game changing.
Tables adjustable to the floor provide the added benefit of preventing back strain. Rather than lifting a large patient onto the table, lower the table to the floor and have the patient walk onto the table. Before walking the patient onto the table, place a flexible canvas stretcher on the table to make sure transport of the patient after the procedure can be shared amongst three people with the easy-to-grab handles of the stretcher. These soft stretchers are one of the best inventions ever.
How to position the patient depends somewhat on the procedure being performed. When performing professional dental cleanings with dental radiographs, some veterinary dentists prefer to place patients in dorsal recumbency for the entire procedure. Though placing the patient in dorsal recumbency can make it more challenging to obtain maxillary radiographs, dorsal recumbency prevents the need for moving the patient’s body during the procedure. If utilizing dorsal recumbency, keep in mind fluids used during the procedure may pool in the back of the throat.
There are some simple steps to minimize the chances of aspiration of fluid, including: 1) proper, but not excessive, inflation of the endotracheal cuff, checking frequently for leaks; 2) packing the back of the throat with a laparotomy sponge; and 3) use of suction. I prefer a laparotomy sponge rather than gauze to pack the back of the throat because gauze can be lost, whereas the long string on the laparotomy sponge will prevent inadvertent retention.
Although I do not routinely perform procedures in dorsal recumbency, there are some procedures, such as cleft palate repairs and some maxillectomies, requiring dorsal recumbency. Most of my procedures are done in lateral recumbency. The patient is intubated in sternal recumbency; both right and left maxillary intraoral radiographs can be obtained while in this position.
Once the patient is placed into lateral recumbency, mandibular intraoral radiographs can be obtained on that side. Prior to performing a professional dental cleaning, a rolled towel can be placed under the patient’s neck to utilize gravity and minimize pooling of fluids in the throat by making the rostral portion of the head closer to the table surface.
Tools of the trade
Finally, we are getting to the good part: instrumentation.
For some of us, one of the alluring aspects of dentistry is the ability to play with so many fun toys. The high-speed dental hand-piece is an essential piece of equipment that can also be a source of catastrophic complications if used improperly.
Like many dental instruments, total control must be maintained throughout its use to avoid damage to unintended structures. The “modified pen grasp” is the preferred method of holding the dental hand-piece and the ultrasonic scaler (Figure 1A). The modified pen grasp involves the hand-piece resting between the index finger and middle finger on the top of the hand-piece, balanced by the thumb on the bottom of the hand-piece. This grasp allows for the necessary finesse to perform subtle movements when moving the working end of a bur.
Rarely, when using a straight bur on a low-speed hand-piece, the “palm grasp” will be the preferred grasp (Figure 1B). Besides a better tactile feel, the modified pen grasp minimizes wrist movements, which may, over time, decrease the chances of developing of carpal tunnel syndrome.
In next month’s column, I will address lighting and magnification. Until then, keep on drilling!
John Lewis, VMD, DAVDC, FF-AVDC OMFS, practices and teaches veterinary dentistry and oral surgery at Veterinary Dentistry Specialists and Silo Academy Education Center, both located in Chadds Ford, Pa.
- Lewis JR, Miller BR (Bassert JM, ed.). Veterinary Dentistry. Clinical Textbook for Veterinary Technicians, 8th ed. St. Louis: Elsevier Saunders, 2014; 1299-1352.