This is from The National Museum of Dentistry in Baltimore. The “treatment” in the mandible shown here was done at the turn of the 20th century by Dr. Vincenzo Guerini, who wrote A History of Dentistry and who made models of ancient dentistry examples he supposedly saw in his travels. This example is only 115 years old, not 2000 years old, and definitely not Egyptian. Whether Dr. Guerini actually saw an Egyptian mummy with this sort of dental appliance is still unknown, as such a mummy does not currently exist.