Three-dimensional stereophotogrammetric analysis of 50 smiles: A study of dento-facial proportions.

OBJECTIVES: The purpose of this study was to analyze 50 smiles using 3D stereophotogrammetry (3D-spg)-based facial reconstruction, to calculate ratios involving measurements of the distances between dental and facial landmarks and to compare these ratios with the golden ratio φ (1.618). MATERIALS AND METHODS: Fifty subjects with no obvious malocclusion participated in this study. For each subject, 4 photographs were acquired using the LifeViz Mini™, an absolute calibration 3D-spg system. Facial and dental landmarks (based on Farkas' definitions) were fixed, and 8 distances were measured. Four ratios were then calculated and compared with the value of 1.618. RESULTS: The ratio "incisal edge of the maxillary central incisor-lower border of the chin/subnasal point-incisal edge of the maxillary central incisor" (IE-Me/SN-IE) was 1.693 ± 0.190, the ratio "right endocanthion-left endocanthion/right exocanthion-right endocanthion" was 1.582 ± 0.173, the ratio "incisal edge of the maxillary central incisor-distal edge of the right canine/distal edge of the right canine-right labial commissure" was 1.670 ± 0.355, and the ratio "right labial commissure-left labial commissure/distal edge of the right canine-distal edge of the left canine" was 1.602 ± 0.136. In contrast, the vertical ratio IE-Me/SN-IE significantly differed from the golden ratio (1 sample t test, P = .009). CONCLUSION: This study revealed that the observed ratios were surprisingly close to the golden ratio. Only the vertical ratio differed from the golden ratio, whereas the horizontal ratios appear to be adequately approximated by φ. CLINICAL SIGNIFICANCE: If the distances from reference points of the face to teeth within a harmonious smile exhibited recurring esthetic proportions, knowledge of such ratios would provide an additional tool for the elaboration of esthetic treatment plans. In addition, this knowledge could provide guidance when planning tooth positions and dental proportions by encouraging consideration of the global nature of the oro-facial sphere.

Aqueous solvation of amphiphilic molecules by extended depolarized light scattering: the case of trimethylamine-N-oxide.

Hydrophilic and hydrophobic interactions strongly affect the solvation dynamics of biomolecules. To understand their role, small model systems are generally employed to simplify the investigations. In this study the amphiphile trimethylamine N-oxide (TMAO) is chosen as an exemplar, and studied by means of extended frequency range depolarized light scattering (EDLS) experiments as a function of solute concentration. This technique proves to be a suitable tool for investigating different aspects of aqueous solvation, being able at the same time to provide information about relaxation processes and vibrational modes of solvent and solute. In the case study of TMAO, we find that the relaxation dynamics of hydration water is moderately retarded compared to the bulk, and the perturbation induced by the solute on surrounding water is confined to the first hydration shell. The results highlight the hydrophobic character of TMAO in its interaction with water. The number of molecules taking part in the solvation process decreases as the solute concentration increases, following a trend consistent with the hydration water-sharing model, and suggesting that aggregation between solute molecules is negligible. Finally, the analysis of the resonant modes in the THz region and the comparison with the corresponding results obtained for the isosteric molecule tert-butyl alcohol (TBA) allow us to provide new insights into the different solvating properties of these two biologically relevant molecules.

Hydrophobic Hydration in Water-tert-Butyl Alcohol Solutions by Extended Depolarized Light Scattering.

Molecular dynamics and structural properties of water-tert-butyl alcohol (TBA) mixtures are studied as a function of concentration by extended depolarized light scattering (EDLS) experiments. The wide frequency range, going from fraction to several thousand GHz, explored by EDLS allows distinguishing TBA rotational dynamics from structural relaxation of water and intermolecular vibrational and librational modes of the solution. Contributions to the water relaxation originating from two distinct populations, i.e. hydration and bulk water, are clearly identified. The dynamic retardation factor of hydration water with respect to the bulk, ξ ≈ 4, almost concentration independent, is one of the smallest found by EDLS among a variety of systems of different nature and complexity. This result, together with the small number of water molecules perturbed by the presence of TBA, supports the idea that hydrophobic simple molecules are less effective than hydrophilic and more complex molecules in perturbing the H-bond network of liquid water. At increasing TBA concentrations the average number of perturbed water molecules shows a pronounced decrease and the characteristic frequency of librational motions reduces significantly, both of which are results consistent with the occurrence of self-aggregation of TBA molecules.

Hydration and aggregation in mono- and disaccharide aqueous solutions by gigahertz-to-terahertz light scattering and molecular dynamics simulations.

The relaxation properties of hydration water around fructose, glucose, sucrose, and trehalose molecules have been studied by means of extended frequency range depolarized light scattering and molecular dynamics simulations. Evidence is given of hydration dynamics retarded by a factor ξ = 5-6 for all the analyzed solutes. A dynamical hydration shell is defined based on the solute-induced slowing down of water mobility at picosecond time scales. The number of dynamically perturbed water molecules N(h) and its concentration dependence have been determined in glucose and trehalose aqueous solutions up to high solute weight fractions (ca. 45%). For highly dilute solutions, about 3.3 water molecules per sugar hydroxyl group are found to be part of the hydration shell of mono- and disaccharide. For increasing concentrations, a noticeable solute-dependent reduction of hydration number occurs, which has been attributed, in addition to simple statistical shells overlapping, to aggregation of solute molecules. A scaling law based on the number of hydroxyl groups collapses the N(h) concentration dependence of glucose and trehalose into a single master plot, suggesting hydration and aggregation properties independent of the size of the sugar. As a whole, the present results point to the concentration of hydroxyl groups as the parameter guiding both sugar-water and sugar-sugar interactions, without appreciable difference between mono- and disaccharides.

Hydration properties of small hydrophobic molecules by Brillouin light scattering.

We study the relaxation of water molecules next to hydrophobic solutes with different functional groups by Brillouin light scattering. Evidence is given for (i) water activation energy in trimethylamine-N-oxide, proline and t-butyl alcohol diluted solutions which is comparable to that of neat water, almost independent from solute mole fraction and (ii) moderate slowdown of relaxation time of proximal water compared to the bulk, which is consistent with excluded volume models. Assuming that the main contribution to viscosity comes from bulk and hydration water, a rationale is given of the phenomenological Arrhenius' laws for the viscosity of diluted aqueous solutions.

Hydrophobic hydration of tert-butyl alcohol studied by Brillouin light and inelastic ultraviolet scattering.

The longitudinal viscosity of diluted water-tert-butyl alcohol solutions in the 10 GHz frequency region has been measured by means of Brillouin light scattering and inelastic ultraviolet scattering. The main advantage of our hypersonic investigation compared to more traditional ultrasonic measurements is that in the gigahertz frequency range slow relaxation processes involving the alcohol dynamics are completely unrelaxed, so that the measured viscosity mainly originates from the hydrogen bond restructuring of water. In contrast with previous determinations, we estimate an activation energy which is independent from the alcohol mole fraction up to X = 0.1, and comparable to that of bulk water. A simple two-component model is used to describe the steep increase of viscosity with increasing alcohol mole fraction, and a retardation factor 1.7 ± 0.2 is found between the relaxation times of hydration and bulk water. These findings endorse a dynamic scenario where the slowing down of hydration water is mainly due to a reduction of configurational entropy and does not involve an arrested, icelike, dynamics.

Angiogenesis in oral squamous cell carcinoma.

Many retrospective studies have recently shown that microvessel density could represent a valid independent prognostic factor for overall survival and disease-free survival for primary tumours. The fact that oral tumours with a higher microvessel density showed a tendency to present distant metastasis and a bad prognosis, suggested that angiogenetic activity would play a pivotal role also in oral carcinomas, exerting a negative effect on the clinical course and representing an independent negative prognostic factor also for this type of tumour. Based on these results, microvessel density was evaluated, in the present study, in 64 cases of squamous cell carcinoma of the oral cavity, using immunohistochemical analysis with anti-CD34 monoclonal antibody. Possible correlations between microvessel density and clinico-pathological parameters were analysed, such as: age, sex, tumour localization and size, TNM stage and histological grading. Statistical analysis has shown that microvessel density differs in the 3 histological groups (G1, G2, G3) (p = 0.0331), and between node-positive and node-negative patients (p < 0.0001). No statistical correlation was observed between microvessel density and other clinical parameters such as age, sex, tumour site and size.

Association between fracture of the diaphysis of the femur and lesion of the ligaments of the knee.

The authors evaluated 97 knees out of a series of 135 fractures of the femur in 130 patients, revealing 34 cases of capsuloligamentous laxity, equal to 35% of the cases. No specific correlation between type of trauma, type and site of fracture, and lesion of the ligaments was observed. The frequency of unrecognized lesions, particularly in the posterior capsule, was made evident. The frequency of ligamentous lesions rises to 44.4% when fracture of the femur is associated with fracture of the homolateral tibia as compared to 26.7% in cases of isolated fracture of the femur. Recurvatum, which was present in a fair number of the cases, was related more to post-fracture therapy and rehabilitation rather than to specific capsuloligamentous lesion of the knee.

An aberrant type of congenital dyserythropoietic anemia associated with a beta-thalassemia trait.

A child is described who suffered from a severe congenital anemia. The anemia persisted and a regular transfusional regimen became necessary. Bone marrow aspirates showed an erythroblastic hyperplasia associated with some dyserythropoietic features. A most striking and constant finding was the presence of many inter-erythroblastic chromatin bridges. The reticulocyte count was always low, in spite of the increased erythropoietic activity. A beta-thalassemia trait inherited from the mother was demonstrated. The hypothesis of dyserythropoiesis/thalassemia syndrome was put forward, based on the assumption that the two genes may have interacted with each other.

[Double-contrast arthrography of the knee: a digital technique study]. / Artrografia a doppio contrasto del ginocchio: studio con tecnica digitale.

From October 1989, in our Radiology Department, digital radiographic techniques have been applied to double-contrast arthrography of the knee. In this preliminary work we examine the diagnostic contribution of computed radiography to arthrographic findings by comparing image quality of conventional and digital radiographs using a dedicated Philips unit. The digital unit is compatible with all the extant radiographic equipment in our department and automatically supplies two images, the first one resembling a conventional radiograph, the second one characterized by a broader exposure range that allows a clear visualization of soft tissues. To obtain high-quality radiographs the processing curves of the system were modified, in particular by shifting the curve leftward, thus reducing its slope, and by amending the parameters related to spatial frequencies. The changes in the reading curves made these images more useful: they were more homogeneous and allowed a better evaluation of fine details. Relative to the second type of images, characterized by both edge enhancement and a broader recording range, it was enough to shift the curve along the X-axis to compensate for a moderate image overexposure. Keeping in mind that the aim of this preliminary work was not compare the two techniques from a diagnostic point of view, in the authors' opinion the two yield similar information for the diagnostic evaluation of meniscal traumas. On the contrary, if the same principles are applied to the evaluation of capsulo-ligamentous components, digital arthrography appears to be more accurate than the conventional technique, the latter being deceptive especially in the evaluation of cruciate ligaments.

Computed radiography in neonatal intensive care.

The Authors report their experience in the employment of a computerized digital radiographic system in Neonatal Intensive Care. The analog screen-film system is replaced by photosensitive imaging plates, scanned after X-ray exposure by a laser that releases the digital image, which can then be manipulated on computer work-stations. In a period of twelve months about 200 chest-abdomen X-ray examinations in Neonatal Intensive Care have been performed using this method with good technical and diagnostic results. The use of digital radiography in the neonatal area is of high interest: this system produces good quality images, there is a reduction in radiation dose and 'retakes', the system allows selective enhancement of different structures and their magnification.

Diagnostic potential of double contrast arthrography of the knee with the digital technique.

Experience with digital radiography applied to double contrast arthrography of the knee performed with a photostimulable phosphor plate is reported. The image processing technique used to improve the digital image is described, and some theoretical considerations are discussed. A preliminary comparison is also made between arthrographic images obtained with conventional screen-film systems and the digital system, especially in respect of the image quality and visualization of the soft tissue structures least well demonstrated with conventional arthrography.

[Echo-guided biopsy in peripheral pulmonary lesions. Our experience]. / Biopsia ecoguidata delle lesioni polmonari periferiche. Nostra esperienza.

Twenty-nine patients with peripheral intrathoracic lesions underwent real-time US and US-guided biopsy. The lesions were mainly atypical fluid collections in 3 patients and mainly solid in the extant 26. Biopsies performed with fine aspirating or cutting needles (20-22 gauge) were successful in all patients; an unquestionable diagnosis was made in 27 cases with cytology and/or histology. Only one patient experienced mild asymptomatic pneumothorax after biopsy, which did not require chest-tube drainage. The authors stress the important diagnostic role of US-guided fine-needle biopsy as an useful and safe method for the evaluation of peripheral intrathoracic lesions.

[Digital radiography in neonatal intensive care]. / La radiografia digitale nella terapia intensiva neonatale.

The authors report their experience with the routinary use of a computerized digital radiography system in Intensive Neonatal Care department. The conventional screen-film system is replaced by photostimulable imaging plates, which are scanned during processing by a laser providing the digital image. The latter is subsequently processable on high-resolution monitors. Over a 6-month period 86 examinations were performed with this method in Intensive Neonatal Care; good technical results were obtained. The use of digital radiography in intensive neonatal care is extremely promising for it allows high-quality images to be obtained, and radiation dose and number of acquisitions to be reduced. Finally, work stations allow both selective visualization of different body structures and their magnification.

Arthrography of the plica syndrome and its significance.

The plica is a synovial fold inside the knee joint that may become symptomatic if for any reason the fold is converted into a bowstring. In 42 patients with chronic knee problems, arthrograms of the knee were obtained with evidence of the plica syndrome. Twenty-four were asymptomatic, 18 symptomatic, and of these 16 were excised. After a mean follow-up period of 3 years, 10 of the symptomatic patients were free of symptoms, while eight were unchanged or worse. The plica syndrome is not common, and careful assessment must be made by exclusion with clinical examination, double-contrast arthrography, and arthroscopy.

Diagnosis and treatment of popliteal cysts.

The authors reviewed 122 patients affected with popliteal cysts and treated between 1975 and 1985 with or without surgery; follow-up ranged from 1 to 7 years (average 3 years and 2 months). The patients were subdivided into 3 age groups, and observed for the clinical, anatomo-pathological and therapeutic differences among them. Cysts affecting children and adults were considered to be acute, or chronic bursitis, and those affecting elderly patients true cysts deriving from the joint cavity. The diagnostic effectiveness of arthrography and sonography is emphasized.

[Double-contrast arthrography of the knee in traumatic capsular-ligamentous lesions. A critical review]. / L'artrografia a doppio mezzo di contrasto del ginocchio nelle lesioni traumatiche capsulo-legamentose. Revisione critica.

The authors conducted a statistical study and a critical review on a series of 1,300 patients examined with double-contrast fluoroscopically guided knee arthrography using a simple examination technique. Arthrographic diagnoses were subsequently compared with arthrotomic (500 patients), arthroscopic (350 patients), and clinical (450 patients) diagnoses. The critical review pointed out the high diagnostic accuracy (90%) and the good sensitivity (87%) of arthrographic examination in patients affected with pathologic conditions of the cruciate ligaments. In collateral ligament diseases and in capsular ruptures arthrographic sensitivity was not as high but still acceptable (74%). Capsular tears and medial collateral ligament tears can be identified when contrast medium is seen leaking from the knee joint. Cruciate ligament tears may be partial or complete: if a tear is partial the synovial surface of the cruciate ligament cannot be identified the cruciate ligament is wavy, lumpy, or focally thin, while in complete tears the synovial surface of the cruciate ligament cannot be identified either entirely or partially.

Fractures of the posterior apophyseal ring of the lumbar vertebral body in young patients. Three cases.

Three cases of posterior apophyseal fracture of a lumbosacral vertebral body are described. This disco-apophyseal lesion is typical of adolescents and sports-related trauma. Like all acute and chronic apophysiolyses it is probably enhanced by a constitutional weakness of the apophyseal area, closely fused with the anulus fibrosus of the disc.