<prompt> How many Champys osteosynthesis lines exist behind and in front of mental foramen?2 ahead of and 2 behind the mental foramen1 ahead of and 2 behind the mental foramen2 ahead of and 1 behind the mental foramen1 ahead of and 1 behind the mental foramen  <response>: Champy described the ideal osteosynthesis lines, which were the areas in mandible which if plated correctly with mini plates and screws, could give adequate functionalstability to the mandible. These were 2 lines in the symphysis and para-symphysis region anterior to the mental foramen and 1 line in the body region that curved upward along the external oblique ridge to the anterior border of ramus in the angle region behind mental foramen. If mini-plates with at least 2 mono-cortical screws of adequate thickness on each side of racture line were applied in these areas, it could give a semi rigid or a functionally stable fixation to the patient without the need of IMF. 