A new method to measure mesiodistal angulation and faciolingual inclination of each whole tooth with volumetric cone-beam computed tomography images.

INTRODUCTION: The purpose of this study was to develop a methodology to measure the mesiodistal angulation and the faciolingual inclination of each whole tooth (including the root) by using 3-dimensional volumetric images generated from cone-beam computed tomography scans. METHODS: A plastic typodont with 28 teeth in ideal occlusion was fixed in position in a dry human skull. Stainless steel balls were fixed to the occlusal centers of the crowns and to the apices or bifurcation or trifurcation centers of the roots. Cone-beam computed tomography images were taken and rendered in Dolphin 3D (Dolphin, Chatsworth, Calif). The University of Southern California root vector analysis program was developed and customized to digitize the crown and root centers that define the long axis of each whole tooth. Special algorithms were used to automatically calculate the mesiodistal angulation and the faciolingual inclination of each whole tooth. Angulation measurements repeated 5 times by using this new method were compared with the true values from the coordinate measuring machine measurements. Next, the root points of 8 selected typodont teeth were modified to generate known angulation and inclination values, and 5-time repeated measurements of these teeth were compared with the known values. RESULTS: Intraclass correlation coefficients for the repeated mesiodistal angulation and faciolingual inclination measurements were close to 1. Comparisons between our 5-time repeated angulation measurements and the coordinate measuring machine's true angulation values showed 5 teeth with statistically significant differences. However, only the maxillary right lateral incisor showed a mean difference that might exceed 2.5° for clinical significance. Comparisons between the 5-repeated measurements of 8 teeth with known mesiodistal angulation and faciolingual inclination values showed no statistically significant differences between the measured and the known values, and no measurement had a 95% confidence interval beyond 1°. CONCLUSIONS: We have developed the novel University of Southern California root vector analysis program to accurately measure each whole tooth mesiodistal angulation and faciolingual inclination, in a clinically significant level, directly from the cone-beam computed tomography volumetric images.

Use of an Oscillating-Rotating Electric Toothbrush and Novel Brush Head to Increase Brushing Motivation and Reduce Plaque Among Orthodontic Patients.

OBJECTIVE: The aim of this case series was to evaluate the effect of the Oral-B® iO™ oscillatingrotating (O-R) electric toothbrush with micro-vibrations and the novel Oral-B Targeted Clean™ brush head on orthodontic patients' plaque accumulation and motivation to brush. METHODS: Five patients, aged 9 to 22 years, with fixed orthodontia and poor oral hygiene were enrolled in the study and instructed on use of the O-R toothbrush with the novel brush head. At the beginning and end of the 9- to 14-week case study interval, patients completed a survey designed to assess estimated brushing time and patients' motivation to brush their teeth. At the same timepoints, each patient's plaque was disclosed with a plaque-disclosing gel, assessed by a dental professional, an photographed. Finally, each patient participated in an exit interview. RESULTS: At the end of the case study participation, all patients' plaque accumulation was greatly reduced (range 15% to 45%) and most patients reported increased motivation to brush their teeth. While mean estimated brushing time remained relatively fl at during the evaluation period (2:34 to 2:42 minutes), the substantial decrease in plaque levels seen with the Targeted Clean brush head shows it provided highly efficient plaque removal. Patients and their caregivers expressed satisfaction with the toothbrush and novel brush head. CONCLUSIONS: The Oral-B iO O-R electric toothbrush and Targeted Clean brush head were well-received by orthodontic patients and their caregivers and produced clinically relevant plaque reductions in this at-risk population.

Accuracy of mesiodistal root angulation projected by cone-beam computed tomographic panoramic-like images.

INTRODUCTION: In this study, we tested the accuracy of the cone-beam computed tomography panoramic (pan)-like image in the projection of mesiodistal tooth angulations. METHODS: A plastic typodont with 28 teeth in ideal occlusion was fixed in position in a dry human skull for imaging with a NewTom 3G volume scanner (AFP Imaging, Elmsford, NY). Gold standard angular measurements of each tooth were calculated by using a coordinate measuring machine (CMM) (Faro International, Lake Mary, Fla) and compared with the corresponding measurement derived from each CBCT pan-like image. Imaging processing was accomplished with the proprietary software. RESULTS: Statistically significant differences between the CMM and CBCT pan-like image mesiodistal angular projections were found for 16 of the 28 teeth, although only the mean difference and confidence intervals of teeth 22, 12, and 33 (FDI numbering system) were above at the applied tolerance limit of +/-2.5 degrees (3.675 degrees with 95% confidence interval of [3.330 degrees, 4.020 degrees], 2.006 degrees [1.339 degrees, 2.672 degrees] and 2.179 degrees [1.800 degrees, 2.557 degrees], respectively). The maxillary roots with the exception of teeth 16 and 26 were projected with greater distal angulations. The mandibular roots with the exception of teeth 44, 47, and 36 were projected with greater mesial angulations than the CMM gold standard measurement. CONCLUSIONS: Compared with previous studies on the accuracy of conventional pan radiographs, the mesiodistal angular projection of teeth on the CBCT pan-like image is closer to the true mesiodistal angulation. If the practitioner is well acquainted with how the information from the CBCT is processed to create the pan-like image, it can be a useful tool for evaluating mesiodistal root angulations.

Mandibular asymmetry diagnosis with panoramic imaging.

INTRODUCTION: Our objective was to determine the diagnostic capability of panoramic imaging in any of its forms to detect mandibular asymmetry. METHODS: Several electronic databases were searched. Abstracts that appeared to fulfill the initial selection criteria (mandibular or craniofacial asymmetry, panoramic imaging, and evaluation of validity or accuracy of diagnosis with an appropriate gold standard) were selected, and full articles from these abstracts were gathered. The references from these articles were also examined for possible articles that could have been missed. RESULTS: Only 11 articles met all criteria. Vertical measurements, although more accurate than horizontal or angular measurements, are still not true representations of the real objects they correspond to. Magnification values reported by the manufacturer might not correspond to the calculated magnification value and be uniform across the panoramic imaging entire area. CONCLUSIONS: Caution is advised when using conventional or digital panoramic images to assess mandibular asymmetry. Understanding the limitations of every form of panoramic imaging is required. Future studies with panoramic images generated from 3-dimensional data are required to determine whether they overcome the limitations of conventional and digital panoramic images.