Factors affecting mandibular residual ridge resorption in edentulous patients: a preliminary report

The aim of the study was to assess the rate of mandibular residual ridge resorption in edentulous patients and to analyse the factors which determine this process. A group of 35 edentulous patients aged between 51 and 89 years, with a mean age of 74 (65-78) years, were included in the study. Individual factors (age, gender and duration of edentulousness), local biochemical parameters (oral hygiene and history of periodontal diseases) and systemic biochemical parameters (calcium and phosphate metabolism, diet, smoking, alcohol intake and systemic diseases), as well as physical factors involved in the process (the use of prosthetic dentures), were analysed. The study was performed on the basis of the results of dental examinations, assessment of panoramic radiograms, research surveys and total calcium and phosphate serum levels, which were determined using a calorimetric method. Bone resorption in the mandible affected all the study patients to varying extents. More than half the edentulous patients showed a high degree of mandibular residual ridge resorption. The duration of mandibular edentulism was found to be closely associated with values of the radiological IC/IM index, which is generally considered to reflect the degree of mandibular resorption. Total calcium serum levels were shown to correlate positively with the value of IC/IM index in these patients

The bifid anterior coracoscapular ligament: a new morphological variation and its potential clinical implications

The suprascapular notch (SSN) is the typical site of compression and injury of the suprascapular nerve (SN), which results in a neuropathy known as suprascapular nerve entrapment. The SSN is enclosed from the top by the superior traverse scapular ligament (STSL), creating a tunnel for the SN. On the both sides of the suprascapular notch, below the STSL, the anterior coracoscapular ligament (ACSL) is found. This fibrous band can potentially narrow the opening and contribute to the occurrence of suprascapular entrapment syndrome. This study presents a first case of a bifid anterior coracoscapular ligament coexisting with atypical suprascapular nerve course that has never been described in the literature. Knowledge of such anatomical variations can be helpful in arthroscopic and open procedures of the suprascapular region and confirms the safety of operative decompression for entrapment of the suprascapular nerve

The location of the infraorbital foramen in human skulls to used a new anthropometric landmarks as a usefull method for maxillofacial surgery

The aim of the study was to determine the localization of the infraorbital foramen in relation to chosen anthropometric landmarks as novel reference points: nasion, rhinion and frontomalare orbitale, and to verify their symmetry.Sixty-four sides of thirty-two human skulls were investigated. The distances between the infraorbital foramina and nasion, rhinion, frontomalare orbitale, and the distances between two contralateral infraorbital foramens were measured. The symmetry was analyzed and statistical analysis was performed. The mean distance and standard deviation (mean±SD) between the right infraorbital foramen and the nasion, rhinion and right frontomalare orbitale were 45.23±3.20 mm, 39.84±1.72 mm, 36.28±1.50 mm, respectively, and between the left infraorbital foramen and the nasion, rhinion and left frontomalare orbitale were 44.38±2.76 mm, 38.88±2.01 mm, and 36.31±2.19 mm, respectively. The results presented in this study may be particularly helpful for surgery in patients with oedema of the infraorbital region when the other landmarks are difficult to localize

Morphological study of linea aspera variations – proposal of classification and sexual dimorphism

The linea aspera is a roughened, longitudinally-oriented irregular crest composed of two lips located on the posterior surface of the femoral shaft. The purpose of this research was to investigate the morphological variations of the linea aspera in humans. The study was carried out on 90 femurs. Osteometric measurements of the bones were taken using two complementary methods: classical osteometry and a new one based on the analysis of digital photographic documentation of the femur using MultiScanBase v.18.03 software. The analysis allowed four types of the linea aspera to be determined: parallel (type I  - 27.2%), concave (type II – 25.7%),  convex (type III – 5.7%) and variform (type IV – 41.4%). The frequency of the each type in female and male was also described. Better knowledge of the anatomical variations of the linea aspera may be helpful in Orthopaedy and Radiology to distinguish pathological from normal anatomical variations

The trifid superior transverse scapular ligament – case report and review of the literature

During dissection of a 75-year-old Caucasian female cadaver, a trifid superior transverse scapular ligament (STSL) was found. The suprascapular nerve and vessels ran inferior to the STSL though the suprascapular notch. Measurements of the structures of the suprascapular region were taken using two complementary but independent methods: a classical method using an electronic digimatic caliper and a new one based on an analysis of digital photographic documentation of the STSL. The knowledge of anatomic variations of the superior transverse scapular ligament is important because this structures is the most commonly recognized possible predisposing factors of suprascapular nerve entrapment and can be helpful in diagnosis, surgical and arthroscopic treatment of this pathology

Variations in the topography of the infraorbital canal/groove complex: a proposal for classification and its potential usefulness in orbital floor surgery

Background: The aim of the study was to precisely describe and classify the infraorbital canal/groove (IOC/G) complex in dry human skulls and to evaluate the presence of asymmetry in the IOC/G complex.Materials and methods: Seventy orbits of 35 human skulls were investigated.The following distances were measured: the distance between the posterior and anterior margin of the infraorbital groove (S-C); the posterior margin of the infraorbital canal and the infraorbital foramen (C-IOF); and the total length of the infraorbital canal-groove complex (S-C-IOF). The symmetry of the contralateral measurements was analysed.Results: Three types of the IOC/G complex were distinguished: types I, II, III, whose respective incidences were 11.4%, 68.6%, 20.0%. The mean length of the infraorbital groove plus canal complex on the right and left with standard deviation were 27.78 ± 3.69 mm and 28.06 ± 3.37 mm, respectively.Conclusions: The results presented in this study may be particularly helpful for surgery in patients with blow-out fractures and different endoscopic and reconstructive procedures in the region of the inferior orbital wall. The type III IOC/G complex, according to our classification, seems the most likely to be exposed to trauma during surgical manipulations.

Infraorbital groove localisation for the endoscopic decompression of the orbit in Graves’ disease

Background: The aim of our study was to determine the localisation of the inferior margin of the optic canal in relation to the infraorbital canal/groove complex (IOC/G complex) and zygomaticoorbitale (ZO) as the potential useful landmarks for reducing dangerous complications following surgical and invasive procedures. Materials and methods: Sixty-four orbits of thirty-two human skulls were investigated. The distances between: the inferior margin of the optic canal and the posterior margin of the infraorbital groove measured at its medial border (OC-S); the inferior margin of the optic canal and the posterior margin of the roof of the infraorbital canal (OC-C); the inferior margin of the optic canal and the zygomaticoorbitale (OC-ZO) — were measured. The left/ /right symmetry ratio and the asymmetry index were counted. The symmetry between the contralateral measurements was analysed and statistical analysis was performed. Results: On the right side the mean distance from the inferior margin of the optic canal to: the posterior margin of the infraorbital groove measured at its medial border; to the posterior margin of the roof of the infraorbital canal; and to the zygomaticoorbitale were: 23.41 ± 3.10 mm; 34.44 ± 5.30 mm; and 47.53 ± 4.13 mm, respectively. On the left side the mean distance from the inferior margin of the optic canal to: the posterior margin of the infraorbital groove measured at its medial border; to the posterior margin of the roof of the infraorbital canal; to the zygomaticoorbitale were 23.69 ± 2.80 mm; 36.75 ± 5.10 mm; 46.84 ± 3.24 mm, respectively. Conclusions: The presented measurements may be particularly helpful for endoscopic decompression in patients with the thyroid ophthalmopathy to avoid the complications

Widespread, long-term admixture between grey wolves and domestic dogs across Eurasia and its implications for the conservation status of hybrids

Hybridisation between a domesticated species and its wild ancestor is an important conservation problem, especially if it results in the introgression of domestic gene variants into wild species. Nevertheless, the legal status of hybrids remains unregulated, partially because of the limited understanding of the hybridisation process and its consequences. The occurrence of hybridisation between grey wolves and domestic dogs is well-documented from different parts of the wolf geographic range, but little is known about the frequency of hybridisation events, their causes and the genetic impact on wolf populations. We analysed 61K SNPs spanning the canid genome in wolves from across Eurasia and North America and compared that data to similar data from dogs to identify signatures of admixture. The haplotype block analysis, which included 38 autosomes and the X chromosome, indicated the presence of individuals of mixed wolf-dog ancestry in most Eurasian wolf populations, but less admixture was present in North American populations. We found evidence for male-biased introgression of dog alleles into wolf populations, but also identified a first-generation hybrid resulting from mating between a female dog and a male wolf. We found small blocks of dog ancestry in the genomes of 62% Eurasian wolves studied and melanistic individuals with no signs of recent admixed ancestry, but with a dog-derived allele at a locus linked to melanism. Consequently, these results suggest that hybridisation has been occurring in different parts of Eurasia on multiple timescales and is not solely a recent phenomenon. Nevertheless, wolf populations have maintained genetic differentiation from dogs, suggesting that hybridisation at a low frequency does not diminish distinctiveness of the wolf gene pool. However, increased hybridisation frequency may be detrimental for wolf populations, stressing the need for genetic monitoring to assess the frequency and distribution of individuals resulting from recent admixture

Cyclic voles and shrews and non-cyclic mice in a marginal grassland within European temperate forest

Cyclic population dynamics of small mammals are not restricted to the boreal and arctic zones of Eurasia and North America, but long-term data series from lower latitudes are still less common. We demonstrated here the presence of periodic oscillations in small mammal populations in eastern Poland using 22-year (1986–2007) trapping data from marginal meadow and river valley grasslands located in the extensive temperate woodland of Białowieża Primeval Forest. The two most common species inhabiting meadows and river valleys, root vole Microtus oeconomus and common shrew Sorex araneus, exhibited synchronous periodic changes, characterised by a 3-year time lag as indicated by an autocorrelation function. Moreover, the cycles of these two species were synchronous within both habitats. Population dynamics of the striped field mouse Apodemus agrarius was not cyclic. However, this species regularly reached maximum density 1 year before the synchronized peak of root voles and common shrews, which may suggest the existence of interspecific competition. Dynamics of all three species was dominated by direct density-dependent process, whereas delayed density dependent feedback was significant only in the root vole and common shrew. Climatic factors acting in winter and spring (affecting mainly survival and initial reproduction rates) were more important than those acting in summer and autumn and affected significantly only the common shrew. High temperatures in winter and spring had positive effects on autumn-to-autumn changes in abundance of this species, whereas deep snow in combination with high rainfall in spring negatively affected population increase rates in common shrew

Persistence in diving American mink

Background American mink forage on land and in water, with aquatic prey often constituting a large proportion of their diet. Their long, thin body shape and relatively poor insulation make them vulnerable to heat loss, particularly in water, yet some individuals dive over 100 times a day. At the level of individual dives, previous research found no difference in dive depth or duration, or the total number of dives per day between seasons, but mink did appear to make more dives per active hour in winter than in summer. There was also no difference in the depth or duration of individual dives between the sexes, but there was some evidence that females made more dives per day than males. However, because individual mink dives tend to be extremely short in duration, persistence (quantified as the number of consecutive dives performed) may be a more appropriate metric with which to compare diving behaviour under different scenarios. Results Mink performed up to 28 consecutive dives, and dived continually for up to 36 min. Periods of more loosely aggregated diving (termed ‘aquatic activity sessions’) comprised up to 80 dives, carried out over up to 162.8 min. Contrary to our predictions, persistence was inversely proportional to body weight, with small animals more persistent than large ones, and (for females, but not for males) increased with decreasing temperature. For both sexes, persistence was greater during the day than during the night. Conclusions The observed body weight effect may point to inter-sexual niche partitioning, since in mink the smallest animals are females and the largest are males. The results may equally point to individual specialism’s, since persistence was also highly variable among individuals. Given the energetic costs involved, the extreme persistence of some animals observed in winter suggests that the costs of occasional prolonged activity in cold water are outweighed by the energetic gains. Analysing dive persistence can provide information on an animal’s physical capabilities for performing multiple dives and may reveal how such behaviour is affected by different conditions. Further development of monitoring and biologging methodology to allow quantification of hunting success, and thus the rewards obtained under alternative scenarios, would be insightful