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Four-handed zones: right-handed operator

Also called: clock concept, zones of activity, operating zones

Picture the patient's head as a clock face: each team member and item has a zone.

Four-handed dentistry means the operator and assistant work together so neither wastes motion. Zones are named by clock positions, with the top of the patient's head at 12. For a right-handed operator: operator's zone 7 to 12 o'clock, static zone 12 to 2, assistant's zone 2 to 4, transfer zone 4 to 7.

How to spot it

  1. Operator sits on the patient's right side or behind the head (7-12).
  2. Assistant sits on the patient's left (2-4), about 4 to 6 inches higher than the operator for a good view.
  3. The tray and less-used equipment sit behind the patient's head in the static zone (12-2).

On the tray, in order

  1. Instruments are exchanged in the transfer zone (4-7), below the patient's chin.
  2. The operator moves within the zone depending on the arch and tooth; the assistant stays mostly in place.
  3. Raise your stool when working on the lower arch to see into the mouth.

Safety and care

  1. Never pass instruments over the patient's face.
  2. Keep hoses and cords out of the transfer zone.

Related

Sources: Dentalcare.com CE643. The Concepts of Four-handed Dentistry Including Ergonomic Instrument Transfer. Pages: zones of activity, single-handed transfer, two-handed transfer, scissors/hinged instruments, syringe transfer, non-locking forceps