Semi-adjustable articulator with mounted casts. An articulator is a mechanical device used in dentistry to which casts of the maxillary (upper) and mandibular (lower) teeth are fixed, reproducing recorded positions of the mandible in relation to the maxilla.
The Greek scholar Heron of Alexandria created the earliest known automatic door in the 1st century AD during the era of Roman Egypt. The first foot-sensor-activated automatic door was made in China during the reign of Emperor Yang of Sui (r. 604â618), who had one installed for his royal library.
Cut Wooden Door in Half. Securely mark cut point of door with pine plank fastened tightly to the door with woodworking clamps, then use circular saw to cut the solid door into two panels: a top panel and a bottom panel. BPF_original_gates-interior-dutch-door_step-6-cut-wooden-door-in-half_h.