The jargon can be confusing.  There are 4 main types of delivery units.  The delivery is the equipment that holds and controls the handpieces.  There is no ‘best’, it simply depends on how a user has been trained, personal preference and room design. Our range includes over the patient, covering both the drop hose or whip arm, behind the patient, under the patient, and cart.

‘Over the Patient’

Largely used in European countries and favours the dentist, providing the best ergonomics. No back twisting or head-turning is needed to select instruments.  Called over the patient because there is an arm that stretches ‘over the patient’.  There are two types of ‘over the patient, either ‘drop hose’ or whip arm (sometimes called continental). Drop hose, over the patient:


Whip arm, over the patient:


‘Behind The Patient’

Largely the traditional UK working method used. This is primarily seen on Belmont equipment and is suited to the compact UK surgeries, where patient entry is often at the toe of the chair. The main benefit this system provides is it allows the bracket table to be moved around behind the patient to the nurse preparation zone, whilst the patient enters the chair, then moved to the working position when ready to begin treatment. This hides the instruments from the patient view.  Some view this delivery system as unergonomic as the dentist may have to twist their neck and shoulders to pick up and replace instruments, however, due to its flexibility and practicality, it remains the number 1 system used in the UK.


‘Under The Patient’

Used largely by A-dec, this system mounts the delivery unit arm from underneath the patient chair. This provides a compromise between the benefits of ‘over the patient’ of dentist ergonomics, whilst still allowing good patient entry into the chair, as they can access the toe of the chair from either side, depending on the position of the arm.



Mostly used in environments where flexibility is key, such as oral surgery and theatres. Having the delivery unit on a cart allows you to move it completely out of the way or position wherever required. When the delivery unit is not needed it can be stored out of sight.  The main challenge with this system is the presence of the ‘umbilical hose’ which trails to the unit from the service box.