Sample Size and Geometric Morphometrics Methodology Impact the Evaluation of Morphological Variation.

Geometric morphometrics has had a profound impact on our understanding of morphological evolution. However, factors such as sample size and the views and elements selected for two-dimensional geometric morphometric (2DGM) analyses, which are often dictated by specimen availability and time rather than study design, may affect the outcomes of those analyses. Leveraging large intraspecific sample sizes (n > 70) for two bat species, Lasiurus borealis and Nycticeius humeralis, we evaluate the impact of sample size on calculations of mean shape, shape variance, and centroid size. Additionally, we assessed the concordance of multiple skull 2D views with one another and characterized morphological variation in skull shape in L. borealis and N. humeralis, as well as a closely related species, Lasiurus seminolus. Given that L. seminolus is a morphologically cryptic species with L. borealis, we assessed whether differences in skull shape and in 2DGM approach would allow species discrimination. We found that reducing sample size impacted mean shape and increased shape variance, that shape differences were not consistent across views or skull elements, and that trends shown by the views and elements were not all strongly associated with one another. Further, we found that L. borealis and L. seminolus were statistically different in shape using 2DGM in all views and elements. These results underscore the importance of selecting appropriate sample sizes, 2D views, and elements based on the hypothesis being tested. While there is likely not a generalizable sample size or 2D view that can be employed given the wide variety of research questions and systems evaluated using 2DGM, a generalizable solution to issues with 2DGM presented here is to run preliminary analyses using multiple views, elements, and sample sizes, thus ensuring robust conclusions.

A morfometria geométrica teve um impacto profundo na compreensão da evolução morfológica. No entanto, fatores como o tamanho amostral, vista anatômica e os elementos selecionados para as análises de morfometria geométricas bidimensionais (MG2D), que geralmente são determinados pela disponibilidade de espécimes e de tempo ao invés do design de estudo, podem afetar os resultados dessas análises. Utilizando grandes tamanhos de amostra intraespecífica (n > 70) em duas espécies de morcegos, Lasiurus borealis e Nycticeius humeralis, avaliamos o impacto do tamanho amostral nos cálculos da média e da variância da forma, e do tamanho do centroide. Adicionalmente, avaliamos a concordância entre vários planos 2D do crânio e caracterizamos a variação morfológica da forma cranial em L. borealis e N. humeralis, bem como em uma outra espécie proximamente relacionada, Lasiurus seminolus. Dado que L. seminolus é uma espécie morfologicamente críptica em relação a L. borealis, avaliamos se as diferenças no formato do crânio e na abordagem de MG2D utilizada permitiriam discriminar as espécies. Descobrimos que a redução do tamanho da amostra impactou o formato médio e aumentou a variância da forma, que as diferenças na forma não foram consistentes entre as vistas ou elementos cranianos, e que as tendências apresentadas pelos planos anatômicos e pelos elementos não foram fortemente associadas umas às outras. Adicionalmente, constatamos que as formas de L. borealis e L. seminolus, quantificadas por MG2D, foram estatisticamente diferentes em todas as vistas e elementos. Esses resultados enfatizam a importância em selecionar tamanhos amostrais, vistas 2D e elementos anatômicos adequados, com base na hipótese testada. Devido à grande diversidade de perguntas de pesquisa e de sistemas avaliados com MG2D, provavelmente não exista um tamanho amostral ou vista 2D que possam ser aplicados de forma generalizada. No entanto, uma solução geral para os problemas envolvendo MG2D aqui apresentados é conduzir análises preliminares utilizando várias vistas anatômicas, elementos e tamanhos amostrais, garantindo assim conclusões mais robustas.

Paediatric dental A&E service during the COVID-19 pandemic in the Greater London area.

PURPOSE: The UK government introduced a nationwide lockdown on the 23rd March 2020 to prevent the spread of COVID-19. All elective hospital and dental practice assessments and procedures were mandated to stop. Key hospital dental workers were required to work, and Guy's and St Thomas' NHS Foundation Trust became a designated Urgent Dental Care Centre (UDC) for the greater London area. The paediatric dental emergency walk-in service was suspended and replaced with a telephone triage system and evaluation of digital images sent by parents/carers when needed. The aim of this paper is to describe the emergency service provided by staff in the department of Paediatric Dentistry at St Thomas' Hospital during the first lockdown. METHODS: A prospective service evaluation of the modified paediatric dental emergency service was carried out between 25th March and 29th May 2020. RESULTS: Four-hundred and sixty-four patients accessed the paediatric dental emergency service via telephone during the service evaluation period. Of these, 192 (41%) had dental pain, 121 (26%) had pain and swelling of dental origin, and 89 (19%) had trauma. CONCLUSIONS: Remote telephone consultations and digital photographs were useful to screen emergency paediatric dental patients, but lack of face-to-face consultations with radiographic assessment and access to general anaesthetic services were major limiting factors.

Biomaterial-based endochondral bone regeneration: a shift from traditional tissue engineering paradigms to developmentally inspired strategies.

There is an urgent, clinical need for an alternative to the use of autologous grafts for the ever increasing number of bone grafting procedures performed annually. Herein, we describe a developmentally inspired approach to bone tissue engineering, which focuses on leveraging biomaterials as platforms for recapitulating the process of endochondral ossification. To begin, we describe the traditional biomaterial-based approaches to tissue engineering that have been investigated as methods to promote in vivo bone regeneration, including the use of three-dimensional biomimetic scaffolds, the delivery of growth factors and recombinant proteins, and the in vitro engineering of mineralized bone-like tissue. Thereafter, we suggest that some of the hurdles encountered by these traditional tissue engineering approaches may be circumvented by modulating the endochondral route to bone repair and, to that end, we assess various biomaterials that can be used in combination with cells and signaling factors to engineer hypertrophic cartilaginous grafts capable of promoting endochondral bone formation. Finally, we examine the emerging trends in biomaterial-based approaches to endochondral bone regeneration, such as the engineering of anatomically shaped templates for bone and osteochondral tissue engineering, the fabrication of mechanically reinforced constructs using emerging three-dimensional bioprinting techniques, and the generation of gene-activated scaffolds, which may accelerate the field towards its ultimate goal of clinically successful bone organ regeneration.

Evaluating the Antibacterial Properties of Polyacetylene and Glucosinolate Compounds with Further Identification of Their Presence within Various Carrot (Daucus carota) and Broccoli (Brassica oleracea) Cultivars Using High-Performance Liquid Chromatography with a Diode Array Detector and Ultra Performance Liquid Chromatography-Tandem Mass Spectrometry Analyses.

Ongoing consumer concerns over using synthetic additives in foods has strongly influenced efforts worldwide to source suitable natural alternatives. In this study, the antibacterial efficacy of polyacetylene and glucosinolate compounds was evaluated against both Gram positive and Gram negative bacterial strains. Falcarinol [minimum inhibitory concentration (MIC) = 18.8-37.6 µg/mL] demonstrated the best overall antibacterial activity, while sinigrin (MIC = 46.9-62.5 µg/mL) was the most active glucosinolate compound. High-performance liquid chromatography with a diode array detector analysis showed falcarinol [85.13-244.85 µg/g of dry weight (DW)] to be the most abundant polyacetylene within six of the eight carrot (Daucus carota) cultivars investigated. Meanwhile, sinigrin (100.2-244.3 µg/g of DW) was the most abundant glucosinolate present within the majority of broccoli (Brassica oleracea) cultivars investigated using ultra performance liquid chromatography-tandem mass spectrometry analysis. The high abundance of both falcarinol and sinigrin within these respective species suggests that they could serve as potential sources of natural antibacterial agents for use as such in food products.

Tissue engineering scaled-up, anatomically shaped osteochondral constructs for joint resurfacing.

Arthroplasty is currently the only surgical procedure available to restore joint function following articular cartilage and bone degeneration associated with diseases such as osteoarthritis (OA). A potential alternative to this procedure would be to tissue-engineer a biological implant and use it to replace the entire diseased joint. The objective of this study was therefore to tissue-engineer a scaled-up, anatomically shaped, osteochondral construct suitable for partial or total resurfacing of a diseased joint. To this end it was first demonstrated that a bone marrow derived mesenchymal stem cell seeded alginate hydrogel could support endochondral bone formation in vivo within the osseous component of an osteochondral construct, and furthermore, that a phenotypically stable layer of articular cartilage could be engineered over this bony tissue using a co-culture of chondrocytes and mesenchymal stem cells. Co-culture was found to enhance the in vitro development of the chondral phase of the engineered graft and to dramatically reduce its mineralisation in vivo. In the final part of the study, tissue-engineered grafts (~ 2 cm diameter) mimicking the geometry of medial femorotibial joint prostheses were generated using laser scanning and rapid prototyped moulds. After 8 weeks in vivo, a layer of cartilage remained on the surface of these scaled-up engineered implants, with evidence of mineralisation and bone development in the underlying osseous region of the graft. These findings open up the possibility of a tissue-engineered treatment option for diseases such as OA.

Investigating geographic variation in mortality in the context of organ donation.

Organ procurement organizations (OPOs) report a nearly fourfold difference in donor availability as measured by eligible deaths per million population (PMP) based on hospital referrals. We analyzed whether mortality data help explain geographic variation in organ supply as measured by the number of eligible deaths for organ donation. Using the 2007 National Center for Health Statistics' mortality data, we analyzed deaths occurring in acute care hospitals, aged ≤ 70 years from cerebrovascular accidents and trauma. These deaths were mapped at the county level and compared to eligible deaths reported by OPOs. In 2007, there were 2 428 343 deaths reported in the United States with 42 339 in-hospital deaths ≤ 70 years from cerebrovascular accidents (CVA) or trauma that were correlated with eligible deaths PMP (r(2) = 0.79.) Analysis revealed a broad range in the death rate across OPOs: trauma deaths: 44-118 PMP; deaths from CVA: 34-118 PMP; and combined CVA and trauma: 91-229 PMP. Mortality data demonstrate that deaths by neurologic criteria of people who are likely to be suitable deceased donors are not evenly distributed across the nation. These deaths are correlated with eligible deaths for organ donation. Regional availability of organs is affected by deaths which should be accounted for in the organ allocation system.

The isolation of bifidobacteria from occlusal carious lesions in children and adults.

The aim of this study was to enumerate and identify bifidobacteria from occlusal carious lesions in permanent and deciduous teeth. Samples of infected dentine were obtained from 24 active occlusal lesions in deciduous teeth and from 15 occlusal lesions in permanent teeth. Plaque samples from sound occlusal surfaces of 12 caries-free adults and 12 children were also obtained. The bifidobacterial strains were isolated in mupirocin-containing selective media, Gram-stained and subcultured for identification. Total bacterial counts were determined using fastidious anaerobic agar, and isolates were identified using genus-specific PCR primers and were confirmed by 16S rRNA sequencing. Bifidobacteria were isolated from 13 of the 15 occlusal lesions in the adults and formed 5.09 +/- 2.11% of the total cultivable flora. In the children, bifidobacteria were isolated from 16 of the 24 occlusal lesions and formed 7.4 +/- 2.6% of the total flora. No bifidobacteria were isolated from the occlusal surfaces of caries-free adults or children. A total of 424 bifidobacteria were identified and these were Bifidobacteriumdentium, Parascardovia denticolens, Scardoviainopicata, Bifidobacterium longum, Scardovia genomosp. C1 and Bifidobacterium breve. B. dentium was present in 14 out of the 16 bifidobacteria-positive samples from the lesions on the deciduous teeth and in 7 out of the 13 positive lesions in adults (p = 0.04). The present data suggest that bifidobacteria may play a role in the progression of occlusal caries lesions in both children and adults.

Antimicrobial properties of dentine bonding agents determined using in vitro and ex vivo methods.

AIMS: To determine the antimicrobial properties of a selection of dentine bonding agents [DBAs] using the disc diffusion and direct contact methods and an ex vivo method using extracted carious permanent molar teeth. METHODS: DBAs (n=15) were tested using Streptococcus mutans UA159 in disc diffusion and direct contact methods. In the ex vivo study 6 DBAs were selected and pre- and post-treatment samples of carious dentine (n< or =12) were taken. Samples were also taken post-acid-etching. The number of microorganisms in dentine sample was determined and compared. RESULTS: The inhibition zones and percent growth inhibition were related to the pH of the culture medium containing the DBA (p<0.01). Clearfill Protect Bond exhibited the greatest bacterial killing followed by ibond (99.8%+/-0.08 and 98.2+/-1.4, respectively). The phosphoric acid etchant alone resulted in an 83% killing. The in vitro tests results did not correlate. The ex vivo killing reflected the percent growth inhibition observed in the direct contact method. CONCLUSION: A guide to the potential antimicrobial activity of a DBA may be gained from an assessment of its pH when added to bacteriological culture medium. The direct contact method gives a better reflection of the killing of bacteria in infected dentine than the disk diffusion method. Killing in the ex vivo model gives a more realistic and more reliable method for determining the antibacterial activity of a given DBA and that comparisons of the relative inhibitory activity of DBAs should be tested using this ex vivo model.

Diversity of Veillonella spp. from sound and carious sites in children.

Detailed data on the distribution of Veillonella in caries-free and caries-active subjects are scarce. We hypothesized that the diversity of the genus would be lower in caries lesions than in plaque from caries-free individuals. The proportions of Veillonella were not significantly different in the two groups. All isolates (n = 1308) were genotyped by REP-PCR, and different genotypes (n = 170) were identified by 16S rRNA, dnaK, and rpoB sequencing. V. parvula, V. dispar, and V. atypica were in both groups, V. denticariosi only in caries lesions, and V. rogosae only from the caries-free individuals (p < 0.009). Lesions were more likely to harbor a single predominant species (p = 0.0018). The mean number of genotypes in the lesions was less than in the fissure (p < 0.001) or buccal (p = 0.011) sites. The Veillonella from caries-free sites were more diverse than those from caries lesions, and may be related to the acidic environment of caries lesions.

Microbiological assessment of occlusal brown-spot lesions in primary molars.

Conventional cultural methods were used to compare the plaque flora and the level of infection of the dentine underlying 51 occlusal brown-spot lesions and 21 sound occlusal sites on the primary dentition. Freshly extracted primary molar teeth were used, and occlusal brown-spot lesions and sound occlusal sites were identified using laser fluorescence (LF) and clinical visual methods. A standardized plaque sample was taken from each site, and an LF score was recorded for one discrete site per tooth. The teeth were carefully opened at each predetermined site to determine the clinical status of the underlying dentine, and samples were collected using a sterile bur. The microbiota of the plaque and dentine samples were enumerated and identified. The mean LF scores for the sound sites and brown-spot lesions were 1.2 and 30.5 (p < 0.001), and all the sound sites exhibited hard sound dentine, but 6 out of 51 brown spots exhibited softened dentine. Overall there was no significant (p > 0.1) difference between the level of infection of the dentine of the sound and brown-spot sites, although some sites in the brown-spot lesions yielded high numbers of bacteria. However, the numbers of bacteria as log10(CFU per sample + 1) +/- SE recovered from the plaque above the brown-spot lesions were significantly greater than above the sound sites, i.e. 2.89 +/- 0.24 and 0.89 +/- 0.33, respectively. These data indicate that brown-spot lesions may be more plaque retentive than sound sites and that they are either arrested or arresting lesions, which may require preventive intervention.

Sotos syndrome with hypodontia.

Sotos syndrome, or cerebral gigantism, is a rare genetic condition characterized by tall stature, gigantism, dolichocephaly, advanced bone age and learning disability. The purpose of this case report is to highlight the dental management of a 10-year-old boy with Sotos syndrome who presented with hypodontia and dental caries.

Intraligamental analgesia for post-operative pain control in children having dental extractions under general anaesthesia.

AIM: This was to assess the effectiveness and safety of intraligamental local analgesia (ILA) for postoperative pain control in children having dental extractions under general anaesthesia (GA). The variables affecting the effectiveness of ILA were also investigated. METHODS: Data were collected from children having permanent molars extracted under GA using a randomised half mouth study design. ILA (bupivicaine 0.5% with 1:200,000 adrenaline) was used on the randomly assigned experimental side prior to extraction of the teeth, and the contralateral control side received no ILA. Children were interviewed pre- and post-operatively by the principal investigator (PA) who was blind to the side of ILA. Pre- and post-operative anxiety levels of each child were measured using the Venham Picture Test (VPT). Patients were asked to rate which side was better in terms of pain control, whether they felt numbness and whether they preferred the numbness. Their post-operative pain levels were also measured using the visual analogue scale (VAS). Self-inflicted trauma following ILA was noted. RESULTS: Thirty children, with a mean age of 11.3 years (SD+/-1.7) completed the study. None of the patients had self-inflicted soft tissue trauma following ILA. Nineteen children (63%) found that pain control was better post-operatively on the side with ILA. Twenty-one children (70%) reported numbness following ILA of whom 14 (67%) said that they preferred this. VAS scores were not significantly different between the experimental and control sides. A higher percentage of boys (85%) than girls (47%) rated the ILA side "better" (p = 0.034). VPT scores were significantly higher for girls postoperatively (p = 0.048). CONCLUSION: ILA was a useful and safe adjunct for postoperative pain control in children having permanent teeth extracted under GA. The technique was found to be more effective in boys than girls. However, less than half the children in this study preferred the side with numbness. Further research is needed to determine effective methods of pain control in children following dental GA and to investigate the reasons for gender differences of pain perception in children.

The microflora of the erupting first permanent molar.

The relationship between microflora, eruption status and caries status in the first permanent molar of young children was investigated in 177 children aged 6-7 years. A significantly greater proportion of fully erupted teeth were classified as sound and plaque-free compared to partially erupted teeth. Fully erupted teeth yielded greater numbers and proportions of mutans streptococci compared with significantly greater numbers and proportions of Actinomyces israelii in partially erupted teeth. Logistical regression analysis showed significant associations between white spot lesions in partially erupted teeth and increased numbers of Streptococcus oralis, mutans streptococci and Streptococcus salivarius whereas the presence of Actinomyces naeslundii was associated with health. Significantly greater numbers and proportions of S. oralis and S. salivarius were isolated from partially erupted teeth with white spot lesions whereas Streptococcus mutans was isolated in significantly greater numbers and proportions from fully erupted molars with white spots. This study suggests that organisms other than mutans streptococci are associated with caries development in erupting permanent molar teeth.

Nasopalatine duct cyst: a case report.

A case of a nasopalatine duct cyst is reported in an 8-year-old. The clinical presentation was of intermittent palatal swelling and the diagnosis was confirmed with radiological and histological examination. This type of cyst is rare in children and should not be excluded from a differential diagnosis in younger age groups.

Macrodontia of a mandibular second premolar: a case report.

Localized macrodontia is very rare. The majority of cases have been reported in mandibular second premolars. This paper describes the dental management of a child who presented with macrodontia of a mandibular right second premolar.

Comparison between visual examination and a laser fluorescence system for in vivo diagnosis of occlusal caries.

This study compared a laser fluorescence (LF) system (DIAGNOdent) with a visual caries scoring system for in vivo detection and diagnosis of occlusal caries under the conditions of an epidemiological study, in 132 mandibular and 38 maxillary first permanent molars in 170 children (mean age: 6.85 +/- 0.58 years). The teeth were cleaned and occlusal caries status in a selected investigation site recorded using both visual and LF systems. The LF readings were interpreted both according to the cut-off points recommended by the manufacturers and those based on laboratory research with histological validation. The percentage agreement of the LF and visual scoring system was better using the cut-off limits recommended by the manufacturer. Histological validation was not possible in this clinical study, but it appeared that either the LF method was overscoring some lesions or the visual method was underscoring them. Since the LF instrument cannot be expected to differentiate caries from hypomineralisation, it should probably be used as an adjunct to a clinical examination.

Genotypic heterogeneity of Streptococcus oralis and distinct aciduric subpopulations in human dental plaque.

The genotypic heterogeneity of Streptococcus oralis isolated from the oral cavity was investigated using repetitive extragenic palindromic PCR. Unrelated subjects harbored unique genotypes, with numerous genotypes being isolated from an individual. S. oralis is the predominant aciduric bacterium isolated from noncarious tooth sites. Genotypic comparison of the aciduric populations isolated at pH 5.2 with those isolated from mitis-salivarius agar (MSA) (pH 7.0) indicated that the aciduric populations were genotypically distinct in the majority of subjects (chi(2) = 13.09; P = 0.0031). Neither the aciduric nor the MSA-isolated strains were stable, with no strains isolated at baseline being isolated 4 or 12 weeks later in the majority of subjects. The basis of this instability is unknown but is similar to that reported for Streptococcus mitis. Examination of S. oralis strains isolated from cohabiting couples demonstrated that in three of five couples, genotypically identical strains were isolated from both partners and this was confirmed by using Salmonella enteritidis repetitive element PCR and enterobacterial PCR typing. These data provide further evidence of the physiological and genotypic heterogeneity of non-mutans streptococci. The demonstration of distinct aciduric populations of S. oralis implies that the role of these and other non-mutans streptococci in the caries process requires reevaluation.

The oral microbiota of children undergoing liver transplantation.

This study investigated the oral microbiota of children undergoing liver transplantation. Oral swabs were taken using a standardized procedure from 27 children before liver transplantation and at 3 and 100 days post-transplantation and from 27 healthy controls at baseline and 90 days. Viridans streptococci, yeasts, staphylococci, enterococci and Enterobacteriaceae were enumerated and identified using conventional techniques. The oral microbiota of the patients changed significantly immediately post-transplantation, but by the final examination, it had returned to baseline levels. The oral microbiota of the controls did not change significantly. The numbers and proportions of Streptococcus salivarius, Streptococcus sanguis and Streptococcus gordonii as percentages of the total streptococcal counts and of the total anaerobic counts decreased significantly 3 days post-transplantation (P < or = 0.006). There were no significant changes in the numbers and proportions of Streptococcus oralis and Streptococcus mitis isolated pre- and post-transplantation. The isolation frequencies and numbers of yeasts were significantly higher in patients than controls. Staphylococci were isolated in low numbers from all children. Enterococci and Enterobacteriaceae were isolated infrequently from patients.

Oral health in children undergoing liver transplantation.

AIMS: To determine the prevalence of dental caries in children undergoing liver transplantation and to compare the plaque, gingivitis, and gingival overgrowth indices and oral mucosal lesions in children before and after liver transplantation. PATIENTS AND METHODS: Patients undergoing liver transplantation at King's College Hospital were examined before transplantation, at 3 and 106 days post-transplantation. Healthy children from the Greenwich Health District, south-east London, were matched to the liver transplant patients by age, gender, socio-economic factors and the presence or absence of active dental caries. RESULTS: Twenty-seven liver transplant patients (mean age: 7 years and 10 months; SD 3 years and 5 months) and 27 controls (mean age: 8 years and 6 months; SD 3 years and 7 months) were examined. The mean dmft and DMFT scores were 2.3 (SD 4.1) and 0.8 (SD 1.4), respectively, in the liver transplant patients, and 1.2 (SD 2.2) and 0.9 (SD 1.5), respectively, in the controls. There were no significant differences between either the mean plaque or gingivitis indices for the primary and permanent teeth in patients before and after transplantation. There were no significant differences between the liver transplant patients and the controls for either mean plaque or gingivitis indices at each examination time. Gingival overgrowth was present in 41% of liver recipients receiving cyclosporin with or without nifedipine, but not in the majority receiving tacrolimus at the final examination. Oral mucosal lesions were absent in both the patients and controls at each examination time. CONCLUSIONS: The oral health of the children undergoing liver transplantation was inadequate. Funding and implementation of an oral health care programme must become a priority for all children before and after liver transplantation.

The dental management of a child with LEOPARD syndrome.

This report describes the dental management of a child with LEOPARD syndrome who presented with multiple grossly carious primary teeth. Comprehensive dental care was carried out under general anaesthesia.