Clinical Trial Details
— Status: Completed
Administrative data
| NCT number |
NCT06280027 |
| Other study ID # |
MUDHF_BK1 |
| Secondary ID |
|
| Status |
Completed |
| Phase |
|
| First received |
|
| Last updated |
|
| Start date |
June 5, 2023 |
| Est. completion date |
December 22, 2023 |
Study information
| Verified date |
February 2024 |
| Source |
Marmara University |
| Contact |
n/a |
| Is FDA regulated |
No |
| Health authority |
|
| Study type |
Observational
|
Clinical Trial Summary
In the web-based cross-sectional study 180 participants were included. Half of them (n = 90)
were patients (laypeople) of the university clinic and the remaining half were restorative
dentists and prosthodontists with similar levels of clinical experience (at least 3 years of
academic training).
A frontal view full-face portrait image of a 25-year-old female was selected as a model for
the study, with a smile exhibiting good dental alignment, a quite good midline position, and
tooth size symmetry.
The original image was digitally modified by a single restorative instructor using Photoshop
CC (Adobe, USA) software program. The modifications were divided into three parts. The first
part was the generation of midline discrepancy at different levels. The midline was digitally
moved to the right side of the patient 1 - 4 millimeters, gradually. The midline movement was
performed together with the whole maxillary arch.
The second part was the generation of individual crown width disproportions. Accordingly, the
mesiodistal width of the left central, lateral, and canine was digitally decreased one by
one, gradually, while the width of the symmetrical teeth on the right side was simultaneously
increased.
The third part was the generation of distributed crown width disproportions. Accordingly, the
total mesiodistal width of the left central, lateral, and canine was equally decreased,
gradually, while the total width of the symmetrical teeth on the right side was
simultaneously increased.
In total, 15 images were displayed in random order to the participants including the original
image. An online survey was generated to quantitatively evaluate the level of esthetic
perception. Subsequently, the participants were asked to evaluate the level of smile
esthetics of the presented random images, without being informed about the digital
manipulations of the images. The participants were even not informed about the original
image. They were expected to answer the question "How esthetic do you consider this smile?"
The evaluation of each image was performed via a Visual analog scale VAS, ranging from point
0 (extremely not esthetic) to point 100 (extremely esthetic).
Description:
The web-based cross-sectional study was designed and conducted in a university clinic between
June and December 2023. 180 participants were included in the study. Half of them (n = 90)
were patients (laypeople) of the university clinic and the remaining half were restorative
dentists and prosthodontists with similar levels of clinical experience (at least 3 years of
academic training).
A frontal view full-face portrait image of a 25-year-old female was selected as a model for
the study, with a smile exhibiting good dental alignment, a quite good midline position, and
tooth size symmetry. A perfectly symmetrical face was not demanded for the model in this
study as the human face is considered usually not symmetrical. The frontal smiling image was
captured using a DSLR full-frame camera (D750, Nikon, Japan), a macro objective (105 mm VR
Nikkor, Nikon), and a dual paraflash/softbox (VL400, Visico, China). The image was saved in
RAW data format and named as the original image.
The original image was digitally modified by a single restorative instructor using Photoshop
CC (Adobe, USA) software program. The modifications were divided into three parts. The first
part was the generation of midline discrepancy at different levels. The midline was digitally
moved to the right side of the patient 1 - 4 millimeters, gradually. The midline movement was
performed together with the whole maxillary arch. Simultaneously, the maxillary right first
molar was gradually darkened to provide a natural-like space at the right buccal corridor.
The second part was the generation of individual crown width disproportions. Accordingly, the
mesiodistal width of the left central, lateral, and canine was digitally decreased one by
one, gradually, while the width of the symmetrical teeth on the right side was simultaneously
increased. Therefore, disproportions of 1 mm and 2 mm were digitally generated for each
tooth. For instance, to achieve 1 mm of disproportion on the central incisor, the left
central width was decreased by 0.5 mm, while the right central width was increased by 0.5 mm.
The third part was the generation of distributed crown width disproportions. Accordingly, the
total mesiodistal width of the left central, lateral, and canine was equally decreased,
gradually, while the total width of the symmetrical teeth on the right side was
simultaneously increased. Therefore, the distributed disproportions of 1 - 4 mm were
digitally generated for the group of teeth. For instance, to achieve 1 mm of distributed
disproportion, the total width of the left central, lateral, and canine was decreased by 0.5
mm, and the total width of the anterior teeth on the right side was increased by 0.5 mm. 0.5
mm was shared equally by each tooth. Simultaneously, the maxillary right first molar was
gradually darkened to provide a natural-like space at the right buccal corridor.
In total, 15 images were displayed in random order to the participants including the original
image. An online survey was generated to quantitatively evaluate the level of esthetic
perception. At the beginning of the survey, the participants declared their profession, age,
and gender. All the images were presented to the participants on a digitally calibrated
monitor (iPad Pro 12.9", Apple Inc., USA) to minimize the standardization limitations.
Subsequently, the participants were asked to evaluate the level of smile esthetics of the
presented random images, without being informed about the digital manipulations of the
images. The participants were even not informed about the original image. They were expected
to answer the question "How esthetic do you consider this smile?" The evaluation of each
image was performed via a Visual analog scale VAS, ranging from point 0 (extremely not
esthetic) to point 100 (extremely esthetic). The participants moved a tab on the visual
analog scale to a new position, based on their subjective perception of the presented smile
esthetics. The scorings were carried out during midday (10:00 AM-14:00 PM), with standardized
artificial lighting conditions and without directly exposing the monitor to the sunlight. The
distance between the participant and the screen was consistently 60 cm, which stands for the
typical distance between two people during social contact. Each participant could complete
the survey once without a time limit and was limited to performing again. A total of 180
participants completed the survey.
