mandibles
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Mandibles of representatives of the Holarctic crayfish families Astacidae, Cambaridae, and Cambaroididae were examined using SEM, and the results were analyzed in a phylogenetic framework. The intraspecific variability of the incisor process was found to be higher than its interspecific variability, mainly due to extensive abrasion of its ridge during intermolt periods. The plesiomorphic state of the crayfish mandibles highlights the dentate-crenate type of the incisor process and the extensive ribbed molar field with a multicuspidate caudal part, typical of the two parastacid crayfish examined for comparison. For Holarctic crayfish, the initial evolutionary type of the incisor is also the dentate-crenate one, but the molar field has a bowl-shaped caudal part and reduced cephalic part, both of which have been shown, for example, for Cambaroides. Similar mandibles are also widely present in American cambarids, which further evolved a blade-like incisor process (some Faxonius spp.) or a tricuspidate or double-bladed caudal molar field (some Procambarus spp.). The molar field in Astacidae crayfish is subdivided and rugose. The results of the present study indicate that little phylogenetic information is conveyed by the mandible shape at the species or genus level. Evolutionary changes are indicated mainly on the level of the main crayfish families. RESEARCH HIGHLIGHTS: Mandible shape can be an additional characteristic to distinguish crayfish families and selected genera. Obvious differences exist in the molar process rather than in the incisor ridge.
- MeSH
- anatomie srovnávací * MeSH
- biologická evoluce * MeSH
- druhová specificita MeSH
- fylogeneze MeSH
- mandibula anatomie a histologie diagnostické zobrazování MeSH
- řezáky diagnostické zobrazování MeSH
- severní raci anatomie a histologie MeSH
- shazování tělního pokryvu MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- srovnávací studie MeSH
A macroscopic, microscopic and scanning electron microscope study was performed on the pathological bone changes of the mandibles of wild red deer (n = 61) exhibiting severe dental fluorosis. The animals originated from a highly fluoride polluted area in Central Europe (Ore mountains and their southern foreland, Czech-German border region) and constituted 11.2 % of the studied red deer sample (n = 545) from this area. Pathologically increased wear and fracture of fluorosed teeth caused a variety of mandibular bone alterations, including periodontal breakdown, periostitis, osteitis and chronic osteomyelitis. As a further consequence of severe dental attrition, opening of the pulp chamber and formation of periapical abscesses were occasionally observed. In case of severe periodontal breakdown, loss of teeth from the mandibles was found. In addition to the inflammatory bone changes, the occurrence of osteofluorotic alterations was also diagnosed in the specimens with the highest bone fluoride concentrations (> 4000 mg F-/kg dry wt). These changes comprised extended apposition of periosteal bone onto the mandibular cortex as well as deformation of the mandibular body, which was attributed to a fluoride-induced osteomalacia. The present study provided circumstantial evidence that, in addition to fluoride induced dental lesions, the occurrence of marked periodontal disease and tooth loss is an important factor responsible for a reduction of life expectancy in severely fluorotic wild red deer.
- MeSH
- dentální fluoróza patologie veterinární MeSH
- fluoridy * MeSH
- mandibula patologie ultrastruktura MeSH
- mikroskopie elektronová rastrovací MeSH
- vysoká zvěř anatomie a histologie MeSH
- znečištění životního prostředí * MeSH
- ztráta zubů chemicky indukované MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Česká republika MeSH
- Německo MeSH
A study was conducted to determine whether the mandibles of the detrito-/bryophagous groundhopper Tetrix tenuicornis are subject to mechanical wear as a result of feeding, as is the case for grasshoppers that feed on silica-rich grasses. Abrasion was evaluated by measuring the length and width of the 3rd incisor and length of the 4th incisor in adults of different ages collected under natural conditions during one season. Although T. tenuicornis and other groundhoppers avoid feeding on grasses, we found that mandible abrasion increased with T. tenuicornis age. Age-related abrasion of the incisors of left and right mandibles was statistically significant in both sexes but the degree of abrasion was greater for females than males, apparently reflecting differences in the frequency and magnitude of feeding. Degree of abrasion also differed between right and left mandibles, probably because of differences in how each mandible is used during food processing. Abrasion of cuticular mandible structures may reduce the effectiveness of food processing late in the season.
- MeSH
- mandibula patologie MeSH
- Orthoptera anatomie a histologie fyziologie MeSH
- sexuální faktory MeSH
- stárnutí * MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
According to many investigations, changes in mandibular morphology can occur synchronously with changes in the environment, and sexual dimorphism of the mandible can be influenced by the environment. Sexual dimorphism during the last 1200 years was evaluated using geometric morphometric analysis of virtual cranial models. The method of geometric morphometrics allows differences in size and shape to be assessed separately. We analyzed groups of adult individuals dating to Early Middle Ages, High Middle Ages, Early Modern Ages and from a modern Czech population (21st century). Significant sexual dimorphism in mandibular size was found in all populations. A trend in the sexual dimorphism of size was seen, with differences between the sexes increasing gradually over time. Size changes in female mandibles were a better reflection of environmental conditions and climate than size changes in male mandibles. Regarding changes in the sexual dimorphism of shape, significant dimorphism was found in all four samples. However, the pattern of mandibular shape dimorphism was different and varied considerably between samples. There was only one stable shape trait showing sexual dimorphism across all four samples in our study: the gonion lies more laterally in male than in female mandibles and male mandibles are relatively wider than female mandibles. Sexual dimorphism of shape is not influenced by the climate; instead sexual selection might play a role. This research supports earlier studies that have found that the degree and pattern of sexual dimorphism is population-specific and the factors regulating sexual dimorphism today may not be the same as those in the past.
- MeSH
- dějiny 15. století MeSH
- dějiny 16. století MeSH
- dějiny 17. století MeSH
- dějiny 18. století MeSH
- dějiny 19. století MeSH
- dějiny 20. století MeSH
- dějiny 21. století MeSH
- dějiny středověku MeSH
- dieta MeSH
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mandibula anatomie a histologie MeSH
- podnebí MeSH
- sexuální faktory * MeSH
- životní prostředí MeSH
- zkameněliny * MeSH
- Check Tag
- dějiny 15. století MeSH
- dějiny 16. století MeSH
- dějiny 17. století MeSH
- dějiny 18. století MeSH
- dějiny 19. století MeSH
- dějiny 20. století MeSH
- dějiny 21. století MeSH
- dějiny středověku MeSH
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- historické články MeSH
- práce podpořená grantem MeSH
- srovnávací studie MeSH
- Geografické názvy
- Evropa MeSH
Jednou z možností chirurgické léčby otevřeného skusu je chirurgická counter-clockwise rotace dolní čelisti nebo maxilo-mandibulárního komplexu. Oílem této studie bylo posoudit stabilitu výsledků chirurgické terapie otevřeného skusu pomocí sagitální osteotomie větve dolní čelisti s counter-clockwise rotací okluzní roviny a zjistit, zda je stabilita OOW rotace dolní čelisti ovlivněná počtem destiček (minidlah) rigidní osteosyntézy v dolní čelisti. Soubor zahrnoval 26 pacientů, kteří podstoupili OOW rotaci horní i dolní čelisti. Bylo porovnáváno 8 kefalometrických parametrů ve třech časových obdobích - po ortodontické dekompenzaci vady (T0), maximálně sedm dní po chirurgické korekci (T1) a minimálně jeden rok po chirurgickém zákroku (T2). Po vyhodnocení výsledků měřeníjsme dospěli k závěru, že stabilita CCW rotace dolní čelisti není závislá na počtu použitých minidlah.
One of the possible approaches to surgical treatment of anterior open-bite is the counter-clockwise rotation Of the mandible or the whole maxillo-facial complex. The aim of this study was to evaluate stability of sagittal osteotomy of the mandiblar ramus and counter-clockwise rotation of the occlusal plane and find out whether the stability of CCW rotation is affected by the number of miniplates of rigid osteosynthesis in the mandible. Our sample comprised 26 patients who unden/vent OOW rotation of both upper and lower jaw. A total of 8 cephalometric parameters were compared in 3 time periods - after the orthodontic decompensation of the anomaly (T0), maximum 7 days after surgical treatment (Tl), and at least 1 year after surgery (T2). Evaluation of results leads us to the conclusion that the stability of OOW rotation of the mandible is not affected by the number of miniplates used.
Aim: The aim of the presented study was to compare differences in craniofacial morphology with a focus on the degree and intensity of mandible growth in patients with Pierre Robin sequence, patients with isolated cleft palate, and healthy population. Material and method: Growth changes were measured in 40 patients with isolated cleft palate and in 20 patients with Pierre Robin sequence in 2 cephalograms taken at the interval of at least two years. The first cephalogram was taken at the age of 9-12 (T0), and it was clear from the OPG that it was performed prior to a growth spurt. The second cephalogram was taken after at least 2 years under the same technical conditions, i.e. at the age of 12.5–16 years (T1). The values were compared with reference values of healthy population of the same age taken from the study by Riola (1974). Results: In patients with Pierre Robin sequence the mandible is hypoplastic compared to patients with isolated cleft palate and healthy individuals. At T0 the mandible in patients with Pierre Robin sequence reached 92.8 % of the average length of the mandible in patients with isolated cleft palate (p = 0.001), at T1 it was 92 % (p = 0.0002). A comparison with healthy population revealed greater discrepancy. At T0 the mandible of patients with Pierre Robin sequence reached 91.3 % of the length of the mandible in healthy individuals (p < 0.0001), at T1 it was 91 % (p < 0.0001). The most significant discrepancy contributing to the mandible hypoplasia in patients with Pierre Robin sequence was found in the length of the mandible body. Conclusion: In patients with Pierre Robin sequence the mandible is permanently insufficient. The growth appears constant, it does not accelerate or decelerate during a growth spurt.
- MeSH
- dítě MeSH
- kefalometrie přístrojové vybavení statistika a číselné údaje MeSH
- kohortové studie MeSH
- lidé MeSH
- mandibula * patologie růst a vývoj MeSH
- mladiství MeSH
- Pierre Robinův syndrom * diagnostické zobrazování patologie MeSH
- retrospektivní studie MeSH
- rozštěp patra diagnostické zobrazování patologie MeSH
- Check Tag
- dítě MeSH
- lidé MeSH
- mladiství MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- klinická studie MeSH
