CBCT craniometric measurements are accurate to a subvoxel size and potentially can be used as a quantitative orthodontic diagnostic tool. Two-dimensional cephalometric norms cannot be readily used for three-dimensional measurements because of differences in measurement accuracy between the two exams.

The term "asymmetry" is used to make reference to dissimilarity between homologous elements, altering the balance between structures. Facial asymmetry is common in the overall population and is often presented subclinically. Nevertheless, on occasion, significant facial asymmetry results not only in functional, but also esthetic issues. Under these conditions, its etiology should be carefully investigated in order to achieve an adequate treatment plan. Facial asymmetry assessment comprises patient's first interview, extra- as well as intraoral clinical examination, and supplementary imaging examination. Subsequent asymmetry treatment depends on patient's age, the etiology of the condition and on the degree of disharmony, and might include from asymmetrical orthodontic mechanics to orthognathic surgery. Thus, the present study aims at addressing important aspects to be considered by the orthodontist reaching an accurate diagnosis and treatment plan of facial asymmetry, in addition to reporting treatment of some patients carriers of such challenging disharmony.

Mandibular asymmetry was not independently associated with sex, age, or absence of posterior teeth. The only verified independent association was between mandibular asymmetry and sagittal jaw relationship.

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Objective: To test the accuracy of a mathematical model (algorithm) that corrects measurements made on conventional lateral head films to corresponding dimensions observed in a cone beam computed tomography (CBCT) scan in human subjects. Materials and Methods: Thirteen subjects had lateral cephalograms taken with a conventional cephalometric machine as well as a CBCT scan. Measurements of midface length, mandibular length, and lower anterior face height (LAFH) from both examinations were calculated. Two other groups of measurements were derived mathematically from the dimensions directly quantified on the lateral cephalogram: the magnification correction group and the algorithm correction group. The data were analyzed statistically, using repeated measures analysis of variance (ANOVA). Results: All measurements from the lateral cephalogram were significantly different from the corresponding measurements derived from the CBCT. Simply taking into account the image magnification did not correct the 2-dimensional (2D) linear measurement obtained from a conventional cephalogram into a 3-dimensional (3D) linear measurement made on a CBCT scan, unless the structures from which the distance will be measured are located on the midsagittal plane. When the algorithm was used to correct the 2D measurements, however, there were no statistically significant differences between the CBCT group and the algorithm group. Conclusions: Using the mathematical formula presented herein, 2D cephalometric measurements from landmarks both on and off the midsagittal plane can be corrected into a 3D CBCT measurement with accuracy. By applying this algorithm to other existing cephalometric longitudinal growth studies, control groups and standards for CBCT images could be derived without exposing untreated subjects to radiation. (Angle Orthod. 2011;81:3-10.)

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The assessment of the golden proportion and width/height ratio of upper anterior teeth in patients with upper lateral incisor agenesis treated with either implants or tooth re-contouring may assist dentists and patients in deciding the best treatment option based on the peculiarities of each case.

Objective: The aim of this study was to evaluate the dentoalveolar effects of rapid maxillary expansion in children with unilateral complete cleft lip and palate in comparison with non-cleft patients. Methods: The experimental group (EG) was composed of 25 patients with unilateral and complete cleft lip and palate (9 males and 15 females) with a mean age of 10.6 years. The control group (CG) comprised of 27 patients without cleft lip and palate (14 males and 13 females) with a mean age of 9.1 years. Dental models of the maxillary dental arch were obtained immediately preexpansion (T1) and 6 months post-expansion (T2) at the time of appliance removal. Digital dental models were obtained using the 3Shape R700 3D laser scanner (3Shape A/S, Copenhagen, Denmark). Transversal widths, arch perimeter, arch length, palatal depth, palatal volume, canine and posterior tooth inclination were digitally measured. Paired t-test was used to perform interphase comparisons and independent t-test to perform intergroup comparisons (p<0.05). Results: In the experimental group, the expansion produced a significant increase of all maxillary transverse measurements, palatal volume, arch perimeter and palatal depth while decreased the arch length. RME caused a buccal tip of posterior teeth in patients with UCLP. No differences were observed between experimental and control groups for all the measurements performed except for the intermolar distance (6-6), which showed a greater increase in patients with cleft. Conclusion: Rapid maxillary expansion showed similar dentoalveolar effects in children with UCLP and without oral clefts.