Facial soft tissue changes during the pre-pubertal and pubertal growth phase: a mixed longitudinal laser-scanning study

BACKGROUND/OBJECTIVES: Facial soft tissues changes during growth roughly tend to mimic the underlying hard tissues, but not completely. The aim of this mixed longitudinal study was to assess facial growth among pre-pubertal and pubertal subjects without malocclusion using a non-invasive three-dimensional laser scanning system. SUBJECTS/METHODS: Fifty-nine subjects (30 females and 29 males) aged at baseline 5.4-8.9 years with normal occlusion were clustered into the younger, older pre-pubertal, and pubertal groups according to age and the absence/presence of a standing height growth spurt. Three-dimensional facial images were obtained using laser scanners for five consecutive years. Several transversal, sagittal, and vertical parameters were assessed for between and within group comparisons. RESULTS: Significant overall changes of almost all parameters were seen within each group (P 0.05). The younger pre-pubertal group showed greater annual growth rates of lip prominence; both pre-pubertal groups showed greater rates in facial middle third height. The pubertal group showed greater annual rates in facial profile angle changes during the growth peak. LIMITATIONS: A high standing height increment (7cm) was used as the threshold for subject allocation in the pubertal group. CONCLUSIONS: Soft tissue facial growth has generally similar amounts and rates irrespective of the pubertal growth spurt. Pre-pubertal subjects show greater annual rates of facial middle third height changes while pubertal subjects show greater annual rates of chin protrusion

Innovative Conceptual Model of Socio-Cultural Components of Quality of Life in Elderly Persons

Glavni cilj istraživanja je istražiti utjecaj sociokulturnih čimbenika na kvalitetu života starijih osoba u Republici Hrvatskoj. Teorijski cilj istraživanja odnosi se na oblikovanje teorijskog konstrukta utjecaja sociokulturnih čimbenika na kvalitetu života starijih osoba te metodom modeliranja oblikovati model sociokulturnih čimbenika kvalitete života starijih osoba u Republici Hrvatskoj. Pozadina: Problem istraživanja je identifikacija sociokulturnih sastavnica kvalitete života starijih osoba u Republici Hrvatskoj. Osnovna svrha istraživanja je identificirati sastavnice modela sociokulturnih dimenzija koje utječu na kvalitetu života osoba starije životne dobi u Republici Hrvatskoj. Dizajn: U istraživanju je primijenjena kvantitativna istraživačka paradigma. Za postizanje teorijskih ciljeva istraživanja korištene su opće znanstvene metode. Podatci su prikupljeni upitnicima. Metode: Teorijski ciljevi istraživanja ispunjeni su pregledom novije znanstvene literature. U svrhu ovog istraživanja kao mjerni instrumenti primijenjeni su WHOQOL-BREF upitnik i Hofstedeov upitnik. Rezultati: Na temelju obrađenih podataka istraživanja napravljeni su konceptualni multivarijatni regresijski modeli zadovoljavajuće domene kvalitete života osoba starije životne dobi. Načinjeni multivarijatni regresijski modeli predikcije pojedinih domena kvalitete života u kojima prediktorske varijable u multivarijatnom okružju definiraju utjecaj na te domene. Način odabira prediktorskih varijabli uključivao je postavljene ciljeve (dobnu, spolnu, regionalnu, bračnu komponentu te sve domene Hofstedeovog upitnika). Zaključak: U konceptualnom modelu shematski je prikazano da sociokulturne sastavnice kvalitete života ovise o društvenoj nejednakosti, životnim usmjerenjima, kontroli neizvjesnosti, djelovanju pojedinca individualizmom ili kolektivizmom, te odnosom prema muškarcu i ženi. Sve to zajedno određuje nacionalnu kulturu i predstavlja sociokulturni kapital određenog društva. Postoje razlike prema spolu koje su određene kontrolom neizvjesnosti, tjelesnim i psihičkim zdravljem, socijalnim odnosimsa, osobnim stavovima i religioznosti, te okolinom u kojoj osoba živi. Važnost za kliničku praksu: Socijalna gerontologija je mlada znanstvena disciplina i istraživanja na njenom području nalaze svoju primjenu u modernom društvu implementacijom rezultata istraživanja u socijalno i političko okruženje inovativnim modelima u skrbi za starije osobe.The main objective of the study was to investigate the influence of socio-cultural factors on the quality of life in elderly persons in Croatia. The theoretical objective of the study was to form a theoretical construct of the influence of socio-cultural factors on the quality of life of the elderly and to create a model of the socio-cultural factors of the quality of life of the elderly in Croatia using the modelling method. Background: The study problem was to identify the sociocultural components of the quality of life in elderly persons in Croatia. The main purpose of the study was to identify the components of the model of socio-cultural dimensions that have an impact on the quality of life in elderly persons in Croatia. Design: The quantitative research paradigm was applied to the study. To achieve the theoretical objectives of the study, general scientific methods were used. Data were collected through questionnaires. Methods: The theoretical objectives of the study were reached by reviewing recent scientific literature. For the purpose of this study, the WHOQOL- BREF and the Hofstede questionnaires were used as measuring instruments. Findings: The conceptual multivariate regression models of a satisfactory domain of quality of life in elderly persons were created based on processed study data. The multivariate regression models for the prediction of certain domains of quality of life in which predictor variables in a multivariate environment define the impact on these domains were created. The method of selecting predictor variables included the set objectives (age, gender, regional, and marital components and all dimensions of the Hofstede questionnaire). Conclusion: The conceptual model presents a schematic overview of the socio-cultural components of the quality of life that depend on social inequality, life orientations, uncertainty control, acts by individuals through individualism or collectivism, and the attitude towards men and women. All this combined determines a national culture and represents the socio-cultural capital of a certain society. There are differences by gender that were determined by uncertainty control, physical and mental health, social relations, personal attitudes and religiosity, and the environment in which a person lives. Importance for clinical practice: Social gerontology is a young scientific discipline and research in this field finds its application in modern society by implementing research results on the social and political environment with innovative models of care for elderly persons

Uporaba računalnika pri urah geometrije v 2. razredu osnovne šole

magistrsko del

Repousser les limites de la dimension transversale. Asymétrie faciale, volume du palais et posture linguale chez les enfants ayant une occlusion croisée unilatérale postérieure : évaluation tridimensionnelle d’un traitement précoce

Les occlusions croisées postérieures sont présentées comme les traits de malocclusions les plus fréquentes en denture temporaire chez les enfants caucasiens. Non traitée, l’asymétrie faciale due à une latérodéviation mandibulaire en denture temporaire peut entraîner une croissance défavorable avec pour conséquence une asymétrie faciale squelettique. Une fonction et/ou une posture linguale inadéquates sont souvent citées comme des facteurs étiologiques importants. La mise en œuvre d’un traitement orthodontique précoce semble bénéfique et souhaitable pour créer les conditions d’un développement dentaire, fonctionnel et squelettique normal de la région orofaciale. Toutefois, le succès du traitement de l’occlusion croisée unilatérale en denture temporaire peut être mis en cause, dans la mesure où il est difficile d’évaluer objectivement la correction de l’asymétrie faciale et la fonction et/ou la posture linguale inadéquate chez des enfants en croissance. Bien que la photographie faciale soit un important outil diagnostique en orthodontie, son principal inconvénient est qu’elle représente un objet tridimensionnel en seulement deux dimensions. La fonction et la posture linguale sont difficiles à apprécier de façon fiable lors d’un examen clinique. Des outils 3D modernes sont disponibles pour le diagnostic de l’occlusion croisée unilatérale postérieure en permettant une évaluation non invasive, valide et objective de la morphologie faciale, du volume du palais, de la fonction et de la posture linguale. Ils peuvent dès lors représenter dans le futur une partie importante du diagnostic morphologique et fonctionnel en orthodontie et orthopédie dento-faciale avant, pendant et après le traitement

Ocena korozijskih lastnosti titanovih dentalnihzlitin, izdelanih s SLM postopkom

Titanium alloys are known for their excellent biocompatible properties. The development of additive-manufacturing technologies has increased the interest in the use of Ti-6Al-4V, produced by selective laser melting (SLM) method, also in dentistry, i.e., prosthodontics and orthodontics. In the present paper, the effect of laser printing parameters in the selective laser melting (SLM) process on the porosity and corrosion behavior of Ti-6Al-4V dental alloy was metallographically and electrochemically studied. All the tests were performed in artificial saliva at 37 °C. Different forms of Ti-6Al-4V alloy were selected: a reference sample, i.e., pre-fabricated milling disc in wrought condition and four different 3D-printed samples made from Ti-6Al-4V powder using the SLM method, one being heat treated. Electrochemical, spectroscopic and hardness measurements were employed in the study. It was shown that the SLM-produced Ti-6Al-4V samples with different printing parameters have similar microstructural and electrochemical properties, while the electrochemical properties of a reference and thermally treated 3D-printed sample were different, most probably due to the change in the microstructure of the alloys. The corrosion properties were related to the microstructural properties as well as to the pore density.Titanove zlitine so znane po odličnih biokompatibilnih lastnostih. Razvoj aditivnih tehnologij je povečal zanimanje za uporabo Ti-6Al-4V, proizvedenega z metodo selektivnega laserskega taljenja (SLM) v zobozdravstvu - tako v protetiki kot v ortodontiji. V prispevku smo metalografsko in elektrokemijsko proučili vpliv parametrov laserskega tiska pri procesu selektivnega laserskega taljenja (SLM) na poroznost in korozijsko obnašanje dentalne zlitine Ti-6Al-4V. Vsi testi so bili opravljeni v umetni slini pri telesni temperaturi 37 °C. Izbrane so bile različne oblike zlitine Ti-6Al-4V: referenčni vzorec (v obliki diska za rezkanje v kovanem stanju) in štirje različni 3D natisnjeni vzorci iz prahu Ti-6Al-4V po metodi selektivnega laserskega taljenja (SLM), pri čemer je eden toplotno obdelan. Pri raziskavi so bile uporabljene elektrokemijske, spektroskopske metode in meritve trdote. Pokazalo se je, da imajo vzorci Ti-6Al-4V, izdelani s postopkom SLM, z različnimi parametri, podobne mikrostrukturne in elektrokemijske lastnosti, medtem ko so bile elektrokemijske lastnosti referenčnega in termično obdelanega 3D natisnjenega vzorca različne, najverjetneje zaradi različne mikrostrukture te zlitine. Korozijske lastnosti so bile povezane z mikrostrukturnimi lastnostmi, pa tudi z gostoto por

Three-dimensional longitudinal evaluation of palatal vault changes in growing subjects

Objective: To evaluate palatal vault change in children and to assess the reliability of two palatal parameters in assessing growth modifications. Subjects and Methods: A group of 26 healthy white children aged 5.3 ± 0.3 years (15 boys, 11 girls) were randomly selected. Impressions of the upper dental arches were obtained at baseline and at 12, 18, and 30 months follow-up. Three-dimensional digital images of study casts were obtained using a laser scanning device. Palatal surface area and palatal volume were measured on the digital study casts at each time point. Effect size (ES) coefficients were calculated for both parameters as indices of diagnostic reliability in individual subjects when at least equal to 1.0. Results: Significant increases in palatal surface area and volume were seen over the observation period (P < .001). ES coefficients for palatal surface area were greater than those for palatal volume. However, even for the former parameter, only the value taken at 30 months was above the threshold. Conclusions: Growth of the palatal vault was significant during the observation period, which coincides with primary and mixed dentition stages. Palatal surface area appears to be more reliable than palatal volume in assessment of growth modifications in individual subjects

Tribocorrosive study of new and in vivo exposed nickel titanium and stainless steel orthodontic archwires

The surface, corrosion and wear properties of new and in vivo exposed nickel titanium (NiTi) and stainless steel (SS) archwires used in orthodontic treatment were investigated. Electrochemical and tribo-electrochemical tests in artificial saliva were performed in order to define corrosion properties and to estimate wear rate of new and in vivo exposed NiTi and SS archwires. The surface chemical analysis of the passive film on the NiTi and SS archwires before and after tribocorrosion tests was performed by Auger Electron Spectroscopy (AES). In vivo exposed NiTi and SS archwires had better electrochemical properties than new archwires due to the protective nature of oral deposits. Total wear and coefficients of friction were higher among in vivo exposed archwires and higher in NiTi archwires in comparison to SS archwires. The estimated thickness of the TiO2 passive film on as-received NiTi is 8 nm, while the passive Cr2O3 film on as-received SS is just 1–2 nm. On in vivo exposed NiTi archwire, a 60–80 nm thick organic film/dental plaque was observed, and on SS, it was thinner, at about 60 nm. This research shows the importance of combining AES with electrochemical testing, to characterize tribocorrosive properties of NiTi and SS orthodontic archwires

Three-dimensional evaluation of early crossbite correction: a longitudinal study

The aim of this longitudinal study was to assess whether correction of unilateral posterior crossbite in the primary dentition results in improvement of facial symmetry and increase of palatal surface area and palatal volume. A group of 60 Caucasian children in the primary dentition, aged 5.3 ± 0.7 years, were collected at baseline. The group consisted of 30 children with a unilateral posterior crossbite with midline deviation of at least 2 mm (CB) and 30 without malocclusion (NCB). The CB group was treated using an acrylic plate expander. The children’s faces and dental casts were scanned using a three-dimensional laser scanning device. Non-parametric tests were used for data analysis to assess differences over the 30 months period of follow-up. The CB children had statistically significantly greater facial asymmetry in the lower part of the face (P < 0.05) and a significantly smaller palatal volume (P < 0.05) than the NCB children at baseline. There were no statistically significant differences between the two groups at 6, 12, 18, and 30 months follow-ups. Treatment of unilateral posterior crossbite in the primary dentition period resulted in an improvement of facial symmetry in the lower part of the face (P < 0.05) and increase of the palatal surface area and palatal volume (P < 0.001). At 30 months, relapse was observed in eight children (26.7 per cent). Treatment of unilateral posterior crossbite in the primary dentition improves facial symmetry and increases the palatal surface area and the palatal volume, though it creates normal conditions for normal occlusal development and skeletal growth