The korean journal of orthodontics (대한치과교정학회지)

The Korean Association Of Orthodontists (대한치과교정학회)
권호 표지
DOI QR코드

DOI QR Code

Influence of the angles and number of scans on the accuracy of 3D laser scanning

3 차원 레이저 스캔영상 채득 시 스캔각도와 횟수에 따른 정확도

  • Lee, Kyung-Min (Department of Orthodontics, Dental Science Research Institute, School of Dentistry, 2nd Stage of Brain Korea 21, Chonnam National University) ;
  • Song, Hyo-Young (Department of Orthodontics, Dental Science Research Institute, School of Dentistry, 2nd Stage of Brain Korea 21, Chonnam National University) ;
  • Lee, Ki-Heon (Department of Orthodontics, Dental Science Research Institute, School of Dentistry, 2nd Stage of Brain Korea 21, Chonnam National University) ;
  • Hwang, Hyeon-Shik (Department of Orthodontics, Dental Science Research Institute, School of Dentistry, 2nd Stage of Brain Korea 21, Chonnam National University)
  • 이경민 (전남대학교 치의학전문대학원 치의학연구소, 2단계 BK21 연구사업단, 교정학교실) ;
  • 송효영 (전남대학교 치의학전문대학원 치의학연구소, 2단계 BK21 연구사업단, 교정학교실) ;
  • 이기헌 (전남대학교 치의학전문대학원 치의학연구소, 2단계 BK21 연구사업단, 교정학교실) ;
  • 황현식 (전남대학교 치의학전문대학원 치의학연구소, 2단계 BK21 연구사업단, 교정학교실)
  • Received : 2011.01.10
  • Accepted : 2011.03.03
  • Published : 2011.04.30
Download PDF
⟨ Previous Next ⟩

Abstract

Objective: To investigate whether the accuracy of 3D laser scanning is influenced by the angles and number of scans. Methods: Using a 3D laser scanner, 10 manikins with facial markers were scanned at 7 horizontal angles (front view and at $20^{\circ}$, $45^{\circ}$, and $60^{\circ}$ angles on the right and left sides). Three-dimensional facial images were reconstructed by 6 methods differing in the number and angles of scans, and measurements of these images were compared to the physical measurements from the manikins. Results: The laser scan images were magnified by 0.14 - 0.26%. For images reconstructed by merging 2 scans, excluding the front view; and by merging 3 scans, including the front view and scans obtained at $20^{\circ}$ on both sides; several measurements were significantly different than the physical measurements. However, for images reconstructed by merging 3 scans, including the front view; and 5 scans, including the front view and scans obtained at $20^{\circ}$ and $60^{\circ}$ on both sides; only 1 measurement was significantly different. Conclusions: These results suggest that the number and angle of scans influence the accuracy of 3D laser scanning. A minimum of 3 scans, including the front view and scans obtained at more than $45^{\circ}$ on both sides, should be integrated to obtain accurate 3D facial images.

본 연구는 3차원 레이저 스캐너를 이용하여 안면 입체영상을 재구성할 때 스캔각도와 횟수에 따른 입체영상의 정확도를 평가하고자 시행되었다. 사람의 얼굴형상을 한 두부 마네킹 10개를 대상으로 안면에 마커를 부착하고 비접촉식 3차원 레이저 스캐너를 이용하여 정면, 정면에 대해 각각 좌우 20도, 45도, 60도 측방면을 스캔하고 좌우 20도 측방면을 스캔한 2가지 영상, 정면과 좌우 20도 측방면을 스캔한 3가지 영상, 좌우 45도 측방면을 스캔한 2가지 영상, 정면과 좌우 45도 측방면을 스캔한 3가지 영상, 정면과 좌우 60도 측방면을 스캔한 3가지 영상, 정면과 좌우 20도, 60도 측방면을 스캔한 5가지 영상 등 6가지 방법으로 3차원 역설계 소프트웨어 프로그램을 이용하여 재구성한 각 방법에 따른 입체영상에서 마커간 거리를 측정하고 마네킹에서의 실측치와 비교하였다. 마네킹 실측치에 대한 레이저 스캔영상 계측치의 확대율은 0.14 - 0.26%로 나타났다. 좌우 20도 측방면을 스캔한 경우, 정면과 좌우 20도 측방면을 스캔한 경우와 좌우 45도 측방면을 스캔한 경우는 여러 계측치가 실측치와 차이를 보인 반면, 정면과 좌우 45도 혹은 정면과 좌우 60도 측방면을 스캔한 경우와 정면과 좌우 20도와 60도를 스캔한 경우는 한 계측치 (Pn-Pg')를 제외한 모든 계측항목에서 실측치와 통계적으로 유의한 차이를 보이지 않았다. 본 연구 결과는 스캔각도와 횟수가 안면 입체영상의 정확도에 영향을 미치는 것을 의미하며 정확한 재구성을 위해서는 좌우 45도 이상의 측방면을 스캔 하는 것이, 그리고 정면을 포함하여 최소 3개의 영상을 이용하여 합성하는 것이 바람직함을 시사하였다.

Keywords

References

  1. Mah J, Hatcher D. Current status and future needs in craniofacial imaging. Orthod Craniofac Res 2003;6(Suppl 1):10-6. https://doi.org/10.1034/j.1600-0544.2003.230.x
  2. Kusnoto B, Evans CA. Reliability of a 3D surface laser scanner for orthodontic applications. Am J Orthod Dentofacial Orthop 2002;122:342-8. https://doi.org/10.1067/mod.2002.128219
  3. Kau CH, Richmond S, Zhurov AI, Knox J, Chestnutt I, Hartles F, et al. Reliability of measuring facial morphology with a 3-dimensional laser scanning system. Am J Orthod Dentofacial Orthop 2005;128:424-30. https://doi.org/10.1016/j.ajodo.2004.06.037
  4. Kau CH, Richmond S, Savio C, Mallorie C. Measuring adult facial morphology in three dimensions. Angle Orthod 2006;76:773-8.
  5. Baik HS, Lee HJ, Jeon JM. A proposal of soft tissue landmarks for craniofacial analysis using 3-dimensional laser scan imaging. Word J Orthod 2006:7:7-14
  6. Kau CH, Zhurov A, Richmond S, Cronin A, Savio C, Mallorie C. Facial templates: a new perspective in three dimensions. Orthod Craniofac Res 2006;9:10-7. https://doi.org/10.1111/j.1601-6343.2006.00359.x
  7. Baik HS, Jeon JM, Lee HJ. A study of facial soft tissue of Korean adults with normal occlusion using a three-dimensional laser scanner. Korean J Orthod 2006;36:14-29.
  8. Kau CH, Zhurov A, Richmond S, Bibb R, Sugar A, Knox J, et al. The 3-dimensional construction of the average 11-yearold child face: a clinical evaluation and application. J Oral Maxillofac Surg 2006;64:1086-92. https://doi.org/10.1016/j.joms.2006.03.013
  9. Moss JP, Linney AD, Lowey MN. The use of three-dimensional techniques in facial esthetics. Semin Orthod 1995;1:94-104. https://doi.org/10.1016/S1073-8746(95)80096-4
  10. Kau CH, Zhurov A, Bibb R, Hunter L, Richmond S. The investigation of the changing facial appearance of identical twins employing a three-dimensional laser imaging system. Orthod Craniofac Res 2005;8:85-90. https://doi.org/10.1111/j.1601-6343.2005.00320.x
  11. Hennessy RJ, Moss JP. Facial growth: separating shape from size. Eur J Orthod 2001;23:275-85. https://doi.org/10.1093/ejo/23.3.275
  12. McDonagh S, Moss JP, Goodwin P, Lee RT. A prospective optical surface scanning and cephalometric assessment of the effect of functional appliances on the soft tissues. Eur J Orthod 2001;23:115-26. https://doi.org/10.1093/ejo/23.2.115
  13. Ismail SF, Moss JP, Hennessy R. Three-dimensional assessment of the effects of extraction and nonextraction orthodontic treatment on the face. Am J Orthod Dentofacial Orthop 2002;121:244-56. https://doi.org/10.1067/mod.2002.121010
  14. Moss JP, Ismail SF, Hennessy RJ. Three-dimensional assessment of treatment outcomes on the face. Orthod Craniofac Res 2003;6(Suppl 1):126-31. https://doi.org/10.1034/j.1600-0544.2003.245.x
  15. Kau CH, Cronin A, Durning P, Zhurov AI, Sandham A, Richmond S. A new method for the 3D measurement of postoperative swelling following orthognathic surgery. Orthod Craniofac Res 2006;9:31-7. https://doi.org/10.1111/j.1601-6343.2006.00341.x
  16. McCance AM, Moss JP, Fright WR, Linney AD, James DR. Three-dimensional analysis techniques--Part 2: Laser scanning: a quantitative three-dimensional soft-tissue analysis using a color-coding system. Cleft Palate Craniofac J 1997;34:46-51. https://doi.org/10.1597/1545-1569(1997)034<0046:TDATPL>2.3.CO;2
  17. Ferrario VF, Sforza C, Poggio CE, Serrao G. Facial three-dimensional morphometry. Am J Orthod Dentofacial Orthop 1996;109:86-93. https://doi.org/10.1016/S0889-5406(96)70167-1
  18. Choi HH, Cho JH, Park HJ, Oh HK, Choi JH, Hwang HS, et al. Validity of superimposition range at 3-dimensional facial images. J Korean Assoc Maxillofac Plast Reconstr Surg 2009;31:149-57.
  19. Broadbent BH. A new x-ray technique and its application to orthodontia. Angle Orthod 1931;1:45-66.
  20. Sanborn RT. Differences between the facial skeletal patterns of Class III malocclusion and normal occlusion. Angle Orthod 1955;25:208-22.
  21. Steiner CC. The use of cephalometrics as an aid to planning and assessing orthodontic treatment. Am J Orthod 1960;46:721-35. https://doi.org/10.1016/0002-9416(60)90145-7
  22. Song JM, Lee KH, Hwang HS. A comparative study of guiding methods for natural head posture in cephalometrics. Korean J Orthod 2005;35:341-50.
  23. Kim EH, Hwang HS. The validity of head posture aligner in posteroanterior cephaiometry. Korean J Orthod 2000;30:543-52.
  24. Downs WB. Analysis of the dentofacial profile. Angle Orthod 1956;26:191-212.
  25. Besl PJ, Mckay ND. A method for registration of 3-D shapes. IEEE Trans Pattern Anal Mach Intell 1992;14:239-56. https://doi.org/10.1109/34.121791

Cited by

  1. The Evaluation of Working Casts Prepared from Digital Impressions vol.38, pp.6, 2013, https://doi.org/10.2341/12-352-l
  2. Three-Dimensional Reproducibility of the Soft Tissue Landmarks Taken by Structured-Light Facial Scanner in Accordance with the Head Position Change vol.9, pp.4, 2011, https://doi.org/10.3390/healthcare9040428