Pacific Coast Society of Orthodontists Bulletin Winter 2017 - 30

Resident Research Review

University of Alberta

Dr. Carlos Flores Mir
Professor and Graduate
Orthodontic Program Director,
University of Alberta

A video of this research can be
found at www.pcsortho.org.

The Orthodontic Graduate Program at the University of Alberta was instituted in 1970. For its
first 30 years, it was a two-resident-per-year program. Since 2000, the number of residents has
increased, initially to three, and then in the last
15 years, to four per year. It is a fully accredited
Commission on Dental Accreditation (CODA)
program that allows its graduating residents to
practice the specialty of orthodontics in Canada
and the United States.
The program is located in Edmonton in the
province of Alberta. Edmonton and its surrounding satellite cities host 1.1 million people. The
latest figures show a student population of 38,311
from 148 countries, hosted in 388 undergraduate
programs and 500 graduate programs in 18
faculties. The University of Alberta is Canada's
fifth-largest research institution.
There are seven orthodontic graduate programs
in Canada. All of them are three-year programs
that award a Master of Science degree. Hence, all
graduate students have to successfully defend an
MSc thesis. Research topics covered by graduating residents over the past five years have varied,
but can be roughly grouped into the following
categories: orthodontic biomechanics (with a
strong ex-vivo approach); impact of ultrasound
on oral health tissue healing and facilitation of
orthodontic movement; CBCT use for orthodontic
diagnosis and treatment planning; use of fixed
Class II correctors in clinical practice; knowledge
translation of evidence-based clinical concepts;
and data analysis of complex three-dimensional
(3D) orthodontic datasets.
The following is a summary of some of these
topics and an overall summary of the findings.
Dr. Carlos Flores Mir: CBCT Imaging
of Adenoid Hypertrophy
The prevalence of adenoid hypertrophy is significant; it is the most common cause of pediatric
sleep disorders among children and adolescents.1
The overarching idea of this series of projects

was to assess the possibility of using CBCT imaging,2-4 when available for other reasons, to screen
for adenoid hypertrophy and to compare it with
the current reference standard diagnosis by an
otorhinolaryngologist (OHNS) using nasopharyngoscopy (NP), commonly called nasoendoscopy. A
pool of available CBCT scans and their respective
NP-based adenoid hypertrophy diagnoses were
explored. Randomly selected orthodontists from
Edmonton and a significant number of boardcertified oral and maxillofacial radiologists
(OMFRs) from North America were invited to
participate. The inter-examiner reliability of
orthodontists and OMFRs to classify adenoid
hypertrophy on a four-level scale was excellent
and very good, respectively.2,3 Both groups of specialists improved when the adenoid hypertrophy
was classified dichotomously as healthy/
unhealthy and analyzed via the Kappa test. Participating orthodontists showed large variability
with a poor agreement on the degree of adenoid
obstruction compared to the OHNS diagnosis
(reference standard).3 This suggests that orthodontists had poor overall diagnostic accuracy for
this specific scenario. The OMFRs' reliability was
greater than 80%, assuring their consistency and
accuracy on screening adenoid hypertrophy
using CBCT scans.2 Finally, health professionals
should not rely solely on CBCT volumetric and
cross-sectional measurements produced by the
evaluated automatic reconstruction software to
assess an upper airway constriction related to
adenoid hypertrophy. The software was reliable,
but the generated output for volume and the
cross-sectional area did not reflect the actual
constriction determined by the OHNS via NP
very well.4
Comfort and Pain While Using Fixed Class II
Correctors
Forsus devices are commonly used Class II fixed
correctors. The levels of comfort and pain associated with the conventional use of the Forsus
while attached to a rectangular SS wire, but also
as part of an Xbow appliance were explored.5 This
RCT included 41 adolescent participants. Their

PCSO Bulletin  Winter 2017

https://www.ualberta.ca/about/facts/students http://www.pcsortho.org

Table of Contents for the Digital Edition of Pacific Coast Society of Orthodontists Bulletin Winter 2017