scholarly journals Morphofunctional compensation of masseter muscles in unilateral posterior crossbite patients

2016 ◽  
Vol 60 (2) ◽  
Author(s):  
G. Cutroneo ◽  
G. Vermiglio ◽  
A. Centofanti ◽  
G. Rizzo ◽  
M. Runci ◽  
...  

Unilateral posterior crossbite is a widespread, asymmetric malocclusion characterized by an inverse relationship of the upper and lower buccal dental cusps, in the molar and premolar regions, on one side only of the dental arch. Patients with unilateral posterior crossbite exhibit an altered chewing cycles and the crossbite side masseter results to be less active with respect to the contralateral one. Few studies about morphological features of masticatory muscle in malocclusion disorders exist and most of these have been performed on animal models. The aim of the present study was to evaluate morphological and protein expression characteristics of masseter muscles in patients affected by unilateral posterior crossbite, by histological and immunofluorescence techniques. We have used antibody against PAX-7, marker of satellite cells, and against α-, β-, γ-, δ-, ε- and ζ-sarcoglycans which are transmembrane glycoproteins involved in sarcolemma stabilization. By statistical analysis we have evaluated differences in amount of myonucley between contralateral and ipsilateral side. Results have shown: i) altered fibers morphology and atrophy of ipsilateral muscle if compared to the contralateral one; ii) higher number of myonuclei and PAX-7 positive cells in contralateral side than ipsilateral one; iii) higher pattern of fluorescence for all tested sarcoglycans in contralateral side than ipsilateral one. Results show that in unilateral posterior crossbite hypertrophic response of contralateral masseter and atrophic events in ipsilateral masseter take place; by that, in unilateral posterior crossbite malocclusion masticatory muscles modify their morphology depending on the function. That could be relevant in understanding and healing of malocclusion disorders; in fact, the altered balance about structure and function between ipsilateral and contralateral muscles could, long-term, lead and/ or worsen skeletal asymmetries.

Medicina ◽  
2009 ◽  
Vol 45 (2) ◽  
pp. 147 ◽  
Author(s):  
Antanas Šidlauskas ◽  
Kristina Lopatienė

The epidemiological data on the prevalence of malocclusion is an important determinant in planning appropriate levels of orthodontic services. The occurrence of occlusal anomalies varies between different countries, ethnic and age groups. The aim of this study was to describe the prevalence of malocclusion among Lithuanian schoolchildren in the 7–9-, 10– 12-, and 13–15-year age groups assessing occlusal morphology. The study included 1681 schoolchildren aged 7–15 years. The crowding, spacing, overbite, overjet, the relationship of the first upper and lower molars according Angle’s classification, and posterior crossbite were assessed. The study demonstrated that only 257 children had normal occlusion, and 44 had undergone orthodontic treatment among them. The greatest overjet in the studied contingent was 11 mm, and the negative overjet – 3 mm. The overbite ranged between 0 and 6 mm with a mean of 2.29±1.23 mm. Posterior crossbite was recorded in 148 children (8.8%). This study showed that the prevalence of malocclusion among 7–15-year-old Lithuanian schoolchildren is 84.6%. The most common malocclusion was dental crowding. The upper dental arch crowding was registered for 44.1% and lower for 40.3% of all schoolchildren. The class I molar relationship was detected in 68.4% of the subjects, class II – in 27.7%, and class III – in 2.8%.


Author(s):  
Amin G. Ades ◽  
Donald R. Joondeph ◽  
Robert M. Little ◽  
Michael K. Chapko

2021 ◽  
Vol 11 (10) ◽  
pp. 4649
Author(s):  
Giovanna Vermiglio ◽  
Antonio Centofanti ◽  
Maria Grazia Piancino ◽  
Maria Chiara Malandrino ◽  
Michele Runci Anastasi ◽  
...  

Unilateral posterior crossbite is a malocclusion disease that involves morpho-functional characteristics of masseter muscle; a normal or increased activity of contralateral muscle and a reduced activity of the ipsilateral muscle during unilateral crossbite have been shown. Since the extracellular matrix plays a key role in in mechano-transduction of transmitting forces during muscle contraction, the aim of the present study was to analyse the behaviour of extracellular matrix in this type of malocclusion through immunofluorescence reactions against laminin, collagen IV, MMP-2 and MMP-9. Our results show an increased expression of Laminin, Collagen IV, and MMP-9 in the contralateral side if compared to the ipsilateral side. No differences have been found in MMP-2 expression between contralateral and ipsilateral muscles. Since the increased expression of Laminin, Collagen IV and MMP-9 is associated with muscle hypertrophy and MMP-2 is associated with muscle atrophy, our results support the existence of a hypertrophic response of contralateral muscle during unilateral posterior crossbite that probably aims to compensate the altered function of the ipsilateral one.


2020 ◽  
Vol 5 (4) ◽  
pp. 80
Author(s):  
Giovanna Vermiglio ◽  
Antonio Centofanti ◽  
Guglielmo Ramieri ◽  
Michele Tepedino ◽  
Michele Runci Anastasi ◽  
...  

A unilateral posterior crossbite is a malocclusion where the low activity of the affected masseter muscle is compensated by the contralateral muscle hypertrophy. It is still unknown if, in the same condition, myogenesis with new fibre formation takes place. Aim: the aim of the present study was to evaluate the expression of myogenesis markers, such as Myf5 and MyoD, in masseter muscles of unilateral posterior crossbite patients. Materials and methods: biopsies from fifteen surgical patients with unilateral posterior crossbites have been analysed by immunofluorescence reactions. The results show the expression of Myf5 and MyoD in the contralateral muscle but not in the ipsilateral one. Moreover, statistical analysis shows the higher number of satellite cells in the contralateral side if compared to the ipsilateral one. Conclusions: these results suggest that in contralateral muscle, hyperplastic events take place, as well as hypertrophy.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Xin Mao ◽  
Jun Kang Chow ◽  
Pin Siang Tan ◽  
Kuan-fu Liu ◽  
Jimmy Wu ◽  
...  

AbstractAutomatic bird detection in ornithological analyses is limited by the accuracy of existing models, due to the lack of training data and the difficulties in extracting the fine-grained features required to distinguish bird species. Here we apply the domain randomization strategy to enhance the accuracy of the deep learning models in bird detection. Trained with virtual birds of sufficient variations in different environments, the model tends to focus on the fine-grained features of birds and achieves higher accuracies. Based on the 100 terabytes of 2-month continuous monitoring data of egrets, our results cover the findings using conventional manual observations, e.g., vertical stratification of egrets according to body size, and also open up opportunities of long-term bird surveys requiring intensive monitoring that is impractical using conventional methods, e.g., the weather influences on egrets, and the relationship of the migration schedules between the great egrets and little egrets.


Author(s):  
Robert Stojanov ◽  
Sarah Rosengaertner ◽  
Alex de Sherbinin ◽  
Raphael Nawrotzki

AbstractDevelopment cooperation actors have been addressing climate change as a cross-cutting issue and investing in climate adaptation projects since the early 2000s. More recently, as concern has risen about the potential impacts of climate variability and change on human mobility, development cooperation actors have begun to design projects that intentionally address the drivers of migration, including climate impacts on livelihoods. However, to date, we know little about the development cooperation’s role and function in responding to climate related mobility and migration. As such, the main aim of this paper is to outline the policy frameworks and approaches shaping development cooperation actors’ engagement and to identify areas for further exploration and investment. First, we frame the concept of climate mobility and migration and discuss some applicable policy frameworks that govern the issue from various perspectives; secondly, we review the toolbox of approaches that development cooperation actors bring to climate mobility; and third, we discuss the implications of the current Covid-19 pandemic and identify avenues for the way forward. We conclude that ensuring safe and orderly mobility and the decent reception and long-term inclusion of migrants and displaced persons under conditions of more severe climate hazards, and in the context of rising nationalism and xenophobia, poses significant challenges. Integrated approaches across multiple policy sectors and levels of governance are needed. In addition to resources, development cooperation actors can bring data to help empower the most affected communities and regions and leverage their convening power to foster more coordinated approaches within and across countries.


2021 ◽  
Vol 61 (3) ◽  
pp. 320-340
Author(s):  
Kate Rousmaniere

AbstractThis essay examines the history of what is commonly called the town-gown relationship in American college towns in the six decades after the Second World War. A time of considerable expansion of higher education enrollment and function, the period also marks an increasing detachment of higher education institutions from their local communities. Once closely tied by university offices that advised the bulk of their students in off-campus housing, those bonds between town and gown began to come apart in the 1970s, due primarily to legal and economic factors that restricted higher education institutions’ outreach. Given the importance of off-campus life to college students, over half of whom have historically lived off campus, the essay argues for increased research on college towns in the history of higher education.


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