Introduction-The aim of this study was to assess the differences in airway shape and volume among subjects with various facial patterns.

Class III malocclusion is a consequence of maxillary deficiency and/or mandibular prognathism, often resulting in an anterior crossbite and a concave profile. 1 Young patients with maxillary hypoplasia are usually treated with a facemask: heavy anterior traction is applied on the maxilla to stimulate its growth and to restrain or redirect mandibular growth. Forward and downward movement of the maxilla as well as favorable changes in the amount and direction of mandibular growth has been reported. [2][3][4][5] However, these forces generally result in a posterior rotation of the mandible and an increased vertical dimension of the face. 2,4,6 Moreover, dental compensations (proclination of the upper incisors and uprighting of the lower incisors) are observed as a consequence of the application of forces on the teeth, 4,7 and facemask wear is usually limited to 14 hours per day at best. Titanium miniplates used for anchorage now offer the possibility to apply pure bone-borne orthopedic forces between the maxilla and the mandible for 24 hours per day, avoiding any dentoalveolar compensations.

Objective: To test the hypothesis that there is no difference in the active treatment effects for maxillary advancement induced by bone-anchored maxillary protraction (BAMP) and the active treatment effects for face mask in association with rapid maxillary expansion (RME/FM). Materials and Methods: This is a study on consecutively treated patients. The changes in dentoskeletal cephalometric variables from start of treatment (T1) to end of active treatment (T2) with an average T1-T2 interval of about 1 year were contrasted in a BAMP sample of 21 subjects with a RME/FM sample of 34 patients. All subjects were prepubertal at T1. Statistical comparison was performed with t-tests for independent samples. Results: The BAMP protocol produced significantly larger maxillary advancement than the RME/ FM therapy (with a difference of 2 mm to 3 mm). Mandibular sagittal changes were similar, while vertical changes were better controlled with BAMP. The sagittal intermaxillary relationships improved 2.5 mm more in the BAMP patients. Additional favorable outcomes of BAMP treatment were the lack of clockwise rotation of the mandible as well as a lack of retroclination of the lower incisors. Conclusions: The hypothesis is rejected. The BAMP protocol produced significantly larger maxillary advancement than the RME/FM therapy. (Angle Orthod. 2010;80:799-806.)

Introduction In this study, we compared the precision of landmark identification using displays of multi-planar cone-beam computed tomographic (CBCT) volumes and conventional lateral cephalograms (Ceph). Methods Twenty presurgical orthodontic patients were radiographed with conventional Ceph and CBCT techniques. Five observers plotted 24 landmarks using computer displays of multi-planer reconstruction (MPR) CBCT and Ceph views during separate sessions. Absolute differences between each observer’s plot and the mean of all observers were averaged as 1 measure of variability (ODM). The absolute difference of each observer from any other observer was averaged as a second measure of variability (DEO). ANOVA and paired t tests were used to analyze variability differences. Results Radiographic modality and landmark were significant at P <0.0001 for DEO and ODM calculations. DEO calculations of observer variability were consistently greater than ODM. The overall correlation of 1920 paired ODM and DEO measurements was excellent at 0.972. All bilateral landmarks had increased precision when identified in the MPR views. Mediolateral variability was statistically greater than anteroposterior or caudal-cranial variability for 5 landmarks in the MPR views. Conclusions The MPR displays of CBCT volume images provide generally more precise identification of traditional cephalometric landmarks. More precise location of condylion, gonion, and orbitale overcomes the problem of superimposition of these bilateral landmarks seen in Ceph. Greater variability of certain landmarks in the mediolateral direction is probably related to inadequate definition of the landmarks in the third dimension.

CBCT can reproduce conventional cephalometric geometry with similar precision and accuracy. Orthogonal CBCT projections provided greater accuracy of measurement for midsagittal plane dimensions than perspective CBCT or conventional cephalometric images.

Introduction-The objective of this study was to evaluate a new method for superimposition of 3-dimensional (3D) models of growing subjects.

The increasing use of cone-beam computed tomography (CBCT) requires changes in our diagnosis and treatment planning methods as well as additional training. The standard for digital computed tomography images is called digital imaging and communications in medicine (DICOM). In this article we discuss the following concepts: visualization of CBCT images in orthodontics, measurement in CBCT images, creation of 2-dimensional radiographs from DICOM files, segmentation engines and multimodal images, registration and superimposition of 3-dimensional (3D) images, special applications for quantitative analysis, and 3D surgical prediction. CBCT manufacturers and software companies are continually working to improve their products to help clinicians diagnose and plan treatment using 3D craniofacial images.The numbers of clinicians using 3-dimensional (3D) records during diagnosis and treatment planning stages are increasing steadily. Cone-beam computed tomography (CBCT) scanners are becoming more efficient with reduced acquisition time, and software packages developed to process, manage, and analyze 3D images are also undergoing a rapid growth phase. The management of CBCT images differs from that of conventional 2-dimensional (2D) images. Most orthodontists were trained in the 2D era, and the transition to 3D images requires a learning stage. With today's hardware and software improvements, the learning curve is not as steep, but some basic concepts should be taken into account with this new technology.The purpose of this article is to give the clinician some core concepts for 3D diagnosis and treatment planning. The current commercial software applications for clinical management of craniofacial CBCT images are presented and compared with the current standards. The concepts presented here are applicable regardless of the constantly changing software applications. DICOM FILESIn the early 1980s, the American College of Radiology and the National Electrical Manufacturers Association joined forces to standardize the coding of images obtained through computed tomography and magnetic resonance imaging. After successive improvements, in

Introduction Bone-anchored maxillary protraction has been shown to be an effective treatment modality for the correction of Class III malocclusions. The purpose of this study was to evaluate 3-dimensional changes in the maxilla, the surrounding hard and soft tissues, and the circummaxillary sutures after bone-anchored maxillary protraction treatment. Methods Twenty-five consecutive skeletal Class III patients between the ages of 9 and 13 years (mean, 11.10 ± 1.1 years) were treated with Class III intermaxillary elastics and bilateral miniplates (2 in the infrazygomatic crests of the maxilla and 2 in the anterior mandible). Cone-beam computed tomographs were taken before initial loading and 1 year out. Three-dimensional models were generated from the tomographs, registered on the anterior cranial base, superimposed, and analyzed by using color maps. Results The maxilla showed a mean forward displacement of 3.7 mm, and the zygomas and the maxillary incisors came forward 3.7 and 4.3 mm, respectively. Conclusions This treatment approach produced significant orthopedic changes in the maxilla and the zygomas in growing Class III patients.