Keywords
3D facial scan - midline deviation - crown lengthening - interdisciplinary dentistry
- patient satisfaction
Introduction
Today's society's increasing fascination with cosmetic dentistry necessitates orthodontic
treatment. In cosmetic dentistry, orthodontic treatment is a frequently done procedure.
It is implemented to obtain an esthetically pleasing appearance and a healthy occlusion
by aligning the teeth.[1]
[2] As patient expectations for esthetic outcomes rise, especially among adults, orthodontic
treatment alone may not solve all esthetic concerns. Patients are increasingly pursuing
results that extend beyond mere tooth alignment and functional correction, but also
anticipating improvements in smile harmony that can be obtained with an interdisciplinary
approach.[3]
[4]
Smile harmony encompasses a multidimensional balance among teeth alignment, gingival
contour, and facial aesthetics, which may be assessed at the dimension of the face
in all three spatial planes (the relationships of teeth to each other, to soft tissues,
and to facial characteristics/macroesthetic), the correlation of lips, teeth, and
gingiva (miniesthetic), and the fine structures of dental and gingival esthetics (microesthetic).[5]
[6] Key smile element such as the smile arc, buccal corridor, dental component (size,
shape, color, alignment, crown angulation, midline, arch symmetry), and gingival display
play critical roles in esthetic perception.[5] Midline deviation is a significant parameter in microesthetic analysis. Typically
evaluated by millimetric displacement from the facial midline, recent studies show
that the perceived esthetics of midline deviation is also influenced by the direction
of deviation in relation to the facial flow line. Displacements toward the side of
natural facial asymmetry designated as the “green zone” are regarded as more acceptable
than those in the contrary direction “red zone,” even with a deviation of up to 4 mm.[7] The proportional width and height of anterior teeth, including the application of
the golden ratio and the apparent width proportions also impact esthetic judgement.[5]
[6] Therefore, to attain long-term, harmonious smile outcomes, it is necessary to take
a comprehensive and individualized strategy with an interdisciplinary approach between
orthodontists, prosthodontists, and periodontists.
Recent advancements in digital dentistry have transformed the management of interdisciplinary
approaches for esthetic situations. Digital technologies such three-dimensional (3D)
facial scanning, digital smile design, intraoral scanning, and computer-aided design
(CAD)/computer-aided manufacturing (CAM) systems have helped clinician to plan and
perform restorative treatment with remarkable accuracy and reliability.[8] This digital approach enables clinicians visualize the final outcome prior to treatment
initiation, enhancing communication among specialists and aligning the treatment plan
with the patient's facial characteristics and esthetic preferences. Dental software
helps with digital planning, visualization, treatment order, and exact execution of
surgical and restorative operations.[9]
[10]
Facial asymmetry and midline deviation are typically addressed through surgical intervention,
with 3D virtual planning employed to enhance precision in outcomes.[11] This case report demonstrated how a patient who had orthodontic treatment improved
their smile using a complete digital process that involved 3D facial scanning, intraoral
scanning, and CAD/CAM zirconia veneers to create a personalized smile. This case report
highlighted a novel nonsurgical, comprehensive facial-driven strategy to address the
increasing cosmetic demand through the integration of digital technologies in interdisciplinary
treatment.
Case Report
Case Presentation
The patient provided written informed consent for the publication of this case report
and the associated photographs. This case report was prepared in accordance with the
CARE (CAse REport) guidelines. A 29-year-old female patient presented to the clinic
with the chief complaint of unsatisfactory esthetics due to previous veneer placement
by an unlicensed dental professional. She expressed the desire to improve the appearance
and function of her anterior teeth and report dissatisfaction with the existing veneer,
describing them as bulky and unnatural. Extraoral examination revealed a noticeable
occlusal cant and slight facial asymmetry ([Fig. 1]). Intraoral examination showed maxillary dental midline was shifted 4.3 mm to the
right side, cups-to-cups relationship, missing teeth maxillary canines (teeth #13
and #23), and mandibular central incisor (teeth #41). The molar relationship revealed
class II occlusion on both side, and canine class II on the left side. The overjet
measured 3.4 mm, and the overbite was 3.8 mm. Patient also exhibited a constricted
maxillary arch. Previously placed veneers on the anterior teeth (teeth #12, #11, #21,
and #22) appeared overcontoured and poorly adapted ([Fig. 2]). Cephalometric analysis indicated a skeletal class II relationship (A point-Nasion-B
point = 7.33 degrees) with normal maxilla (Sella-Nasion-A point = 82.51 degrees) and
retrognathic mandible (Sella-Nasion-B point = 75.17 degrees), hyperdivergent growth
pattern ([Fig. 3]). The patient exhibited good health, with no prior history of medical conditions.
The treatment objective was to correct dental midline deviation, achieve optimal occlusion,
maintain facial balance, and improve dental and facial esthetics.
Fig. 1 Pretreatment extraoral photographs. (A) Resting position. (B) Smile.
Fig. 2 Pretreatment intraoral photographs.
Fig. 3 (A) Pretreatment panoramic radiograph and lateral cephalogram. (B) Posttreatment panoramic and lateral cephalogram.
Case Management
In the beginning of the interdisciplinary treatment plan, orthodontic correction was
performed with the utilization of a self-ligating fixed appliance system (Protect
PT K; Protect Orthodontics, Zhejiang, China). Both the midline deviation and the occlusal
cant were resolved by the utilization of unilateral posterior segmental distalization
using the assistance of temporary anchorage devices (TADs) that were positioned in
the left posterior maxilla.
After achieving optimal tooth position and occlusion, a postorthodontic esthetic digital
workflow was commenced. This procedure encompassed digital facial scanning, intraoral
scanning, periodontal crown lengthening, endodontic therapy, and final esthetic rehabilitation
using facially directed CAD/CAM zirconia veneers on teeth 14 to 24.
Orthodontic treatment was performed over 11 months. High torque brackets were applied
to teeth #21 and #22 and standard torque to teeth #11 and #12. TADs (Jeil Medical
Corporation, Seoul, Korea: diameter 2 mm, length 12 mm) were placed for skeletal anchorage
([Fig. 4]). Segmental distalization was used to close the space and correct midline discrepancies.
A favorable occlusal relationship was obtained at the conclusion of the treatment,
as evidenced by the correction of occlusal plane canting, the coincidence of upper
dental midlines with the upper jaw, and the attainment of canine class I ([Fig. 5]).
Fig. 4 Intraoral photograph during treatment phase using self-ligating appliance and temporary
anchorage device.
Fig. 5 Postdebonding intraoral photographs.
Following debonding, a 3D facial scan and intraoral scan was conducted to assess smile
esthetics in relation to face features. The digital smile analysis was then conducted
using a dental design software program (Exocad dental CAD; Exocad GmbH, Germany) ([Fig. 6]). Crown lengthening was performed on the gingiva of teeth #14 to #24 to provide
optimal gingival contouring using a temporary crown as diagnostic and esthetic guide.
A mock-up was placed based on the planned design and evaluated over a period of 7
days. The result showed that anterior contacts were stable and functionally safe with
no sign of premature contact or fracture. The cervical soft tissue exhibited health
contours with no sign of inflammation indicating good biocompatibility and proper
marginal adaption of the temporary restorations.
Fig. 6 Right and lateral views from a three-dimensional (3D) facial scan.
During the final appointment, the try-in of the zirconia CAD/CAM crowns was conducted
in the patient's mouth, followed by interocclusal adjustment and assessment of canine
guidance as well as protrusive and lateral movements, prior to glazing. The cementation
of the glazed zirconia crowns was performed using dual-cure resin cement. The posttreatment
frontal smile photograph showed a significant improvement in dental midline positioning,
where the midline has been realigned toward the green zone, defined as the direction
consistent with the patient's facial flow line. This realignment reflects a more harmonious
integration between the dental and facial midlines, contributing to a more balanced
and symmetrical appearance of the smile. As a result, the corrected midline not only
enhances the visual coherence of the dentofacial structures but also reinforces the
esthetic perception of facial symmetry and smile harmony ([Fig. 7]). The digital restorative workflow is illustrated in [Fig. 8].
Fig. 7 (A) Pretreatment frontal smile showing dental midline deviation toward the red zone.
(B) Posttreatment image demonstrating midline correction into the green zone, aligned
with the facial flow line.
Fig. 8 Illustration of the digital workflow in case management.
While the orthodontic treatment successfully addressed the dental midline deviation
and occlusal concerns, the patient opted for veneers to further enhance the esthetic
quality of her smile. The veneers were chosen to give the patient a more durable,
precise, and customized esthetic result that met their expectations for a polished
and natural-looking smile. This was especially important because the patient already
had overcontoured veneers that did not fit well. The veneers were the last step in
making the perfect smile that fit with the patient's face and overall dental health.
Subsequent to all the procedures, a removable Essix retainer is positioned to maintain
the stability of the orthodontic outcomes.
Discussion
The successful outcome of this case emphasizes the importance of an interdisciplinary
digital approach in esthetic rehabilitation postorthodontic therapy. Despite achieving
orthodontic alignment, the patient had esthetic issues that orthodontics alone could
not resolve. Orthodontic therapy is gradually developed as an important phase in a
comprehensive esthetic rehabilitation process, wherein the use of digital technologies
allows clinicians to establish outcomes based on entire facial harmony rather than
solely on dental parameters.[11]
[12]
In the current case, smile redesign was initiated through a 3D facial scan and intraoral
scanner. To operationalize this into a restorative plan, digital smile design was
performed using Exocad software. By integrating 3D facial scan data with intraoral
scans, clinicians were able to create a facially guided virtual model that allowed
real-time modifications of tooth proportion, display, and gingival display. This approach
corresponds to macroesthetic concepts for facially driven treatment planning, aiming
for natural esthetic harmony by coordinating dental structures with facial symmetry,
lip mobility, and soft tissue dynamics.[6]
[11]
Despite achieving satisfactory occlusal alignment through orthodontic treatment, some
esthetic limitations persisted, particularly involving tooth proportion. Crown lengthening
was performed on teeth 14 to 24 in this patient to facilitate veneer installation.
The crown lengthening procedure is predicated on two fundamental principles: the establishment
of biological width and the maintenance of sufficient keratinized gingiva around the
tooth.[13] In this instance, a temporary crown was employed as both a diagnostic and esthetic
guide to facilitate crown lengthening. Before the crown lengthening procedure, the
temporary crown was fabricated in advance using a dental design software program to
evaluate and mark the ideal gingival contour in accordance with the intended final
smile design. As described in the previous report, using a temporary crown placed
over the teeth to guide the desired contour through crown lengthening can help improve
visualization and surgical precision and reduce procedure time, resulting in stable
esthetic outcomes over long-term follow-up.[14]
[15]
The integration of 3D-printed temporary materials has further streamlined the digital
restorative workflow. Recent studies have shown that 3D-printed resins exhibit favorable
surface roughness, superior microhardness, and acceptable color stability compared
with traditional bisacrylic and acrylic resins, while maintaining full compatibility
with digital protocols.[16] These materials allow clinicians to produce temporaries with better dimensional
accuracy and surface characteristics, enhancing tissue compatibility and improving
patient satisfaction during the provisional phase.[17]
The digital veneer procedure starts with 3D digital smile design and virtual mock-up
creation, followed by 3D printing of the virtual mock-ups to encourage patient treatment
acceptance, and concludes with a chairside preparation guide aimed at optimizing enamel
conservation during preparation. This protocol allows for the superimposition of mock-up
scans and prepared teeth scans, ensuring that the final restoration faithfully replicates
the planned esthetics while minimizing invasiveness and maximizing restorative fit.[18]
[19] In this case, teeth #14 and #24 were morphologically modified with veneer to substitute
missing canine. This approach was chosen to restore both esthetic and functional guidance
within the smile arc, particularly in the absence of natural canines (teeth #13 and
#23).
CAD/CAM-fabricated monolithic zirconia veneers offer excellent biocompatibility, stable
esthetics, and low abrasiveness to opposing dentition.[20]
[21] Designed at minimal thicknesses (0.2–0.3 mm), they enable conservative tooth preparation
with precise marginal adaptation, often eliminating the need for subgingival finishing.
Integrating these restorations into a fully digital workflow improves mechanical and
esthetic outcomes while streamlining laboratory procedures without compromising clinical
accuracy.[21]
[22] Following favorable orthodontic treatment, teeth are susceptible to relapse to their
initial positions without a retention period.[23] A removable Essix retainer was invented thereafter to avert relapse. The Essix was
utilized nightly for 12 months, thereafter 3 to 4 nights per week. Follow-up assessments
at 3, 6, and 12 months evaluated midline stability, space management, occlusion, periodontal
health, and prosthesis hygiene.
The integration of CAD/CAM technology and digital smile design was valuable, but making
the digital workflow even better—especially when it comes to intraoral scanning, 3D
smile design, and real-time digital adjustments—could lead to even more accurate results.
Furthermore, further investigation into the long-term stability and adaptability of
3D-printed temporaries could enhance tissue compatibility and the patient experience.
Conclusion
This clinical case underscores the effectiveness of a digitally guided interdisciplinary
approach in postorthodontic esthetic rehabilitation. By integrating 3D facial scanning,
intraoral scanning, digital smile design, and CAD/CAM-fabricated zirconia veneers,
precise planning and execution were achieved to create a harmonious smile that integrates
both facial and dental parameters. The use of a temporary crown as a diagnostic and
surgical guide allowed for accurate gingival contouring during crown lengthening,
while 3D-printed temporaries enhanced provisional esthetics and facilitated improved
patient communication.
The fully digital workflow facilitated predictable esthetic outcomes, conservative
tooth preparation, and enhanced functional and visual integration. This approach exemplifies
the evolving role of digital dentistry in delivering individualized, minimally invasive
treatments in complex interdisciplinary cases. Future research could investigate the
feasibility of incorporating artificial intelligence into smile design to improve
precision and customization.
