An 11-Year-Old Boy, Ronald, Has an Overjet and Is Being

An 11-year-old boy, Ronald, has an overjet and is being treated by an orthodontist. At a routine appointment, Ronald mentions that he feels some pressure in the area of his maxillary anterior incisors and asks if this is unusual. The orthodontist examines Ronald, makes some adjustments to his appliance, and reviews his radiographs. He informs Ronald that he is pleased with the movement of his teeth and that he may feel occasional pressure throughout treatment. Which factors contribute to forming new bone (select all that apply) ?

A) PDL tension/compression
B) Sustained orthodontic force
C) Osteoclastic activity
D) Osteoblastic activity
E) Not of above