scholarly journals Understanding the Lingual Frenulum: Histological Structure, Tissue Composition, and Implications for Tongue Tie Surgery

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Nikki Mills ◽  
Donna T. Geddes ◽  
Satya Amirapu ◽  
S. Ali Mirjalili

Lingual frenotomy has become an increasingly common surgical procedure, performed for a broad range of indications from birth through adulthood. This study utilizes histology to define the structure and tissue composition of the lingual frenulum and floor of mouth (FOM) fascia. En bloc specimens of anterior tongue, lingual frenulum, and FOM tissues were harvested from ten embalmed adult cadavers. An additional three fresh tissue cadaveric specimens were frozen with the tongue supported in an elevated position, to enable harvesting and paraffin embedding of the elevated lingual frenulum as a discrete specimen. All 13 specimens were prepared as ten-micron coronal sections using stains to determine the general morphology of the lingual frenulum, its relationship to neighbouring structures (Mason’s Trichrome), presence of elastin fibers (Verhoeff-van Gieson), and collagen typing (Picrosirius Red). Our results have shown a submucosal layer of fascia spanning horizontally across the FOM was present in all specimens, with variability in fascial thickness and histologic composition. This FOM fascia suspends the sublingual glands, vessels, and genioglossus from its deep surface. The elevated lingual frenulum is formed by a central fold of this FOM fascia together with the overlying oral mucosa with variability in fascial thickness and composition. With tongue elevation, the fascia mobilizes to a variable extent into the fold forming the frenulum, providing a structural explanation for the individual variability in lingual frenulum morphology seen in clinical practice.

Author(s):  
O.V. Mareev ◽  
◽  
G.O. Mareev ◽  
M.E. Gutynina ◽  
D.A. Maksimova ◽  
...  

2019 ◽  
Author(s):  
Vera Weisbecker ◽  
Thomas Guillerme ◽  
Cruise Speck ◽  
Emma Sherratt ◽  
Hyab Mehari Abraha ◽  
...  

AbstractBackgroundWithin-species skull shape variation of marsupial mammals is widely considered low and strongly size-dependent (allometric), possibly due to developmental constraints arising from the altricial birth of marsupials. However, species whose skulls are impacted by strong muscular stresses – particularly those produced through mastication of tough food items – may not display such intrinsic patterns very clearly because of the known plastic response of bone to muscle activity of the individual. In such cases, shape variation should not be dominated by allometry; ordination of shape in a geometric morphometric context through principal component analysis (PCA) should reveal main variation in areas under masticatory stress (incisor region/zygomatic arches/mandibular ramus); but this main variation should emerge from high individual variability and thus have low eigenvalues.ResultsWe assessed the evidence for high individual variation through 3D geometric morphometric shape analysis of crania and mandibles of thre species of grazing-specialized wombats, whose diet of tough grasses puts considerable strain on their masticatory system. As expected, we found little allometry and low Principal Component 1 (PC1) eigenvalues within crania and mandibles of all three species. Also as expected, the main variation was in the muzzle, zygomatic arches, and masticatory muscle attachments of the mandibular ramus. We then implemented a new test to ask if the landmark variation reflected on PC1 was reflected in individuals with opposite PC1 scores and with opposite shapes in Procrustes space. This showed that correspondence between individual and ordinated shape variation was limited, indicating high levels of individual variability in the masticatory apparatus.DiscussionOur results are inconsistent with hypotheses that skull shape variation within marsupial species reflects a constraint pattern. Rather, they support suggestions that individual plasticity can be an important determinant of within-species shape variation in marsupials (and possibly other mammals) with high masticatory stresses, making it difficult to understand the degree to which intrinsic constraint act on shape variation at the within-species level. We conclude that studies that link micro- and macroevolutionary patterns of shape variation might benefit from a focus on species with low-impact mastication, such as carnivorous or frugivorous species.


2020 ◽  
Vol 19 (4) ◽  
pp. 10-14
Author(s):  
Z. Masna

The individual face shape, the ratio of its proportions, the articulation capabilities of each person to a significant extent depend on the characteristics of occlusion and occlusion, in turn, are determined by the size, shape and ratio of dental, alveolar and basal arches. Two of them - alveolar and basal - pass at the corresponding levels of the alveolar areas of the jaws, which means that it is almost impossible to correct them, therefore they play the role of landmarks for setting the dental arch during dental prosthetics. A full-fledged aesthetic and functional restoration of the maxillofacial region after prosthetics largely depends on the dentist taking into account the individual morphological characteristics of the jaws, their cellular areas and specifically the morphometric parameters of the collar and basal arches. In order to determine the possible variants of the shape of the alveolar and basal arches of the upper jaw and the patterns of their ratio during the routine dental examination, 55 people (27 men and 28 women) aged 21-60 years with preserved maxillary dentition were examined. It has been established that the alveolar and basal arches of the upper jaw can have the shape of five geometric shapes: an oval, a semicircle, an ellipse, a trapezoid or a square. In this case, the shape of the collar and basal arches can coincide or be combined in various combinations. The analysis of the obtained results showed that in men the alveolar arch most often had the shape of an oval (70%), in women - an oval or semicircle (43%, respectively). With the aim of possible variants of the alveolar and basal arches form determination and peculiarities of their correlation 55 individuals (27 men and 28 women) in age of 21-60 years with the preserved teeth row were examined during planned dental examination. All examined were patients of the “Dental clinic of dr. Dakhno” (Kyiv). Computer tomographic investigation was made to these patients according to medical indications, scanning was made parallely to the occlusal plane. Image reconstruction was conducted with the use of highly dimentional bone algorithm. Alveolar and basal arch form of the upper jaw were determined on the images. It was established that alveolar and basal arches of the upper jaw can have a form of five geometrical figures: oval, semicircle, ellipse, trapeze or square. Form of the alveolar and basal arches can match or can combine in different combinations. Received results analysis testified that alveolar arch has a form of the oval in men and oval or semicircle – in women. Basal arch in men also most frequently has a form of oval, less often – semicircle, square and trapeze. In women basal arch more often has a form of trapeze or semicircle, less often – oval or square. In men alveolar and basal arches form matched in 41% of cases, in women – only in 31% of cases among total amount of all examined individuals. Most often alveolar and basal arches matched in the form of oval and semicircle, only in one case arches of the trapeze form matched in man, in woman – square form. Maxillary alveolar and basal arches form variants analysis let to determine areas, where distance between alveolar crests was maximal. Most variable this index was in individuals with the oval form of the alveolar arch on the level of 16-26, 17-27 or 18-28 teeth. Peculiarities of the alveolar and basal arches form of the alveolar process of the upper jaw in male and female individuals are characterized with expressed individual variability. These peculiarities consideration during dental prosthesis let avoid series of complications connected with the pressure redistribution on the osseous tissue of the jaws during articulation. 


Antibiotics ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 479
Author(s):  
Kirstin Vach ◽  
Ali Al-Ahmad ◽  
Annette Anderson ◽  
Johan Peter Woelber ◽  
Lamprini Karygianni ◽  
...  

The influence of a change in nutrition on the oral microbiota are discussed in literature, but usually only changes of population mean values are reported. This paper introduces simple methods to also analyse and report the variability of patients’ reactions considering data from the culture analysis of oral biofilm. The framework was illustrated by an experimental study exposing eleven participants to different nutrition schemes in five consecutive phases. Substantial inter-individual variations in the individual reactions were observed. A new coherence index made it possible to identify 14 instances where the direction of individual changes tended to coincide with the direction of the mean change with more than 95% probability. The heterogeneity in variability across different bacteria species was limited. This allowed us to develop recommendations for sample sizes in future studies. For studies measuring the concentration change of bacteria as a reaction to nutrition change, the use of replications and analysis of the variability is recommended. In order to detect moderate effects of a change in nutrition on the concentration of single bacterial taxa, 30 participants with three repetitions are often adequate. Insights into the relationship between nutrition and the microbial composition can be helpful for the development of dietary habits that promote the establishment of a healthy microbial flora and can therefore prevent the initiation of oral diseases such as caries and periodontitis.


2012 ◽  
Vol 58 (2) ◽  
pp. 358-362 ◽  
Author(s):  
Ned A. Dochtermann ◽  
C. M. Gienger

Abstract Understanding how population sizes vary over time is a key aspect of ecological research. Unfortunately, our understanding of population dynamics has historically been based on an assumption that individuals are identical with homogenous life-history properties. This assumption is certainly false for most natural systems, raising the question of what role individual variation plays in the dynamics of populations. While there has been an increase of interest regarding the effects of within population variation on the dynamics of single populations, there has been little study of the effects of differences in within population variation on patterns observed across populations. We found that life-history differences (clutch size) among individuals explained the majority of the variation observed in the degree to which population sizes of eastern fence lizards Sceloporus undulatus fluctuated. This finding suggests that differences across populations cannot be understood without an examination of differences at the level of a system rather than at the level of the individual [Current Zoology 58 (2): 358–362, 2012].


2020 ◽  
Vol 117 (50) ◽  
pp. 31754-31759
Author(s):  
Sang Hyun Choi ◽  
Vikyath D. Rao ◽  
Tim Gernat ◽  
Adam R. Hamilton ◽  
Gene E. Robinson ◽  
...  

The duration of interaction events in a society is a fundamental measure of its collective nature and potentially reflects variability in individual behavior. Here we performed a high-throughput measurement of trophallaxis and face-to-face event durations experienced by a colony of honeybees over their entire lifetimes. The interaction time distribution is heavy-tailed, as previously reported for human face-to-face interactions. We developed a theory of pair interactions that takes into account individual variability and predicts the scaling behavior for both bee and extant human datasets. The individual variability of worker honeybees was nonzero but less than that of humans, possibly reflecting their greater genetic relatedness. Our work shows how individual differences can lead to universal patterns of behavior that transcend species and specific mechanisms for social interactions.


Diagnostics ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 170 ◽  
Author(s):  
Asseel Khalaf ◽  
Caroline L. Hoad ◽  
Elaine Blackshaw ◽  
Jaber Alyami ◽  
Robin C. Spiller ◽  
...  

Measurement of gastric emptying is of clinical value for a range of conditions. Gamma scintigraphy (GS) has an established role, but the use of magnetic resonance imaging (MRI) has recently increased. Previous comparison studies between MRI and GS showed good correlation, but were performed on separate study days. In this study, the modalities were alternated rapidly allowing direct comparison with no intra-individual variability confounds. Twelve healthy participants consumed 400 g of Technetium-99m (99mTc)-labelled soup test meal (204 kcal) and were imaged at intervals for 150 min, alternating between MRI and GS. The time to empty half of the stomach contents (T1/2) and retention rate (RR) were calculated and data correlated. The average T1/2 was similar for MRI (44 ± 6 min) and GS (35 ± 4 min) with a moderate but significant difference between the two modalities (p < 0.004). The individual T1/2 values were measured, and MRI and GS showed a good positive correlation (r = 0.95, p < 0.0001), as well as all the RRs at each time point up to 120 min. Gastric emptying was measured for the first time by MRI and GS on the same day. This may help with translating the use of this simple meal, known to elicit reliable, physiological, and pathological gastrointestinal motor, peptide, and appetite responses.


2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Chang-Hee Han ◽  
Jeong-Hwan Lim ◽  
Jun-Hak Lee ◽  
Kangsan Kim ◽  
Chang-Hwan Im

It has frequently been reported that some users of conventional neurofeedback systems can experience only a small portion of the total feedback range due to the large interindividual variability of EEG features. In this study, we proposed a data-driven neurofeedback strategy considering the individual variability of electroencephalography (EEG) features to permit users of the neurofeedback system to experience a wider range of auditory or visual feedback without a customization process. The main idea of the proposed strategy is to adjust the ranges of each feedback level using the density in the offline EEG database acquired from a group of individuals. Twenty-two healthy subjects participated in offline experiments to construct an EEG database, and five subjects participated in online experiments to validate the performance of the proposed data-driven user feedback strategy. Using the optimized bin sizes, the number of feedback levels that each individual experienced was significantly increased to 139% and 144% of the original results with uniform bin sizes in the offline and online experiments, respectively. Our results demonstrated that the use of our data-driven neurofeedback strategy could effectively increase the overall range of feedback levels that each individual experienced during neurofeedback training.


1932 ◽  
Vol 55 (4) ◽  
pp. 653-665 ◽  
Author(s):  
Robert P. Bogniard ◽  
George H. Whipple

When hemoglobin is set free in the circulation the kidney plays an important part in the conservation of iron. When the renal threshold is not exceeded by the hemoglobin in the blood there is little or no excess iron deposited in the kidney but when superthreshold doses of blood hemoglobin are given the epithelium of the convoluted tubules accumulates much iron and the iron analyses may show 5 times normal values. The normal dog (140 to 150 per cent hemoglobin) has a large reserve store of iron in the liver, spleen and marrow. Diets may modify this storage of iron in these tissues. To bring conclusive proof relating to the individual diet factors, the reserve store of iron should be depleted by an anemia period of 2 to 3 months. Complete removal of red cells from tissue capillaries is essential for accurate iron assays of fresh tissue. The method described accomplishes this without causing gross tissue edema. The lowest iron content is observed in the pancreas, stomach, jejunum, colon and urinary bladder. These figures average from 1 to 2 mg. iron per 100 gm. fresh tissue. This shows that smooth muscle and mucous membranes contain little iron. Striated muscle (heart, psoas) shows a relatively low iron content but uniform values close to 4 mg. per 100 gm. tissue. Lungs show a considerable fluctuation with low iron values in anemia (3.7 mg.) and higher values in health (6 to 7 mg.). The spleen shows maximal fluctuations and the highest reserve storage of iron per 100 gm. fresh tissue. The spleen iron analyses show low values in anemia (7 to 15 mg.) and wide differences in controls (25 to 50 mg.). With hemoglobin injections the iron storage is conspicuous and iron analyses may run as high as l50 to 175 mg. iron per 100 gm. fresh tissue. Bone marrow of the rib runs in parallel with the spleen as regards iron storage following hemoglobin injections and depletion following anemia periods. The liver because of its weight always contains the main bulk of the iron stored in the blood free tissues of the body. Its store is depleted by anemia even to levels of 4 to 5 mg. iron per 100 gm. fresh tissue. In the normal dog the iron store in the liver averages 25 mg. per 100 gm. tissue. Frequent hemoglobin injections may increase this level to 31 mg. iron per 100 gm. The liver is considered the most active clearing house for iron storage and utilization.


1974 ◽  
Vol 22 (11) ◽  
pp. 1019-1027 ◽  
Author(s):  
IZHAK NIR ◽  
DANIEL C. PEASE

Kidney tissue, incubated in a phosphate-sucrose buffer with diaminobenzidine (DAB), subsequently was embedded in polymerized glutaraldehyde-urea (Pease and Peterson, 1972). The highly polar character of this embedment retains lipids in ultrathin sections and thus permits a precise localization of reaction products in relation to cytomembranes. Furthermore, since conventional organic solvents are not used during processing, it is thought that oxidized DAB polymers certainly remain in place. Their density can be enhanced by exposing mounted sections to OsO4 vapor, rather than by en bloc staining. DAB oxidation takes place only in the compartment between the inner and outer mitochondrial membranes. When aldehyde-fixed tissue is incubated, the deposits are largely limited to the intracristal spaces, whereas when fresh tissue is incubated, the entire compartment is uniformly filled. Morphologic features of fresh, unfixed tissue are stabilized by ethylene glycol and so survive incubation best when about 30% of this substance is added to the medium.


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