Abstract: Ligature systems retain an arch wire within a slot of an orthodontic bracket. According to some embodiment, the ligature system retains an arch wire within a slot of an orthodontic bracket by means of a retaining element which is capable of being unidirectionally mechanically locked within the slot of the orthodontic bracket to retain an arch wire therewithin. The retaining element may comprise a pair of opposed outwardly projecting retaining edges. In some embodiments, the retaining element comprises a planar or curved retaining plate. The ligature system may include a central block in which the retaining plate is embedded such that the retaining edges extend outwardly therefrom. The ligature system may also include spike protruding outwardly from such central block so as to engage with the arch wire positioned subjacently thereto.

Abstract: A method and apparatus for aligning the dento-facial region of a human. In one embodiment the method comprises providing an alignment appliance containing one or more optical elements; causing or instructing a human to cause the optical elements of the alignment device to come into contact with the dento-facial region, measuring or instructing the human to measure data regarding one or more characteristics of optical elements of the alignment appliance; modifying or causing to modify the alignment appliance to come into contact with the dento-facial region at different areas or by applying different forces to align the one or more teeth and repeating or causing to repeat one or more of steps of the method to align the dento-facial region of a human.

Abstract: Force magnitudes and/or directions may be determined objectively using orthodontic brackets having an elastomeric member which allows one portion of the bracket to be resiliently moveable relative to at least on other portion of the bracket. In a preferred embodiment, the brackets include a lower base member, an upper bracket member, and an elastomeric layer interposed between the lower base and upper bracket members. The orthodontic bracket is advantageously employed as part of a system whereby the orthodontic bracket includes a force indicator which distorts in response to relative movement between the at least one and other portions of the bracket to provide an indication of force applied to the bracket. An optical detector may be provided to optically detect the indicator and issue an output signal indicative of the relative resilient movement between the lower base and upper bracket members.

Abstract: A method and system are disclosed for analyzing images of fiducials that provide an indication of the forces and/or torques applied to an orthodontic bracket. The mass of each of the pixels forming the fiducial image are multiplied by the square of the distance of the pixel along the image's x axis, the product of the distances of the pixel along the image's x and y axes, and the square of the distance of the pixel along the image's y axis. The second order moments of inertia about the centroid of the fiducial are calculated and used to form a first matrix. The first matrix is diagonalized into a second matrix, from which the fiducial 's first and second principal axes are determined. These axes are then used to measure the size of the fiducial in the image.

Abstract: Methods and related apparatus for positioning and aligning any portion of the dento-facial region of a person. In one embodiment the method includes (a) providing or measuring any aspect of one or more alignment appliances to a person; (b) casting a shadow or making a mark on one or more areas of the dento-facial region of the person or the one or more alignment appliances in close proximity to one or more areas of the dento-facial region of the person with one or more light sources or marking devices; (c) measuring and analyzing data regarding one or more of the size, shape, length, and position of the one or more shadows or marks relative to other shadows or marks, one or more areas of the dento-facial region of the person or the one or more alignment appliances to obtain data; and (e) adjusting or replacing the alignment appliance or modifying the dento-facial alignment treatment plan of the person to align one or more areas of the dento-facial region of the person.

Abstract: Knife blades having exceptionally sharp cutting edges are formed from wafers of monocrystalline silicon using known semiconductor processing technology. In one embodiment, an elongated ridge having a flat top covered by an etchant mask is etched to undercut the mask and to shape the ridge side walls to inwardly converge towards the ridge tip. The mask is removed and a sharp ridge apex is provided by a series of oxide forming and oxide stripping processes. Individual knife blades of silicon, each comprising a ridge having a sharp cutting edge, are shaped from the wafer. In another embodiment, the silicon wafer is etched entirely through between top and bottom surfaces to form a tapered etched wall intersecting the bottom wall at a highly acute edge. The edge is sharpened by the oxide forming and oxide stripping process to form a cutting edge in the completed blade. In both embodiments, various etch masks and etching procedures are used for providing blades of various shapes.