The developmental basis for scaling of mammalian tooth size.

When evolution leads to differences in body size, organs generally scale along. A well-known example of the tight relationship between organ and body size is the scaling of mammalian molar teeth. To investigate how teeth scale during development and evolution, we compared molar development from initiation through final size in the mouse and the rat. Whereas the linear dimensions of the rat molars are twice that of the mouse molars, their shapes are largely the same. Here, we focus on the first lower molars that are considered the most reliable dental proxy for size-related patterns due to their low within-species variability. We found that scaling of the molars starts early, and that the rat molar is patterned equally as fast but in a larger size than the mouse molar. Using transcriptomics, we discovered that a known regulator of body size, insulin-like growth factor 1 (Igf1), is more highly expressed in the rat molars compared to the mouse molars. Ex vivo and in vivo mouse models demonstrated that modulation of the IGF pathway reproduces several aspects of the observed scaling process. Furthermore, analysis of IGF1-treated mouse molars and computational modeling indicate that IGF signaling scales teeth by simultaneously enhancing growth and by inhibiting the cusp-patterning program, thereby providing a relatively simple mechanism for scaling teeth during development and evolution. Finally, comparative data from shrews to elephants suggest that this scaling mechanism regulates the minimum tooth size possible, as well as the patterning potential of large teeth.

An eosimiid primate of South Asian affinities in the Paleogene of Western Amazonia and the origin of New World monkeys.

Recent fossil discoveries in Western Amazonia revealed that two distinct anthropoid primate clades of African origin colonized South America near the Eocene/Oligocene transition (ca. 34 Ma). Here, we describe a diminutive fossil primate from Brazilian Amazonia and suggest that, surprisingly, a third clade of anthropoids was involved in the Paleogene colonization of South America by primates. This new taxon, Ashaninkacebus simpsoni gen. et sp. nov., has strong dental affinities with Asian African stem anthropoids: the Eosimiiformes. Morphology-based phylogenetic analyses of early Old World anthropoids and extinct and extant New World monkeys (platyrrhines) support relationships of both Ashaninkacebus and Amamria (late middle Eocene, North Africa) to the South Asian Eosimiidae. Afro-Arabia, then a mega island, played the role of a biogeographic stopover between South Asia and South America for anthropoid primates and hystricognathous rodents. The earliest primates from South America bear little adaptive resemblance to later Oligocene-early Miocene platyrrhine monkeys, and the scarcity of available paleontological data precludes elucidating firmly their affinities with or within Platyrrhini. Nonetheless, these data shed light on some of their life history traits, revealing a particularly small body size and a diet consisting primarily of insects and possibly fruit, which would have increased their chances of survival on a natural floating island during this extraordinary over-water trip to South America from Africa. Divergence-time estimates between Old and New World taxa indicate that the transatlantic dispersal(s) could source in the intense flooding events associated with the late middle Eocene climatic optimum (ca. 40.5 Ma) in Western Africa.

Mutation-specific pathophysiological mechanisms define different neurodevelopmental disorders associated with SATB1 dysfunction.

Whereas large-scale statistical analyses can robustly identify disease-gene relationships, they do not accurately capture genotype-phenotype correlations or disease mechanisms. We use multiple lines of independent evidence to show that different variant types in a single gene, SATB1, cause clinically overlapping but distinct neurodevelopmental disorders. Clinical evaluation of 42 individuals carrying SATB1 variants identified overt genotype-phenotype relationships, associated with different pathophysiological mechanisms, established by functional assays. Missense variants in the CUT1 and CUT2 DNA-binding domains result in stronger chromatin binding, increased transcriptional repression, and a severe phenotype. In contrast, variants predicted to result in haploinsufficiency are associated with a milder clinical presentation. A similarly mild phenotype is observed for individuals with premature protein truncating variants that escape nonsense-mediated decay, which are transcriptionally active but mislocalized in the cell. Our results suggest that in-depth mutation-specific genotype-phenotype studies are essential to capture full disease complexity and to explain phenotypic variability.

Assessment of the efficiency of DNA isolation and profiling applying a temperature-driven method in human remains.

The identification of human remains is of utmost importance in a variety of scenarios. One of the primary identification methods is DNA. DNA extraction from human remains could be difficult, particularly in situations where the remains have been exposed to environmental conditions and other insults. Several studies tried to improve extraction by applying different approaches. ForensicGEM Universal (MicroGem) is a single-tube approach to DNA extraction and a temperature-driven method that could have some advantages with respect to previous techniques, among them, reducing the risk of contamination, not requiring specialized equipment, or several steps to perform. The aim of this study was to assess, for the first time, the efficiency of DNA extraction and quality of STR profiles applying the MicroGem protocol and modifications of this protocol from tooth samples in comparison with automatic extraction (AE). Our results indicated that AE and MicroGem performed similar, though with variability depending on the MicroGem modifications, increasing the DNA yield and STR profile quality when DNA is concentrated with Microcon. These findings demonstrated the efficiency of this methodology for DNA extraction from human remains while also providing a simple and quick technique suitable to apply in a variety of forensic scenarios.

Age estimation in adults by canine teeth: a systematic review of the Cameriere method with meta-analysis on the reliability of the pulp/tooth area ratio.

The age estimation of an adult using methods accessible to the forensic routine is a goal pursued by forensic experts. Cameriere, Ferrante and Cingolani (2004) proposed the use of the pulp/tooth area ratio of canine teeth as a promising variable, but its reliability has shown conflicting results in the scientific literature. This article aimed to carry out a systematic review with meta-analysis to verify whether the pulp/tooth area ratio of canine teeth includes a variable that can be used alone to estimate dental age in adults. A systematic search was carried out in six databases using keywords related to the theme in Portuguese, English, and Spanish. The study selection process followed pre-established eligibility criteria. Assessments were carried out regarding risk of bias and publication bias of selected studies, and meta-analysis was carried out considering Pearson's correlation coefficient between pulp/tooth area ratio and chronological age as effect measure. Most selected studies showed low risk of bias; no publication bias was found when all studies were considered, and potential publication bias was found when outliers were removed. Despite the high heterogeneity among studies and the need for more research, it could be observed that the pulp/tooth area ratio has strong negative correlation with chronological age, and the pulp/tooth area ratio could be derived from both periapical radiographs and orthopantomographs. Therefore, it is suggested that there is scientific evidence that the pulp/tooth area ratio obtained from canine teeth is reliable for dental age estimation in adults.

Exosomes miR-92a-3p from human exfoliated deciduous teeth inhibits periodontitis progression via the KLF4/PI3K/AKT pathway.

BACKGROUND: Periodontitis is a chronic inflammatory disease mediated by dysbiosis of the oral microflora, resulting in the destruction of periodontal tissue. Increasing evidence suggested that mesenchymal stem cell (MSCs) and exosomes derived from MSCs play a critical role in periodontal tissue regeneration. However, whether stem cells from exfoliated deciduous teeth (SHED)-secreted exosomes can improve the therapeutic potential of periodontitis is largely unknown. OBJECTIVE: Here, we aim to evaluate the effect of SHED-exosomes on inflammation, apoptosis and osteogenic differentiation in periodontitis. METHODS: The periodontitis cell model was constructed by stimulating periodontal ligament stem cells (PDLSCs) with lipopolysaccharide (LPS), and the periodontitis rats were established by ligation. RESULTS: First, we isolated exosomes from the SHED, and we figured out that exosomes secreted by SHED were enriched in miR-92a-3p and the exosomes enhanced proliferation and osteogenic differentiation and reduced apoptosis and inflammatory responses in PDLSCs. In addition, we found that SHED-exosomes alleviated inflammatory effect and elevated the expression of osteogenic-related genes in periodontitis rat model. Moreover, miR-92a-3p targeted downstream Krüppel-Like Transcription Factor 4 (KLF4) and regulated the PI3K/AKT pathway. Finally, our data indicated that upregulation of KLF4 or activation of PI3K/AKT by 740Y-P counteracted the inhibitory effect of SHED-exosomes on periodontitis progression. CONCLUSION: Taken together, our finding revealed that exosomal miR-92a-3p derived from SHED contributed to the alleviation of periodontitis development and progression through inactivating the KLF4/PI3K/AKT signaling pathway, which may provide a potential target for the treatment of periodontitis.

Deciduous teeth from the New Hampshire birth cohort study: Early life environmental and dietary predictors of dentin elements.

BACKGROUND: Sparse research exists on predictors of element concentrations measured in deciduous teeth. OBJECTIVE: To estimate associations between maternal/child characteristics, elements measured in home tap water during pregnancy and element concentrations in the dentin of shed deciduous teeth. METHODS: Our analysis included 152 pregnant person-infant dyads followed from the second trimester through the end of the first postnatal year from the New Hampshire Birth Cohort Study. During pregnancy and early infancy, we collected dietary and sociodemographic information via surveys, measured elements in home tap water, and later collected naturally exfoliated teeth from child participants. We measured longitudinal deposition of elements in dentin using LA-ICP-MS. Multivariable linear mixed models were used to estimate associations between predictors and dentin element concentrations. RESULTS: We measured 12 elements in dentin including those previously reported (Ba, Mn, Pb, Sr, Zn) and less frequently reported (Al, As, Cd, Cu, Hg, Li, and W). A doubling of Pb or Sr concentrations in water was associated with higher dentin Pb or Sr respectively in prenatally formed [9% (95%CI: 3%, 15%); 3% (1%, 6%)] and postnatally formed [10% (2%, 19%); 6% (2%, 10%)] dentin. Formula feeding from birth to 6 weeks or 6 weeks to 4 months was associated with higher element concentrations in postnatal dentin within the given time period as compared to exclusive human milk feeding: Sr: 6 weeks: 61% (36%, 90%) and 4 months: 85% (54%, 121%); Ba: 6 weeks: 35% (3.3%, 77%) and 4 months: 42% (10%, 83%); and Li: 6 weeks: 61% (33%, 95%) and 4 months: 58% (31%, 90%). SIGNIFICANCE: These findings offer insights into predictors of dentin elements and potential confounders in exposure-health outcome relationships during critical developmental periods.

Functional extracellular vesicles from SHEDs combined with gelatin methacryloyl promote the odontogenic differentiation of DPSCs for pulp regeneration.

BACKGROUND: Pulp regeneration is a novel approach for the treatment of immature permanent teeth with pulp necrosis. This technique includes the combination of stem cells, scaffolds, and growth factors. Recently, stem cell-derived extracellular vesicles (EVs) have emerged as a new methodology for pulp regeneration. Emerging evidence has proven that preconditioning is an effective scheme to modify EVs for better therapeutic potency. Meanwhile, proper scaffolding is of great significance to protect EVs from rapid clearance and destruction. This investigation aims to fabricate an injectable hydrogel loaded with EVs from pre-differentiated stem cells from human exfoliated deciduous teeth (SHEDs) and examine their effects on pulp regeneration. RESULTS: We successfully employed the odontogenic induction medium (OM) of SHEDs to generate functional EV (OM-EV). The OM-EV at a concentration of 20 µg/mL was demonstrated to promote the proliferation and migration of dental pulp stem cells (DPSCs). The results revealed that OM-EV has a better potential to promote odontogenic differentiation of DPSCs than common EVs (CM-EV) in vitro through Alizarin red phalloidin, alkaline phosphatase staining, and assessment of the expression of odontogenic-related markers. High-throughput sequencing suggests that the superior effects of OM-EV may be attributed to activation of the AMPK/mTOR pathway. Simultaneously, we prepared a photocrosslinkable gelatin methacryloyl (GelMA) to construct an OM-EV-encapsulated hydrogel. The hydrogel exhibited sustained release of OM-EV and good biocompatibility for DPSCs. The released OM-EV from the hydrogel could be internalized by DPSCs, thereby enhancing their survival and migration. In tooth root slices that were subcutaneously transplanted in nude mice, the OM-EV-encapsulated hydrogel was found to facilitate dentinogenesis. After 8 weeks, there was more formation of mineralized tissue, as well as higher levels of dentin sialophosphoprotein (DSPP) and dentin matrix protein-1 (DMP-1). CONCLUSIONS: The effects of EV can be substantially enhanced by preconditioning of SHEDs. The functional EVs from SHEDs combined with GelMA are capable of effectively promoting dentinogenesis through upregulating the odontogenic differentiation of DPSCs, which provides a promising therapeutic approach for pulp regeneration.

Survival time analysis of remaining teeth following replacement of unilateral free-end missing teeth: A comparison between fixed implant-supported prostheses and removable partial dentures.

OBJECTIVES: This retrospective study aimed to investigate the differences in tooth loss rate between fixed implant-supported prostheses (FISPs) and removable partial dentures (RPDs) in cases of unilateral free-end missing teeth. MATERIALS AND METHODS: The data of 324 patients who underwent treatment with FISPs or RPDs for unilateral free-end missing teeth and satisfied the applicable criteria, were evaluated (47 in the FISPs group and 277 in the RPDs group). After propensity score (PS) matching, which was used to extract patients with similar background factors related to prosthetic selection at baseline, survival time analyses were performed with tooth loss as the endpoint. The adjusted variables were age, sex, number of restored teeth, periodontal status, and the practicing dentist's experience in years. The remaining teeth were classified into subcategories in relation to the missing molars. RESULTS: Overall, 58 patients (29 in each group) selected by PS matching were evaluated in the final analysis. The total number of lost teeth was 35 (FISPs group: n = 10; RPDs group: n = 25). The mean (±SD) period to tooth loss and the 10-year survival rates in the FISPs and RPDs groups were 51.6 (±30.1) months and 42.3 (±29.7) months, 70.5% and 16.4%, respectively. The log-rank test showed that significantly longer survival time in FISPs compared with RPDs. CONCLUSIONS: After adjustments for confounding factors using PS matching, replacing unilateral free-end missing teeth with FISPs may exhibit a lower tooth loss rate in adjacent and contralateral teeth compared to replacing with RPDs.

Nutrition Status Plays a Partial Mediation Role in the Relationship between Number of Teeth and Frailty: A Cross-Sectional Multicenter Study.

INTRODUCTION: Although the relationship between the number of teeth and frailty has been extensively studied, the mediating role of nutrition status in the association between the number of teeth and frailty remains to be clarified. METHODS: A number of 6,664 participants lived in the communities of West China were analyzed in our study. Physical frailty was determined based on the phenotype established by Fried. Nutrition status was evaluated using the Mini Nutrition Assessment-Short Form (MNA-SF) scale. Multiple linear regression was employed to evaluate the direct relationships between the number of teeth, nutrition, and frailty. Mediation models and structural equation model (SEM) pathway analysis were used to test the mediating role of nutrition status in the relationship between the number of teeth and frailty. RESULTS: Among the 6,664 participants aged over 50 years old, the prevalence of frailty was 6.2%. Multiple linear regression analysis showed a significant total relationship between the number of teeth (ß = -0.359, 95% CI: -0.473 to -0.244, p < 0.001) and frailty. After adjusting for MNA-SF scores, the relationship between the number of teeth and frailty remained significant (ß = -0.327, 95% CI: -0.443 to -0.211, p < 0.001), indicating a partial mediating effect of nutrition. Mediation analysis verified that nutrition partially mediated the relationship between the number of teeth and frailty (indirect effect estimate = -0.0121, bootstrap 95% CI: -0.0151 to -0.0092; direct effect estimate = -0.0874, bootstrap 95% CI: -0.1086 to -0.0678) in the fully adjusted model. This mediating effect occurred through influencing weight loss, low level of physical activity, and debility. SEM framework pathway analysis confirmed the association between the number of teeth, nutrition, and frailty. CONCLUSIONS: Our findings demonstrated that frailty was correlated with the number of teeth and poorer nutritional status, with nutrition partially mediating the correlation between the number of teeth and frailty. Our results supported early nutritional evaluation and intervention in oral health to decrease the risk of frailty.

Empirically derived dietary patterns in relation to periodontitis and number of teeth among Norwegian adults.

OBJECTIVES: To explore dietary patterns in relation to periodontitis and number of teeth. DESIGN: A cross-sectional study. SETTING: We used data from the seventh survey of the Tromsø Study in Norway, 2015-2016. Three periodontitis groups were compared: (i) no periodontitis/slow bone loss; (ii) moderate bone loss; and (iii) rapid bone loss. Number of teeth was categorised as 25-28, 20-24 and ≤ 19. Dietary patterns were identified by principal component analysis. Multiple logistic regression was applied to examine associations between tertiles of dietary pattern scores and periodontitis, and between these same tertiles and number of teeth. PARTICIPANTS: 1487 participants (55·5 % women) aged 40-79 years who were free of major chronic diseases, attended an oral health examination and completed a FFQ. RESULTS: Four dietary patterns were identified, which explained 24 % of the total variability in food intake: fruit and vegetables, Westernised, meat/fish and potatoes, and refined grain and dessert. The fruit and vegetables pattern was inversely associated with periodontitis characterised by rapid bone loss when compared with no periodontitis/slow bone loss (OR tertile 3 v. 1 0·49, 95 % CI: 0·25, 0·98). Participants who were in the highest tertile of the refined grain and dessert pattern (tertile 3 v. 1) had 2·38- and 3·52-fold increased odds of having ≤ 19 than 20-24 and 25-28 teeth, respectively. CONCLUSION: Out of four identified dietary patterns, only the fruit and vegetables pattern was negatively associated with advanced periodontitis. A more apparent positive association was observed between the refined grain and dessert pattern and having fewer teeth (≤ nineteen teeth).

Luminescence of favipiravir in skin appendages and sclera. A controlled study and literature review.

BACKGROUND/OBJECTIVES: Favipiravir is an antiviral agent, recently used for COVID-19 infections. Several reports associate favipiravir intake with Wood's lamp fluorescence of hair, nails, and sclera. The present study was designed to elucidate the positivity rates, and sites of favipiravir-related fluorescence and to unravel the site-specific changes in fluorescence positivity rates by a function of time past exposure. METHODS: The study population comprised 50 patients and 50 control individuals. All patients in the patient group had received a full dose of favipiravir for COVID-19 infection. Fifty volunteers served as the control group. Wood's lamp examination was performed in a completely darkened room, and the positivity rate, extent, pattern, and distribution of fluorescence were recorded. RESULTS: Wood's light revealed fluorescence of the fingernails, toenails, sclera, and hair in 35 (70%), 35 (70%), 22 (44%), and 8 (16%) patients, respectively. No control individual tested positive by Wood's lamp. Statistical analysis revealed significant differences between patient and control groups in terms of Wood's light luminescence in the fingernails (p = .000), toenails (p = .000), sclera (p = .000) and hair (p = .003). Although fingernail, toenail, and hair fluorescence positivity rates declined or ceased at or after 91 days of favipiravir exposure, ocular fluorescence positivity rates were prolonged up to 188 days. CONCLUSIONS: These findings confirm that favipiravir may produce fluorescence of nails, sclera, and hair, detectable by Wood's light starting from the initial month and peaking at second- and third months following exposure to the medication. Although nail and hair fluorescence tend to abate after 3 months, ocular fluorescence may persist even longer than 6 months after cessation of the medication.

Baseline masticatory muscles' performance may predict pain relief in temporomandibular disorders.

OBJECTIVES: To compare masticatory muscles' recruitment in patients with temporomandibular disorders and asymptomatic control subjects. To evaluate if the masticatory muscles' recruitment pattern may predict symptoms' improvement after temporomandibular disorders treatment. MATERIALS AND METHODS: Standardized surface electromyography of anterior temporalis and superficial masseters muscles were recorded and compared at baseline in 26 patients with arthrogenous temporomandibular disorders (study group) and 26 asymptomatic subjects (control group). The study group was treated pharmacologically and by means of five arthrocentesis sessions. Pre-, during-, and post-treatment pain and mandibular function were assessed and compared among timepoints. Clinical improvement in terms of pain and mandibular function was correlated with pre-treatment standardized surface electromyography values. RESULTS: Temporomandibular disorders patients showed improved maximum mouth opening and pain during and after treatment with arthrocentesis compared to baseline (T-test p < 0.01). Standardized surface electromyography values were significantly different in temporomandibular disorders subjects compared to controls (T-test p < 0.05). Improvement in pain at rest after treatment was inversely correlated with pre-treatment masseters standardized surface electromyography symmetry (R-coefficient 0.3936; p < 0.05). CONCLUSIONS: Temporomandibular disorders patients showed a different muscular recruitment pattern compared to controls. The lesser the pre-treatment masseters symmetry, the greater the improvement of pain at rest after treatment.

Oral Neuropathy Associated with Commonly used Chemotherapeutic Agents: A Narrative Review.

PURPOSE OF REVIEW: Chemotherapy-induced peripheral neuropathy (CIPN) is a frequent complication of cytotoxic chemotherapeutic agents; its incidence largely varies, depending on type, dose, agent and preexisting risk factors. Oral-and-perioral-CIPN (OCIPN) is underreported. Neurotoxic agents can cause jaw pain or numbness. This review aims to present available data on OCIPN RECENT FINDINGS: A narrative literature review, following SANRA guidelines was conducted. PubMed and Cochrane databases were searched until September 2023. Articles referring to neuropathy or neuropathic pain due to head and neck cancer, head and neck radiotherapy, oropharyngeal mucositis, infection or post-surgical pain were excluded. Platinum-based chemotherapeutics, taxanes, vinca alkaloids, immunomodulatory and alkylating agents can cause OCIPN. Platinum-based chemotherapeutics can cause orofacial cold sensitivity, orofacial and jaw pain, oral cavity tingling and teeth hypersensitivity. Taxanes may induce oral cavity and tongue numbness and tingling as well as hot hypersensitivity. Vinca alkaloids may cause jaw, teeth and lips pain and oral mucosa hyperalgesia. Immunomodulatory drugs can cause lips, tongue and perioral numbness, while alkylating agents induce tongue and lips tingling and teeth cold-hypersensitivity. Chemotherapy may cause OCIPN due to changes in cellular structure and function, like alterations in membrane receptors and neurotransmission. OCIPN should be documented and physicians, dentists and health care providers should be alerted.

Association between tea types and number of teeth: a cross-sectional study of the Chinese Longitudinal Healthy Longevity Survey.

BACKGROUND: Previous studies have suggested that tea consumption may have a positive impact on oral health. However, the effects of different tea types on oral health remain unclear. Therefore, this study aimed to determine the association between residual teeth and consumption habits of different types of tea (green tea, black tea, oolong tea, and scented tea) in older adults. METHODS: We conducted a secondary analysis using data from the Chinese Longitudinal Healthy Longevity Survey in 2018. In a sample of 6,387 older adults, we performed logistic regression analysis to examine the relationship between persistent tea consumption and oral health according to sex and brushing frequency. The indices for particularly healthy oral health and relative health were set at more than 20 teeth and more than 10 teeth, respectively. RESULTS: The study included 2,725 males and 3,662 females, both aged 65 and older. Among individuals with more than 20 teeth, drinking green tea significantly improved oral health in men (adjusted odds ratio [ORs]: 1.377; 95% confidence interval [CI]: 1.082-1.752) and drinking black tea significantly improved the oral health of women (ORs: 2.349, 95%CI: 1.028-5.366). In the daily brushing group, green tea had a significant beneficial effect on increasing the number of teeth in men and black tea had a significant beneficial effect in women. Among individuals with more than 10 teeth, drinking green tea significantly improved oral health in men (ORs: 1.539; 95% CI: 1.209-1.959) and drinking green tea and scented tea significantly improved the oral health of women (ORs: 1.447, 95%CI: 1.052-1.991; ORs: 1.948, 95%CI: 1.137-3.340). In the daily brushing group, consumption of green tea and black tea had significant beneficial effects on increasing the number of teeth in men, whereas that of green tea, black tea, and scented tea had significant beneficial effects in women. CONCLUSION: Long-term green tea consumption in males and black tea consumption in females were significantly associated with maintaining functional dentition (≥20 teeth). Similarly, long-term green tea consumption in males and green tea and scented tea consumption in females were associated with avoiding severe tooth loss (≥10 teeth). Furthermore, in the daily tooth brushing group, long-term consumption of black tea was associated with avoiding severe tooth loss in both sexes. However, tea consumption alone had no effect on oral health without good brushing habits.

Capturing the smile: Exploring embodied and social acts of smiling.

Smiling is an embodied and complex social act. Smiling is presented as facilitating individual health and wellbeing, but the value placed on smiling raises questions about structural conditions acting on the body. While smiling has been considered sociologically, psychologically and historically, we argue that further exploration of the embodied smile offers fruitful avenues for future research. This article attempts to advance understanding of the smile and its importance by: (I) Bringing together literature on smiling as a social act and smiling as embodied. (II) Systematically identifying key themes, which recognise sociological insights and the relevance of oral health. (III) Pointing to useful directions for future sociological research into smiling. In this article, we review literature on body techniques; impression management and social interaction; gender, race and smiling; and emotional, aesthetic and affective labour. We move on to embodiment, considering the mouth as a body project and in relation to the ageing body, before reflecting on the significance of oral health and dentistry. We highlight future directions for sociological research on smiling, building on eight interrelated and cross-cutting themes: norms and expectations, aesthetic ideals, self and identity, health and wellbeing, body work, commodification and labour, inclusion and exclusion and resistance.

The clinical outcomes of vital intact teeth close to large cystic lesions of endodontic origin: A prospective clinical study.

AIM: To evaluate the indication of the endodontic treatment for vital intact teeth with the root apex involved in large radicular cystic lesions of endodontic origin. METHODOLOGY: This prospective cohort study enrolled healthy participants with radicular cysts of endodontic origin and with the root apex of vital intact teeth involved in the bone defect, as determined by cone beam computed tomography (CBCT). Thirty-two sound vital teeth were analysed by thermal (TPT) and electric pulp tests (EPT) before surgery (T0) and 1 week (T1), 2 weeks (T2), 3 months (T3) and 6 months (T4) post-surgery. Student's t-test (p < .05) was used to compare the EPT values at baseline and T4. anova (p < .05) was used to analyse the EPT variations for all maxillary and mandibular teeth. McNemar test (p < .05) was used to compare the results according to variation in EPT values gathering by variation, no variation and no response. RESULTS: At T1, 75 and 65.7% of teeth responded positively whilst 25 and 34.3% did not respond to EPT and TPT, respectively. The variation of the EPT values between T0 and T1 was observed for 50.0% of teeth, whilst no variation was noticed in 25.0% of teeth. At T4, 90.6 and 87.5% of teeth responded positively whilst 9.4 and 12.5% did not respond to EPT and TPT, respectively. At T4, variation of the EPT values between T0 and T4 was observed for 28.1%, whilst no variation was noticed in 62.5% of teeth. There were no statistical differences in EPT results between T0 and T4 (p > .05), but significant differences were observed for EPT values between T1 and T4 (p < .05), and between mandibular and maxillary teeth. The pulp sensibility of maxillary teeth worsened after surgery, before reverting progressively to T0 values, whilst no statistically significant differences were observed for mandibular teeth at the different time points. CONCLUSIONS: These data support the inconsistence of the prophylactic endodontic treatment in healthy vital teeth with apex involvement in large cystic lesions of endodontic origin. Post-surgery follow-up with TPT and EPT is recommended to assess pulp status.

Vital pulp therapy-Factors influencing decision-making for permanent mature teeth with irreversible pulpitis: A systematic review.

BACKGROUND: There is an increased tendency towards adopting minimally invasive interventions in dentistry, supported by advancement in materials and techniques. However, the decision-making process in choosing conservative or invasive treatments is influenced by several factors, particularly in permanent teeth with irreversible pulpitis. OBJECTIVES: The objective of the study was to systematically review the literature regarding factors that influence decision-making for vital pulp therapy (VPT) as definitive treatment option in permanent mature teeth diagnosed with irreversible pulpitis. METHODS: Two independent reviewers searched five electronic databases (PubMed, Embase, Web of Science, Scopus and Cochrane Library). Grey literature was searched through Google Scholar and contact with experts. Defined search keys were applied, and all peer-reviewed literature published with no language nor publication date limits were included. The All studies investigating the factors influencing treatment decision-making in mature permanent teeth with irreversible pulpitis were included. The quality of included studies was assessed by two independent reviewers using the Joanna Briggs Institute quality assessment tool. RESULTS: Six articles were included in the review. All included studies used questionnaires to characterize clinician preferences and attitudes in choosing treatment options for mature permanent teeth with irreversible pulpitis. The available evidence suggests that dentist-related factors have a significant influence on the chosen treatment in teeth with irreversible pulpitis, with speciality training and years of experience influencing the choice of VPT over other treatment options. COVID-19 reportedly swayed the dentists' decision to favour VPT. Only one article studied the influence of patient-related factors, such as age and presence of spontaneous pain on decision-making. Of note, a history of cardiovascular disease moved dentists towards prescribing VPT. DISCUSSION: Collectively, the included studies demonstrated an overriding influence of dentist-related factors on choosing among treatment options for painful teeth diagnosed with irreversible pulpitis. Patient-related factors were acknowledged but there are also potential factors such as socio-economic constraints that were not included in the component studies. CONCLUSION: In teeth with irreversible pulpitis clinicians educational background influence the decision towards a specific treatment option. Further data, preferably derived from clinical records, is necessary in future investigations to explore the effect of other important factors related to both dentists and patients. REGISTRATION: PROSPERO database (CRD42022339653).

Prevalence and virulence factors of haemolytic Enterococcus faecalis isolated from root filled teeth associated with periradicular lesions: A laboratory investigation in Thailand.

AIM: Previous endodontic research has provided limited understanding of the prevalence and roles of haemolytic and non-haemolytic Enterococcus faecalis strains in root filled teeth. This study aimed to determine the prevalence of these strains in root filled teeth with periradicular lesions and investigate their associated virulence factors. METHODOLOGY: A total of 36 root canal samples were collected from 36 subjects. The prevalence of E. faecalis was determined using culture and PCR methods. Antibiotic susceptibility of haemolytic and non-haemolytic E. faecalis strains was assessed using the broth dilution assay. The cytokine stimulation in periodontal ligament (PDL) cells and neutrophil migration were evaluated using real-time PCR and migration assay, respectively. Cell invasion ability of the strains was assessed using a cell culture model. Additionally, the virulence gene expression of the haemolytic and non-haemolytic strains was investigated using real-time PCR. The Mann-Whitney U and Spearman's ρ tests were used to examine the significant difference between the two strains and to analyse the correlation between phenotype and gene expression, respectively. RESULTS: Enterococcus faecalis was detected in 33.3% and 88.9% of samples by culture and real-time PCR, respectively. Haemolytic strains were found in 36.4% of subjects. Non-haemolytic strains exhibited susceptibility to erythromycin and varying susceptibility to tetracycline, while all haemolytic strains were resistant to both antibiotics. Haemolytic strains significantly upregulated the expression of IL-8, OPG and RANKL in PDL cells (p < .05). Notably, the fold increases in these genes were higher: IL-8 (556.1 ± 82.9 vs. 249.6 ± 81.8), OPG (2.2 ± 0.5 vs. 1.3 ± 0.2) and RANKL (1.8 ± 0.3 vs. 1.2 ± 0.1). Furthermore, haemolytic strains had a greater effect on neutrophil migration (68.7 ± 15.2% vs. 46.9 ± 11.4%) and demonstrated a higher level of internalization into oral keratinocyte cells (68.6 ± 0.4% vs. 33.8 ± 0.5%) (p < .05). They also showed enhanced expression of virulence genes associated with haemolysin, surface proteins, collagen-binding and aggregation substances. Gelatinase activity was only detectable in non-haemolytic strains. CONCLUSIONS: This study revealed that haemolytic strains E. faecalis possessed enhanced abilities in host invasion and a higher abundance of virulence factors, suggesting their potential contribution to more severe disease manifestations.

Biomimetic pulp scaffolds prepared from extracellular matrix derived from stem cells from human exfoliated deciduous teeth promote pulp-dentine complex regeneration.

AIM: To evaluate the role of biomimetic pulp scaffolds derived from the extracellular matrix derived of stem cells from human exfoliated deciduous teeth (SHED-ECM-PS) in promoting pulp-dentine complex regeneration. METHODOLOGY: SHED-ECM-PS was prepared through cell aggregation and decellularization techniques. Histological and immunofluorescence analyses, scanning electron microscopy, and DNA quantification assays were used to characterize the SHED-ECM-PS. Additionally, a tooth slice implantation model was established to evaluate the effects of SHED-ECM-PS on regeneration of the pulp-dentine complex in vivo. Extraction medium for SHED-ECM-PS was prepared, and its effect on bone marrow mesenchymal stem cells (BMMSCs) was assessed in vitro. Cell counting kit-8 and Ki-67 staining assays were performed to determine cell proliferation. The rate of apoptosis was evaluated by flow cytometry. Wound healing and transwell assays were conducted to evaluate cell migration. Alizarin red S staining was performed to examine mineralized nodule formation. Western blotting was used to detect the expression of osteogenic and odontogenic markers. The results were analysed using an independent two-tailed Student's t-test. p < .05 was considered statistically significant. RESULTS: SHED-ECM-PS was successfully constructed, exhibiting a striped dental pulp-like shape devoid of nuclear structures or DNA components, and rich in fibronectin, collagen I, DMP1 and DSPP. Notably, SHED-ECM-PS showed no impact on the proliferation or apoptosis of BMMSCs. Histological analysis revealed that dental pulp fibroblasts formed an interwoven mesh in the root canal, and angiogenesis was observed in the SHED-ECM-PS group. Moreover, a continuous, newly formed tubular dentine layer with polarized odontoblast-like cells was observed along the inner wall of the root canal. SHED-ECM-PS promoted the migration, polar alignment and mineralized nodule formation of BMMSCs and specifically elevated the expression levels of odontogenic markers, but not osteogenic markers, compared with the control group in vitro. CONCLUSION: SHED-ECM-PS exhibited no cytotoxicity and promoted pulp-dentine complex regeneration in vivo as well as cell migration and odontogenic differentiation of BMMSCs in vitro. These findings provide evidence that SHED-ECM-PS, as a novel biological scaffold, has the potential to improve the outcomes of REPs.