Benjamin Pliska

Associate Professor

Research Classification

Sleep and Sleep Disorders
Oro-Dental Disorders

Research Interests

Facial growth and development
sleep medicine

Relevant Degree Programs

 

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Master's students
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Graduate Student Supervision

Master's Student Supervision (2010 - 2018)
Craniofacial morphology and the use of neonatal non-invasive ventilation therapy (2018)

Objective: A prospective cohort study with the overall objective to characterize the three-dimensional facial morphology of preterm infants over the course of the first 18 months of corrected age, participating in the Neonatal Follow-up Program of B.C. Women’s Hospital in Vancouver, BC. The specific aims of this project are to: 1. Characterize the three-dimensional facial morphology of a cohort of preterm infants at 4, 8 and 18 months of corrected age. 2. Determine the effects of the duration of NIV therapy on facial morphology at 4, 8 and 18 months of corrected age. 3. Evaluate the feasibility, time, adverse events, and minimum effect size to predict an appropriate sample size to improve study design prior to performance of a full scale longitudinal research project. Methods: To achieve this goal, infants reporting for follow-up at 4, 8 and 18 months of age corrected for prematurity will be screened for defined eligibility and imaged with a 3dMD surface-imaging camera, and facial morphometric parameters will be related to anthropometric data at birth and the specific characteristics of respiratory therapy received during the neonatal period or longer. Results: The study obtained 43 facial images: 10 images for the four-month cohort; 13 images for the 8-month cohort; 20 images for the 18-month cohort. The mean gestation age is 26 weeks, birth weight is 822 grams, birth length is 32.6 cm, and birth head circumference is 23.8 cm. The mean NIV therapy duration is 45 days and the mean NICU stay is 101 days. There was statistical significant negative correlation between intercanthal width versus duration of NIV therapy in the 4-month cohort. Conclusion: There were not any statistical significant correlations between the duration of NIV therapy and the linear distances measured in the transverse, vertical and anterior-posterior plane other than the intercanthal width. The duration of NIV therapy did not have any statistical significant correlation with measured facial angles and facial ratios. This pilot study was however not powered to detect a difference. There is overall positive feasibility for acceptability, demand, implementation, practicality, adaptation, integration and expansion of the research project.

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Reliability of upper pharyngeal airway assessment using dental CBCT (2017)

Introduction: Upper airway analysis is an often-cited use of CBCT imaging in orthodontics, however the reliability of airway measurements using this technology is not fully understood. The purpose of this study was to determine the intra-examiner and inter-examiner reliability of the complete process of volumetric and cross-sectional area assessments of the upper airway using CBCT imaging. Methods: Five examiners of varying levels of education and clinical experience performed manual orientation, slice and threshold selection, and measured nasopharyngeal, oropharyngeal, hypopharyngeal, and total upper pharyngeal airway volumes in addition to minimum cross-sectional area on the CBCT images of 10 patients. All measurements were repeated after 4-weeks. Intra and inter-examiner reliability was calculated using ICC and 95% CI. Results: Threshold selection showed poor intra and inter-examiner reliability, while minimum cross-sectional area showed moderate intra and poor inter-examiner reliability. Intra-examiner reliability of volumetric measurements varied based on the anatomical region assessed with ICC ranging from 0.747-0.976, and was worst for hypopharynx and best for the oropharynx. Inter-examiner reliability of volume measurements was generally lower, with ICC ranging from 0.175-0.945, and was worst for nasopharynx and best for the oropharynx. Conclusions: This study, for the first time, assessed the reliability of upper airway analysis with CBCT when all steps of image processing and measurement are performed by each examiner. Reliability improved with examiner experience, though was generally low for the hypopharynx and nasopharynx volumes and overall minimal cross sectional area. The oropharyngeal volume was the only parameter to have excellent intra-examiner and inter-examiner reliability.

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Effect of orthodontic treatment on the upper airway volume (2014)

Introduction: Currently, the influence of orthodontic treatment on the volume of the upper airway is not well understood. The aim of this study is to examine the effects of orthodontic treatment both with and without extractions on the anatomical characteristics of the upper airway in adults. Methods: For this retrospective study, the pre and post orthodontic treatment CBCT scans of adult patients treated at the UMN Division of Orthodontics between 2008 and 2012 were reviewed. From a pool of 1680 patient records, 74 patients met the eligibility criteria of the study and were included for further analysis. 3D imaging analysis software was used to segment and measure upper airway regions including the nasopharynx (NP), the retropalatal (RP) and retroglossal (RG) areas of the oropharynx, as well as total airway (TA). Coefficient of variation and the intraclass correlation coefficient were calculated. The Wilcoxon signed-rank test was used to compare volumetric and minimal cross-sectional area changes from pre (T0) to post (T1) treatment.Results: The reliability was high for all measurements with an ICC ≥0.82. Cephalometric analysis revealed no significant skeletal changes from T0 to T1. The T0 to T1 treatment changes for the upper airway for the extraction and non-extraction groups were as follows: TA: 1039.6 ± 3674.3mm³ vs. 1719.2.2 mm³ ± 4979.2, NP: 136.1 mm³ ± 1379.3 vs -36.5 mm³ ± 1139.8, RP: 412.7 mm³ ± 3042.5 vs. 399.3 mm³ ± 3294.6 , and RG 412.5mm³ ± 1503.2 vs. 1109.3mm³ ± 2328.6, respectively. The treatment changes for all airway regions examined were not significantly (p>0.05) different between the extraction and non-extraction groups. Similarly, changes in the minimum cross-sectional area were also not significantly different between the two types of treatment. Conclusions: Orthodontic treatment in adults does not cause clinically significant changes to the volume or minimally constricted area of the upper airway.

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Publications

 
 

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