Method and apparatus for designing and forming a custom orthodontic appliance and for the straightening of teeth therewith

A method of fabricating an orthodontic appliance for positioning upper and lower teeth of a patient to preferred finish positions in the upper and lower jaws of the patient, the method comprising the steps of:

• measuring, in three dimensions, the shapes of individual upper and lower teeth and measuring the shape of the lower jaw of the patient, producing thereby digitized upper and lower tooth data and lower jaw shape data, and inputing the digitized data to a specially programmed computer processor;
• deriving, with the computer processor, a lower arch configuration from the digitized lower jaw shape data;
• deriving, with the computer processor, a tooth-bearing lower jaw configuration based on assembly of the lower teeth along the lower arch configuration with adjacent teeth in contact with each other and a crown long axis of each tooth intersecting the lower arch configuration at the gum, the teeth being spaced mesio-distally along the arch in accordance with measured dimensions of the teeth in a mesio-distal direction;
• with the computer processor, vertically adjusting the tooth bearing lower jaw configuration such that the incisal tips of lower anterior teeth and buccal cusp tips of lower posterior teeth are in substantially the same occlusal plane and are inclined at predetermined angles of inclination;
• with the computer processor, reconfiguring the tooth-bearing lower arch configuration to provide a finished tooth bearing lower jaw configuration by labially-lingually repositioning the lower teeth to place the incisal and buccal cusp tips thereof in a smooth arch in the occlusal plane with adjacent teeth in contact with each other;
• with the computer processor, deriving a tooth-bearing finished upper tooth configuration in which:
• the upper posterior teeth have their central groove/marginal ridge intersections lying horizontally on the finished tooth bearing lower jaw configuration and vertically on an occlusal plane;
• the upper teeth anterior to the cuspids have their incisal tips positioned below the occlusal plane to achieve predetermined overlaps and are horizontally labially offset from the finished tooth bearing lower jaw configuration so as to establish a predetermined clearance between the lower anterior teeth lingual faces and the labial faces of the lower anterior teeth;
• the cuspids have their incisal tips labially offset from the finished tooth bearing lower jaw configuration and on an archform between the buccal cusp tips of the first maxillary bicuspids and the incisal edges of the maxillary laterals;
• with the computer processor, calculating bracket configurations, including bracket slot angle and bracket slot depth, for individual upper and lower tooth brackets, and calculating upper and lower archwire shapes, based upon the calculated finished tooth positions, predetermined upper and lower archwire planes, the tooth shapes, and the positions of the brackets on the teeth;
• producing control signals carrying information based on results of the step of calculating bracket configurations and lower and upper archwire shapes;
• and
• driving machines with the control signals and thereby fabricating upper and lower archwires to conform to the calculated archwire shapes and fabricating brackets to conform to the calculated bracket configurations.

A method of positioning upper and lower teeth of a patient to preferred finish positions in upper and lower jaws of the patient, at which the teeth occlude in an occlusal plane, and for positioning upper and lower cuspids with cusp tips thereof extending respectively below and above the occlusal plane to provide for cuspid rise occlusion, the method comprising the steps of:

• digitizing shapes of individual upper and lower teeth of a patient and producing thereby signals containing digitized upper and lower tooth data, the data including data of distances of the individual teeth from an axis through pivot points which join the upper and lower jaws and data of vertical distances between cusp tips and marginal ridges of maxillary posterior teeth;
• calculating from the digitized data contained in the signals, with the aid of a digital computer, based upon the distances, a minimum cuspid rise necessary for opposing pairs of cuspids to clear after all other opposing pairs of teeth clear when the jaws open;
• assembling a custom orthodontic appliance configured to move the teeth of the patient, including moving the cuspids to at least the calculated minimum cuspid rise;
• and
• orthodontically moving the cuspids of patient, with the assembled appliance, to vertical positions relative to the other teeth of the patient at least to the calculated cuspid rise.

A method of making an orthodontic appliance to move teeth of a patient to preferred finish positions in the upper and lower jaws of the patient, the method comprising the steps of:

• providing an orthodontic appliance manufacturing system including:
• a data input sub-system for digitizing input data of anatomical shapes from the mouth of the patient and generating input signals carrying the digitized input data,
• a data processing sub-system for processing the input signals and generating, in response thereto, output signals carrying machine readable information, and
• an appliance hardware manufacturing sub-system for fabricating, in response to the output signals, a custom orthodontic appliance for the treatment of the patient by moving the teeth of the patient to the preferred finish positions;
• producing, with the data input sub-system, input signals carrying:
• digitized input data containing information of relative positions of a plurality of mandibular trough defining points on the lower jaw of the patient;
• deriving, with the data processing sub-system:
• from the mandibular trough defining point information, a mandibular trough skeletal archform that is a mathematical representation of the shape of a root constraining trough portion of the lower jaw;
• generating, with the data processing sub-system, from the derived skeletal archform, output signals carrying machine readable information for operating the appliance hardware manufacturing sub-system to fabricate a custom orthodontic appliance connectable to teeth of the patient, the appliance being of a custom configuration such that forces are exerted thereby on teeth to which it is connected at respective connection points thereon to urge the teeth toward respective finish positions;
• and
• fabricating, with the appliance hardware manufacturing sub-system, in response to the output signals and in accordance with the machine readable information, the custom orthodontic appliance of the custom configuration.

A method of achieving maxillary expansion in an orthodontic treatment of a patient, comprising the steps of:

• digitizing data correlated to shapes of teeth, including maxillary teeth, of the patient;
• digitizing data of the initial distance between selected points on the surfaces of contralateral maxillary teeth of the patient;
• inputing the digitized data into a especially programmed digital computer;
• calculating, with the computer, finish positions of the maxillary teeth of the patient based at least in part on the digitized data of the shapes of the maxillary teeth;
• recalculating, with the computer, the distance between selected points based on the calculated finish positions of the maxillary teeth;
• comparing, with the computer, the recalculated distance with the initial distance and producing a tangible record of the difference of the comparison;
• based on the results of the calculating and recalculating steps, operating manufacturing equipment and thereby fabricating an orthodontic appliance configured for moving the teeth of the patient to the calculated finish positions when installed on the teeth of the patient whose maxilla has been expanded by the amount of the difference between the initial and recalculated distances between the selected points;
• providing the fabricated appliance and the tangible record for treatment of the patient;
• and
• expanding the maxilla of the patient by the difference based on information in the tangible record and installing the appliance on the teeth of the patient and treating the patient therewith.

A method of orthodontically positioning teeth in a patient's mouth, comprising the steps of:

• sensing anatomical shapes from the mouth of the patient;
• digitizing data of the sensed anatomical shapes from the mouth of the patient;
• calculating an archform, in a digital computer, at least in part from the digitized data;
• with the digital computer, determining the centerline of the calculated archform;
• with the digital computer, comparing corresponding contralateral points on the archform on opposite sides of the centerline and, on the basis of the comparison and the calculated archform, calculating a modified archform that is symmetrical about the centerline;
• with the digital computer, calculating finish positions of the teeth to symmetrically position corresponding contralateral teeth relative to the modified archform and producing a digitized record based on the calculated finish positions;
• fabricating an arcuate orthodontic appliance in response to and in accordance with the digitized record;
• securing the fabricated appliance to the teeth of the patient;
• and
• orthodontically positioning the teeth in the patient's mouth with the fabricated appliance.

A method of providing an orthodontic appliance for connection to the teeth of a patient with optimal spacing from the gums of a patient and clearance with teeth of the opposite jaw of the patient, the method comprising the steps of:

• digitizing data of shapes of the teeth of the patient and of geometry of parts of an appliance to be connected thereto;
• calculating, with a programmed digital computer from the digitized data, finish positions of the teeth of the patient and relationships between points on surfaces of teeth of the opposite jaws when the teeth are occluded and in the calculated finish positions;
• calculating, with the computer from the digitized data, appliance connection points on the surfaces of the teeth of one jaw of the patient having a calculated spacing from the gums of a patient and a calculated clearance with teeth of the opposite jaw of the patient;
• fabricating an appliance for moving the teeth of the patient to the calculated finish positions when connected to the teeth at the calculated connection points;
• and
• connecting the appliance to the teeth of the patient at the calculated connection points.

A method of forming an orthodontic appliance for achieving cuspid rise in the orthodontic treatment of a patient, the method comprising the steps of:

• collecting tooth shape data from teeth of the patient;
• processing the collected data with a specially programmed digital computer, thereby identifying occluding pairs of respective upper and lower posterior teeth of the patient, and determining with the computer for each pair from the collected tooth shape data a vertical distance of the highest extent of the lower tooth of the pair above the lowest extent of the upper tooth of the pair when the jaws are in a closed position;
• with the computer, performing a calculation for adjusting each determined vertical distance by a factor proportionally related to a distance of each pair from a pivot axis between the upper and lower jaws;
• and,
• with the computer, designing an appliance based on the results of the calculation, generating control signals carrying information of the calculated design, and operating manufacturing equipment in response to the generated control signals and thereby forming an orthodontic appliance for the positioning of the cuspids of the patient such that the total cuspid rise is equal to at least the largest adjusted vertical distance of the posterior tooth pairs such that, as the jaws close, contact occurs between pairs of cuspids before contact occurs between pairs of other teeth.

A method of forming an orthodontic appliance for moving teeth of a patient to preferred finish positions, the method comprising the steps of:

• sensing the shape of the lower jaw of the patient;
• digitizing the sensed shape of the lower jaw of the patient and producing thereby signals containing digitized lower shape data;
• deriving with a specially programmed digital computer from the digitized data contained in the signals a skeletal archform mathematically representing the arcuate shape of the patient's cortical bone;
• calculating with the computer finish positions of mandibular teeth of the patient to place the mandibular teeth in an ideal dental archform derived from the skeletal archform and having an arcuate shape mathematically related to the arcuate shape of the skeletal archform;
• calculating with the computer a design of an orthodontic appliance to move the teeth to the calculated finish positions;
• generating control signals containing information of the calculated appliance design;
• and
• operating a fabricating machine in response to the control signals to automatically fabricate the appliance in accordance with the calculated design to place the teeth of the patient on the calculated dental archform.