Corner joints and methods of forming corner joints are described herein. The corner joints may provide the appearance of a mortise and tenon joint on both the exterior and interior surfaces of the corner joint, but include a mitered connection within the joint. Structures including at least one of the corner joints are also described.

The machine (1) comprises: retaining means (3, 4) of a first profiled element (5) and of a second profiled element (6) made of plastic material, which extend along respective longitudinal directions and are each provided with at least one area to be welded (7) substantially inclined by an angle comprised between 10? and 80? with respect to the respective longitudinal direction and at least one main face (5a, 6a) square-shaped, wherein the main face (5a) of the first profiled element (5) is projected with respect to the respective area to be welded (7) and the main face (6a) of the second profiled element (6) is recessed with respect to the relevant area to be welded (7); removal means (16) comprising a pair of milling tools (17) movable in rotation around a relevant axis of rotation (R); suction means (20) adapted to remove the residues of plastic material generated during the removal of the plastic material;
wherein the suction means (20) comprise at least one suction duct (21) arranged around a respective milling tool (17), which comprises a substantially flat abutment portion (24) adapted to internally abut against the main face (5a) of the first profiled element (5) during the removal of the plastic material.