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The accuracy (trueness and precision) of Bellus3DARC-7 and an in-vivo analysis of intra and inter-examiner reliability of digital and manual anthropometry Cover

The accuracy (trueness and precision) of Bellus3DARC-7 and an in-vivo analysis of intra and inter-examiner reliability of digital and manual anthropometry

Australasian Orthodontic Journal
Volume 39 (2023): Issue 1 (January 2023)
By: Jenny Doan,  Nessa Finlay,  Amy Lee,  Thomas Ethell,  Narayan Gandedkar and  Mehmet Ali Darendeliler  
Open Access
|May 2023

Figures & Tables

Figure 1.

Nineteen landmarks marked on a facial map: 1, Reference Point (Ref); 2, Glabella; 3, Right Cheek (R Cheek); 4, Left Cheek (L Cheek); 5, Nasal Tip; 6, Subnasale; 7, Right Commissure (R Commissure); 8, Left Commissure (L Commissure); 9, Soft Tissue Pogonion; 10, Right Alar Base (R Alar Base); 11, Left Alar Base (L Alar Case); 12, Right Gonion (R Gonion); 13, Left Gonion (L Gonion); 14, Left Upper Ear (L Upper ear); 15, Left Tragus (L Tragus); 16, Left Lower Ear (L Lower Ear); 17, Right Upper Ear (R Upper Ear); 18, Right Tragus (R Tragus); 19, Right Lower Ear (R Lower Ear) (Table I).
Nineteen landmarks marked on a facial map: 1, Reference Point (Ref); 2, Glabella; 3, Right Cheek (R Cheek); 4, Left Cheek (L Cheek); 5, Nasal Tip; 6, Subnasale; 7, Right Commissure (R Commissure); 8, Left Commissure (L Commissure); 9, Soft Tissue Pogonion; 10, Right Alar Base (R Alar Base); 11, Left Alar Base (L Alar Case); 12, Right Gonion (R Gonion); 13, Left Gonion (L Gonion); 14, Left Upper Ear (L Upper ear); 15, Left Tragus (L Tragus); 16, Left Lower Ear (L Lower Ear); 17, Right Upper Ear (R Upper Ear); 18, Right Tragus (R Tragus); 19, Right Lower Ear (R Lower Ear) (Table I).

Figure 2.

Examples of 3D digital models captured by the Bellus3D ARC-7 camera. (A) Frontal View. (B) Angled View.
Examples of 3D digital models captured by the Bellus3D ARC-7 camera. (A) Frontal View. (B) Angled View.

Figure 3.

A facial Map outlining the reproducibility of pooled digital measurements taken by all examiners. (Legend: Mean Difference of repeated measurements depicted in Dark green = <0.5 mm, yellow = ≥1.0 mm. Grey=Not determinable).
A facial Map outlining the reproducibility of pooled digital measurements taken by all examiners. (Legend: Mean Difference of repeated measurements depicted in Dark green = <0.5 mm, yellow = ≥1.0 mm. Grey=Not determinable).

Figure 4.

A Facial Map outlining the reproducibility of pooled manual measurements taken by all examiners. (Legend: Mean Difference of repeated measurements depicted in Dark green = <0.5 mm, Light green = <1.0 mm, yellow = ≥1.0 mm).
A Facial Map outlining the reproducibility of pooled manual measurements taken by all examiners. (Legend: Mean Difference of repeated measurements depicted in Dark green = <0.5 mm, Light green = <1.0 mm, yellow = ≥1.0 mm).

Figure 5.

A Facial Map outlining the reproducibility of measurements taken on two consecutive digital models of the same sample. (Legend: Mean Difference of repeated measurements depicted in Dark green = <0.5 mm, Light green = <1.0 mm, yellow = ≥1.0 mm).
A Facial Map outlining the reproducibility of measurements taken on two consecutive digital models of the same sample. (Legend: Mean Difference of repeated measurements depicted in Dark green = <0.5 mm, Light green = <1.0 mm, yellow = ≥1.0 mm).

Figure 6.

A Facial Map outlining the deviation of digital measurements from manual measurements on models (at rest). (Legend: Mean Deviations depicted in Dark green = <0.5 mm, Light green = <1.0 mm, Yellow = ≤1.5 mm, Orange = ≤2.00 mm, Red = >2.00 mm).
A Facial Map outlining the deviation of digital measurements from manual measurements on models (at rest). (Legend: Mean Deviations depicted in Dark green = <0.5 mm, Light green = <1.0 mm, Yellow = ≤1.5 mm, Orange = ≤2.00 mm, Red = >2.00 mm).

Figure 7.

A Facial Map outlining the deviation of digital measurements from manual measurements on models (during smiling). (Legend: Mean Deviations depicted in Dark green = <0.5 mm, Light green = <1.0 mm, Yellow = ≤1.5 mm, Orange = ≤2.00 mm, Red = >2.00 mm).
A Facial Map outlining the deviation of digital measurements from manual measurements on models (during smiling). (Legend: Mean Deviations depicted in Dark green = <0.5 mm, Light green = <1.0 mm, Yellow = ≤1.5 mm, Orange = ≤2.00 mm, Red = >2.00 mm).

Figure 8.

Bell curve displays that the majority of digital vs calliper deviated measurements were within 2 mm.
Bell curve displays that the majority of digital vs calliper deviated measurements were within 2 mm.

Figure 9.

The variability of measurements between landmarks. Green: Measurements between these landmarks had the least variability within and between examiners, for both calliper and digital methods. Grey: Measurements between these landmarks also had the most variability when comparing calliper and digital methods.
The variability of measurements between landmarks. Green: Measurements between these landmarks had the least variability within and between examiners, for both calliper and digital methods. Grey: Measurements between these landmarks also had the most variability when comparing calliper and digital methods.

Figure 10.

Examples of distortion of stickers, digital landmarks and soft tissues. (A) Hairline (B) Ears concealed by hair. (C) Ear lobe. (D) Lips & teeth during smile. (E) Pogonion, with blurred sticker. (F) L Cheek, with double image.
Examples of distortion of stickers, digital landmarks and soft tissues. (A) Hairline (B) Ears concealed by hair. (C) Ear lobe. (D) Lips & teeth during smile. (E) Pogonion, with blurred sticker. (F) L Cheek, with double image.

Appendix 1.

Table containing raw data of difference between the digital and manual inter-landmark measurements (on models at rest).
Table containing raw data of difference between the digital and manual inter-landmark measurements (on models at rest).

Appendix 2.

Table containing raw data of difference between the digital and manual inter-landmark measurements (on models during smiling).
Table containing raw data of difference between the digital and manual inter-landmark measurements (on models during smiling).

Mean difference in measurements of inter-landmark measurements taken on two consecutive digital models of the same sample

Landmark 1Landmark 2Mean Difference (mm)
RefGlabella0.25
GlabellaNose Tip0.19
SubnasalePogonion0.54
R CheekL Cheek0.46
R AlarL Alar0.38
R CommissureL Commissure0.87
R Upper EarR Middle EarN/A
R Middle EarR Lower Ear0.57
R CheekR Gonion0.53
R CheekR Middle Ear0.69
R GonionR Commissure0.51
L Upper EarL Middle Ear0.47
L Middle EarL Lower Ear0.37
L CheekL Gonion0.23
L CheekL Middle Ear0.27
L GonionL Commissure1.11
      Colour Legend:0 - 0.5mm0.5 - 1.0mm1.0 - 1.5mm1.5 - 2.0mm2.0+mm

The mean difference in pooled digital measurements of inter-landmark measurements taken by all examiners

Landmark 1Landmark 2Mean difference (mm)
RefGlabella0.25
GlabellaNose Tip0.19
SubnasalePogonion0.23
R CheekL Cheek0.11
R AlarL Alar0.09
R CommissureL Commissure0.31
R Upper EarR Middle EarN/A
R Middle EarR Lower Ear0.28
R CheekR Gonion0.33
R CheekR Middle Ear0.23
R GonionR Commissure0.29
L Upper EarL Middle Ear0.23
L Middle EarL Lower Ear0.41
L CheekL Gonion0.26
L CheekL Middle Ear0.32
L GonionL Commissure1.16
      Colour Legend:0 to 0.5mm0.5 to 1.0mm1.0 to 1.5mm1.5 to 2.0mm2.0+mm

Landmarks and respective number as marked on facial map in Figure 1

NumberLandmark
1Reference Point
2Glabella
3R Cheek
4L Cheek
5Nasal Tip
6Subnasale
7R Commissure
8L Commissure
9Soft Tissue Pogonion
10R Alar Base
11L Alar Base
12R Gonion
13L Gonion
14L Upper Ear
15L Tragus
16L Lower Ear
17R Upper Ear
18R Tragus
19R Lower Ear

The mean difference in pooled manual measurements of inter-landmark measurements taken by all examiners

Landmark 1Landmark 2Mean Difference (mm)
RefGlabella0.35
GlabellaNose Tip0.64
SubnasalePogonion0.90
R CheekL Cheek1.14
R AlarL Alar0.65
R CommissureL Commissure0.99
R Upper EarR Middle Ear0.70
R Middle EarR Lower Ear0.28
R CheekR Gonion1.28
R CheekR Middle Ear0.80
R GonionR Commissure0.69
L Upper EarL Middle Ear0.72
L Middle EarL Lower Ear0.47
L CheekL Gonion1.38
L CheekL Middle Ear0.62
L GonionL Commissure0.26
      Colour Legend:0 to 0.5 mm0.5 to 1.0 mm1.0 to 1.5 mm1.5 to 2.0 mm2.0+mm

The overall proportion of combined manual measurements within set threshold deviation values, obtained by a single examiner

% of measurements within set threshold deviation of:
≤0.5 mm88%
≤1.0 mm98%
≤1.5 mm100%
≤2.0 mm100%

The mean difference between digital and manual inter-landmark measurements on models (during smiling)

Landmark 1Landmark 2Mean difference (mm)
RefGlabella0.39
L Upper EarL Middle Ear0.31
R Middle EarR Lower Ear0.46
GlabellaNose Tip0.57
L Middle EarL Lower Ear0.66
R CheekR Middle Ear0.79
L CheekL Middle Ear0.95
R CheekR Gonion1.24
L CheekL Gonion1.33
R AlarL Alar1.44
R CheekL Cheek1.68
L GonionL Commissure1.85
R CommissureL Commissure1.88
SubnasalePogonion2.20
R GonionR Commissure2.28
R Upper EarR Middle EarN/A
      Colour Legend:0 to 0.5mm0.5 to 1.0mm1.0 to 1.5mm1.5 to 2.0mm2.0+mm

The proportion of manual measurements within set threshold deviation values, obtained by a single examiner (categorised by interlandmark variables)

Inter-landmark measurements % of measurements within set threshold deviations of:
Landmark 1Landmark 2≤0.5 mm≤1.0 mm≤1.5 mm≤2.0 mm
RefGlabella75%88%100%100%
GlabellaNose Tip38%75%100%100%
SubnasalePogonion50%63%75%88%
R CheekL Cheek25%50%75%88%
R AlarL Alar25%75%100%100%
R CommissureL Commissure25%75%88%88%
R Upper EarR Middle Ear38%88%88%100%
R Middle EarR Lower Ear75%100%100%100%
R CheekR Gonion13%38%50%75%
R CheekR Middle Ear38%75%88%88%
R GonionR Commissure38%75%88%100%
L Upper EarL Middle Ear38%75%88%100%
L Middle EarL Lower Ear63%100%100%100%
L CheekL Gonion13%50%75%75%
L CheekL Middle Ear50%75%88%100%
L GonionL Commissure38%50%63%88%

The mean difference between digital and manual inter-landmark measurements on models (at rest)

Landmark 1Landmark 2Mean difference (mm)
L Upper EarL Middle Ear0.27
R Middle EarR Lower Ear0.52
R CheekR Middle Ear0.56
GlabellaNose Tip0.61
L Middle EarL Lower Ear0.61
RefGlabella0.71
L CheekL Middle Ear0.78
R AlarL Alar0.94
R CheekL Cheek1.10
SubnasalePogonion1.11
R GonionR Commissure1.13
R CommissureL Commissure1.52
L CheekL Gonion1.63
R CheekR Gonion1.76
L GonionL Commissure2.12
R Upper EarR Middle EarN/A
      Colour Legend:0 to 0.5 mm0.5 to 1.0 mm1.0 to 1.5 mm1.5 to 2.0 mm2.0+mm

The proportion of digital measurements within set threshold deviation values, obtained by a single examiner (categorised by interlandmark variables)

Inter-landmark Variables % of measurements within set threshold deviations of:
Landmark 1Landmark 2≤0.5 mm≤1.0 mm≤1.5 mm≤2.0 mm
RefGlabella100%100%100%100%
GlabellaNose Tip88%100%100%100%
SubnasalePogonion75%100%100%100%
R CheekL Cheek100%100%100%100%
R AlarL Alar100%100%100%100%
R CommissureL Commissure75%100%100%100%
R Upper EarR Middle EarN/AN/AN/AN/A
R Middle EarR Lower Ear88%100%100%100%
R CheekR Gonion75%100%100%100%
R CheekR Middle Ear100%100%100%100%
R GonionR Commissure88%88%100%100%
L Upper EarL Middle Ear100%100%100%100%
L Middle EarL Lower Ear75%88%100%100%
L CheekL Gonion88%100%100%100%
L CheekL Middle Ear88%100%100%100%
L GonionL Commissure75%100%100%100%
DOI: https://doi.org/10.2478/aoj-2023-0015 | Journal eISSN: 2207-7480 | Journal ISSN: 2207-7472
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Language: English
Page range: 141 - 157
Submitted on: Feb 1, 2023
Accepted on: Apr 1, 2024
Published on: May 18, 2023
Published by: Australian Society of Orthodontists Inc.
In partnership with: Paradigm Publishing Services
Publication frequency: 1 issue per year
Related subjects:
Medicine,
Basic medical science,
Basic medical science, other

© 2023 Jenny Doan, Nessa Finlay, Amy Lee, Thomas Ethell, Narayan Gandedkar, Mehmet Ali Darendeliler, published by Australian Society of Orthodontists Inc.
This work is licensed under the Creative Commons Attribution 4.0 License.

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