>Magister Scientiae - MSc / Background: Plaster models form an integral part of the traditional orthodontic
records. They are necessary for diagnosis and treatment planning, case presentations
as well as for the evaluation of treatment progress. The accuracy of the measurements
taken for space assessment is crucial prior to treatment planning. The introduction of
digital models overcomes some problems experienced with plaster models. Digital
models have shown to be an acceptable alternative for plaster models.
Aim: The aim of the study was to determine the accuracy of traditional measurement
techniques when compared to the CAD/ CAM measurements in the assessment of
tooth widths and arch perimeter from plaster models.
Method: The mesio-distal tooth widths and arch perimeter of thirty archived plaster
models were measured using a digital caliper to the nearest 0.01 mm and divider to
the nearest 0.1 mm. Corresponding digital models were produced by scanning them
with a CAD/CAM (InEos X5) and space analysis completed by measurements using
InEos Blue software. Measurements were repeated after 1 week from the initial
measurement. The methods were compared using descriptive analysis (mean
difference and standard deviation).
Results: The operator reliability was high for digital models as well as the plaster
models when the measurement tool was the digital caliper (analyzed using the
Pearson correlation coefficient in the paired t-test). The mean values of tooth widths
measurements of CAD/CAM, digital caliper and divider were 6.82 (±0.04), 6.94 (±
0.04) and 7.11 (± 0.04). There was a significant difference between the measurements
made by the CAD/CAM and the divider. Additionally significant differences between
the measurements by digital caliper and divider measurements (p < 0.05) were
observed. No significant difference was found when comparing CAD/CAM to digital
caliper. Positive correlation was displayed between CAD/CAM, digital caliper and the
divider, but the measurements completed with the digital caliper had the highest
correlation with the CAD/CAM. The difference was not significant between the
aforementioned measurement tools (p > 0.05). Arch perimeter measurements showed
no statistical significant difference between CAD/CAM, digital caliper and divider (p
< 0.05).
Conclusion: Archived plaster models stored as records can be converted to digital
models as it will have the same accuracy of measurements. The value of doing a space
analysis with the CAD/CAM system can be performed with similar reliability on the
digital models as a caliper on plaster models.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:uwc/oai:etd.uwc.ac.za:11394/6521 |
| Date | January 2018 |
| Creators | Elmubarak, Mona |
| Contributors | Hudson, Athol, Mulder, Riaan |
| Publisher | University of the Western Cape |
| Source Sets | South African National ETD Portal |
| Language | English |
| Detected Language | English |
| Rights | University of the Western Cape |
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