1,720,973 research outputs found
Sexual dimorphism of the hard tissues in the craniofacial system
No full textU ovom radu riječ je o spolnom dimorfizmu tvrdih tkiva kraniofacijalnog sustava. Određivanje dobi na skeletnim ostacima od velike je važnosti u forenzici, antropologiji, te arheologiji. Prilikom određivanja spolnog dimorfizam potrebno je napraviti razliku između spola i roda. Određivanje spolnog dimorfizam isključivo se odnosi na spol koji je biološki određen, dok je rod sociološki određen. Kost lubanje, nakon zdjelice, smatra se najboljim čimbenikom za određivanje spola radi boljeg zadržavanja morfoloških obilježja. Različite populacije imaju različite karakteristike kostura, zbog čega je analiza specifične populacije za određivanje spola neophodna. Određivanje spola promatrajući lubanju može dovesti do 90% sigurnosti kojeg spola je osoba. Postoji nekoliko područja na lubanji koja su ključna kada se određuje spola. Ključna područja su nuhalna linija, mastoidni proces, supraorbitale, mandibula, glabela, te protuberantia mentalis. Nakon što se odredi spol osobe, proces određivanja dobi i tjelesne visine lakši je za odrediti. Također, područje koje doprinosi određivanje spola na lubanji je humana denticija. U humanoj denticiji spolni dimorfizam očituje se u dimenzijama i morfologiji zubi, obrascima razvoja i nicanja zubi, te ekspresiji proteina amelogenina u caklini zuba. Također, spolni dimorfizam može se očitati i u anomaliji broja zuba.This research paper analyzes the sexual dimorphism of the hard tissues in the craniofacial system. The accurate determination of the age of skeletal remains is crucial in fields such as forensic science, anthropology, and archaeology. When determining sexual dimorphism, it is necessary to make a distinction between sex and gender. Determination of sexual dimorphism exclusively refers to sex, which is biologically determined, while gender is sociologically determined. The skull, after the pelvis, is considered to be the best indicator of the sex of the remains due to the preservation of morphological characteristics. It is important to study a specific population to determine the sex of an individual, as different populations have varying skeletal characteristics. The determination of sex through examination of the skull can result in a 90% certainty of the results. Several key areas of the skull play a crucial role in determining the gender, including the nuchal line, mastoid process, supraorbitals, mandible, glabella, and mental protuberance. Once the sex of an individual is established, it becomes easier to determine their age and height. Also, the area of the skull that contributes to gender determination is the human dentition. In human dentition, sexual dimorphism is manifested in the dimensions and morphology of teeth, patterns of tooth development and eruption, and expression of the protein amelogenin in tooth enamel. Also, sexual dimorphism can be read in the anomaly of the number of teeth
Craniometry - variation in and between populations
Get PDFKraniometrija je dio antropometrije koji se bavi izučavanjem mjera glave i lica u ljudskoj populaciji. Čovjekova je glava sastavljena od kostiju, živaca, žila i mišića te su na njoj smještene oči, uši, nos, usta i zubi, a u njoj najbitniji organ ljudskog tijela, mozak. Dok su kod nekih kultura pronađeni deformiteti kraniofacijalnog kompleksa napravljeni mehaničkim zahvatima na fenotipske odrednice, kod drugih se pak javljaju genetski uvjetovane anomalije. Zbog različite ekspresije navedenih facijalnih obilježja potrebno je mjerenje uz pomoć raznih antropometrijskih i modernih sprava koje ponekad omogućuju trodimenzionalne preglede digitalnih prikaza. Kako bi potvrdili varijacije unutar i među populacijama usporedili smo razlike u ekspresiji i kompleksnosti različitih lubanja i lica. Ženske su lubanje u svim slučajevima manje, dok su muške robusnije. Fenotipska se obiljeţja razlikuju među djecom različite dobi, srednje starih i starih osoba različitog spola, različitih etnoloških i kulturoloških, nekadašnjih i sadašnjih populacija.Craniometry is a part of anthropometry concerned with studying the measurements of cranium and face in human populations. Human head is made up of bones, nerves, veins, and muscles, and on it are located eyes, ears, nose, mouth, and teeth in addition to the most important organ in the human body, brain. While in some cultures deformities on craniofacial complex were made by mechanical procedures, other cultures show genetically conditioned anatomic anomalies. Different expressions of facial characteristics require using a variety of anthropometric and modern tools which sometimes provide three-dimensional examination of digital display. To confirm the variations in and between populations we compared the differences in expression and complexity of different cranias and faces. Female craniums were in all cases smaller, while the male were more robust. Phenotypic characteristics differ between children of different ages, between sexes, different ethnological, and cultural, and between former and current populations
Primjena dentalne procjene dobi u migracijskim procesima
Get PDFU ovom radu riječ je o ulozi dentalne procjene dobi u migracijskim procesima. U okviru tih procesa, metode dentalne procjene dobi najviše se upotrebljavaju za utvrđivanje punoljetnosti. To je važno jer svaka zemlja drugačije tretira maloljetnike i punoljetnike, a migranti u većini slučajeva nemaju pravovaljanu dokumentaciju. Prema najnovijim istraživanja došlo je do izmjena u korištenju dentalnih metoda. Pa tako najkorištenije metode jesu Demirjianova, Al Qahtanieva i Thevissenova metoda. Metode za dentalnu procjenu dobi prednjače pred ostalim medicinskim metodama utvrđivanja dobi zbog najmanje standardne devijacije. Iako im je stopa točnosti poprilično visoka njihova uporaba otvara neka etička pitanja koja nikako ne smiju biti zanemarena.The topic of this master's thesis is the role of age estimation in migration processes using the technique of dental assessment. In the scope of these processes, the methods of dental age assessment are mostly used to determine if a person is a minor or an adult. This is important because every country has different policies regarding minors and the most usual case with the immigrants is they don't have or carry valid personal documents. According to the newest research, there have been some changes in the application of dental methods. The most used methods today are the Demirjian, Al Qahtani and Thevissen method. Because of the lowest standard deviation, the methods of dental assessment are superior to other medical methods of age estimation. Although the precision rate of dental assessment method is high, it's application raises some ethical questions which cannot be ignored
Secular changes in the masticatory system: : caries and malocclusions
No full textOvaj rad sadrži pregled nekih istraživanja karijesa i malokluziija kroz povijest te ih uspoređuje s novijim podacima koje su prikupile svjetske organizacije. Pokazalo se da ove oralne bolesti bilježe porast posljednjih nekoliko desetljeća, što se dovodi u vezu s promjenom ljudske prehrane koja sadrži veći unos ugljikohidrata i šećera, kao i s mnogim društvenim navikama. Rad se osvrnuo i na temporomandibularne poremećaje, koji mogu biti u vezi s malokluzijama. Iako se učestalost ovih bolesti smanjuje, na globalnoj razini ona je i dalje velika i stvara velik problem za zdravstveni sustav. Da bi se učestalost smanjila, potrebno je osigurati obrazovanje o pravilnoj oralnoj higijeni, bolju zdravstvenu skrb, mijenjati društvene navike i podignuti osviještenost o ovim bolestima koje loše utječu na kvalitetu čovjekova života.This thesis contains an overview of some research papers od dental caries and malocclusion throughout history and compares them with more recent data collected by international organizations. It has been shown that these oral diseases have been on the rise in the last few decades, which is linked to a change in the human diet that contains more carbohydrates and sugar, as well as to many social habits. The paper also focused on temporomandibular disorders, which may be related to malocclusions. Although the frequency of these diseases is decreasing, at the global level it is still high and creates a big problem for the health system. In order to reduce the frequency, it is necessary to provide education on proper oral hygiene, better health care, change social habits and raise awareness about these diseases that have a bad effect on the quality of a person's life
Impact of dental cone beam computed tomography optimisation procedures on patient exposure
No full textU ovom doktorskom radu ispitana je primjerenost do sada predloženih dozimetrijskih veličina za procjenu efektivne doze pacijenta pri provedbi postupaka računalnom tomografijom stožastim rendgenskim snopom (CBCT, od engl. cone-beam computed tomography) u dentalnoj medicini i ispitan je utjecaj pojedinih parametara kojima je definiran postupak na ozračenje pacijenta. Ispitivanje je provedeno modeliranjem CBCT uređaja Monte Carlo simulacijom i korištenjem računalnog antropomorfnog fantoma te eksperimentalnim mjerenjima. Simulirane doze organa kreću se od 35 μGy (mozak) do 4136 μGy (površina kosti), a efektivne doze od 21 μSv do 218 μSv, ovisno o kliničkom protokolu. Prosječno efektivnoj dozi najviše doprinose štitna žlijezda (31%), žlijezde slinovnice (25%) i ekstratorakalna regija (21%). Temeljem rezultata istraživanja predlaže se prilikom optimizacije CBCT postupka u dentalnoj medicini koristiti što je moguće manji FOV i umnožak struje i vremena ozračivanja te kut rotacije rendgenske cijevi od 180o, a prilikom odabira položaja FOV-a voditi računa o stohastičkim efektima vezanim uz štitnu žlijezdu, imajući na umu potrebnu kvalitetu snimke. Kao najprimjereniju dozimetrijsku veličinu za CBCT postupke predlaže se DAP (od eng. dosearea product) s obzirom na to da predstavlja dozu i veličinu FOV-a. Iako ovo istraživanje pokazuje ograničenja DAP-a kada se FOV nalazi u blizini štitne žlijezde zbog kojeg ga je potrebno modificirati tako da uzima u obzir i udaljenost od štitne žlijezde, zbog jednostavnosti mjerenja se predlaže koristiti DAP, ali definiran za dva položaja (maksilarni i mandibularni). U radu su dani i konverzijski faktori za procjenu efektivne doze i doze organa iz DAP-a.Cone beam computed tomography (CBCT) used in dental medicine results in complex dose distributions owing to different performance of devices and examination procedures. Consensus within scientific and professional community regarding dosimetric quantity has not been reached yet and conversion factors by which effective dose of the patient could be estimated are not given. The aim of this study is to examine the appropriateness of the suggested dose indices (CT dose index, CBCT dose indices and dose-area product (DAP)) and to show their advantages and disadvantages as well as to examine the influence of scanning parameters defining the CBCT procedure to dose indices, organ doses and effective dose of the patient. Investigation was performed by the use of Monte Carlo simulation and experimental measurements. CBCT dental unit was simulated using Monte Carlo N-Particle transport code (MCNP® 6.1.1beta). For the model verification purposes, PMMA head CTDI phantom and radiochromic films were used. For calculation of organ doses and for the assessment of effective doses computational anthropomorphic phantom was used („Zubal“). Most often clinical protocols involving different exposure geometries including sizes and positions of fields of view (FOV), 180o and 360o X-ray tube rotation angles, different tube current-exposure time products (mAs) and photon energies were simulated. Measured (CTDI and DAP) and simulated dose indices (CBCT dose indices) were compared to effective doses for every exposure geometry and analysed.Organ doses in all simulated CBCT protocols ranged from 35 μGy (brain) to 4119 μGy (bone surface) and effective doses from 22 μSv to 218 μSv, depending on scanning parameters. In average, thyroid gland has the highest contribution to the effective dose (31%) followed by salivary glands (25 %) and extra thoracic region (21%). Results of this study indicate importance of careful choice of FOV's size and its position in optimisation of CBCT procedures considering clinical question and anthropometric features of the patient since size and position of FOV have great impact on organ doses and effective dose, especially on thyroid gland and salivary glands. Choosing 180o for the X-ray tube rotation angle instead of 360o would not decrease image quality but may significantly decrease doses of the organs contributing the most to the effective dose. Due to linear dependence of organ doses and effective dose on mAs, whenever possible lowest mAs should be used, considering level of the image quality required. According to the results of this study, change of tube voltage by ±10 kV does not result in significant change neither of organ doses nor effective dose so further investigation employing greater range of tube potentials while considering image quality is needed. Although DAP introduces a large uncertainty in the risk measure in dental CBCT, after thorough investigation of the relationship of the effective dose and aforementioned dose indices, it is suggested as the most appropriate dose index for the optimisation purposes and estimation of effective dose of the patient since it represents the dose and FOV which are the most important scanning parameters affecting the dose. To decrease uncertainty on the risk measure, the effective dose has to be estimated for FOV position and sizes, considering both, tube rotation angle and tube voltage
Randomized clinical study of the effects of photodynamic therapy and bioceramic filling of root canals on the healing of periapical lesions and the occurence of postoperative pain after endodontic treatment
No full textSvrha doktorskog rada bila je ispitati utjecaj fotodinamske terapije i biokeramičkoga punila korijenskih kanala na cijeljenje periapikalne lezije i pojavnost postoperativnih bolova nakon jednoposjetne revizije endodontskog liječenja. Pacijenti su metodom slučajnog odabira razvrstani u dvije skupine ovisno o završnom protokolu dezinfekcije korijenskih kanala: Skupina 1. UAI (ultrazvučno aktivirano ispiranje) + Fotodinamska terapija (engl. photodynamic therapy, PDT); Skupina 2. UAI (ultrazvučno aktivirano ispiranje). Ukupno je sudjelovalo 77 pacijenata, 38 u PDT skupini i 39 u UAI skupini. U svakoj skupini, kod polovice
ispitanika, korijenski kanali punjeni su biokeramičkim punilom (BioRoot RCS, Septodont, Francuska) (Podskupina A); a druga polovica punilom temeljenim na epoksi smoli AH Plus (AH Plus, Dentsply Sirona, Sjedinjene Američke Države) (Podskupina B). Kod svih pacijenata analizirana je pojavnost i intenzitet bolova s VAS skalom boli, po danima, 7 dana nakon završetka endodontskog liječenja zuba. Kod svih pacijenata napravljena je ciljana snimka zuba konusnom kompjuteriziranom tomografijom (eng. CBCT) prije i godinu nakon revizije endodontskog liječenja. Volumen inicijalne periapikalne lezije i lezije nakon 12 mjeseci
izračunat je softverom OnDemand3D. Dobiveni rezultati statistički su analizirani Fischerovim egzaktnim testom, Smirnov-Kolmogorovljevim i Mann-Whitney U testom uz razinu značajnosti od 0,05. Rezultati su pokazali značajno smanjenje volumena u svim ispitivanim skupinama, i to: PDT/AH+ 79,72% (p<0,05), PDT/BIO 89,58% (p<0,05), UAI/AH+ 86,98% (p<0,05), i UAI/BIO 86,95% (p<0,05). Između ispitivanih skupina nije bilo statistički značajne razlike u smanjenju volumena: PDT/AH+ i PDT/BIO (p=0,784), UAI/AH+ i UAI/BIO (p=0,458), PDT/BIO i UAI/BIO (p=0,458), PDT/AH+ i UAI/AH+ (p=0,970). Fotodinamska terapija nije pokazala superiornost u kliničkim uvjetima u odnosu na ultrazvučno aktiviranu irigaciju kao ni primijenjeni biokeramički materijal u odnosu na punilo temeljeno na epoksi smoli, kako u smanjenju periapikalne lezije, tako i u pojavnosti i intenzitetu postoperativne boli.Aim: The aim of the clinical study was to examine the effect of photodynamic therapy (PDT) and bioceramic root canal filling on periapical lesion healing. Also, the influence of PDT and bioceramic filling on the occurrence and intensity of postoperative pain after a single visit endodontic treatment was examined.
Materials and methods: The study included patients with signs and symptoms of chronic apical periodontitis who required revision, according to the inclusion and exclusion criteria. Patients were divided into two basic groups depending on the type of final root canal disinfection protocol: Group 1. Ultrasonically activated irrigation (UAI) EDTA and 3% NaOCl + PDT (diode laser 660 nm, 100 mW); Group 2. Ultrasonically activated irrigation (UAI) EDTA and 3% NaOCl. In each group, half of the root canals samples were filled with bioceramic filling BioRoot RCS (BioRoot RCS, Septodont, Saint-Maur-des-Fossés, France), and the other half of the samples with epoxy resin-based filling AH Plus (AH Plus, Dentsply, Sirona, Charlotte, USA). Radiological volumetric assessment of periapical lesion healing was done by CBCT analysis by obtaining the exact lesion volume preoperatively and one year after revision. The randomization process was conducted using the Wheel Decide program (www.wheeldecide.com). The study was single-blinded, meaning that the patients were unaware of the group to which they were allocated. The clinical procedures were standardized for both groups. Root canal retreatment was performed under local anesthesia (Articain 4% with Epinephrine 1:100,000, one ampoule, Ubistesin™ forte, 3 M ESPE, Germany) and rubber dam isolation. The traditional access opening was performed under rubber dam isolation. All caries was removed using pearshaped diamond and round carbide burs under water coolant. In cases where there was a significant loss of coronal tooth structure, class I cavities were reconstructed using a composite material (Clearfill Majesty ES2 Classic, Kuraray America, Inc. Suite, USA). The working field was disinfected with 5% NaOCl. The root canal retreatment was performed with Rendo 1, 2, and 3 rotary files (MICROMEGA, Cedex, France) using an endomotor set at 300 rpm and 200 Ncm, according to the manufacturer's recommendations. During retreatment, the root canals were irrigated with 3% NaOCl (30 G needle, Steri Irrigation Tips, DiaDent; Netherlands). The retreatment was considered complete when no signs of remaining guttapercha were visible on the instruments or in the canal. The working length was determined and measured using a Kfile size #10 or #15 up to the apical foramen (value 0 on the apex locator) on Dualpex apex locator (MICROMEGA, Cedex, France). The canals were then instrumented up to the apical foramen using 2Shape 1 and 2 instruments (2Shape, MICROMEGA, Cedex, France) and 5 ml of 3% NaOCl per canal. Endomotor setup was 300 rpm and 200 Ncm. The presence of clean dentinal shavings, clear irrigant, and glassy smooth walls were the preferred indicators of adequate cleaning of the root canals. Additionally, apical cleaning was confirmed when clean dentinal debris was present at the tip of the rotary instrument.
After completion of instrumentation, the final disinfection protocol included: irrigation with 3 ml of 3% NaOCl for 30 s, followed by 3 ml of 15% ethylenediaminotetraacetic acid (EDTA) activated for 60 s, and finally, 3 ml of 3 % NaOCl activated for 30 s. All passive irrigation was performed using 30 G needle (30 G needle, Steri Irrigation Tips, DiaDent; Netherlands) and a 2 ml syringe. After each irrigation step and before the next irrigant, the excess irrigant in the root canal was aspirated using 30 G needle and a syringe.In Group 1 (UAI), EDTA and NaOCl irrigants in the final disinfection protocol were constantly activated using an EndoUltra device (MICROMEGA, Cedex, France) with an ultrasonic noncutting tip placed at 3 mm from the working length. The irrigant was delivered into the root canal, and the ultrasonic device was constantly activated, 30 s for NaOCl and 60 s for EDTA. During activation, irrigants were constantly delivered using 30 G needle and a syringe. In both groups the irrigants were activated in the same manner as explained but with the additional application of photodynamic therapy (PDT) after irrigation in Group 1. The PDT as applied using an HF diode laser (diode laser 660 nm, 100 mW 60 s/root canal, LASER HF COMFORT; HAGER&WERKEN, Duisburg, Germany) set at continuous mode. First, the PS, Toluidine blue (HF EndoPDT solution, Hager&Werken) was applied in the root canal and
distributed along the dentinal walls using a sterile hand Kreamer size #15. The dye was left in the canal for 60 s, then removed by rinsing the canal with 2 ml of sterile saline solution and dried with sterile paper points. Finally, the root canals were irradiated using a fiber tip (320 µm diameter), placed initially 2 mm from the working length, and then moved rotationally for 60 s with rotational motion from the apical to the coronal direction. In the same session, the root canals were obturated using an epoxy resinbased sealer (AH Plus, Dentsply Sirona, Germany) or bioceramic sealer (BioRoot RCS, Septodont, SaintMaurdesFossés, France) and guttapercha cones (MICROMEGA, Cedex, France) using a singlecone
obturation technique. The access cavity was temporarily sealed with a glass ionomer (Fuji IX; GC Corporation, Tokyo, Japan). Every patient received a visual analogue scale (VAS) questionnaire to record occurrence and pain intensity immediately after the retreatment and during the following seven days and analgesic consumption. The protocol was finished seven days after revision with permanent composite filling (Clearfill Majesty ES2 Classic, Kuraray America, Inc. Suite, USA).
Results: Results showed significant periapical lesion volume reduction in all groups: PDT/AH+ 79,72% (p<0,05), PDT/BIO 89,58% (p<0,05), UAI/AH+ 86,98% (p<0,05), i UAI/BIO 86,95% (p<0,05). There were no significant differences between the groups in terms of reduction of periapical lesion volume: PDT/AH+ vs PDT/BIO (p=0,784), UAI/AH+ vs UAI/BIO (p=0,458), PDT/BIO vs UAI/BIO (p=0,458), PDT/AH+ vs UAI/AH+ (p=0,970). Additional use of PDT after UAI did not contribute to the healing of periapical lesions. The intensity of postoperative pain was highest on the first day, but considering the median VAS values, this pain was minimal (median in the range from 0 to 1). Significant differences were recorded only in one comparison - UAI/AH+ and UAI/BIO on the fourth day (P=0.049), but this difference was also not clinically significant
because the median VAS was 0, while the difference related only to the measured ranges of minimum and maximum VAS values. In conclusion, the pain was of low intensity and equal between the groups.
Conclusion: The analysis showed that there was no statistically significant difference between the examined groups, photodynamic therapy did not show superiority in clinical conditions in relation to ultrasound-activated irrigation, nor did the applied bioceramic material in relation to filler based on epoxy resin
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
A study of directional and fluctuating asymmetry of maxillofacial strucutres by using a geometric morphometry method
No full textMorfološka asimetrija kao odstupanje od potpune bilateralne simetrije često se koristi za procjenu genetičke i razvojne (ne)stabilnosti organizma. Kako su obje strane bilateralno simetričnog obilježja upravljane jednakim genima, njihova asimetrija nastaje kao rezultat djelovanja različitih remetilačkih faktora tijekom ontogenetskog razvoja. Za proučavanje rasta i razvoja, poremećaja i bolesti poligenskog nasljeđivanja primjerena je populacija koja je reproduktivno i geografski izolirana jer ima ograničeni genski bazen. Za istraživanje asimetrije lice u ovom istraživanju korištena je populacija otoka Korčule i Visa kao rijedak i vrijedan primjer geografski i reproduktivno izolirane populacije. S druge strane, populacija grada Splita primjer je panmiktične populacije i korištena je kao kontrolna skupina. Za ovo istraživanje koristilo se sveukupno 110 CBCT snimki. Trodimenzionalna rekonstrukcija podataka i trodimenzionalna antropometrijska mjerenja rađena su u softveru Viewbox 4 (dHAL, Greece). Nakon digitalizacije, antropometrijske točke određene su svojim koordinatama (x, y, z) i analizirane su metodama geometrijske morfometrije u programu Mathematica 4.1 (Wolfram Research, Inc., United Kingdom). Totalna, direkcijska i
fluktuacijska asimetrija cijelog kraniofacijalnog skeleta, kranija i mandibule nije ovisna o dobi, spolu ili o mjestu stanovanja (Korčula, Split, Vis). Iznosi za totalnu asimetriju općenito znatno su veći za područje mandibule, nego za područje kranija i za totalnu asimetriju. Postoji direkcijska asimetrija cijelog kraniofacijalnog skeleta, kranija i mandibule kod svih triju skupina ispitanika..Ispitanici s područja Visa imaju najveći iznos direkcijske asimetrije za cijelo područje kraniofacijalnog skeleta i kranija. Ispitanici s područja Korčule imaju najveći iznos direkcijske asimetrije mandibule. Iznos direkcijske asimetrije najmanji je za mandibulu za sve tri skupine ispitanika. Iznosi fluktuacijske asimetrije za područje kranija veći su od fluktuacijske asimetrije mandibule. Vektorskom analizom smjera fluktuacijske asimetrije u odnosu na dob vidi se kako su promjene smjera izraženije u skupini ispitanika starijih od 55 godina i to dominantno u nazo-orbitalnom području Dobne promjene oblika kraniofacijalnog skeleta veće su kod ispitanika ženskog, nego kod ispitanika muškog spola. One imaju stalnu uzlaznu promjenu, no nakon 55 godina krivulja promjene oblika kraniofacijalnog skeleta u ovisnosti o dobi kod ispitanika ženskog spola postaje diskontinuirana s nepredvidljivim uzlaznim i silaznim varijacijama.Developmental processes are extremely complex processes that lead to the creation of a final or current phenotype. Due to their extreme complexity, a perfectly regular and symmetrical process is almost impossible to achieve. The balance of all processes with the interaction of external environmental factors implies the achievement of full functionality of the system with primary or secondary morphological construction. Such construction in its course leaves on the morphology of the organism small markers that can serve as an indicator of certain factors of development, both environmental and genetic (1). The growth and development of the human craniofacial system is under significant control of genetic factors, i.e. under the influence of certain groups of genes whose activation and expression are well programmed. Control genetic mechanisms are largely non-specific in nature, such as regulatory genes that act not only on the craniofacial system, but on the whole organism. On the other hand, there are very specific control patterns of development that establish a species-specific physiognomy with relatively small morphological variations. Although human face variations appear to be large, they are actually minimal given the complexity of the development cycle (2). Different parts of the face have different development in terms of time, speed and direction of growth and development (3). A significant role in the duration of these processes, as well as in lifelong changes is played by different hormonal interactions and the time of action and
concentration of individual hormones, which, each with its own complete or additive effect, contributes to the change of morphological characteristics of the face. Asymmetry is a deviation from the identical shape or size of two sides of the body. It is one of the most common facial features. Due to the lack of use of the mid-sagittal plane, mirror object modelling can provide the most accurate assessment of craniofacial asymmetry. It is widely believed that increased asymmetry indicates the failure of the organism to maintain developmental homeostasis and the overcoming of environmental disorders over
genetic control mechanisms (4). Developmental stability means the body's resistance to various disorders that can affect the body during growth and development, and we can express it by slight random deviations from bilateral symmetry (5). Since fluctuating asymmetry is caused by the inability of the organism to allow the left and right sides to develop equally, it is often used in research as a measure of developmental instability that occurs during the development of the organism (6, 7). If an environmental factor changes, the result is a change in directional asymmetry because this stress acted on both the left and right sides of the body, as a developmental response to environmental factors, depending on positional signals regulating the differences between left and right. Therefore, the variation of directional asymmetry with developmental factors is a special example of a reaction norm, something that affects both sides of the body. Considering that the significant role of heredity in facial development has been pointed out so far, a study of the developmental stability of the facial phenotype would indicate the relationship and interaction of genetic and environmental factors during the growth and
development of the craniofacial system. Despite the overall low level of differentiation in the human population, local factors such as geographical and cultural isolation can greatly affect genetic discontinuity. Clearly distinguished genetic isolates are very valuable for mapping rare and elucidating the mechanism of occurrence of complex genetic diseases (8). Therefore, this study of the asymmetry and shape of the craniofacial skeleton was conducted on an isolated population of Croatian Dalmatian islands and on a panmictic (non-isolated) population of the city of Split. Aim of the study The aims of the study were: 1. To calculate the amounts of total asymmetry of the entire craniofacial skeleton, cranium and mandible and determine whether they are grouped by age and sex and study them in a group of subjects from the area of Korčula, Vis and Split. 2. To determine whether there is direct asymmetry of the entire craniofacial skeleton, cranium and mandible in the group of subjects from the area of Korčula, Vis and Split and, if so, whether there is a difference between these groups and what is its direction. 3. To determine whether there is a fluctuating asymmetry of the entire craniofacial skeleton, cranium and mandible in the group of subjects from the area of Korčula, Vis and Split and, if so, whether there is a difference between these groups and what is its direction. 4. To determine the existence of sex and age differences in the form of the craniofacial skeleton and depending on the place of residence of the subjects (Korčula, Split, Vis). Sample and methods
The studied population of the islands of Korčula and Vis is a rare and valuable example of a geographically and reproductively isolated population. On the other hand, the population of the city of Split is an example of a panmictic population. Since it shares most of the environmental factors with the population of Vis and Korčula, the population of the city of Split was used as a control population. This group is representative of a mixed and nonisolated population.
A total of 110 CBCT images were used for this study. Out of the total number, 46 images belong to the inhabitants of the island of Vis, 15 to the inhabitants of Korčula, and 49 images belong to the population of the city of Split. All images were taken with the same CBCT device (Scanora 3D, Soredex, Finland) and belong to the Project database. All images are of
the same dimensions, field size (FOV) 10 x 14.5 cm, isotropic voxel size 0.25 mm with a total of 300 projection images per subject. The images were stored in the Digital Imaging and Communication in Medicine (DICOM) format. Three-dimensional data reconstruction and three-dimensional anthropometric measurements were performed in Viewbox 4 software (dHAL, Greece). After loading the three-dimensional image and showing the craniofacial skeleton, the region
of interest for each subject was determined individually. It included the entire craniofacial complex, the cranium from the upper bone edge of the left and right orbits to the lower edge of the maxilla, and the entire mandible. The following anthropometric points in the mid-sagittal plane were used: prosthion (pr), anterior nasal spine (sna), posterior nasal spine (snp), incisive foramen (fi), linguale (lng) and infradentale (id). The paired points were: orbital (or), pyriform aperture (ap), zygoorbital (zo), zygomaxillare (zm), mandibular foramen (fma), mental foramen (fme) and coronoid (cn). After digitization, the anthropometric points were determined by their coordinates (x, y, z) and analysed by geometric morphometrics in Mathematica 4.1 (Wolfram Research, Inc., United Kingdom). The following methods were used to analyse the shape and symmetry of the craniofacial skeleton: General Procrustean method of superposition (for standardization of object size),
modelling of an image of an object, and principal components analysis (PCA) (9). Mathematical procedures for determining the total asymmetry were performed according to Mardia et al. (10). The degree of individual morphological asymmetry was calculated as the difference in shape (Procrustean distance) between the configuration of the face and its mirror reflection. The first determined total asymmetry (total asymmetry - TA) of the sample was divided into directional asymmetry (DA) and fluctuating asymmetry (fluctuation asymmetry - FA). The principal components analysis (PCA) indicated the distribution of dominant shape variations within different populations and presented the main differences between them (11).
Differences in asymmetry amounts were checked by analysis of variance (ANOVA). Results Total asymmetry
The total asymmetry for the area of the entire craniofacial skeleton as well as for the cranium and mandible expressed in units of Procrustes distance is not grouped according to age or sex. ANOVA showed that there was no statistically significant difference (R 2= 0.094) in the amount of total asymmetry neither by age and sex of the subjects, nor by place of residence (Vis and Korčula), nor by the amount of inbreeding. Subjects from the area of Korčula differ statistically significantly in the amount of total asymmetry for the area of the mandible compared to the subjects from Vis and Split.
Directional asymmetry The difference in asymmetry between the sexes and between populations depending on the place of residence has not been established. The amount of directional asymmetry is the smallest for the mandible for all three groups of subjects. Subjects from the area of Vis have the highest amount of directional asymmetry for the entire area of the craniofacial skeleton and for the area of the cranium, and subjects from the area of Korčula have the highest amount of directional asymmetry of the mandible. Changes in the direction of directional asymmetry after the age of 55 are visible in all subjects in the orbital and nasal area, while changes in the mandibular area are noticeably small. Changes in the direction of directional asymmetry do not intensify with age. The largest changes are shown by the pyriform aperture point in subjects younger than 55. As the aperture rotates counter clockwise, the right one moves laterocaudally and the left one moves mediocranially. Fluctuating asymmetry There was no statistically significant difference in the amount of fluctuating
asymmetry, neither by age and sex of the subjects, nor by place of residence (Vis and Korčula), nor by the amount of inbreeding. Changes in the direction of fluctuating asymmetry are visible in all subjects on the entire craniomandibular skeleton. Changes in the direction of fluctuating asymmetry are more pronounced in subjects older than 55. The largest changes are visible in the zygoorbital, nasal, and coronoid areas. Shape analysis An F test showed that there was a statistically significant difference in the shape of the craniofacial skeleton between female and male subjects (p= 0.025).
Image 1. Dependence of the change in the shape of the craniofacial skeleton in relation to age in male and female subjects
Changes in the shape of the craniofacial skeleton are greater in female subjects than in male subjects. After the age of 55 (Image 1), the curve of the change in the shape of the craniofacial skeleton in female subjects, which is age-dependent, has a pronounced ascending trajectory, after which it becomes discontinuous with unpredictable ascending and descending
variations. The trajectory curves of men and women are approximately parallel until approximately 55 years of age when in women, the pattern of aging changes and changes in the shape of the craniofacial skeleton caused by aging occur.
Changes in the shape of the craniofacial skeleton in female subjects are more intense than changes in male subjects. In contrast to the intensity, the directions of changes in the shape of the craniofacial skeleton in relation to age in male and female subjects are similar. Changes in the coronoid, anterior nasal spine, and posterior nasal spine points caused by
increasing age occur only in female subjects. Although the subjects are not grouped into clusters according to their place of residence (Korčula, Split, Vis) and there are many overlaps in the shape of the craniofacial skeleton, the F test showed that there is a statistically significant difference in the shape of the craniofacial skeleton between Korčula and Vis.
Discussion The results of this study showed that total asymmetry is not grouped by age or by sex. This is in contrast to studies (12, 13) that have shown that the asymmetry of the human face differs between the sexes, its size is age-dependent and is greatest earlier in life. These findings are in agreement with the Rotterdam study (14) in which total and fluctuating
asymmetry are significantly related to age and sex. The reasons for these contradictory findings, and taking into account that the asymmetry decreases with age, may lie in the different age structure of the examined populations, i.e. the older age structure of the island population that was the subject of this study. The results of this study showed that the amount of direct asymmetry is the smallest by several times for the area of the mandible for all subjects, which leads us to the conclusion that the influence of genotype in these subjects on the area of the mandible is the smallest and that all causes of fluctuating asymmetry of the mandible in this population should be considered as environmental impact. As the amount of fluctuating asymmetry of the mandible is the largest for the area of Split, it is inferred that the environmental impact of the city of Split is strong. The amounts of both total and fluctuating asymmetries of the mandible are smaller than that of the cranium, which generally indicates that the environment has less of an impact on asymmetry of the mandible and that the impact on the cranium is much stronger. The total asymmetry of the mandible is statistically significantly lower in the subjects from the Korčula area, and at the same time, the direct asymmetry in this population is the largest, which means that the amount of the total asymmetry is actually directional and that the asymmetry of the mandible in the Korčula area is almost not at all under environmental impact and that the environmental impact on the onset of asymmetry the mandible in subjects from the area of Vis and Split is much higher. As the largest amounts of Directional asymmetry in the entire craniofacial area, area of the cranium and mandible are divided between island populations, we can think in the direction
of a stronger genetic influence on the phenotype of both populations, by comparing them with the population of the city of Split. As the Functioning asymmetry of the mandible is the largest for the area of Split, environmental impact is the greatest and this is in complete contrast to the impact on the asymmetry of the mandible in subjects from the area of Korčula.
Functioning asymmetry for the entire craniofacial skeleton and the cranium is the largest in subjects from the area of Vis which also shows a strong environmental impact. This environmental impact, which is obviously stronger in the area of Vis and Split in relation to the more isolated population of Korčula, mutually competes and leads to the total asymmetry
of the cranium and mandible being the largest in the area of Vis, but is greatest for the entire craniofacial area in subjects from the area of Split. All this leads us to the following conclusions: the environmental impact on the formation of asymmetry is strong and it has made the populations of Split and Vis similar despite their genetic differences. Microclimate,
the specificities of environmental factors, i.e. their weak influence and isolation in the area of Korčula made the specificity of the genotype manifest itself as the smallest total asymmetry of the mandible. It is correct to view these results through a prism of age, since it is an older population, when the influence of genetics, although still effective, decreases and the
influence of environmental factors increases. As the influence of environmental factors is obviously small on Korčula, all mandibular asymmetry, although statistically significantly small, should be viewed in the light of purely genetic influence.
Observing the direction of directional asymmetry in the subjects of this study, larger changes in the orbital and nasal area are visible in all three groups (Korčula, Split, Vis), while changes in the mandible are noticeably small, which is expected compared to numerical data. Furthermore, comparing the difference in the amount of directional asymmetry with aging, we
see that there are no significantly different changes in directional asymmetry with regards to age, which is consistent with the fact that the largest changes in directional asymmetry are seen at early stages of development. Changes in the direction of individual points as a consequence of directional asymmetry can be interpreted as genotype responses to age-related
changes in the craniofacial skeleton. The greatest changes are shown by the pyriform aperture point, with the aperture rotating counter clockwise, the right one moving laterocaudally, and the left one mediocranially. These changes lead to a distortion of the nasal section to the right. As this one, most previous studies on fluctuating asymmetry is based on a comparison of endogamous, often isolated populations with more exogamous (15, 16, 17). The degree of heterozygosity is associated with lower levels of organizational asymmetry and reflects an increased ability to alleviate genetic and environmental stressors. The higher the degree of heterozygosity in genes encoding proteins or at associated loci (non-random association), the more a better adapted individual is protected from the disorder. In this context, three hypothetical mechanisms are proposed: 1) a “direct effect” effect according to which heterozygosity increases the ability of the multilocus and may result in functional dominance at the locus per se (18, 19). It is also possible that heterozygotes possess enzymes with different catalytic properties and are therefore more biochemically efficient than homozygotes (20). 2) the “local effect hypothesis” suggests heterozygosity as an additional dominance when there is a genetic link (link imbalance) between the neutral marker and the marker under selection (18, 21). And 3) the “general effect” hypothesis states that the advantage of heterozygotes is such that the markers that are detected, which arise from the homozygosity interaction, are loci distributed throughout the genome. A prerequisite for this is that the marker and loci are in the service of identity imbalance which is recorded as the inbreeding coefficient of individuals. A higher inbreeding coefficient means higher marker homozygosity and locus binding ability, while a lower coefficient is associated with heterozygosity and poorer marker-locus link (22,23). As the high degree of inbreeding between subjects in this population was shown in several studies within the Project, and as
facial fluctuating asymmetry cannot be related to kinship, it seems that the correlation of heterozygosity and locus ability in this study cannot be explained by these three models and requires additional identification. The same is the case with the Rotterdam study. One possible explanation is Chapman et al. who showed that even if there are correlations in heterozygosity and locus binding ability, they are very small (usually less than 1% of phenotypic variance) (22). Furthermore, the degree of heterozygosity may, on average, be low enough to significantly affect developmental pathways. It is also reasonable to assume that the environment of an isla
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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