42 research outputs found
Spektrofotometrijska procjena promjene boje zuba dugotrajno izloženih različitim uvjetima = Spectrophotometric evaluation of color alterations of teeth exposed to different conditions in time
Altérations athéroscléreuses de l’artère dentaire inférieure en corrélation avec celles de la bifurcation carotidienne et de l’aorte abdominale
50 corpses from adults aged 20 to 75 have been used in order to study the atherosclerotic lesions occurring in typical regions (bifurcation of the common carotid artery and the abdominal aorta) and their relationship to atherosclerotic changes in the inferior alveolar artery. Histological analysis revealed that atherosclerotic alterations of the inferior alveolar artery may appear sometimes earlier than it would be expected on the ground of age. Intima cell proliferation and thickening of elastic elements in the middle layer of the arterial wall, the first signs of atherosclerosis, were found already at the beginning of the third decade of life when the signs of this process in the typical regions were not yet evident. Atherosclerosis affects essentially the functional capacity of the inferior alveolar artery. The development of atherosclerosis in the wall of this artery favours an hypovascularization of the mandible, which must be of certain importance in every operative procedure in oral surgery, especially in those inducing a severe and long traumatism in bone and soft tissues, such as dental implantations.Cette étude, faite sur 50 cadavres (de 20 à 75 ans) concerne les altérations athéroscléreuses de l’artère dentaire inférieure et leurs rapports avec les altérations athéroscléreuses dans les territoires typiques (bifurcation carotidienne et aorte abdominale). L’examen histologique a fait apparaître que les altérations athéroscléreuses de l’artère dentaire inférieure peuvent être relativement plus évidentes et précoces que l’on ne s’y attendrait compte tenu de l’âge. Une prolifération cellulaire de l’intima et un épaississement de la lame élastique moyenne dans la paroi artérielle, premiers signes de l’athérosclérose, peuvent apparaître dès30 ans, alors que l’on ne trouve pas encore d’altérations de ce type dans les territoires typiques. L’athérosclérose a une influence cruciale sur la capacité fonctionnelle de l’artère dentaire inférieure puisque celle-ci chemine dans le canal osseux, qui empêche sa dilatation. Le développement de l’athérosclérose dans la paroi de cette artère favorise une hypovascularisation de la mandibule, ce qui a une importance certaine lors de toute intervention en chirurgie orale, surtout lorsqu’elle entraîne un traumatisme grave et prolongée de l’os et des parties molles, comme c’est le cas lors de l’insertion d’implants dentaires
Anatomie chirurgicale de la glande sublinguale
Because of its position, the sublingual gland is clinically important especially in the events of injuries and infections in the anterior part of the sublingual region.The morphology and relationships of this gland were studied by dissection methods applied on 80 fresh or formaldehyde fixed preparations of the mouth floor and of the tongue, which were partly (31 preparations) taken out together with the mandible.As for the shape of the gland, three main types were found: 1° the cuneiform type which was the most frequent (71 %), 2° the pyramidal type which was less frequent (16%) and the fusiform type (13%) which comprised the cases of a very elongated gland (up to 65 mm).The space in which the gland lied had four walls. Its internal wall consisted of the mylohyoid muscle and it comprised the hyoglossus muscle as well when the gland was very elongated. The inferior wall consisted of the mylohyoid muscle and sometimes it comprised also a narrow part of the superior surface of the geniohyoglossus muscle. An osseous depression on the internal side of the mandible represented the external wall of the sublingual gland space. The superior wall is clinically the most significant. It consists of the sublingual mucosa and a sublingual fold. This wall represents a main surgical access to the gland. In edentulous mandibles this mucous fold may be at the level of the upper mandibular border which may hinder the use of the lower dental prosthesis.La morphologie et les rapports de la glande sublinguale ont été étudiés par 80 dissections du plancher de la bouche et de la langue.Trois types différents de glandes ont été définis du point de vue forme: le type cunéiforme (71%), le type pyramidal (16%) et le type fusiforme (13%).La loge de la glande sublinguale possède quatre parois: deux (parois inférieure et interne) de nature musculaire, une (paroi externe) de nature osseuse et une (paroi supérieure) de nature muqueuse
Primary cerebral alveolar rhabdomyosarcoma in adult
Primary cerebral rhabdomyosarcomas are very rare and malignant tumors that occur predominantly in the posterior fossa of pediatric patients. We report a rare case of primary cerebral rhabdomyosarcoma located in the supratentorial compartment of a 51 year-old woman together with a review of the pertinent Literature especially regarding the histological diagnosis and pitfalls
Influence of resin cement shade on the color and translucency of ceramic veneers
ABSTRACT Objective This in vitro study evaluated the effect of two different shades of resin cement (RC- A1 and A3) layer on color change, translucency parameter (TP), and chroma of low (LT) and high (HT) translucent reinforced lithium disilicate ceramic laminates. Material and Methods One dual-cured RC (Variolink II, A1- and A3-shade, Ivoclar Vivadent) was applied to 1-mm thick ceramic discs to create thin RC films (100 µm thick) under the ceramics. The RC was exposed to light from a LED curing unit. Color change (ΔE) of ceramic discs was measured according to CIEL*a*b* system with a standard illuminant D65 in reflectance mode in a spectrophotometer, operating in the light range of 360-740 nm, equipped with an integrating sphere. The color difference between black (B) and white (W) background readings was used for TP analysis, while chroma was calculated by the formula C*ab=(a*2+b*2)½. ΔE of 3.3 was set as the threshold of clinically unacceptable. The results were evaluated by two-way ANOVA followed by Tukey's post hoc test. Results HT ceramics showed higher ΔE and higher TP than LT ceramics. A3-shade RC promoted higher ΔE than A1-shade cement, regardless of the ceramic translucency. No significant difference in TP was noted between ceramic discs with A1- and those with A3-shade cement. Ceramic with underlying RC showed lower TP than discs without RC. HT ceramics showed lower chroma than LT ceramics, regardless of the resin cement shade. The presence of A3-shade RC resulted in higher chroma than the presence of A1-shade RC. Conclusions Darker underlying RC layer promoted more pronounced changes in ceramic translucency, chroma, and shade of high translucent ceramic veneers. These differences may not be clinically differentiable
CIE L*a*b*: comparison of digital images obtained photographically by manual and automatic modes
Activation of the unfolded protein response and granulovacuolar degeneration are not common features of human prion pathology
Spektrofotometrijska procjena promjene boje zuba dugotrajno izloženih različitim uvjetima = Spectrophotometric evaluation of color alterations of teeth exposed to different conditions in time
Spektrofotometrijska procjena promjene boje zuba dugotrajno izloženih različitim uvjetima = Spectrophotometric evaluation of color alterations of teeth exposed to different conditions in time
Human teeth consist of organic and anorganic tissue components similair to bones. Therefore, it is assumable that the registration of structural changes of teeth color in different enviromental conditions may prove useful within forensic taphonomy field, for example, for verification of burial environment and postmortem interval (PMI). Registration of very smal alterations of teeth color is nowadays possible due to well developed dental spectrophotometers. It is known that teeth exposed to air quickly dehydrate, but the degree and the pattern of these color changes in time intervals have not been objectively measured. Purpose: The objective was to determine the degree and patern of color alterations of teeth exposed to three different conditions in time. Material and Methods: The impacted third molars were used in this study because they were not previously exposed to any enviromental conditions. Their CIE L*a*b* values after exposure to dry conditions, NaCl and artificial saliva (control) were measured with dental spectrophotometer in time intervals of 1 hour, 24 hours, 1 week, 3 weeks, 5 weeks and 7 weeks by one trained operator. Results: The L*-lightness and the b*-blue-yellow color coordinate increased in dry conditions (p < .001 and p ≤ .050 respectively),which was statistically significant, whereas a*-green-red color coordinate showed shifts of color in this condition which were not statistically significant. The exposure of extracted third molars to dry conditions caused significant increase of L* and b* color coordinate towards more light and more yellow in comparison to the exposure of teeth to artificial saliva and NaCl. The a* color coordinate displayed high variability of its alteration in all tested conditions. Conclusions: The exposure of extracted impacted wisdom teeth to dry conditions caused a considerable consecutive increase of lightness (L*) and blueness-yellowness (b*) in comparison with the exposure of teeth to NaCl and artificial saliva
