`a2) Patent Application Publication co) Pub. No.: US 2007/0031774 Al
`Feb. 8, 2007
`Cinader, JR.et al.
`(43) Pub. Date:
`
`US 20070031774A1
`
`(54) REGISTERING PHYSICAL AND VIRTUAL
`TOOTH STRUCTURES WITH MARKERS
`
`(22)
`
`Filed:
`
`Aug. 3, 2005
`
`Publication Classification
`
`(75)
`
`Inventors: David K. Cinader JR., Yorba Linda,
`CA (US); James D. Cleary, Glendora,
`CA (US); Oliver L. Puttler, La
`Crescenta, CA (US); Richard E. Raby,
`North St. Paul, MN (US)
`
`(51)
`
`Int. CL.
`(2006.01)
`A6IC 3/00
`(52) US. Ch.
`sassosssssussnsnnsnnnsnnnnn 433/24; 433/213
`
`(57)
`
`ABSTRACT
`
`Correspondence Address:
`3M INNOVATIVE PROPERTIES COMPANY
`PO BOX 33427
`
`ST. PAUL, MN 55133-3427 (US)
`
`In general, the invention relates to techniquesfor registering
`a three-dimensional (3D) coordinate system of a physical
`model of a patient’s tooth structure to a 3D coordinate
`system of a virtual model of the same tooth structure.
`Techniques are described to register the complex geometries
`of the physical and virtual tooth structures by using regis-
`tration markers associated with the physical model.
`(21) Appl. No.:—11/195,952
`
`(73) Assignee: 3M Innovative Properties Company
`
`
`
`COLLECT PATIENT IDENTITY AND BASIC
`PATIENT INFORMATION AND CREATE PATIENT
`RECORDIN DATABASE
`
`ACCESS DATABASE AND CREATE MODEL
`RECORD FOR NEW MODEL
`
`SELECT DENTAL IMPRESSION TRAY
`
`UPDATE DATABASE TO ASSOCIATE PATIENT
`RECORD WITH MODEL RECORD
`
`PLACE MARKERSONPATIENT'S TEETH
`
`FORM IMPRESSION OF PATIENT’S TOOTH
`STRUCTURE
`
`110
`
`112
`
`114
`
`116
`
`118
`
`20
`
`REMOVE MARKERS FROM PATIENT'S TEETH
`
`122
`
`UPDATE MODEL RECORD TO
`IMPRESSED STATUS
`
`124
`
`STERILIZE DENTAL IMPRESSION TRAY AND
`SHIP TO MANUFACTURING FACILITY
`
`126
`
`Align EX1028
`Align v. 3Shape
`IPR2022-00144
`
`Align EX1028
`Align v. 3Shape
`IPR2022-00144
`
`
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`Patent Application Publication Feb. 8, 2007 Sheet 1 of 17
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`US 2007/0031774 Al
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`Patent Application Publication Feb. 8, 2007 Sheet 2 of 17
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`US 2007/0031774 Al
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`COLLECT PATIENT IDENTITY AND BASIC
`PATIENT INFORMATION AND CREATE PATIENT
`
`RECORD IN DATABASE
`
`ACCESS DATABASE AND CREATE MODEL
`RECORD FOR NEW MODEL
`
`SELECT DENTAL IMPRESSION TRAY
`
`UPDATE DATABASE TO ASSOCIATE PATIENT
`RECORD WITH MODEL RECORD
`
`FORM IMPRESSION OF PATIENT’S TOOTH
`STRUCTURE
`
`UPDATE MODEL RECORD TO
`IMPRESSED STATUS
`
`STERILIZE DENTAL IMPRESSION TRAY AND
`SHIP TO MANUFACTURING FACILITY
`
`Fig. 2
`
`20
`
`ge
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`24
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`26
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`28
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`32
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`Patent Application Publication Feb. 8, 2007 Sheet 3 of 17
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`US 2007/0031774 Al
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`RECEIVE DENTAL IMPRESSION TRAY AT
`MANUFACTURING FACILITY
`
`STERILIZE AND FORM CASTING
`
`UPDATE MODEL RECORD
`
`CURE AND TRIM CASTING
`
`ATTACH CASTING TO PEDESTAL
`
`SCAN CASTING TO GENERATE 3D DIGITAL MODEL
`
`
`
`EXECUTE BEST FIT ALGORITHM TO REGISTER
`COORDINATE SYSTEMSOF CASTING
`TO DIGITAL MODEL
`
`SEGMENT3D DATAINTO INDIVIDUAL
`COMPONENTS
`
`40
`
`42
`
`44
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`46
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`48
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`50
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`52
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`54
`
`Fig. 3A
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`
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`Patent Application Publication Feb. 8, 2007 Sheet 4 of 17
`
`US 2007/0031774 Al
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`IMPORT 3D DATA FOR EACH COMPONENT
`INTO MODEL RECORD
`
`COMMUNICATE MODEL TO CLINICIAN COMPUTER
`
`RECEIVE PRESCRIPTION DATA AND
`VIRTUAL BRACKET PLACEMENT DATA
`
`PLACE APPLIANCESON CASTING
`
`FORM INDIRECT BONDING TRAY
`
`TRIM INDIRECT BONDING TRAY
`
`UPDATE MODEL RECORD
`
`SHIP INDIRECT BONDING TRAY TO CLINIC
`
`Fig. 3B
`
`56
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`58
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`60
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`62
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`64
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`66
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`68
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`70
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`Patent Application Publication Feb. 8, 2007 Sheet 5 of 17
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`US 2007/0031774 Al
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`ee80
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`Patent Application Publication Feb. 8, 2007 Sheet 6 of 17
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`US 2007/0031774 Al
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`Patent Application Publication Feb. 8, 2007 Sheet 7 of 17
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`US 2007/0031774 Al
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`104
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`Fig. 8
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`
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`Patent Application Publication Feb. 8, 2007 Sheet 8 of 17
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`US 2007/0031774 Al
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`
`
`Teet
`
`
`
`'°4
`
`
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`150
`
`Impression
`
`
` i Pre-existing
` Scan
`
` Scan Patient's
`3D Tooth Datal~
`
`
`Attach Pedestal to Tooth
`Structure in Virtual
`Space
`
`
`
`
`Generate Physical Model
`With Attached Pedestal
`
`1
`
`98
`
`
`
`Mate Pedestal to Robotic
`Device for Automatic
`Bracket Replacement
`
`
`160
`
`Fig. 9
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`
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`Patent Application Publication Feb. 8, 2007 Sheet 9 of 17
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`US 2007/0031774 Al
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`4-90
`
`92
`
`91
`
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`
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`(0, 0, 0)
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`Fig. 10A
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`
`Patent Application Publication Feb. 8,2007 Sheet 10 of 17
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`US 2007/0031774 Al
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`(0, 0, 0)
`
`4.000" ——__
`Fig. 11A
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`Fig. 11B
`
`
`
`Patent Application Publication Feb. 8,2007 Sheet 11 of 17
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`US 2007/0031774 Al
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`+Z
`
`|
`
`4.000" N" NS)mi
`
`Fig. 12B
`
`
`
`Patent Application Publication Feb. 8,2007 Sheet 12 of 17
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`US 2007/0031774 Al
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`Patent Application Publication Feb. 8,2007 Sheet 13 of 17
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`US 2007/0031774 Al
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`Patent Application Publication Feb. 8,2007 Sheet 14 of 17
`
`US 2007/0031774 Al
`
`COLLECT PATIENT IDENTITY AND BASIC
`PATIENT INFORMATION AND CREATE PATIENT
`
`110 RECORD IN DATABASE
`
`ACCESS DATABASE AND CREATE MODEL
`RECORD FOR NEW MODEL
`
`12
`
`1
`
`SELECT DENTAL IMPRESSION TRAY
`
`14
`
`{
`
`UPDATE DATABASE TO ASSOCIATE PATIENT
`RECORD WITH MODEL RECORD
`
`116
`
`PLACE MARKERSON PATIENT'S TEETH
`
`1
`
`18
`
`FORM IMPRESSIONOF PATIENT'S TOOTH
`STRUCTURE
`
`120
`
`IMPRESSED STATUS
`
`:
`
`4
`
`STERILIZE DENTAL IMPRESSION TRAY AND
`SHIP TOMANUFACTURING FACILITY
`
`{
`
`2
`
`6
`
`Fig. 17
`
`
`
`Patent Application Publication Feb. 8,2007 Sheet 15 of 17
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`US 2007/0031774 Al
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`we128
`
`129
`
`Fig. 18
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`130
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`132
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`131
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`Fig. 19
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`
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`Patent Application Publication Feb. 8,2007 Sheet 16 of 17
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`US 2007/0031774 Al
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`133
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`132
`
`Fig. 20
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`US 2007/0031774 Al
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`Patent Application Publication Feb. 8,2007 Sheet 17 of 17
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`
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`138
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`140
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`137
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`Fig. 23
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`137
`
`139
`
`138
`
`Fig. 24
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`
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`US 2007/0031774 Al
`
`Feb. 8, 2007
`
`REGISTERING PHYSICAL AND VIRTUAL TOOTH
`STRUCTURES WITH MARKERS
`
`TECHNICAL FIELD
`
`may be difficult. In some instances, and particularly in
`connection with posterior teeth, the practitioner may have
`difficulty seeing the precise position of the bracket relative
`to the tooth surface. Additionally,
`the appliance may be
`unintentionally bumped from its intended location during
`the time that the excess adhesive is being removed adjacent
`the base of the appliance.
`[0007] Another problem associated with the direct bond-
`ing technique described above concerns the significant
`length of time needed to carry out the procedure of bonding
`each appliance to each individual tooth. Typically, the prac-
`titioner will attempt to ensure that each appliance is posi-
`tionedin its precise, intended location before the adhesive is
`cured, and some time may be necessary before the practi-
`tioner is satisfied with the location of each appliance. At the
`same time, however, the patient may experience discomfort
`and have difficulty in remainingrelatively motionless, espe-
`cially if the patient is an adolescent. As can be appreciated,
`there are aspects of the direct bonding technique that can be
`considered a nuisance for both the practitioner and for the
`patient.
`[0003] A numberof orthodontic appliances in commercial
`Indirect bonding techniques often avoid many of
`[0008]
`use today are constructed on the principle of the “straight
`the problems noted above.
`In general,
`indirect bonding
`wire concept” developed by Dr. Lawrence F. Andrews,
`techniques known in the past have involved the use of a
`D.D.S. In accordance with this concept, the shape of the
`transfer tray having a shape that matches the configuration
`appliances,
`including the orientation of the slots of the
`of at least part of a patient’s dental arch. A set of appliances
`appliances, is selected so that the slots are aligned inaflat
`such as brackets are releasably connected to the tray at
`reference planeat the conclusion of treatment. Additionally,
`certain, predetermined locations. Adhesive is applied to the
`a resilient archwire is selected with an overall curved shape
`base of each appliance, and the tray is then placed over the
`that normally lies in a flat reference plane.
`patient’s teeth until such time as the adhesive hardens. Next,
`the tray is detached from the teeth as well as from the
`appliances, with the result that all of the appliances previ-
`ously connectedto the tray are now bondedto the respective
`teeth at their intended, predetermined locations.
`[0009]
`In more detail, one methodof indirect bonding of
`orthodontic appliances includes the steps of taking an
`impression of each of the patient’s dental arches and then
`makinga replica plaster or“stone” model from each impres-
`sion. Optionally, a soap solution (such as Model Glow brand
`solution from Whip Mix Corporation) or wax is applied to
`the stone model. A separation solution (such as COE-SEP
`brand tinfoil substitute from GC America,
`Inc.) is then
`applied to the stone model and allowedto dry. If desired, the
`teeth of the model can be marked with a pencil to assist in
`placing the brackets in ideal positions.
`[0010] Next, the brackets are bonded to the stone models.
`Optionally, the bonding adhesive can be a chemical curing
`adhesive (such as Concise brand adhesive from 3M) or a
`light-curable adhesive (such as Transbond XT brand adhe-
`sive or Transbond LR brandadhesive, from 3M). Optionally,
`the brackets may be adhesive precoated brackets such as
`those described in U.S. Pat. Nos. 5,015,180, 5,172,809,
`5,354,199 and 5,429,299.
`[0011] A transfer tray is then made by placing a matrix
`material over the model as well as over the brackets placed
`on the model. For example, a plastic sheet matrix material
`maybe held by a frame and exposedto radiant heat. Once
`the plastic sheet material has softened, it is placed over the
`model and the brackets. Air in the space between the sheet
`material and the model is then evacuated, and the plastic
`sheet material assumes
`a configuration that precisely
`matches the shape ofthe replica teeth of the stone model and
`the attached brackets.
`
`[0001] The invention relates to orthodontics and, more
`particularly, computer-based techniques for assisting orth-
`odontic diagnosis and treatment.
`
`BACKGROUND
`
`[0002] The field of orthodontics is concerned with repo-
`sitioning and aligning a patient’s teeth for improved occlu-
`sion and aesthetic appearance. For example, orthodontic
`treatment often involves the use of tiny slotted appliances,
`knownas brackets, which are fixed to the patient’s anterior,
`cuspid, and bicuspid teeth. An archwire is received in the
`slot of each bracket and servesas a track to guide movement
`of the teeth to desired orientations. The ends of the archwire
`
`are usually received in appliances known as buccal tubes
`that are secured to the patient’s molar teeth.
`
`[0004] Whenthe archwire is placed in the slots of the
`straight wire appliances at the beginning of orthodontic
`treatment, the archwireis often deflected upwardly or down-
`wardly from one applianceto the next in accordance with the
`patient’s malocclusions. However,
`the resiliency of the
`archwire tends to return the archwire to its normally curved
`shapethatlies in a flat reference plane. As the archwire shifts
`towardtheflat reference plane, the attached teeth are moved
`in a corresponding fashion toward an aligned, aesthetically
`pleasing array.
`
`In general, orthodontic appliances that are adapted
`[0005]
`to be adhesively bondedto the patient’s teeth are placed on
`the teeth by either one of two methods: a direct bonding
`method, or an indirect bonding method.In the direct bond-
`ing method, the appliance and adhesive are grasped with a
`pair of tweezers or other hand instrument and placed by the
`practitioner on the surface of the tooth in an approximate
`desired location. Next, the appliance is shifted along the
`surface of the tooth as needed until
`the practitioner is
`satisfied with its position. Once the appliance is in its
`precise, intended location, the appliance is pressed firmly
`onto the tooth to seat the appliance in the adhesive. Excess
`adhesive in areas adjacent the base of the appliance is
`removed, and the adhesive is then allowed to cure andfix the
`appliance firmly in place. Typical adhesives include light-
`curable adhesives that begin to harden upon exposure to
`actinic radiation, and two-component chemical-cure adhe-
`sives that begin to harden when the components are mixed
`together.
`
`[0006] While the direct bonding technique described
`aboveis in widespread use andis considered satisfactory by
`many, there are shortcomings that are inherent with such a
`technique. For example, access to surfaces of malposedteeth
`
`
`
`US 2007/0031774 Al
`
`Feb. 8, 2007
`
`[0012] The plastic material is then allowed to cool and
`harden to form a tray. The tray and the brackets (which are
`embedded in an interior wall of the tray) are then detached
`from the stone model and sides of the tray are trimmed as
`maybe desired. Once the patient has returned to the office,
`a quantity of adhesive is placed on the base of the bracket,
`and the tray with the embedded brackets is then placed over
`the matching portions of the patient’s dental arch. Since the
`configuration of the interior of the tray closely matches the
`respective portions of the patient’s dental arch, each bracket
`is ultimately positioned onthe patient’s teeth at precisely the
`same location that corresponds to the previous location of
`the same bracket on the stone model.
`
`[0013] Both light-curable adhesives and chemical curing
`adhesives have been used in the past in indirect bonding
`techniques to secure the brackets to the patient’s teeth. If a
`light-curable adhesive is used, the tray is preferably trans-
`parent or translucent. If a two-component chemical curing
`adhesive is used, the components can be mixed together
`immediately before application of the adhesive to the brack-
`ets. Alternatively, one component may be placed on each
`bracket base and the other component maybe placed on the
`tooth surface. In either case, placing of the tray with the
`embedded brackets on corresponding portions of the
`patient’s dental arch enables the brackets to be bondedto the
`teeth as a group using only a short amountof time that the
`patient is occupying the chair in the operatory. With such a
`technique,
`individual placement and positioning of each
`bracket in seriatim fashion on the teeth is avoided.
`
`[0014] A variety of transfer trays and materials for transfer
`trays have been proposed in the past. For example, some
`practitioners use a soft sheet material (such as Bioplast tray
`material from Scheu-Dental GmbH or Great Lakes Orth-
`
`odontics, Ltd.) for placement over the stone model and the
`appliances on the model. Either a vacuum or positive
`pressure is applied to respectively pull or push the soft
`material into intimate contact with the model andthe appli-
`ances on the model. Next, a stiffer sheet material (such as
`Biocryl sheet material, from Scheu-Dental GmbH or Great
`Lakes Orthodontics, Ltd.) is formed over the softer sheet
`material, again using a either a vacuum orpositive pressure
`forming technique. Thestiffer material provides a backbone
`to the tray, while the softer material
`initially holds the
`appliances and yet is sufficiently flexible to release from the
`appliances after the appliances have been fixed to the
`patient’s teeth.
`
`It has also been proposed in the past to use a
`[0015]
`silicone impression material or a bite registration material
`(such as Memosil 2, from Heraeus-Kulzer GmbH-& Co.
`KG). The silicone material is applied over the appliances
`that are attached to the study model so that the appliances are
`partially encapsulated.
`
`In an article entitled “A New Look at Indirect
`[0016]
`Bonding” by Moskowitz et al. (Journal of Clinical Orth-
`odontics, Volume XXX, Number 5, May 1996, pages 277 et
`sec.), a technique for making indirect bonding trays is
`described using Reprosil
`impression material
`(from
`Dentsply International). The impression material is placed
`with a syringe over brackets that have been previously
`placed on a stone model. Next, a sheet of clear thermoplastic
`material is drawn down over the impression material using
`
`a vacuum-forming technique. The resultant transfer tray is
`then removed from the model for subsequent placement on
`the patient’s dental arch.
`
`Indirect bonding techniques offer a number of
`[0017]
`advantages over direct bonding techniques. For one thing,
`and as indicated above,it is possible to bond a plurality of
`brackets to a patient’s dental arch simultaneously, thereby
`avoiding the need to bond each appliance in individual
`fashion. In addition, the indirect bonding tray helps to locate
`all of the brackets in their proper, intended positions such
`that adjustment of each bracket on the surface of the tooth
`before bonding is avoided. The increased placement accu-
`racy of the appliances that is often afforded by indirect
`bonding techniques helps ensure that the patient’s teeth are
`moved to their proper, intended positions at the conclusion
`of treatment.
`
`in orthodontics is rapidly
`[0018] The state of the art
`moving toward digital and computer-aided techniques.
`These techniques include the use of intra and extra-oral
`scamers, three-dimensional (3D) modeling of a tooth struc-
`ture, and fabrication of orthodontic devices from digital
`data.
`
`SUMMARY
`
`In general, the invention relates to techniques for
`[0019]
`registering a three-dimensional (3D) coordinate system of a
`physical model of a patient’s tooth structure to a 3D coor-
`dinate system of a virtual model of the sametooth structure.
`Techniques are described to register the complex geometries
`of the physical and virtual tooth structures by using regis-
`tration markers associated with the physical model.
`
`In one example, registration markersare arbitrarily
`[0020]
`placed onto the patient’s teeth prior to forming an impres-
`sion of the patient’s teeth. In another example, registration
`markers are arbitrarily placed onto the impression after the
`impression is formedor onto the casting after the casting is
`formed. Scanning the teeth,
`impression, or casting with
`markers generates a digital model of the tooth structure
`containing markers. The locations of the registration mark-
`ers may then assist registration of the coordinate system of
`the physical model to the coordinate system of the 3D digital
`model for creation of a digital orthodontic prescription for
`the patient.
`
`In one embodiment, a method comprises attaching
`[0021]
`markers to a tooth structure of a patient, forming an impres-
`sion of the patient’s tooth structure having the attached
`markers, and registering the impression to a digital model of
`the tooth structure based on knownlocations of the markers.
`
`In another embodiment, an orthodontic marker
`[0022]
`bracket comprises a metallic hemispherical bracket, and a
`bonding pad attached to the metallic hemispherical bracket
`for bonding to a tooth.
`
`In another embodiment, an orthodontic marker
`[0023]
`bracket comprises a light transmitting marker bracket, and a
`bonding pad attached to the light
`transmitting marker
`bracket for bonding to a tooth.
`
`Inanother embodiment, a system comprises a tooth
`[0024]
`markerattached to a tooth structure of a patient, an impres-
`sion of the tooth structure having the attached markers, a
`
`
`
`US 2007/0031774 Al
`
`Feb. 8, 2007
`
`computer that registers the impression to a digital model
`based on known locations of the markers.
`
`FIG. 14 is a top view of an exemplary inverted
`[0040]
`pedestal drilled with holes and tapped with machinethreads.
`
`In another embodiment, a method comprises form-
`[0025]
`ing a physical modelofa patient’s tooth structure, attaching
`markers to the physical model, scanning the physical model
`having markers to generate a digital model of the tooth
`structure, and registering the physical model to the digital
`model with known locations of the markers.
`
`[0026] The invention may provide one or more advan-
`tages. For example, the techniques mayprovideforassisted
`(e.g., automatic or semi-automatic) registration of physical
`and virtual models used during indirect bonding tray fabri-
`cation. Assisted registration may reduce the labor, cost, and
`probability of error during manufacturing of an orthodontic
`appliance, such as an indirect bonding tray. The details of
`one or more embodiments of the invention are set forth in
`
`the accompanying drawings and the description below.
`Other features, objects, and advantages of the invention will
`be apparent from the description and drawings, and from the
`claims.
`
`BRIEF DESCRIPTION OF DRAWINGS
`
`FIG. 15 is a rear elevation view of an exemplary
`[0041]
`inverted pedestal fitted and properly aligned with screws
`strategically located and threaded into the casting material,
`upon a main pedestal, with an enclosing wall.
`
`FIG. 16 is an inverted rear elevation view of an
`[0042]
`exemplary inverted pedestal with screws securing the posi-
`tion of the solid casting.
`
`FIG. 17 is block diagram illustrating an exemplary
`[0043]
`process at a clinic, distinguishable from FIGS. 3A and 3B by
`the placement of marker brackets at the clinic.
`
`FIG. 18 is a perspective view of an exemplary
`[0044]
`metallic hemispherical bracket.
`
`FIG. 19 is a perspective view of an exemplary
`[0045]
`marker tool for attaching marker brackets to a patient’s
`tooth.
`
`FIG. 20 is a cross section of an exemplary hemi-
`[0046]
`spherical cup in bell housing of a marker tool.
`
`[0047]
`FIG. 21 is a perspective view of an exemplary
`surfaced 3D digital model with a marker bracket.
`[0027] FIG.1is a block diagram illustrating an exemplary
`computer environment 2 in which a clinic and a manufac-
`[0048]
`FIG. 22 is a perspective view of an exemplary CNC
`turing facility communicate information throughout an indi-
`machined plate with a surface profile machined intoit.
`rect bonding tray manufacturing process.
`
`[0028] FIG. 2 is a block diagram illustrating an exemplary
`process at a clinic.
`
`[0029] FIGS. 3A and 3B are block diagramsillustrating an
`exemplary process at an indirect bonding device manufac-
`turing facility.
`
`[0030] FIG. 4 is a perspective view of an exemplary
`pedestal of known geometry.
`
`[0031] FIGS. 5A and 5Bare perspective viewsof a digital
`model of a casting attached to a pedestal.
`
`[0032] FIG. 6 is a perspective view of an exemplary
`fixture of a robotic device.
`
`[0033] FIG. 7 is a perspective view of an exemplary
`pedestal with attached model mated to an exemplary fixture
`of a robotic device.
`
`[0034] FIG. 8 is a side elevation view of an exemplary
`casting assembly.
`
`[0036] FIGS. 10A and 10B are an occlusal and distal view
`respectively of an exemplary impression tray with three
`hemispherical dimples.
`
`[0037] FIGS. 11A and 11B are a top and rear elevation
`view respectively of an exemplary main pedestal with three
`pillars.
`
`[0038] FIGS. 12A and 12Bare a top andrear elevation
`view respectively of an exemplary impression tray attached
`to an exemplary main pedestal.
`
`[0039] FIG. 13 is a rear elevation view of an exemplary
`enclosing wall resting on a main pedestal with attached
`impressions.
`
`FIG. 23 is a side view of a casting set into the
`[0049]
`machined surface of an exemplary plate.
`
`FIG. 24 is a perspective view of a casting set into
`[0050]
`the machined surface of an exemplary plate.
`
`DETAILED DESCRIPTION
`
`FIG.1 is a block diagram illustrating an exemplary
`[0051]
`computer environment 2 in which a clinic and a manufac-
`turing facility communicate information throughout an indi-
`rect bonding
`tray manufacturing process. Although
`described with respect to manufacturing of indirect bonding
`trays, the techniques may be applied to other computer-
`implemented processes for assisting orthodontic diagnosis
`and treatment.
`
`[0053] An orthodontic practitioner of clinic 8 utilizes
`dental impression tray 10 to capture an impression of the
`dental arch of patient 6. Clinic 8 stores digital information
`in a patient record within a database to associate the patient
`record with the particular dental impression tray 10. Clinic
`8 may,
`for example, update a local database having a
`plurality of patient records. Alternatively, clinic 8 may
`remotely update a central database within manufacturing
`facility 12 via network 14.
`
`Initially, manufacturing facility 12 produces a den-
`[0052]
`tal impression tray 10 for receiving dental impressions of a
`dental arch or other tooth structure of patient 6. Manufac-
`turing facility 12 ships dental impression tray 10 to clinic 8.
`The dental impression tray 10 is loaded with a quantity of
`impression material just prior to taking the impression at
`[0035] FIG.9is a block diagram of an exemplary process
`clinic 8, or alternatively is preloaded with quantity of
`according to one embodiment of the invention.
`impression material by the manufacturer before shipmentto
`the clinic. Impression tray 10 is adapted to extend along the
`entire dental arch, although as an alternative it is possible to
`use an impressiontray that extends along a fewer numberof
`teeth such as a dental quadrant.
`
`
`
`US 2007/0031774 Al
`
`Feb. 8, 2007
`
`In either case, clinic 8 then returns dental impres-
`[0054]
`sion tray 10 to manufacturing facility 12. Manufacturing
`facility 12 utilizes dental impression tray 10 to construct an
`indirect bonding tray 16 for use in physically placing
`brackets on the teeth of patient 6.
`
`[0055] Construction ofindirect bonding tray 16 involves a
`multi-step process conducted at manufacturing facility 12.
`First, manufacturing facility 12 creates a casting from dental
`impression tray 10. The term “casting” is used generally
`herein to refer to any type of physical model made from
`dental impression tray 10, for example, a replica made from
`plaster of Paris or from a polymeric material such as an
`epoxy that transmits actinic radiation. Suitable epoxy and
`other polymeric materials are described in published U.S.
`patent application 20040219473, which is incorporated by
`reference herein. The term “casting” is also used generally
`herein to refer to a physical model of predicted tooth
`positions, such as a stereolithographic model used in the
`fabrication of tooth positioning trays. Examples of tooth
`positioning trays include those sold by Align Technology of
`Santa Clara, Calif. and those described in U.S. Pat. Nos.
`6,309,215 and 6,705,863, both of which are incorporated by
`reference herein. Optionally, in instances where a digital
`model of the entire arch is not needed, the casting may
`include a fewer number of teeth than the number of teeth
`
`represented in the impression.
`
`In certain embodiments, the casting contains or is
`[0056]
`affixed to one or more registration components having
`knownphysical characteristics. The registration components
`mayhave been placed into the impressiontray at clinic 8 and
`transferred to the casting or may have been attached to or
`embedded within the casting at manufacturing facility 12.
`
`[0057] Next, manufacturing facility 12 scans the casting or
`the impression with one or moreregistration components to
`generate a three-dimensional (3D) digital model of the tooth
`structure. Multiple castings or impressions may be scanned
`simultaneously to reduce the numberof scans. For example,
`scanning a casting of a patient’s upper jaw along with a
`casting of the patient’s lower jaw and bite impression
`enables registration of the models relative to each other (for
`setting the bite) along with registration of the castings to the
`virtual models all in a single scan. The registration compo-
`nents enable manufacturing facility 12 to utilize the digital
`model for receiving prescription data and bracket placement
`data from clinic 8 in order to automatically place brackets
`onto the casting per the clinic’s specifications. Manufactur-
`ing facility 12 then forms indirect bonding tray 16 from the
`casting with the affixed brackets. Lastly, manufacturing
`facility 12 forwards indirect bonding tray 16 to clinic 8 for
`use in a conventionalindirect bonding procedureto place the
`brackets on the teeth of patient 6.
`
`[0058] Manufacturing facility 12 may produce indirect
`bonding tray 16 by placing a matrix material in the form of
`aplastic sheet over the casting and the brackets and exposing
`the matrix material to radiant heat. Air in the space between
`the sheet material and the casting is then forced out by a
`pressure differential between the inner and outer surfaces of
`the sheet material (i.e. either by vacuum forming or positive
`pressure forming), and the plastic sheet material assumes a
`configuration that precisely matches the shape ofthe replica
`teeth of the casting and the attached brackets. Suitable
`indirect bonding trays and methods for making indirect
`
`bonding trays are described, for example, in copending and
`commonly assigned U.S. patent application Ser. No. 10/428,
`301 entitled “Method and Apparatus for Indirect Bonding of
`Orthodontic Appliances”, filed May 2, 2003 to Cleary etal.,
`Ser. No. 10/428,255 entitled “Orthodontic Appliances Hav-
`ing a Contoured Bonding Surface”, filed May 2, 2003 to
`Cleary et al., and Ser. No. 10/678,841 entitled “Method and
`Apparatus for Bonding Orthodontic Appliances to Teeth”,
`filed Oct. 3, 2003 to Cleary et al., all of which are entirely
`incorporated herein by reference.
`
`Asfurther described, techniques may be used to
`[0059]
`assist (e.g., automatically or semi-automatically) registra-
`tion of a physical model to a corresponding digital model for
`automated appliance manufacturing, such as manufacturing
`of an indirect bonding device from the casting. For example,
`the techniques involve attaching or embedding one or more
`registration components of known physical characteristic to
`a physical model of a patient’s tooth structure (e.g., a dental
`impression, bite registration, or casting) prior to scanning
`the physical model. For example, the registration component
`may be a pedestal of known geometry, a pedestal with
`embedded fiducial markers at known locations, a pedestal
`attached to an impression tray containing dimples at known
`locations, a group of three or more tooth markers placed
`directly on a select number of a patient’s teeth prior to
`forming the impression, or a group of three or more tooth
`markers placed on an impressionor casting after forming the
`impression or casting. The phrase “patient’s tooth structure”
`is used generally herein to refer to a replica of the patient’s
`current tooth structure and alternatively to a replica of the
`patient’s predicted tooth structure such as may be expected
`to occur after orthodontic treatment has commenced.
`
`[0060] After scanning the physical model with attached
`registration component or components, a computerregisters
`the coordinate system of the physical model to the coordi-
`nate system of the digital model using the known geometry
`ofthe pedestal or the knownlocation ofthe fiducial markers
`within the pedestal or within the impression tray. Further-
`more, the computer may use the known geometry or known
`location of the registration components to register the coor-
`dinate systems of the physical and digital models to the
`coordinate system of a manufacturing device for automatic
`bracket placement onto the casting. Lastly, an indirect
`bonding device is formed upon the casting with the attached
`brackets.
`
`[0061] The invention may provide one or more advan-
`tages. The techniques may provide for assisted registration
`of physical and virtual models used during manufacturing of
`an orthodontic appliance, such as an indirect bondingtray,
`an individual or set of machined orthodontic brackets, a
`buccal
`tube, a sheath, a button, an arch wire or other
`orthodontic appliances. The techniques may also enable
`simultaneous scanning of multiple components utilized dur-
`ing the virtual modeling and automatic bracket placement
`process. Automatic registration and simultaneous scanning
`may reduce the labor, cost, and probability of error during
`multiple steps of orthodontic appliance manufacturing, such
`as: scanning,registering, virtual bracket placement, physical
`bracket placement, trimming of an indirect bonding tray or
`machining an appliance. The invention may also enable the
`use of roughly formed castings,
`thereby eliminating the
`expense of machining plaster casts.
`
`
`
`US 2007/0031774 Al
`
`Feb. 8, 2007
`
`[0062] FIG. 2 is a block diagram illustrating a process
`conductedat clinic 8 in accordance with one embodiment of
`
`Initially, practitioner at clinic 8 collects
`the invention.
`patient identity and other information from patient 6 and
`creates a patient record (20). As described, the patient record
`maybe located within clinic 8 and optionally configured to
`share data with a database within manufacturing facility 12.
`Alternatively, the patient record may be located within a
`database at manufacturing facility 12 that is remotely acces-
`sible to clinic 8 via network 14.
`
`[0063] When capturing an impression of the tooth struc-
`ture of patient 6, or shortly before or after, practitioner at
`clinic 8 creates a model record for the new model(22). In the
`field of orthodontics, t