An electrosurgical vessel sealing instrument having a first and a second opposing jaw member at a distal end thereof, wherein each jaw member includes a jaw housing, a seal plate having a tissue contacting surface and a side wall, and an insulating region disposed on the side wall of the seal plate. The instrument includes the ability to move the jaw members relative to one another from a first position wherein the jaw members are disposed in spaced relation relative to one another to a second position wherein the jaw members cooperate to grasp tissue. The insulating region enables precision overmolding of the jaw housing to the seal plate, while advantageously reducing thermal spread and edge cutting during vessel sealing procedures.
