Final answer:
The over-the-patient delivery system provides the easiest access to dental hand pieces for dentists without twisting their body.
Step-by-step explanation:
The form of dental delivery that provides the easiest access to the dental hand pieces without twisting the dentist's body is the over-the-patient delivery system. This system positions the dental hand pieces directly over the patient's mouth, allowing the dentist to have a straight, ergonomic posture while accessing the instruments. With this delivery system, the dentist can easily reach and work with the dental hand pieces without straining their body.