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Dr Alain Méthot DMD Msc

This 54-year-old female patient chief complaint was; I am not happy about my smile. This patient had no medical contra-indications to treatment. Dental history revealed extractions and veneers done 10 years ago.

The patient wanted to change her veneers. She presented an inverted smile line caused by an exaggerated curve of Spee and poor upper central width and length ratio. She had a CL III malocclusion involving inter dental spaces discrepancy, with an overjet of 1mm and an overbite of 0.5mm (Figure 15, 16 and 17).

In this case, two pre-op pictures have been taken in different appointments. In many cases, pictures are not perfectly taken according to the Yes and the No, however both can be used to see the esthetic outcome and establish a preliminary diagnosis.

Figure 15 On this pre-op facial picture the YES is aligned with the Camper Plane, which is not adequate for GPS Facebow, on the other side the NO is ok.

For this clinical case, the diagnosis and case presentation was done using the image in (Figure 16) in GPS software.

Figure 16 Pre-op facial picture: on this pre-op picture the YES is aligned with the Frankfurt Plane and the NO is not perfectly aligned, patients head is turned a bit toward the right side. This picture is more adequate to use with GPS Facebow.


Figure 17 Retracted close up pre-op pictures.

The patient exhibited multiple missing teeth, spaces and a gingival recession of 4mm on the upper right first bicuspid (Figure 17).

Using one facial picture is not enough to establish a proper diagnosis; the panoramic X Ray is essential to complete the diagnosis and treatment plans (Figure 18). Models are more useful, however they are not essential with GPS Concept.


Figure 18 The panoramic X Ray contributes to the diagnosis and treatment plans.


- Diagnosis

After placing the Digital Facebow at the intersection of the incisal edge and the dental midline of upper centrals, the “M” Ruler appears over the patients face (Figure 19).


Figure 19 “M” Ruler appears over the patient’s face after placing the Digital Facebow over the facial picture. The system is calibrated with both central widths; the vertical lines of the “M” Ruler are aligned with the long axis of the face and the horizontal lines are aligned with the upper lip line. The horizontal lines are set with a ratio of 1.618 to set the lower facial height with the central length position.

The facial image with the attached “M” lines is automatically zoomed to show a close up view of the smile, this allows the practitioner to move and adjust the M Ruler laterally to fit the device on the maximum of teeth.
In this case, the “M” Ruler has been moved 1 mm toward the left side of the patient to match the maximum of teeth in both quadrants and to align the dental midline with the facial midline. By doing this, we can see that teeth 11-21-22-23-24-25 are not well positioned in the “M” Ruler; orthodontic treatment will be the ideal treatment plan for this patient (Figure 20).

Figure 20 Close up of the smile from the facial image, keeping the alignment of the M Lines over the picture; it is ready to be imported on the articulator.


- Simulation

A virtual 2D diagnostic wax-up was established in Dental GPS software with a morphing technology driven by the “M” Ruler, treatments plans where done with this digital smile design diagnostic device. The patient was informed of the treatment options, including no treatment at all and the risks, benefits and costs of different treatments.
The ideal treatment plan was to consolidate the gaps created from the previously missing teeth...whiten the teeth, and restore a more pleasing proportion to the smile.
To accomplish the ideal treatment plan (Figure 21 a,b), 3 different treatments were necessary:
Stage 1 Orthodontic
Stage 2 Teeth whitening
Stage 3 Veneers and crowns

 

Figure 21 a,b Patient accepted the ideal treatment plan from the picture showing the virtual 2D diagnostic wax up.

The basic plan was to align teeth by re-distributing large spaces into equal spaces to dispose teeth evenly in the arch as prescribed by the “M” Ruler. Based on Dental GPS virtual 2D wax up, the final goal of the treatment was to extrude upper centrals with orthodontics to correct the gingival architecture, to enlarge upper centrals and to correct the dental midline shift. Upper teeth from 15 to 25 needed to be enlarged 0.5mm mesial and distal after orthodontic treatment to fill spaces. Longer centrals will create a nicer smile line and will correct the inverted smile line. A gingival surgery was planed to correct the recession on the upper right first bicuspid. An implant was planned to replace tooth 45. A total of 13 veneers and crowns were planned on teeth 15 to 25 and teeth 45-33 and 34 (Figure 21 b)

Stage 1

The patient accepted to do the ideal treatment by simply seeing the projected smile on the picture with and without M Lines. An orthodontic treatment setup was planned to move teeth and align the arch form.


Figure 22 Pre-op images with the “M” Ruler over the facial image and the ClinCheck 3D model


Figure 23 Pre-op images with the “M” Ruler over the frontal image


Figure 24 Orthodontic prescription done from with the same “M” Ratio

Orthodontic treatment consisted of Invisalign (Align Technology, Santa Clara, CA) therapy. The orthodontic prescription was sent to Invisalign in order to do a ClinCheck. A ClinCheck allows the practitioner to visualize the proposed orthodontic treatment and teeth movement before accepting the case (Figure 24).

Figure 25 Projected result with ClinCheck.

16 aligners were needed to complete the alignment of teeth in a period of 32 weeks in order to distribute the spaces, correct the gingival architecture, the occlusal contacts and arch form. A space of 1 mm between each tooth from tooth 15 to 25 was planed to evenly distribute the big spaces in small spaces in respect with the CL III malocclusion. 1mm spaces will be filled with veneers and crowns (Figure 25,26).
After the orthodontic treatment, new close-up pictures were taken (Figure 27).


Figure 26 Big spaces have been split in 1mm spaces from tooth 15 to tooth 25.


Figure 27 Close-up pictures of the post-up treatment showing 1mm spaces between each teeth, gingival graft have been done on tooth 14. An implant have been placed to replace tooth 45.

Stage 2
Bleaching was performed with trays at home.
Stage 3
A new facial picture was taken after the orthodontic treatment with the correct YES and NO position (Figure 28). The quality of this picture is important to redesign a virtual 2D wax-up to show of the final outcome of the crowns and veneers with the new teeth position. The virtual 2D wax-up Smile Prescription is then sent to the lab. The precision of the correlation between the virtual 2D wax-up and the real wax up in the lab relies on that picture.


Figure 28 A well-centered picture for the Digital Smile Design Lab Prescription


Figure 29 The Digital Facebow is attached at the intersection of the dental midline of the upper centrals on the vertical axis and the incisal edge on the horizontal axis. Once attached on that point it can turn on itself to be aligned with the long axis of the face and the upper lip line.


Figure 30 After 16 Invisalign aligners, the same ratio of the “M” Ruler match the alignment of the new position of teeth in the patient’s face. The dental midline has been corrected to fit with the facial midline and the maxillary fit symmetrically between the 2 corners of the lip with teeth well aligned in both quadrants.


Figure 31 Close-up view of the facial image showing teeth aligned in the maxillary arch.


Figure 32 Close-up of the virtual 2D wax up over the zoomed facial image.

Transferring the 2D axis coordinates to the articulator for the a precise wax-up

The GPS Digital Facebow is connected to the articulator with the GPS Connect 2D to 3D Digital Facebow platform. To transfer the 2D wax-up to the lab, a print out of the Y-axis calibrated “M” lines from the Smile Prescription is placed on top of the platform on the articulator. The printout is cut on the bottom of the page by the dental technician. The “M” lines are placed on the platform with the frontal part of the print out against the Z lines of the platform. The upper centrals of the 3D model will by placed on the Z lines, (the Z-axis is the antero-posterior position of teeth) (Figure 33 a,b). The Pitch, Roll and Yaw of the pre-op model on the articulator will match the Pitch, Roll and Yaw of the pre-op 2D image in GPS Smile Prescription inside GPS software (Figure 33 c,d)
The X-axis in the Smile Prescription will set the height of the platform. The incisal edge position on the digital 2D wax-up will be matched to the 3D wax-up on the platform (Figure 34 a,b)

Figure 33 a,b Transfer of the “M” Lines over the platform on the articulator for wax-up.


Figure 33 c,d Mounting the pre op model using the X-axis in GPS Prescription to set the Roll and Pitch, and the Y-axis of the M Lines to set the Yaw.


Figure 34 a,b Transferring the wax-up to the platform

Figure 35 Correlation between the 2D wax-up of the software and the articulator from the same frontal view.



Figure 36 Sequence of treatment from the beginning to the end.


Figure 37 Post-op close up views showing the results of gingival graph on tooth 14, the crown over the implant on tooth 45 and the veneers and crowns on teeth 15 to 25 and teeth 33 and 34.


Figure 38 Post-op facial picture


Figure 39 Post-op close-up frontal pictures: a post-op picture few weeks after the cementation in 2009 and a post-op picture 5 years after the cementation in 2014.


Discussion
Several parameters are available to assess smile esthetics, such as amount of gingival display, midline position, buccal corridor, incisor width/height ratio, axial inclination, gingival contour, and smile arch appearance. 1
The smile itself cannot be considered separated from the face. Without patient’s facial expression data, it is impossible to make a proper evaluation of the smile and its harmony within the patient’s face. As part of the diagnosis, it is necessary to evaluate facial and dental asymmetries including discrepancies in teeth position. As practitioners, we need to think “global esthetics” by using a full facial view from start to the end of treatment. Close-up pictures of the patient’s smile helps for smile design, however the complete facial picture is required to evaluate how the smile looks on the patient’s face. 2,3

Time is precious in dental offices; taking only one facial picture with GPS makes diagnosis, treatment planning and presentation easy. Glamour pictures and movies are expensive and time consuming. The concept presented in this article uses only one facial image in order to transfer the new smile design to a 3D model on a physical articulator or in 3D software. The same zoom out or zoomed in facial picture most be used to fabricate lab works.

By using GPS software with a pre-op facial photograph and a Panoramic X-ray of the patient, the dental practitioner can make smile design diagnosis and create different treatment plans with different virtual 2D morphed wax-ups lab prescription in less than 10 minutes. The advantage of this concept is that no impression is taken prior to case acceptance, thanks for the precision of the virtual 2D wax-up that saves time and a lot of steps compared with the actual products offered in Digital Smile Design. It is to be remarked that in a 2D environment it is impossible to correlate with precision a 2D facial picture with a 2D close-up picture of the same patient.

The “M” Ruler combined with a morphing technology determines the best smiles for the patient. The “M” Ruler is a symmetrical digital diagnostic device for smile design.
This device uses a mathematical formula related to 3 values:
1- The width of the upper centrals.
2- The width of the arch.
3- The number of teeth in the arch.

The combination of these 3 values determines the correct balance for the teeth displayed within patient’s arch to create a pleasing smile. 4 (Figure 40)

Figure 40 The “M” Ruler
Each patient has a unique pre-op maxillary width and upper central width, which can be changed by the practitioner to get a better arch form or esthetic smile. Maxillary teeth best position should be disposed between the “M” lines in respect with the number of teeth shown in the actual smile, or on a new smile with a different upper arch width, form, and/or centrals width. Those Y-axis vertical lines guide the dental professional to see the best position of the upper arch and teeth in the patient’s face, lips and gums during smile design creation. The visual simulation allows the patient to understand the treatment plan from the pre-operative image to the final cementation of the restorations with 2 overlay images. Several projects with different treatments can be simulated and discussed with the patient in the first or a second consultation, while traditional laboratory wax-up allows the patient to visualize only one smile design possibility often with no idea of the final esthetic result in respect to the facial appearance.
Traditional mock-ups help, today, practitioners and patients to evaluate the Smile Design. However, in many cases of diastases or teeth malposition, the mock-up itself – derived from the traditional wax-up - still gives only one alternative and cannot simulate the final result without reducing teeth. In these situations, they can be considered a limited procedure. On the other hand, it’s a lot of work and a costly process to take impressions of both arches and a bite, make a wax-up and take time to try a mock-up in the patient’s mouth for an evaluation.
Even if a diagnostic wax-up is made by the dental laboratory and shown to the patient, or if a provisional is made from the wax-up and acts as a physical mock-up in the patient’s mouth, this single proposed wax-up may not be the optimal esthetic solution for that particular patient and requires other modifications and clinical appointments. 5

The virtual 2D wax-up simulated by practitioner through the computer can produce an electronic prescription, called GPS Connect that can be sent to the laboratory to create an accurate wax-up of the proposed simulated smile. The lab technician has access to the patient facial parameters in the prescription to see the exact position of soft tissue on the model mounted on the articulator.
After simulating the final outcome in respect to the facial anatomy, the electronic prescription of GPS Connect transfers the 2D information’s to the 2D to 3D Digital Facebow in order to position the upper cast on the articulator or any 3D software with the exact Pitch, Roll and Yaw shown in the Smile Prescription. This method can reproduce the virtual 2D wax-up on provisional and final restorations (Fig. 41 a,b, 42, a,b). The “M” ruler, included in the GPS Connect tool, guides the wax-up of the future smile with the entire coordinates derived from the facial image.
This process is actually the easiest and most accurate way to transmit to the lab the complete esthetic data deriving from the aspect of facial soft and hard tissues. This gives the technician a complete idea of the impact of soft tissues to the execution of the prosthetic work.


Figure 41 a,b An example of a GPS simulation for 4 veneers on four upper incisors

 

Figure 42 a,b The project is then connected to the Cerec platform via GPS Connect in order to project and realize the veneers

With GPS concept, once the position of the maxillary cast has a correlation between the Smile Prescription and the traditional articulator or the 3D software, it is possible to fabricate provisional and final restorations that consistently duplicate the virtual 2D wax-up. It guides the lab technician to position each final restoration according to length, width, shape and position to establish the new smile line, occlusal plane and vertical dimension of occlusion. The ceramist simply follows the Smile Prescription to create the final restorations.

Conclusion

This article demonstrates the accuracy of imaging using the 2D to 3D Digital Facebow© and the correlation between the GPS protocol for the 3D cast positioning system from a single facial image of a patient with the combination of the “M” Ruler©, a digital diagnostic device for smile design.
Practitioners are able to fit the best possible smiles in minutes into the patient’s face by trying different simulated smiles using morphing technology before creating predictable and pleasing smiles for their patients. This simple protocol saves lot of time and chair side adjustments. Moreover, patients get better cosmetic dental treatments by seeing previously their best custom smiles, and can actively participate in the smile design creating process.
The first advantage of the GPS software is the rapidity in diagnosing and makes different treatment plans. This concept allows practitioners to increase the cosmetic workflow in their practice.
The second advantage relies in sharing the esthetic proposal with the patient, making him/her an active participant in the treatment plan.
The third advantage is transferring with precision all the coordinates of the computer-simulated bi-dimensional proposal into a 3D wax-up, then allows the dentist, all associated specialists and the laboratory technician to access and share information regarding the treatment plan, ongoing procedural status, and the final results of the case. Should any mid-stream correction be necessary, it is relatively simple to inform and receive consent from all the persons involved in smile design process. The 2D to 3D digital smile design process from a 2D image to a 3D model is patent pending.

References

1. Sabri R. OVERVIEW The Eight Components of a Balanced Smile. Journal of Clinical orthodontics 2005 ; 39 :155-167
2. Fradeani M, Barducci G Esthetic Rehabilitation in Fixed Prosthodontics, Volume 1. Esthetic Analysis: A Systematic Approach to Prosthetic Treatment. Quintessence ed. 2004
3. Methot A. Springing from Diagnosis: Photographic diagnosis and treatment planning. Journal of Cosmetic Dentistry Vol 28 No1 Spring 2012:114-124
4. Methot A. M Proportions. The new golden rules in dentistry. Canadian Journal of Cosmetic Dentistry 2006: 34-40
5. Goodlin, R.M. Minimally invasive Dentistry Cdn J Cos Dent Vol 4 No1 April 2008:43-45

 

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