Etiological Mechanisms and Genetic/Biological Modulation Related to PTH1R in Primary Failure of Tooth Eruption

Primary failure of eruption (PFE) is a rare disorder that is characterized by the inability of a molar tooth/teeth to erupt to the occlusal plane or to normally react to orthodontic force. This condition is related to hereditary factors and has been extensively researched over many years. However, the etiological mechanisms of pathogenesis are still not fully understood. Evidence from studies on PFE cases has shown that PFE patients may carry parathyroid hormone 1 receptor (PTH1R) gene mutations, and genetic detection can be used to diagnose PFE at an early stage. PTH1R variants can lead to altered protein structure, impaired protein function, and abnormal biological activities of the cells, which may ultimately impact the behavior of teeth, as observed in PFE. Dental follicle cells play a critical role in tooth eruption and root development and are regulated by parathyroid hormone-related peptide (PTHrP)-PTH1R signaling in their differentiation and other activities. PTHrP-PTH1R signaling also regulates the activity of osteoblasts, osteoclasts and odontoclasts during tooth development and eruption. When interference occurs in the PTHrP-PTH1R signaling pathway, the normal function of dental follicles and bone remodeling are impaired. This review provides an overview of PTH1R variants and their correlation with PFE, and highlights that a disruption of PTHrP-PTH1R signaling impairs the normal process of tooth development and eruption, thus providing insight into the underlying mechanisms related to PTH1R and its role in driving PFE.

Factors influencing root resorption in retained mandibular second deciduous molars with congenital absence of second premolars: a cross-sectional study

BACKGROUND

There are currently no studies that quantitatively compare the relationship of root resorption to the patient's systemic history or craniofacial and intraoral morphology, especially in relation to possible host factors. Thus, this study aimed to clarify the factors associated with root resorption in retained mandibular second deciduous molars with the congenital absence of second premolars and predict the prognosis of retained mandibular second deciduous molars.

METHODS

A cohort of 5547 patients who visited the orthodontic clinic at Tokyo Medical and Dental University Dental Hospital between 2013 and 2022 was screened. Lateral cephalometric radiographs, panoramic radiographs, upper and lower dental models, and orthodontic treatment questionnaires were used as reference materials to apply the inclusion and exclusion criteria. Ultimately, 111 patients were included in the analyses. The patients were divided into two groups based on the root resorption levels of the retained mandibular second deciduous molars. Those with less root resorption were classified under the good condition (GC) group, whereas those with more root resorption were classified under the poor condition (PC) group. Demographic, clinical, and cephalometric parameters were compared between the groups. A multivariate logistic regression model was used to predict the probability of root resorption.

RESULTS

The prevalence of congenitally missing mandibular second premolars with persistent mandibular second deciduous molars was 2.0%. In a total of 111 patients, eighty-three teeth (53.2%) were classified into the GC group, whereas 73 teeth (46.8%) were classified into the PC group. The Frankfort-mandibular plane angle (FMA) [odds ratio (OR): 0.87], Frankfort-mandibular incisor angle (FMIA) (OR: 0.93), overbite (OR: 1.38), adjacent interdental space (OR: 1.46), distance from occlusal plane (OR: 0.80), and caries treatment (OR: 7.05) were significantly associated with the root resorption of the retained mandibular second deciduous molars.

CONCLUSIONS

Our findings suggest that skeletal morphology, oral morphological patterns, and history contribute to root resorption in retained mandibular second deciduous teeth with congenital absence of subsequent permanent teeth.

Investigation of the presence of Non-carious cervical lesions (NCCLs) in ancient adult skulls: analyzing data from prehistoric and historical samples through a systematic review and meta-analysis

OBJECTIVES

Historically, the prevalence of caries has undergone significant changes, particularly increasing with the industrialization of sugar consumption. When examining ancient populations, lower caries rates are discovered, attributed in part to dietary factors. These populations consumed abrasive foods, leading to occlusal wear and reduced non-axial occlusal forces, potentially influencing Non-Carious Cervical Lesions (NCCLs). Although some attribute NCCLs to abfraction, the mechanism remains debated. This systematic review aims to evaluate the presence of NCCLs in ancient populations, shedding light on the factors contributing to their occurrence.

MATERIALS AND METHODS

The present systematic review was registered on PROSPERO, and the manuscript was prepared following PRISMA guidelines.

RESULTS

After the literature search and article screening, data from 6 studies were included in the meta-analysis, with only 2 reporting NCCLs in ancient skulls, encopassing 17 subjects in 805 examined skulls, suggesting their presence even before the widespread use of toothbrushes. This finding indicates a potential etiopathogenic mechanism linked to abfraction, but the cause is complex and involves abrasive and erosive factors closely tied to dietary habits.

CONCLUSIONS

In summary, NCCLs were present in ancient populations, albeit with a much lower prevalence. Their occurrence cannot be solely attributed to wear mechanisms but must be connected to abrasive factors related to diet or practices with religious and cultural significance, such as the use of labrets.

CLINICAL RELEVANCE

Th the knowledge of NCCLs presence in acient sculls is crucial today for better understand the associated risk factors. In this context, the analysis of ancient skulls allows us to discern the role that tooth brushing and diet played in the formation of NCCLs, over the past century.

Identification of novel candidate genes associated with non-syndromic tooth agenesis in Mongolian families

OBJECTIVES

This study aimed to identify genetic variants associated with non-syndromic tooth agenesis (TA) in nine families from Mongolia using whole-exome sequencing (WES) and bioinformatics analysis.

MATERIAL AND METHODS

The study enrolled 41 participants, including three inherited and six non-inherited families. WES analysis was performed on 14 saliva samples from individuals with non-syndromic TA. The potential candidate genes were identified through variant filtering and segregation analysis. The filtered variants were then analyzed in silico mutation impact analysis.

RESULTS

WES analysis identified 21 variants associated with TA, and 5 of these variants met all filtering criteria. These variants were located in the exome region of MAST4, ITGA6, PITX2, CACNA1S, and CDON genes. The variant in PITX2 was found in eight participants from inherited and non-inherited families, while the MAST4 variant was identified in 6 participants from inherited families.

CONCLUSIONS

The study identified various genetic variant candidates associated with TA in different family groups, with PITX2 being the most commonly identified. Our findings suggest that MAST4 may also be a novel candidate gene for TA due to its association with the Wnt signaling pathway. Additionally, we found that five candidate genes related to focal adhesion and calcium channel complex were significant and essential in tooth development.

CLINICAL RELEVANCE

Identifying new pathogenic genes associated with TA can improve our understanding of the molecular mechanisms underlying the disease, leading to better diagnosis, prevention, and treatment. Early detection of TA based on biomarkers can improve dental management and facilitate orthodontic and prosthetic treatment.

Effect of arginine-fluoride varnish on preventing enamel erosion by paediatric liquid medicaments

BACKGROUND

The study objective was to examine the effect of arginine-sodium fluoride (Arg-NaF) varnish on preventing enamel erosion by acidic paediatric liquid medicaments (PLM).

METHODS

The treatment groups were: 1) 2% Arg-NaF; 2) 4% Arg-NaF; 3) 8% Arg-NaF; 4) NaF; 5) MI (CPP-ACFP) varnishes; and 6) no varnish. The pH of PLM (paracetamol and chlorpheniramine) was measured at baseline and after immersing the Perspex® blocks coated with varnishes at 0 min, 30 min, 1 h, and 4 h. Seventy-two enamel specimens (n = 72) were randomly divided into 2 groups by PLM and further by treatment groups. Then, the specimens were pre-treated with varnishes and subjected to erosive cycles (5 min, 2×/day for 4 days) by PLM. After each erosive challenge, the specimens were stored in artificial saliva. At baseline and after 4 days, the specimens were assessed for surface roughness (Ra) using 2D-surface profilometric analysis (SPA) and atomic force microscopy (AFM). Additionally, the Ca/P ratio was determined using scanning electron microscopy with energy-dispersive X-ray spectroscopy. Paired samples dependent t-test, 1-way ANOVA and 2-way ANOVA with Bonferroni post-hoc tests were used to analyse data with the level of significance set at p < 0.05.

RESULTS

The pH of PLM with 8% Arg-NaF was significantly higher than the other groups at 30 min and 4 h (p < 0.05). With paracetamol, no significant difference was observed between the baseline and post-erosive cycle measured enamel Ra (by SPA/AFM) and Ca/P ratio for all treatment groups (p > 0.05). The Ra determined by AFM, at the post-erosive cycle with chlorpheniramine, when treated with 4 and 8% Arg-NaF was significantly lower than the other groups (p < 0.05); except CPP-ACFP (p > 0.05). With the chlorpheniramine post-erosive cycle, the Ca/P ratio for 4, 8% Arg-NaF and CPP-ACFP treated specimens was significantly higher than the baseline Ca/P (p < 0.05).

CONCLUSION

The 4%/8% Arg-NaF and MI varnish® application exhibit an enhanced preventive effect against low pH (pH < 3.0) PLM-mediated enamel erosive challenges compared to 5% NaF varnish.

Acquired pellicle engineering with the association of cystatin and vitamin E against enamel erosion

OBJECTIVE

Evaluate CaneCPI-5 associated with Vitamin E in acquired enamel pellicle (AEP) engineering to prevent dental erosion.

METHODS

180 human enamel specimens were divided into 12 groups and treated with the following solutions: Cane+VitT and Cane+VitS- CaneCPI-5 + Vit E; Vit+CaneT and Vit+CaneS- Vit E + CaneCPI-5; VitT and VitS- Vit E; CaneT and CaneS- CaneCPI-5; ControlT and ControlS - AmF/NaF/SnCl2; WaterT and WaterS- Deionized water. Groups' name followed by "T" were first treated (200 μl; 2 min) and then incubated in human saliva (200 μl; 1 h) to form the AEP. For groups followed by "S", the AEP was formed and then treatment was applied. The erosive challenge consisted of immersion in 1% citric acid (1 min, 1x/day, for 3 days). The percentage of superficial hardness loss (%SHL) and the relative surface reflection intensity (%SRI) were subjected to normality and homogeneity tests, Shapiro-Wilk and Levene tests, respectively. Subsequently, the data were analyzed using two-way ANOVA, Tukey's test and Pearson's correlation (p < 0.005).

RESULTS

For%SHL and%SRI, water controls showed significantly lower protective capacity. Cane+VitT, Cane+VitS, and Vit+CaneS presented the lowest%SHL, and VitT and VitS did not differ from Vit+CaneT, but they were different from the other groups (p = 0.002). The greatest%SRI was found for the Cane+VitT, Vit+CaneT, VitT, Cane+VitS, Vit+CaneS, and VitS groups, which did not significantly differ. CaneT and ControlT, showed similar reflections compared to CaneS and ControlS.

CONCLUSION

CaneCPI-5 and Vitamin E demonstrated a synergistic protective effect against initial erosion.

CLINICAL SIGNIFICANCE

The results open up new possibilities for preventive approaches against erosion through the acquired pellicle engineering, with the combination of CaneCPI-5 and Vitamin E, which demonstrated to be more effective than commercial stannous mouthwash. Further research is warranted to explore the potential of this combination in diverse clinical settings.

Enamel defects of Axenfeld-Rieger syndrome and the role of PITX2 in its pathogenesis

OBJECTIVES

To investigate the detailed ultrastructural patterns of dental abnormalities affected by Axenfeld-Rieger syndrome (ARS) with a heterozygous microdeletion involving paired-like homeodomain 2 (PITX2) and explored the underlying molecular mechanisms driving enamel defects.

SUBJECTS AND METHODS

Sanger sequencing, genomic quantitative PCR analysis, and chromosomal microarray analysis (CMA) were used to screen the disease-causing mutation in one ARS proband. An exfoliated tooth from an ARS patient was analyzed with scanning electron microscopy and micro-computerized tomography. A stable Pitx2 knockdown cell line was generated to simulate PITX2 haploinsufficiency. Cell proliferation and ameloblast differentiation were analyzed, and the role of the Wnt/β-catenin pathway in proliferation of ameloblast precursor cells was investigated.

RESULTS

An approximately 0.216 Mb novel deletion encompassing PITX2 was identified. The affected tooth displayed a thinner and broken layer of enamel and abnormal enamel biomineralization. PITX2 downregulation inhibited the proliferation and differentiation of inner enamel epithelial cells, and LiCl stifmulation partially reversed the proliferation ability after Pitx2 knockdown.

CONCLUSIONS

Enamel formation is disturbed in some patients with ARS. Pitx2 knockdown can influence the proliferation and ameloblast differentiation of inner enamel epithelial cells, and PITX2 may regulate cell proliferation via Wnt/β-catenin signaling pathway.

Fluoride varnishes supplemented with nano-sized sodium trimetaphosphate reduce enamel erosive wear in vitro

OBJECTIVE

To evaluate the effect of fluoride (F) varnishes with sodium trimetaphosphate (TMP) on erosive tooth wear (ETW) in vitro.

METHODS

Enamel blocks (n = 100) were divided into 5 experimental groups (n = 20/group): Placebo (Pla - without F/TMP); 5 % NaF (NaF); 5 % NaF + 5 % micrometric TMP (NaF+5 %MICRO); 5 % NaF + 2.5 % nano-sized TMP (NaF+2.5 %NANO), and 5 % NaF + 5 % nano-sized TMP (NaF+5 %NANO). Blocks received a single varnish application (6 h contact), and were submitted to 4 daily erosive challenges (ERO, 0.05 M citric acid, pH 3.2, 90 s, under agitation), for 5 days. After ERO, half of the blocks (n = 10/group) were subjected to brushing abrasion (ERO+ABR). Profilometry, surface hardness (SH), and cross-sectional hardness (ΔKHN) were determined. The data were submitted to 2-way ANOVA and Fisher's LSD test (p < 0.05).

RESULTS

Enamel wear was significantly lower for ERO compared with ERO+ABR for all varnishes tested (p < 0.001), following the pattern NaF+5 %NANO < NaF+5 %MICRO < NaF < NaF+2.5 %NANO < Pla (both for ERO and ERO+ABR). The highest SH loss was observed for Pla and the lowest for NaF (ERO) and NaF+2.5 %NANO (ERO+ABR), without significant differences among NaF+2.5 %NANO, NaF, and NaF+5 %MICRO. The highest ΔKHN values were observed for NaF+5 %MICRO and NaF+5 %NANO at 5-30 µm, with less marked differences among the groups at 30-70 µm (ERO and ERO+ABR).

CONCLUSIONS

The addition of TMP to F varnishes significantly improves protection against ETW in vitro. The use of 5 % nano-sized TMP further enhances such effects.

CLINICAL SIGNIFICANCE

F varnishes containing TMP can reduce enamel loss caused by ERO or ERO+ABR.

Influence of Different Mouthwashes on the Efficacy of Fluoridated Dentifrices in Prevention of Enamel Erosion: An In Vitro Study

AIM

The purpose of the current study was to evaluate the impact of three various mouthwashes on the effectiveness of fluoride dentifrices in preventing enamel erosion.

MATERIALS AND METHODS

A total of 120 sound intact human premolar teeth which were extracted for orthodontic treatment were selected for the study. A 3 × 3 mm window section was positioned in the middle of the coronal surface of the tooth in order to define the study area. Each sample was placed in a solution of 1% citric acid (pH 3.5) for 10 minutes in order to produce an eroded surface. All samples were divided into two main groups (60 samples each) as follows: Group A for sodium fluoride dentifrices and group B for stannous fluoride dentifrices, again it is subdivided into: CHX: Chlohex ADS®, EO: Listerine®, CPC: Colgate® Plax (20 samples in each subgroup). After that, samples underwent the pH cycling model for 5 days. Samples were examined for surface loss using a scanning electron microscope.

RESULTS

In sodium fluoride dentifrices group, before intervention, the surface loss was 3.12 ± 1.03 in CHX group, 3.08 ± 1.20 in EO group, and 3.09 ± 0.96 in CPC group. After intervention, the less surface loss found with CHX group (2.18 ± 0.84), followed by CPC (2.34 ± 0.74) and EO group (2.46 ± 0.97). In stannous fluoride dentifrices group, before intervention, the surface loss in CHX group was 3.26 ± 1.19, in EO group, it was 3.18 ± 1.31, and in CPC group, it was 3.22 ± 1.06. After intervention, the less surface loss found with CHX: group (1.90 ± 0.54), followed by CPC (2.24 ± 0.28) and EO group (2.38 ± 0.20).

CONCLUSION

The present study concluded that the fluoride dentifrices' preventive effects against tooth surface loss were unaffected by a different mouthwashes with varying compositions and major constituents. In terms of erosion, fluoridated toothpaste containing stannous fluoride was found to provide better surface loss protection than sodium fluoride.

CLINICAL SIGNIFICANCE

Primary prevention and the eradication of contributing causes are the greatest strategies for preventing erosion. Simultaneously, antibacterial agent in the mouthwashes may help in enhancing the effect of fluoride in the enamel, owing to their high affinity for teeth structures. Therefore, in addition to cause-related treatment, further efforts to reduce tooth tissue loss are also necessary.

Developmental enamel defects and dental anomalies of number and size in children with growth hormone deficiency

Growth hormone is meaningfully involved in the processes of tooth cells differentiation and tissue formation. The aim of the study was to evaluate the occurrence of dental anomalies: microdontia, macrodontia, hypodontia and developmental defects of enamel (DDE) amongst a group of isolated growth hormone deficient (GHD) patients and healthy children. This cross-sectional study was based on a group of 101 Caucasian children: 33 with GHD (mean age 10.94, SD 2.51) and 68 being healthy, normal height subjects (mean age 10.4, SD 2.38). The dental examination in primary and permanent teeth was carried out by one trained and calibrated dentist, in accordance with the WHO guidelines. It was observed that 33% of GHD patients suffer from dental anomalies (hypodontia, microdontia or macrodontia), the difference between the study group and the control group was statistically significant (33% vs 4%, p < 0.001). Hypodontia and microdontia/macrodontia were the most common problems affecting 18% and 21% of the GHD individuals, respectively. The prevalence of DDE did not differ significantly between GHD group and the control group (58% vs 48%, p > 0.05). As children with GHD present more dental anomalies than their healthy coevals, clinicians should be aware of the possible oral health problems associated with GHD and consider dental screening and management as part of the patient's overall health care plan.

The Impact of Prenatal Vitamin D on Enamel Defects and Tooth Erosion: A Systematic Review

Prenatal Vitamin D has been suggested to be critical for dental health in children, affecting outcomes including the prevalence of enamel defects and tooth erosion. This systematic review aimed to evaluate the potential impact of prenatal Vitamin D levels on these dental health outcomes. A total of seven studies, involving 6978 participants, were included after a comprehensive search of PubMed, Web of Science, and Scopus from 2013 to June 2023. The average age of mothers varied across studies, with Vitamin D levels or supplementation practices displaying significant variation among the study populations. The age of children at examination ranged from 3.6 to 6.6 years. The analysis demonstrated a diverse association between Vitamin D levels and dental outcomes, with enamel defects reported in 21.1% to 64% of the children and opacities ranging from 36% to 79.5% across studies. Maternal Vitamin D insufficiency was identified as a significant risk factor for enamel defects in one study (OR: 3.55), whereas high prenatal Vitamin D levels indicated a protective effect against Hypomineralized Second Primary Molars (OR: 0.84) and Molar Incisor Hypomineralization (OR: 0.95) in another. Conversely, low Vitamin D levels increased the risk of enamel hypoplasia (OR: 1.29) and dental decay. The maternal and child demographics varied greatly across the studies, and the assessment and prevalence of Vitamin D deficiency or insufficiency were heterogenous. This review illuminates the potential influence of prenatal Vitamin D on dental health in children, underscoring the importance of adequate Vitamin D levels during pregnancy. However, more robust research is required to establish the optimal Vitamin D intake during pregnancy to ensure healthy dental outcomes in children.

Combined use of stannous fluoride-containing mouth rinse and toothpaste prevents enamel erosion in vitro

OBJECTIVE

To compare the protective effect of commercial stannous-containing mouth rinses on enamel erosion in a simulated 5-day in vitro cycling model.

MATERIALS AND METHODS

81 human enamel specimens were embedded in resin blocks and divided into nine groups as follows; group 1: stannous fluoride (1000SnF2) toothpaste; groups 2,3, and 4 were the same as group 1 plus Elmex®, PerioMed™, and Meridol®, respectively, group 5: stannous fluoride (1450SnF2) toothpaste, groups 6, 7, and 8 were the same as group 5 plus Elmex®, PerioMed™, and Meridol®, respectively, group 9: negative control. An erosive challenge was induced with a 1 min hydrochloric acid (0.01 M, pH 2.2) treatment 3 times per day. Each cycle included immersing in the toothpaste slurry twice for two minutes and a one-minute rinse. The enamel slabs were immersed in artificial saliva between each erosive cycle and incubated overnight at 37 °C. Surface hardness loss and enamel loss were determined by Knoop surface hardness and non-contact profilometry, respectively. Finally, enamel surfaces were analyzed by scanning electron microscopy and X-ray energy dispersive spectroscopy (SEM/EDS).

RESULTS

All three mouth rinses had similar protective effects against erosion when using adjunct with 1000 SnF2 toothpaste (p > 0.05). With 1450 SnF2 toothpaste, Elmex® presented significantly lower surface hardness loss than Meridol® (p < 0.05). The combined use of Elmex® or PerioMed™ with toothpaste provided significantly better erosion protection than toothpaste alone, either 1000 or 1450 SnF2. In addition, 1000SnF2 toothpaste adjunct with mouth rinse is comparable to 1450 SnF2 toothpaste alone in preventing enamel erosion.

CONCLUSION

All three mouth rinses reduced enamel erosion. The additional use of a high concentration stannous containing mouth rinse with 1450 SnF2 toothpaste increases the protective effect against enamel erosion in vitro.

CLINICAL SIGNIFICANCE

To date, no standard protocol for preventing dental erosion is available. There are three stannous-containing mouth rinses on the market; however, no study compared their efficacy or indicated whether using adjuncts with anti-erosion toothpaste provides additional benefits. This study found that adding stannous mouth rinse to twice-daily toothpaste increases erosion protection.

Non-traumatic emergency department dental visits among patients 0-25 years of age: A systematic review and meta-analysis

BACKGROUND

Nontraumatic dental conditions (NTDC) that made children attending to emergency departments (EDs) of tertiary hospitals can put significant financial and time strain on hospitals.

AIM

The aim of this systematic review and meta-analysis was to calculate the prevalence of paediatric presentations to EDs of tertiary hospitals for NTDC and describe the characteristics of these presentations.

DESIGN

A systematic search strategy using PubMed, Embase and Web of Science databases was performed to identify studies quantifying NTDC presentations to EDs of tertiary hospitals from inception through to July 2022. Eligible studies were critically appraised using the Joanna Briggs Institute checklist for studies reporting prevalence.

RESULTS

The search identified 31 099 studies, from which 14 were found to meet the inclusion criteria. A random effects model was used for meta-analysis, and the prevalence of NTDC reported through EDs of tertiary hospitals ranged from 52.3% to 77.9%.

CONCLUSIONS

Nontraumatic dental conditions, which may be preventable when caused by dental caries, made up a high proportion of dental visits to tertiary hospital EDs. Public health initiatives should be considered to reduce the burden of NTDC on EDs.

Pre-, Peri-, and Postnatal Risk for the Development of Enamel Defects in Permanent Dentition: A Birth Cohort in Southern Brazil

Purpose: The purpose of this study was to find potential risk factors associated with the occurrence of developmental defects of enamel (DDE) in permanent dentition of a birth cohort in Southern Brazil. Methods: This study is a 2004 birth cohort carried out in the city of Pelotas, Rio Grande do Sul, Brazil. A subsample of 996 children was clinically examined at 12 to 13 years of age. The pre- and perinatal variables used for this study were: twin pregnancy; type of delivery; prematurity; birth weight; Apgar score in the first and fifth minute; health problems at birth; and intensive care unit admission at birth. Gender and family income variables were also collected. Some postnatal variables were collected: "hospitalization in the first 24 months"; "breastfeeding"; "respiratory diseases in the first 48 months"; "urinary infection in the first 48 months"; and "ear pain in the first 48 months." To assess an association between the presence of DDE and various risk factors, unadjusted and adjusted Poisson regression with robust variance was performed with a respective prevalence ratio. Results: The prevalence of DDE was 40.8 percent. The variables investigated did not present a statistical association with DDE. Conclusion: No association of developmental defects of enamel in permanent dentition with any of the factors investigated in this study was found.

Dietary and metabolic effects on the oral status of patients with phenylketonuria: a nation-based cross-sectional study

OBJECTIVES

The aim of this study was to compare the prevalence of oral diseases (caries, periodontal disease, enamel defects) between patients with phenylketonuria (PKU), their siblings, and a matched control group.

MATERIALS AND METHODS

A total of 109 patients with PKU, 14 siblings of PKU patients, and 100 healthy individuals aged 6 to 68 years were recruited. All participants completed a questionnaire based on their health status. The patients' decayed/missing/filled teeth index (dmft/DMFT), gingival bleeding index (GBI), plaque control record (PCR), periodontal screening and recording index (PSR), and developmental enamel defects index (DDE) were recorded. Descriptive statistics and regression modeling were used to examine potential associations between the exposure and the outcomes of interest.

RESULTS

Patients with PKU had 1.6 times more caries (95% confidence interval (CI) 1.22 to 2.20; p = 0.001), seven times more enamel defects (95% CI 3.94 to 14.21; p < 0.001), and four times higher PSR values (95% CI 2.26 to 7.15; p < 0.001) than the control group. The siblings had significantly fewer enamel defects but no significant differences in caries and periodontal parameters compared to the PKU patients.

CONCLUSIONS

The results showed a higher risk for the development of caries, periodontitis, and enamel defects in PKU patients.

CLINICAL RELEVANCE

Implementation of preventive measures and regular dental care is necessary for patients with PKU.

Clinical status and assessment of caries on first permanent molars in a group of 6- to 13-year-old Tunisian school children

AIM

The present survey aimed to highlight the clinical status of first permanent molars (FPMs) among a group of children aged between 6 and 13 years in public primary schools in Tunisia and to determine the association between FPMs' dental caries, gingival bleeding, malocclusion, dental fluorosis, and enamel defects.

MATERIALS AND METHODS

The survey involved a cross-sectional study based on a dental examination conducted in public primary schools in Monastir Tunisia. A dental caries assessment was performed on FPMs using the International Caries Detection and Assessment System classification; the number of carious lesions in permanent and temporary dentition was established using the decayed/missing/filled teeth (DMFT) index. The Gingival Index and the Dental Aesthetic Index were used to determine the occurrence of gingival bleeding and malocclusions. Dean's index and the modified Development Defects of Enamel index were used to define the enamel defects. The χ² test was used to assess the difference between more than two groups, and the level of statistical significance was set at .05%.

RESULTS

A total of 545 children and 2080 FPMs were examined. The prevalence of dental caries in FPMs was recorded to be 35.8%. The overall mean DMFT index of the study population was 1.62 and the mean DMFT index was 1.41. The proportion of carious FPMs increased significantly with the age of the children (p < .05). The mandibular first permanent molar presented higher caries prevalence than its maxillary counterpart (p < .05). The presence of surfaces affected by molar incisor hypomineralization was recorded in 4.3% and the presence of surfaces affected by fluorosis was recorded in 4.6% of FPMs. No association was reported between FPMs' dental caries, gingival bleeding, malocclusion, and enamel defects (p > .05).

CONCLUSION

Although the prevalence of caries in FPMs was considered moderate, health promotion programs should be implemented on a large scale to decrease the prevalence of dental caries among school children.

Enamel Developmental Defect Masking on Central Incisor with Infiltrant Resin

The aim of this paper is to present a case of masking of a hypoplastic lesion using the infiltrating resin technique, without use of drilling or any loss of tooth structure. A 22-year-old female patient complained of a noncarious white spot on the buccal surface of the upper right central incisor which affected the esthetics of her smile. Despite the tooth discoloration, the tooth structure was intact, with no depressions, cracks, or grooves. During the anamnesis, she reported that the white spot had been present since childhood. On the basis of the information provided by the patient and collected during intraoral clinical examination, it was determined that the stain was suggestive of enamel hypoplasia. The treatment proposed to the patient was the application of infiltrating resin to mask the hypoplasia on the surface of the tooth enamel without any loss of tooth structure. In this case, Icon infiltrating resin proved to be efficient in masking the hypoplastic lesion. The final appearance of the treated tooth was satisfactory, with homogeneity and gloss on the surface, which minimized the characteristics of an unpleasant smile.

Pathophysiology of Demineralization, Part I: Attrition, Erosion, Abfraction, and Noncarious Cervical Lesions

PURPOSE OF THE REVIEW

Compare pathophysiology for infectious and noninfectious demineralization disease relative to mineral maintenance, physiologic fluoride levels, and mechanical degradation.

RECENT FINDINGS

Environmental acidity, biomechanics, and intercrystalline percolation of endemic fluoride regulate resistance to demineralization relative to osteopenia, noncarious cervical lesions, and dental caries. Demineralization is the most prevalent chronic disease in the world: osteoporosis (OP) >10%, dental caries ~100%. OP is severely debilitating while caries is potentially fatal. Mineralized tissues have a common physiology: cell-mediated apposition, protein matrix, fluid logistics (blood, saliva), intercrystalline ion percolation, cyclic demineralization/remineralization, and acid-based degradation (microbes, clastic cells). Etiology of demineralization involves fluid percolation, metabolism, homeostasis, biomechanics, mechanical wear (attrition or abrasion), and biofilm-related infections. Bone mineral density measurement assesses skeletal mass. Attrition, abrasion, erosion, and abfraction are diagnosed visually, but invisible subsurface caries <400μm cannot be detected. Controlling demineralization at all levels is an important horizon for cost-effective wellness worldwide.

Delayed Eruption In Cleidocranial Dysplasia

Cleidocranial dysplasia is a rare autosomal dominant disorder of bones mainly affecting bones formed by intra-membranous and endochondral ossification. It presents clinically as brachycephalic skull, frontal bossing, depressed nasal bridge, hypertelorism, delayed closure of fontanelles, delayed eruption of permanent teeth, missing clavicles and wide pelvis. It runs in families; sporadic cases are rarer. Just over than 1000 cases have been reported. We are presenting here 2 cases of cleidocranial dysplasia in siblings.

Hospital Inpatient Admissions of Children and Adolescents for Nontraumatic Dental Conditions in Florida

Purpose: Barriers to regular dental care may lead to children being hospitalized for dental problems. The purpose of this study was to examine trends related to pediatric hospital inpatient admissions for nontraumatic dental conditions (NTDCs) in Florida between 2006 and 2016. Methods: Data were from the Florida Department of Health inpatient admission database and included zero- to 19-year-old patients. The authors calculated age-specific and age-adjusted rates of inpatient admission for NTDCs and the proportion of all hospitalizations they comprise. Results: There were 6,217 inpatient admissions for NTDCs of zero- to 19-year-olds in Florida between 2006 and 2016. The median charge was $21,654 per admission, and total charges were $196,220,470. Medicaid was the primary payer. Admission rates increased in all age groups, and age-adjusted rates increased by 62 percent during that period. The two most common NTDC diagnoses were periapical abscess without sinus tract and cellulitis of the mouth. Conclusions: The rate and cost for hospital inpatient admissions to treat nontraumatic dental conditions increased significantly for children and adolescents in Florida during the past decade. Establishment of a dental home at an early age and removing barriers to receiving regular and periodic dental care may result in more effective and efficient use of health care resources and better patient outcomes.

Feasibility of establishing tele-dental approach to non-traumatic dental emergencies in medical settings

PURPOSE

Non-traumatic dental condition visits (NTDCs) represent about 1.4% to 2% of all Emergency Department (ED) visits and are limited to palliative care only, while associated with high cost of care. Feasibility of establishing a tele-dental approach to manage NTDCs in ED and Urgent care (UC) settings was undertaken to explore the possibility of utilizing remote tele-dental consults.

METHODS

Participants with NTDCs in ED/UCs were examined extra and intra-orally: (1) directly by ED provider, (2) remotely by tele-dental examiner (trained dentist) using intra-oral camera and high-definition pan-tilt-zoom (PTZ) camera, (3) directly by treating dentist post ED/UC visit (if applicable) and, (4) secondary assessment by tele-dental reviewer. Comparisons were drawn between differential diagnoses and recommended managements provided by ED/UC providers, tele-dental examiner, treating dentist, and tele-dental reviewer.

RESULTS

13 patients participated in the study. The overall inter-rater agreement between the tele-dental examiner and tele-dental reviewer was high while it was low between tele-dentists and the ED providers. The preliminary testing of tele-dental intervention in the ED/UC setting demonstrated potential feasibility in addressing the NTDC landing in ED/UC. Larger interventional studies in multi-site setting are needed to validate this approach and especially evaluate impact on cost, ED/UC workflow and patient outcomes.

CLINICAL SIGNIFICANCE

Using tele-dentistry to triage non-traumatic dental visits to the emergency room may be a promising approach. Once this approach is validated through a larger study, tele-dental outreach could help in directing non-traumatic dental emergency patients to the appropriate dental setting to provide treatment for the patients.

Functional Analysis of PTH1R Variants Found in Primary Failure of Eruption

Although many variants of the parathyroid hormone 1 receptor (PTH1R) gene are known to be associated with primary failure of eruption (PFE), the mechanisms underlying the link remains poorly understood. We here performed functional analyses of PTH1R variants reported in PFE patients-namely, 356C>T (P119L), 395C>T (P132L), 439C>T (R147C), and 1148G>A (R383Q)-using HeLa cells with a lentiviral vector-mediated genetic modification. Two particular variants, P119L and P132L, had severe reduction in a level of N-linked glycosylation when compared with wild-type PTH1R, whereas the other 2 showed modest alteration. PTH1R having P119L or P132L showed marked decrease in the affinity to PTH_1-34, which likely led to severely impaired cAMP accumulation upon stimulation in cells expressing these mutants, highlighting the importance of these 2 amino acid residues for ligand-mediated proper functioning of PTH1R. To further gain insights into PTH1R functions, we established the induced pluripotent stem cell (iPSC) lines from a patient with PFE and the heterozygous P132L mutation. When differentiated into osteoblastic-lineage cells, PFE-iPSCs showed no abnormality in mineralization. The mRNA expression of RUNX2, SP7, and BGLAP, the osteoblastic differentiation-related genes, and that of PTH1R were augmented in both PFE-iPSC-derived cells and control iPSC-derived cells in the presence of bone morphogenetic protein 2. Also, active vitamin D₃ induced the expression of RANKL, a major key factor for osteoclastogenesis, equally in osteoblastic cells derived from control and PFE-iPSCs. In sharp contrast, exposure to PTH_1-34 resulted in no induction of RANKL mRNA expression in the cells expressing P132L variant PTH1R, consistent with the idea that a type of heterozygous PTH1R gene mutation would spoil PTH-dependent response in osteoblasts. Collectively, this study demonstrates a link between PFE-associated genetic alteration and causative functional impairment of PTH1R, as well as a utility of iPSC-based disease modeling for future elucidation of pathogenesis in genetic disorders, including PFE.

Quantitative evaluation of masking effect of resin infiltration on developmental defects of enamel

OBJECTIVE

Qualitative developmental defects of enamel (DDEs) are characterized by an intact hypermineralized surface enamel layer and a porous subsurface hypomineralized layer. This structure is similar to natural early caries lesions, which are effectively arrested by resin infiltration, a micro-invasive clinical procedure. An additional reported effect in early enamel caries is recovery of enamel translucency. Due to structural similarities, a similar mechanism is expected in qualitative DDEs. The objective of the present study was to observe quantitative color masking of qualitative DDEs when subjected to resin infiltration.

METHOD AND MATERIALS

A total of 70 selected enamel defects were subjected to resin infiltration in a nonrandomized study design. Each defect was subjected to photographic imaging using a digital camera both pre- and post-intervention. Each image was assessed using ImageJ digital software (National Institutes of Health) for CIE L*a*b coordinates.

RESULTS

There were significant changes observed in L*a*b coordinates of all DDEs, when subjected to resin infiltration.

CONCLUSION

The resin infiltration intervention was successful in masking the "white" opaque discolorations of developmentally affected enamel.

Collecting a Dental Payment during the Civil War - a Case of Persistence

The livelihood of the practicing dentist depends upon timely payment for the dental services provided. Receiving payment has never been an entirely predictable occurrence. There are countless reasons that commonly delay the collection of a dental debt and sometimes the debtor is forgiven when the amount of debt is outweighed by the perceived difficulty of collecting it. This narrative tells the story of a perseverant dentist, Dr. Lloyd Macgill and his successful pursuit of a debt while the Civil War raged on, at times not far from his office, and long after the death of the patient who owed him for services rendered.