Final answer:
The dental quadrants are formed by a midsagittal plane that passes between the central incisors of the maxilla and mandible.
Step-by-step explanation:
The dental quadrants are formed by a plane that passes between the teeth in the maxilla and mandible. Specifically, this dividing plane is the midsagittal plane, which splits the body into equal right and left halves. When we apply this to the dentition, the midsagittal plane passes between the central incisors in both the upper and lower jaws, therefore the correct answer is sagittal, central.
Remember that a midsagittal plane divides an organism into symmetrical right and left halves, as demonstrated in various anatomical diagrams. On the other hand, frontal planes separate the front and back of the body, and transverse planes divide an organism into upper and lower parts.