No abstract

No abstract

Objectives: To evaluate, by using cone beam computed tomography,

Objective: To compare the effects of extraction vs nonextraction orthodontic treatments on oropharyngeal airway volume. Materials and Methods: An existing patient database was screened for pretreatment (T0) and posttreatment (T1) cone beam computed tomography (CBCT) scans and complete medical histories. Twenty patients treated with removal of four premolars (ExtG) and 20 controls (NExtG), were matched for age, gender, ethnicity, height, weight, body mass index, and oropharyngeal (OP) volumes, among other variables. Constructed lateral cephalograms (three skeletal and four dental variables) and OP volumes were measured at T0 and T1 using Dolphin Imaging 11.0. Independent sample t-tests were used to compare the groups at T0 and the outcome variables at T1. Paired sample t-tests were used to compare the mean changes from T0 to T1. Statistical significance was set at P # .05. Results: Changes from T0 to T1 were found to be significant in both groups for CoA, CoGn, U1-FH, and IMPA. In the ExtG alone, U1-Na Perp and L1-Na Perp were also significantly different from T0 to T1. Despite the observed differences, no significant differences were found at the end of treatment between the mean OP volumes for either group (12,675.6 6 4483.6 for ExtG; 12,002.7 6 2857.0 for NExtG, P . .05). Similarly, the mean changes in OP volume (1082.6 mm 3 and 1701.1 mm 3 for ExtG and NExtG, respectively) and increase in mean minimal constricted axial areas (17.4 mm 2 and 1.9 mm 2 for ExtG and NExtG, respectively, P . .05) from T0 to T1 were not significant for the two groups. Conclusion: Extraction of four premolars with retraction of incisors does not affect OP airway volume.

The aim of this study was to evaluate the oropharyngeal (OP) and nasal passage (NP) volumes along with various airway variables of patients with normal nasorespiratory functions having different dentofacial skeletal patterns and to evaluate the correlations between different variables and the airway. One hundred and one patients (57 males and 44 females, aged 14-18 years) having pre-treatment cone beam computed tomography images and complete medical records were selected. The patients were divided into five groups as Class I (CI, 81 ≥ SNA ≥ 77; 80 ≥ SNB ≥ 76; 3 ≥ ANB ≥ 1), Class II maxillary protrusion (CIIMaxP, SNA > 81; 80 ≥ SNB ≥ 76; ANB > 3), Class II mandibular retrusion (CIIMandR, 81 ≥ SNA ≥ 77; SNB < 76; ANB > 3), Class III maxillary retrusion (CIIIMaxR, SNA < 77; 80 ≥ SNB ≥ 76; ANB < 1), and Class III mandibular protrusion (CIIIMandP, 81 ≥ SNA ≥ 77; SNB > 80; ANB < 1). Posterior airway space, area of the most constricted region at the base of the tongue (minAx), and OP volume were significantly higher for the CIIIMandP group, whereas CIIMandR subjects had the lowest values. The only significant difference for the NP volume was between CI and CIIMandR groups where a smaller volume for the CIIMandR group was observed. The minAx was the variable that presented the best correlation with the OP airway volume. It seems that a detailed analysis of airway may prove to be a valuable diagnostic addition in orthodontics.

No abstract

No abstract

Facial asymmetry index in normal young adults Orthod Craniofac Res 2013; 16: 97-104. Abstract Objectives-To differentiate a symmetric face from an asymmetric face by analyzing a three-dimensional (3D) facial image and plotting the asymmetry index (AI) on a facial symmetry diagram. Setting and Sample Population-Sixty healthy Chinese adults (30 men and 30 women, mean age: 27.7 + 4.9 years old) without any craniofacial deformity were recruited on a voluntary basis from a medical center. Material and Methods-A 3D facial image of each participant was captured by a GENEX 3D FACE CAM system. Sixteen facial landmarks, as defined by Farkas, were selected on each 3D facial image. The AI was calculated for each landmark. Results-The norm for the AI varied from 0.76 to 2.82. The landmarks located on the upper face had a smaller AI than the landmarks located on the lower face. A facial symmetry diagram was designed according to the mean, one standard deviation, and 2 standard deviations of AI for each landmark. Conclusions-The 3D facial asymmetry can be documented with AI. The landmarks located on the upper face had a smaller AI than the landmarks located on the lower face. The facial symmetry diagram can identify efficiently the location of asymmetry on a face.