Date of Award

Summer 2018

Document Type


Degree Name

Master of Science (MS)



First Advisor

Ahuja, Bhoomika

Second Advisor

Liu, Dawei

Third Advisor

Nimeri, Ghada


Introduction: Space analysis and radiographic analyses are crucial elements in developing an orthodontic treatment plan. It is imperative that the orthodontist makes accurate measurements in order to come up with the most effective treatment options for each patient. Some practitioners refrain from direct measurements to determine arch length discrepancies and instead determine the amount of crowding by using direct visual approximation. In addition, more orthodontists do not routinely trace all cephalograms taken. If more and more orthodontists are using direct visual approximation to determine angular cephalometric measurements, it is important to assess the accuracy and reliability of these measurements. This study will focus on two critical aspects of the orthodontic diagnosis: space analysis and lateral cephalometric findings. As continuation of a 2017 pilot study, this research will: 1. Assess the accuracy of orthodontists’ visual approximation 2. Assess how their visual approximation impacts the overall treatment plan. Methods and Materials: One hundred and twenty seven orthodontic residents and clinicians were recruited in this project and completed a survey that included a section on demographics, 3 upper and lower occlusal photos of 3 orthodontic cases, and 3 cases of traced cephalograms. The survey was created using Google Forms and was distributed by the American Association of Orthodontists. Results: An assessment of the effects on demographics on arch length assessment and cephalometric assessment were done using chi square tests and one way ANOVA. Results showed a trend to overestimate crowding. No clear associations between any demographics and results were found. Results showed a trend to overestimate crowding. Cephalometric responses did not have a high level of accuracy. Conclusion: On average, orthodontists overestimated all arch length discrepancy measurements. Overall, orthodontists were not accurate at approximating cephalometric measurements, with a total of 54% choosing the correct measurement range. As both the amount of crowding and mandibular plane angle increased, more participants chose to treat the case with extractions. Transverse expansion was the most commonly used method to treat cases non-extraction.