Validity and reliability of palatal rugae morphometric assessment with 3D laser scanned models

Aim: To assess the reliability and validity of morphometric features on 3D digital models produced by scanning maxillary dental casts of Malaysian Malay subjects. Methods: Dental casts of 20 subjects were scanned using a 3D laser scanner (Next Engine Inc., Santa Monica, California, USA). The palatal rugae morphometric features were assessed on the resulting 3D models using 3-Matic Research 9.0 software (Materialise NV, Heverlee, Belgium). The assessments were repeated by the first and second authors to assess the intra- and interexaminer reliability, respectively. Rugae morphometric features were also evaluated on the conventional plaster models to assess the validity of the 3D method. Results: Kappa values of the validity ranged from 0.807 to 0.922 for rugae shape, size category and direction. The intraclass correlation coefficient (ICC) for rugae number validity was 0.979. For intra-examiner reliability, kappa values ranged from 0.716-1.000 for rugae shape, size category and direction. The ICC for rugae number intra-examiner reliability was 0.949. Kappa values of interexaminer reliability for rugae shape, size category and direction were 0.723-885, while the ICC of rugae number was 0.896. Conclusion: Palatal rugae analyses on 3D digital models scanned by the 3D Next Engine laser scanner using 3-Matic Research 9.0 software are valid and reliable

Treatment Outcome Based on GOSLON Score of Multiple Factors in Unilateral Cleft Lip and Palate Children of Four Different Ethnic

Objective: To evaluate and compare the effect of each congenital and postnatal treatment factors in treatment outcome based on dental arch relationship (DAR) of four different populations at a time using GOSLON yardstick. Material and Methods: 432 unilateral cleft lip and palate subjects (Japanese, Malay ethnic group, Bangladeshi and Pakistani populations) age 5 to 12 years were taken before orthodontic treatment and alveolar bone grafting. The DAR was assessed by GOSLON Yardstick. Independent t-test was performed to compare the GOSLON score for each factors. A multiple comparison (Anova) was also conducted between the GOSLON score of four different populations. The significance level was set at p<0.05. Results: Statistically no significant different was found among the congenital factors. However, the family history of Class III malocclusion showed most likely to associate with, though there was no significant difference (p=0.069). Significant difference revealed between two techniques of cheiloplasty in both Malay ethnic group and Pakistani population (p=0.038 and p=0.000, respectively). Gender and Techniques of palatoplasty also showed significant difference in Pakistani population (p=0.026 and p=0.000, respectively). Japanese and Bangladeshi population showed no significant differences. Also no significant differences found between the GOSLON score and different countries. Conclusion: The treatment outcome based on DAR significantly varies in individual population [Malay ethnic group (cheiloplasty); Pakistan (gender, cheiloplasty and palatoplasty)].

The Reliability and Validity of the Measurements in Unilateral Cleft Lip and Palate Laser Scanned 3D Dental Casts

Abstract Objective: To evaluate the reliability and validity of the Next Engine 3D Laser scanner. Material and Methods: A total of 30 dental casts of unilateral cleft lip and palate (UCLP) children with 90 linear variables were measured using digital caliper while the laser-scanned 3D dental casts (LS3DM) were measured using Mimics Software. All scanned data coordinates (in x, y, z) were transferred into Mimics software in STL format to be measured. All the variables were measured using a computer mouse accurate to 0.5 mm. The intra-class correlation coefficient (ICC) was used to evaluate the intra- and inter-examiner reliabilities and also for the validity of two methods Results: Intra-examiner reliabilities of digital caliper and LS3DM were found excellent (ICC 0.916-0.995) and inter-examiner reliabilities of LS3DM were good to excellent (ICC 0.816-0.990). The validity of LS3DM measurements was confirmed based on the ICC values were in the range of 0.913-0.996. The overall time frame for conducting measurements was shorter using a laser-scanned model (10 min.) than using a digital caliper (5 hours) Conclusion: The LS3DM is a valid reliable tool for future high impact research in our institution.

Fracture resistance of over-flared root canals filled with MTA and resin-based material: an in vitro study

Aim: To measure the fracture resistance of over-flared roots filled with a variety of materials (gutta-percha-nano HA, resilon-epiphany, composite and mineral trioxide aggregate - MTA) using the Instron machine test and micro-computed tomography (Micro CT) Scan. In addition, scanning electron microscopy (SEM) images were used to illustrate the type of fracture patternsof the specimens. Methods: One hundred and twenty extracted human mandibular single rooted premolars were selected. A total of 105 out of the selected teeth were prepared to the working length and over-flared, leaving the apical 5 mm undisturbed. Fifteen samples had no treatment and were used as a positive control group (Group +ve). The 105 test teeth were further divided into 7 groups of 15 samples each. One of the 7 groups was designated as negative control (Group -ve) where teeth were over prepared and left without obturation.Remaining groups were filled with gutta-percha-nanoHA (Group1), gutta-percha-nano HA+composite (Group 2), gutta-percha-nano HA+MTA (Group 3), resilon-epiphany (Group 4),resilon-epiphany+composite (Group 5), and resilon-epiphany+MTA (Group 6). Fracture resistance of all samples was measured using the Instron testing machine. Three samples from each group had the depth of their fracture line measured by Micro CT Scan, and 2 samples from each group had their fracture pattern illustrated using SEM. Results: The highest fracture resistance was observed in Group +ve, followed by Groups 3, 6, 5, 2, 4, 1, and Group -ve, with values (in N) of: 1598 (641.0), 1190.5(424.2), 1164.7 (489.4), 821.2 (220.9), 683.4(179),658.4 (211.3), 658.4 (99.0), 158.3(49.3), respectively. Statistical analysis for root fracture resistance showed highly significant difference between all groups with p value < 001.Conclusions: Micro CT Scan and SEM analysis indicated the ability of MTA to withstand vertical force.