Reliability of traditional cephalometric landmarks as seen in three-dimensional analysis in maxillary expansion treatments.
OBJECTIVE
To evaluate intra-examiner and inter-examiner reliability of 3D CBCT-generated landmarks previously used in traditional 2D cephalometry.


METHODS
Twenty-four CBCTs NewTom 3G (Aperio Services, Verona, Italy) were randomly selected from patients participating in a clinical trial involving maxillary expansion treatments. The principal investigator located the landmarks five times, and four other investigators located the same landmarks once. Intra-examiner and inter-examiner reliability values were determined using intraclass correlation coefficients (ICCs). To assist in interpretation of the clinical significance of landmark identification differences, average mean differences for x, y, and z landmark coordinates were determined from the repeated assessments. Landmarks then were separated into groups with respect to the region they represented and then were compared via repeated measures ANOVA and multiple comparisons via Bonferroni corrected alpha.


RESULTS
Intra-examiner and inter-examiner reliability for x, y, and z coordinates for all landmarks were acceptable, all being greater than 0.80. Most of the mean measurement differences obtained from trials within the principal investigator in all three axes were less than 1.5 mm. Inter-examiner mean measurement differences generally were larger than the intra-examiner differences.


CONCLUSIONS
Based on this, the best landmarks for use in verifying expansion treatment results are Ekm, buccal surface, and apexes of upper molars, upper premolars and upper canines, and buccal surfaces of lower molars and lower canines. Foramen Spinosum, ELSA, Auditory External Meatus, and Dorsum Foramen Magnum demonstrated adequate reliability for determining a standardized reference system.
Orthodontic Graduate Program, Faculty of Medicine and Dentistry, University of Alberta, Canada. manuel@ualberta.ca
Manuel O
MO
Lagravère
Jillian M
JM
Gordon
Ines H
IH
Guedes
Carlos
C
Flores-Mir
Jason P
JP
Carey
Giseon
G
Heo
Paul W
PW
Major
D002508:Cephalometry / Q000379:methods* / Q000706:statistics & numerical data; D054893:Cone-Beam Computed Tomography / Q000379:methods* / Q000706:statistics & numerical data; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000379:methods* / Q000706:statistics & numerical data; D008437:Maxilla / Q000033:anatomy & histology; D008963:Molar / Q000033:anatomy & histology; D009666:Nose / Q000033:anatomy & histology; D015588:Observer Variation; D009915:Orbit / Q000033:anatomy & histology; D010155:Palatal Expansion Technique; D015050:Zygoma / Q000033:anatomy & histology