Comparison of Preoperative Measurement Methods of Alveolar Cleft Volume Using Cone Beam Computed Tomography between Computer Simulation and Water Displacement Methods.

OBJECTIVE: To compare the use of a computer simulation by Mimics software and the water displacement method as means for measurement of alveolar cleft volume on cone beam computed tomography (CBCT) data. DESIGN: Prospective study. SETTLING: Institutional research. PATIENTS: Patients with unilateral complete cleft lip and palate (UCCLP) who would undergo alveolar bone grafting. INTERVENTIONS: CBCT images of twenty patients with UCCLP were included in the study. In the first method, the water displacement method was adopted to measure volume of plasticine filled in the alveolar cleft imprinted on 3D printed model of maxilla. In the second method a volumetric assessment function in Mimics software was adopted to measure volume of 3D virtual model of alveolar cleft constructed from CBCT images. A comparison on the alveolar cleft volumes derived from the two methods was assessed using the statistical paired t-test. MAIN OUTCOME MEASURE: The paired-t test showed no statistically significant difference between alveolar cleft volumes measured by the two methods (P = 0.075). RESULTS: Mean volume of the alveolar cleft measured by the water displacement method was 1.03 ± 0.31 ml whereas by the computer simulation using Mimics software the value was 1.00 ± 0.31 ml. The mean difference between the two methods was 0.03 ± 0.08 ml. CONCLUSION: The computer simulation by Mimics software as a means for measurement of alveolar cleft volume on CBCT data is as accurate as the measurement by the water displacement method.

Root surface areas of maxillary permanent teeth in anterior normal overbite and anterior open bite assessed using cone-beam computed tomography.

PURPOSE: The aim of this study was to compare the root surface areas of the maxillary permanent teeth in Thai patients exhibiting anterior normal overbite and in those exhibiting anterior open bite, using cone-beam computed tomography (CBCT). MATERIALS AND METHODS: CBCT images of maxillary permanent teeth from 15 patients with anterior normal overbite and 18 patients with anterior open bite were selected. Three-dimensional tooth models were constructed using Mimics Research version 17.0. The cementoenamel junction was marked manually. The root surface area was calculated automatically by 3-Matic Research version 9.0. The root surface areas of each tooth type from both types of bite were compared using the independent t-test (P<.05). The intraclass correlation coefficient was used to assess intraobserver reliability. RESULTS: The mean root surface areas of the maxillary central and lateral incisors in individuals with anterior open bite were significantly less than those in those with normal bite. The mean root surface area of the maxillary second premolar in individuals with anterior open bite was significantly greater than in those with normal bite. CONCLUSION: Anterior open-bite malocclusion might affect the root surface area, so orthodontic force magnitudes should be carefully determined.

Comparison of 2 root surface area measurement methods: 3-dimensional laser scanning and cone-beam computed tomography.

PURPOSE: The aim of this study was to compare the use of 3-dimensional (3D) laser scanning and cone-beam computed tomography (CBCT) as methods of root surface measurement. MATERIALS AND METHODS: Thirty teeth (15 maxillary first premolars and 15 mandibular first premolars) from 8 patients who required extractions for orthodontic treatment were selected. Before extraction, pre-treatment CBCT images of all the patients were recorded. First, a CBCT image was imported into simulation software (Mimics version 15.01; Materialise, Leuven, Belgium) and the root surface area of each tooth was calculated using 3-Matic (version 7.01, Materialise, Leuven, Belgium). After extraction, all the teeth were scanned and the root surface area of each extracted tooth was calculated. The root surface areas calculated using these 2 measurement methods were analyzed using the paired t-test (P<.05). Correlations between the 2 methods were determined by calculating the Pearson correlation coefficient. The intraclass correlation coefficient (ICC) was used to assess intraobserver reliability. RESULTS: The root surface area measurements (230.11±41.97 mm2) obtained using CBCT were slightly greater than those (229.31±42.46 mm2) obtained using 3D laser scanning, but not significantly (P=.425). A high Pearson correlation coefficient was found between the CBCT and the 3D laser scanner measurements. The intraobserver ICC was 1.000 for 3D laser scanning and 0.990 for CBCT. CONCLUSION: This study presents a novel CBCT approach for measuring the root surface area; this technique can be used for estimating the root surface area of non-extracted teeth.