Application of Optical Impression in Presurgical Infant Orthopedics （Second Report）
—Effect of Cleft Form—
2018 Volume 43 Issue 1 Pages 12-19
Details
2018 Volume 43 Issue 1 Pages 12-19
In order to reduce the risk of vomiting and aspiration when taking alginate impressions, we are now using intraoral scanners for fabricating palatal plates in presurgical infant orthopedics （PIO） for cleft lip and/or palate （CLP） patients. In our previous study, we reported the effect of wetness and movement on the optical scanning time and accuracy using intraoral scanners. Since the cleft form and size vary greatly among CLP infants, we examined the effect of these factors on the scanning time and accuracy in this study.
Two resin casts of two unilateral CLP infants who visited the Orthodontic Clinic of Meikai University Hospital were used. The maximum alveolar length （31.0-32.0mm） and maximum alveolar width （45.0mm） were both comparable among the two cases, but the cleft form and size were quite different. Case 1 （30days old） was a right unilateral CLP infant with alveolar and palatal clefts of 2.0mm and 11.5mm, respectively. Case 2 （20days old） was a left unilateral CLP infant with alveolar and palatal clefts of 11.5mm and 18.0mm, respectively.
The optical scanning time was significantly longer in case 2 than in case 1 by 82％. The effect of wetness and movement on scanning time was larger in case 2 than in case 1. It was likely that the longer scanning time in case 2 was due to the larger surface area and the three-dimensional cleft form with undercuts. In our previous study, we reported that the application of a landmark between the alveolar cleft reduced the scanning time. In this study, the effect of two materials having different surface smoothness on reducing the scanning time was examined. As a result, the smoother surface material more effectively reduced the scanning time, without affecting the scanning accuracy.
The findings suggest that a larger cleft requires a longer optical scanning time. The application of the smooth surface material between the alveolar cleft is likely to reduce the scanning time significantly.
