A periodontist is a dentist who specializes in the prevention, diagnosis, and treatment of periodontal disease, and in the placement of dental implants. Periodontists are also experts in the treatment of oral inflammation.
Ground speed. Ground speed is the horizontal speed of an aircraft relative to the ground. An aircraft heading vertically would have a ground speed of zero. Information displayed to passengers through the entertainment system often gives the aircraft ground speed rather than airspeed.
With a top speed of 35 mph, Karma is no slouch. Again, the Mavic bests it with a top speed of 40 mph, but that's not a huge difference, and requires being in Sport mode, which disables the obstacle avoidance. For most people, then, Karma will feel plenty fast.