The objectives of this study were to evaluate (1) the impact of maxillary incisor inclination on the aesthetics of the profile view of a smile, (2) to determine the most aesthetic inclination in the profile view of a smile and correlate it with facial features, and (3) to determine if dentists, orthodontists, and laypeople appreciate differently incisor inclination in smile aesthetics. A smiling profile photograph of a female subject (22 years of age) who fulfilled the criteria of soft tissue normative values and a balanced smile was obtained. The photograph was manipulated to simulate six lingual and labial inclinations at 5 degree increments to a maximum of 15 degrees. The seven photographs were randomly distributed in a binder to three groups of raters (30 dentists, 30 orthodontists, and 30 laypeople) who scored the attractiveness of the photographic variations using a visual analogue scale. Comparison of the mean scores was carried out by repeated analysis of variance, univariate tests, and multiple Bonferroni comparisons. The results showed a statistically significant interaction between the rater's profession and the aesthetic preference of incisor inclination (P = 0.013). The profile smile corresponding to an increase of 5 degrees in a labial direction had the highest score among all professions and among male and female raters. Orthodontists preferred labial crown torque; dentists and laypeople did not appreciate excessive incisor inclination in either the lingual or the labial directions. The most preferred smile matched with a maxillary incisor inclined 93 degrees to the horizontal line and +7 degrees to the lower facial third.

Objective: To assess the volumetric changes and the maxillary response of the naso-maxillary complex (NMC) following rapid maxillary expansion (RME). Materials and Methods: Thirty consecutive patients (14 males and 16 females) with a mean age at first observation of 9.5 ± 1.8 years for males and of 11.8 ± 1.7 years for females, presenting a posterior unilateral or bilateral crossbite and requiring RME, were selected for the study. Each patient underwent expansion to correct the transverse occlusal relationships. Computed tomography scans were taken before RME (T1) and at the end of the active expansion phase (T2). Measurements were performed on scanned images. The Kolmogorov-Smirnov test was performed; the mean differences between measurements at T1 and T2 were compared using the t -test (α = .05). Results: All volumetric, maxillary, transverse skeletal anterior and posterior variables as well as all dental anterior and posterior linear and angular variables representing the NMC displayed statistically highly significant increases after RME ( P < .001). Conclusions: After RME the total volume of the NMC increased by 12%, the nasal volume by 17%, and the maxillary volume by 10.6%. The maxillary and the nasal contributions represented 69.75% and 30.25%, respectively.

Une étude critique des plans d'orientation et de référence en céphalométrie est réalisée. Les données reposent sur les mesures céphalométriques d'une recherche qui a été menée sur un échantillon de 90 jeunes adultes libanais, répartis en 43 filles et 47 garçons, et dont les téléradiographies ont été prises suivant la position d'équilibre naturel.Cette étude a permis de faire une mise au point sur l'importance du Plan Horizontal en tant que plan d'orientation et plan de référence, grâce à la reproductibilité fiable de la position d'équilibre naturel et la grande variabilité des plans de référence intracraniens par rapport au Plan Vertical, suite à la faible corrélation trouvée entre des mesures se basant sur la vraie horizontale comme plan de référence (AB - horizontale) et des mesures se basant sur des plans ou des points intracraniens (ANB) comme référence. Cette étude a également permis de déterminer les variations de certaines mesures angulaires sagittales (SNA, SNB, SNPog) prises suivant deux orientations différentes : le plan de Francfort et la position d'équilibre naturel. A critical study of orientation and reference planes used in cephalometrics is undergone. The data consists of cephalometric measurements evaluated in a sample of 90 young lebanese adults, divided into 43 girls and 47 boys, whose lateral cephalograms were registered according to the natural head position.This study shows the importance of the true horizontal as orientation and reference planes, due to the high reproducibility of the natural head position, and the high variability of the intra-cranial reference planes as compared to the true vertical, as well as the low correlation among measurements based on the true horizontal as a reference plane (AB-horizontal), and the measurements based on the intra-cranial planes and points (ANB) as reference. This study also evaluated the variations of some angular and sagittal measurements (SNA, SNB, SNPog) registered according to two orientations: Frankfort plane and the natural head position.