The 289 area code was created as an area code overlay for the Mississauga (Streetsville) area. Unlike the previous solutions, this process did not require the place to be geographically separated by different area codes.
Ionizing radiation is a term used for radiation whose quanta have energy to directly or indirectly ionize (one or more electrons are released from the atom of the given substance) molecules or atoms while passing through matter, hence the name ionizing radiation.
Redness of the skin and local loss of facial hair are common side effects of external beam radiation. Depending on skin texture, the dermatitis may form an outline of the radiation field. The practical significance is that the skin may be sensitive to pressure and neck positioning during dental treatment.