Craniofacial growth covaries weakly with initial shape in 12-year old children

Postgraduate Thesis uoadl:1315384 551 Read counter

Unit:
Κατεύθυνση Ορθοδοντική (Κλινικές Ειδικεύσεις)
Βιβλιοθήκη Οδοντιατρικής
Deposit date:
2016-03-24
Year:
2016
Author:
Κατσαδούρης Αλέξιος
Supervisors info:
Δ. Χαλαζωνίτης, Αναπλ. Καθηγητής, Η. Μπιτσάνης, Επικ. Καθηγητής, Ι. Σηφακάκης, Λέκτορας
Original Title:
Craniofacial growth covaries weakly with initial shape in 12-year old children
Languages:
English
Translated title:
Συσχέτιση του σχήματος του κρανιοπροσωπικού συμπλέγματος με αλλαγές κατά την αύξηση σε παιδιά ηλικίας 12 ετών
Summary:
Aim:
There is great variation of growth among individuals. The question whether
patients with different skeletal discrepancies grow differently is biologically
interesting but also important in designing clinical trials. The aim of the
present study was to evaluate if growth direction depends on the initial
craniofacial pattern.
Subjects and Method:
The sample consisted of 350 lateral cephalograms of 175 subjects (91 females,
84 males) followed during normal growth without any orthodontic treatment. The
examined ages were 12 (T1) and 14 (T2) years. The cephalograms were obtained
from the American Association of Orthodontists Foundation (AAOF) Craniofacial
Growth Legacy Collection (Burlington, Fels, Iowa and Oregon growth studies). We
digitally traced 15 curves on each cephalogram, comprehensively covering the
craniofacial skeleton, and located 127 points on the curves, 116 of which were
sliding semilandmarks and 11 fixed. Procrustes alignment, principal component
analysis (PCA) and two-block partial least squares (2B-PLS) analysis were
performed, after sliding the semilandmarks to minimize bending energy.


Results:
The first 10 principal components (PCs) described approximately 71% of the
total shape variance. PC1 was related to shape variance in the vertical
direction (low/high angle skeletal pattern) and PC2 was mainly related to shape
variance in the anteroposterior direction (class II/class III pattern). PC3 was
mainly related to the shape variance of the mandibular angle. All subjects
shared a similar growth trajectory in shape space. We did not find any
correlation between the initial shape and the magnitude of shape change between
T1 and T2, but males showed a greater shape change than females. The direction
of shape change was moderately correlated to the initial shape (RV coefficient:
0.14, P < 0.001).
Conclusions:
The initial shape of the craniofacial complex covaried weakly with the
direction of shape change during growth.
Keywords:
Growth, Craniofacial Complex, Morphometrics, Procrustes Analysis
Index:
Yes
Number of index pages:
1
Contains images:
Yes
Number of references:
54
Number of pages:
65
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