[The jaws of Altamira man (upper paleolithic)].

125 years ago, 25 km away from where S.F.O.

[Corrosion and calculus. How can the wire/bracket slide mechanics be improved?].

Sliding mechanics are widely used in fixed orthodontic devices. Parasitic phenomena that block or slow the movement have, until now, been relatively neglected. The friction that appears at the interface of the wire/bracket/ligature opposes the free sliding action, necessary to allow the motor forces to displace the dental units that are guided on an appropriately shaped metal arch.