Standardization of 3-D CT measurements for length and angles by matrix transformation in the 3-D coordinate system

Hideki Kitaura, Koichi Yonetsu, Hideki Kitamori, Kazuhide Kobayashi, Takashi Nakamura

Research output: Contribution to journalArticlepeer-review

33 Citations (Scopus)


Objective: We attempted to establish a new 3-D cephalometry with helical computed tomography (CT) by introducing the matrix transformation of the 3D coordinate system. Subjects and Methods: Three-dimensional cephalometric landmarks on the craniofacial bones were expressed as 3-D vector's originating from the center of the sella. These vectors were standardized by the matrix transformation so that the midsagittal plane and cranial base line coincided with the XZ plane and X axis of the 3-D coordinate system, respectively. We also applied this new method to trace the normal growth of the craniofacial bones in 44 patients with head and neck cancer (age range, 5 to 26 years; 19 women and 25 men). Results: The accuracy for length measurements was less than 3% of standard error of means with a slice thickness of 1 or 3 mm for 28 out of the 29 length measurements recorded. The precision errors by repeated measurements were 0.8% to 1.0% coefficients of variation for intra- and interobserver variability. Standardization of 3-D vectors representing the cephalometric landmarks allowed us to assess successfully the age-related transition of these landmarks of the patients' craniofacial bones. Conclusion: A new assessment method for 3-D CT cephalometry has been developed by standardizing cephalometric landmarks using a matrix transformation of the 3-D coordinate system. This new assessment method may offer potential in planning plastic and reconstructive surgery.

Original languageEnglish
Pages (from-to)349-356
Number of pages8
JournalCleft Palate-Craniofacial Journal
Issue number4
Publication statusPublished - 2000 Jul
Externally publishedYes


  • Coordinate system
  • Helical computed tomography
  • Matrix transformation
  • Three-dimensional cephalometry

ASJC Scopus subject areas

  • Oral Surgery
  • Otorhinolaryngology


Dive into the research topics of 'Standardization of 3-D CT measurements for length and angles by matrix transformation in the 3-D coordinate system'. Together they form a unique fingerprint.

Cite this