| abstract |
A new orthodontic bracket has a mesial-distal extending labially-open arch wire slot that in gingival-occlusal cross section is curved at its lingual face about a mesial distal axis and has its gingival and occlusial faces which usually are straight smoothly joining the lingual face and extending away from one another to form a slot opening of greater gingival-occlusial dimension. A spring retainer member embraces the gingival, occlusial and labial faces and is movable between a slot open position and a slot closed position, in the latter of which it opposes any protrusion of an arch wire out of the slot caused by misalignment between the slot and the arch wire The retainer is held in the slot closed position by latches which permit a small movement of the retainer away from the fully slot closed position, but which oppose such movement by spring and cam action. In a final stage of the orthodontic procedure the bracket is used with an arch wire of D-cross-section matched at its curved face to the curvature of the slot lingual face; the wire holds the teeth in the desired arch configuration while they are moved along it, anti-tipping forces of suitable low value being produced if the the wire tilts in the slot by spring reaction of the bracket retainer against the wire. |