Clinical application of a digital semi-rigid bridge space maintainer fabricated from polyetheretherketone for premature loss of primary molars.

BACKGROUND: Premature loss of primary molars can be treated with a band loop space maintainer (SM). However, fabricating a conventional band loop SM requires multiple clinical and laboratory procedures, which can potentially affect the accuracy of the SM. Moreover, the conventional SM is unable to fully restore masticatory function and maintain the vertical dimension of the edentulous space. In this current study, a fully digital workflow to fabricate a semi-rigid bridge SM made from polyetheretherketone (PEEK) has been described and evaluated for its clinical effectiveness. METHODS: A total of 15 children (eight males and seven females) between the ages of 4-8 years, who experienced the premature loss of a single primary molar, were included in this study. Digital impressions were taken using the CEREC CAD/CAM chair system and imported into CAD software to design the semi-rigid bridge SM, which was fabricated using PEEK block as the maintainer material. The digital SM was tried-in and bonded to the abutment with resin cement. The edentulous space was measured immediately after bonding (T0) and 1 month (T1), 3 months (T2), and 6 months (T3) after treatment. The periodontal condition and mobility of the SM and abutment were also examined. RESULTS: The use of digital impressions resulted in a decreased occurrence of the pharyngeal reflex. The digital semi-rigid bridge SM, fabricated with PEEK, was both convenient and aesthetically pleasing, and successfully restored the anatomy and masticatory function of the missing primary molar. None of the 15 semi-rigid bridge SMs or abutments became loose or fell off during the study, and only one child presented with gingivitis. Furthermore, the difference in the edentulous space at T0, T1, T2, and T3 was not statistically significant (all P > 0.05). CONCLUSIONS: The digital semi-rigid bridge SM fabricated with PEEK was clinically effective in maintaining the missing space and had advantages over the traditional band/crown loop SM.

Sleep disorders and an increased risk of Parkinson's disease in individuals with non-apnea sleep disorders: a population-based cohort study.

Sleep disorders are common non-motor symptoms in patients with Parkinson's disease. Our study aims to explore the relationship between non-apnea sleep disorders and future Parkinson's disease. This is a cohort study using a nationwide database. The participants were recruited from the Taiwan National Health Insurance Research Database between 2000 and 2003. A total of 91 273 adult patients who had non-apnea sleep disorders without pre-existing Parkinson's disease were enrolled. An age-, gender-, income-, urbanization- and Charlson comorbidity index score-matched control cohort consisting of 91 273 participants was selected for comparison. The two cohorts were followed for the occurrence of Parkinson's disease, death or until the end of 2010, whichever came first. The Kaplan-Meier analyses revealed patients with non-apnea sleep disorders tended to develop Parkinson's disease (log-rank test, P < 0.001). After a multivariate adjustment in a Cox regression model, non-apnea sleep disorders was an independent risk factor for the development of Parkinson's disease [crude hazard ratio: 1.63, 95% confidence interval (CI): 1.54-1.73, P < 0.001; adjusted hazard ratio: 1.18, 95% CI: 1.11-1.26, P < 0.001]. In the subgroup analysis, patients with chronic insomnia (lasting more than 3 months) had the greatest risk (crude hazard ratio: 2.91, 95% CI: 2.59-3.26, P < 0.001; adjusted hazard ratio: 1.37, 95% CI: 1.21-1.55, P < 0.001). In conclusion, this study revealed that non-apnea sleep disorders, especially chronic insomnia, are associated with a higher risk for future Parkinson's disease.

Establishment of Immortalized BMP2/4 Double Knock-Out Osteoblastic Cells Is Essential for Study of Osteoblast Growth, Differentiation, and Osteogenesis.

Bone morphogenetic proteins 2 and 4 (BMP2/4) are essential for osteoblast differentiation and osteogenesis. Generation of a BMP2/4 dual knock-out ((ko/ko)) osteoblastic cell line is a valuable asset for studying effects of BMP2/4 on skeletal development. In this study, our goal was to create immortalized mouse deleted BMP2/4 osteoblasts by infecting adenoviruses with Cre recombinase and green fluorescent protein genes into immortalized murine floxed BMP2/4 osteoblasts. Transduced BMP2/4(ko/ko) cells were verified by green immunofluorescence and PCR. BMP2/4(ko/ko) osteoblasts exhibited small size, slow cell proliferation rate and cell growth was arrested in G1 and G2 phases. Expression of bone-relate genes was reduced in the BMP2/4(ko/ko) cells, resulting in delay of cell differentiation and mineralization. Importantly, extracellular matrix remodeling was impaired in the BMP2/4(ko/ko) osteoblasts as reflected by decreased Mmp-2 and Mmp-9 expressions. Cell differentiation and mineralization were rescued by exogenous BMP2 and/or BMP4. Therefore, we for the first time described establishment of an immortalized deleted BMP2/4 osteoblast line useful for study of mechanisms in regulating osteoblast lineages.

The association of infrared imaging findings of the breast with prognosis in breast cancer patients: an observational cohort study.

BACKGROUND: To evaluate whether infrared (IR) imaging findings are associated with prognosis in patients with invasive breast carcinomas. METHODS: This study was approved by the institutional review board of the research ethics committee of our hospital, and all participants gave written informed consent. From March 2005 to June 2007, we enrolled 143 patients with invasive breast cancer that underwent preoperative IR imaging. We used five IR signs to interpret breast IR imaging. Cox proportional hazards model was used to evaluate the effect of IR signs on long-term mortality. RESULTS: During a median follow-up of 2451 days (6.7 years), 31 patients died. Based on the Cox Proportional Hazards Model, IR1 sign (the temperature of cancer site minus that of the contralateral mirror imaging site) was positively associated with mortality in the univariate analysis (overall mortality hazard ratio [HR], 2.29; p = 0.03; disease-specific mortality HR, 2.57; p = 0.04) as well as the multivariate analysis after controlling for clinicopathological factors (overall mortality HR, 3.85; p = 0.01; disease-specific mortality HR, 3.91, p = 0.02). In patients with clinical stage I and II disease, IR1 was also positively associated with mortality (overall mortality HR, 3.76; p = 0.03; disease-specific mortality HR, 4.59; p = 0.03). Among patients with node-negative disease, IR1 and IR5 (asymmetrical thermographic pattern) were associated with mortality (p = 0.04 for both IR1 and IR5, chi-squared test). CONCLUSION: Breast IR findings are associated with mortality in patients with invasive breast carcinomas. The association remained in patients with node-negative disease. TRIAL REGISTRATION: NCT00166998 .

Evaluation of the treatment response to neoadjuvant chemotherapy in locally advanced breast cancer using combined magnetic resonance vascular maps and apparent diffusion coefficient.

PURPOSE: To evaluate the treatment response of locally advanced breast cancer (LABC) to neoadjuvant chemotherapy using magnetic resonance (MR) vascular maps and apparent diffusion coefficient (ADC) at 3T. Materials and Methods Thirty-one patients with LABC who underwent breast MR studies before, after the first course, and after completing neoadjuvant chemotherapy were enrolled. Vascular morphology was retrieved via Hessian matrix and the voxels of the vessels and volume of vessels were measured automatically. Whole tumor mean ADC values were calculated. Clinical responders were defined as >50% tumor reduction in the final MR studies. Pathologically complete responders were also recorded. RESULTS: There were 21 clinical responders and 10 nonresponders. Compared to the nonresponders after the first course, the responders were characterized by more vascular reduction of the breast lesion and decreased bilateral vascular discrepancy (voxels and volume), and increments in the ADC value and ADC percentage of the lesions (all P < 0.05). There were three pathological complete responders who showed more apparent early vascular reduction of the lesion breast (voxels and volume) and increments in the ADC value than others (P = 0.02, 0.01 and 0.02, respectively). CONCLUSION: The early changes of MR vascular maps and ADC are associated with the final treatment response of LABC.

Sleep Apnea and Risk of Panic Disorder.

PURPOSE: Epidemiological studies have identified a trend in the development of depressive and anxiety disorders following a diagnosis of sleep apnea. The relationship between sleep apnea and subsequent panic disorder, however, remains unclear. METHODS: Using a nationwide database, the Taiwan National Health Insurance Research Database, patients with sleep apnea and age-, sex-, income-, and urbanization-matched control patients who did not have sleep apnea were enrolled between 2000 and 2010. Patients with a prior diagnosis of panic disorder before enrollment were excluded. The 2 cohorts were observed until December 31, 2010. The primary endpoint was occurrence of newly diagnosed panic disorder. RESULTS: A total of 8,704 sleep apnea patients and 34,792 control patients were enrolled. Of the 43,496 patients, 263 (0.60%) suffered from panic disorder during a mean follow-up period of 3.92 years, including 117 (1.34%) from the sleep apnea cohort and 146 (0.42%) from the control group. The Kaplan-Meier analysis revealed a predisposition of patients with sleep apnea to develop panic disorder (log-rank test, P <.001). After multivariate adjustment, the hazard ratio for subsequent panic disorder among the sleep apnea patients was 2.17 (95% confidence interval, 1.68-2.81; P <.001). CONCLUSIONS: Sleep apnea appears to confer a higher risk for future development of panic disorder.

Sleep apnoea patients have higher mortality when confronting sepsis.

BACKGROUND: Sleep is essential for the maintenance of an intact immune function. Patients with sleep apnoea experience frequent sleep interruption due to apnoea-related arousals, possibly adversely impacting their immunity and affecting their outcomes when confronting sepsis. This case-control study aimed to compare the outcomes of sepsis patients with and without sleep apnoea. METHODS: From 2000 to 2009, 168 sleep apnoea patients who were first admitted for sepsis were identified from the Taiwan National Health Insurance Research Database. Also, 672 sepsis patients without sleep apnoea, who were matched by age, gender and Charlson's comorbidity index scores, served as controls. Hospital outcomes of the two groups were compared. Binary logistic regression was employed for multivariate analysis. RESULTS: The mortality rates of sepsis patients with and without sleep apnoea were 60.1% and 47.9%, respectively (P = 0. 005). After multivariate adjustment, sleep apnoea (OR: 1.805, 95% CI: 1.227-2.656, P = 0.003), presence of shock (OR: 3.600, 95% CI: 2.144-6.046, P < 0.001) and number of organs with dysfunction (OR: 1.591, 95% CI: 1.087-2.329, P = 0.017) were found to be independently associated with mortality. Sleep apnoea patients who needed continuous positive airway pressure treatment had an even higher risk of mortality. CONCLUSIONS: Sepsis patients with sleep apnoea may have poorer hospital outcomes than those without sleep apnoea.

Sleep apnea and risk of pneumonia: a nationwide population-based study.

BACKGROUND: Evidence evaluating the risk of pneumonia in patients with obstructive sleep apnea is limited and mostly focuses on patients who receive continuous positive airway pressure (CPAP) therapy or on pediatric patients. We aimed to explore the risk of incident pneumonia among adults with sleep apnea, either with or without the need of CPAP therapy. METHODS: From Jan. 1, 2000, we identified adult patients with sleep apnea from the Taiwan National Health Insurance Research Database. A control cohort without sleep apnea, matched for age, sex and comorbidities, was selected for comparison. The 2 cohorts were followed until Dec. 31, 2010, and observed for occurrence of pneumonia. RESULTS: Of the 34,100 patients (6816 study patients and 27,284 matched controls), 2757 (8.09%) had pneumonia during a mean follow-up period of 4.50 years, including 638 (9.36%) study patients and 2119 (7.77%) controls. Kaplan-Meier analysis showed a higher incidence of pneumonia among patients with sleep apnea (log rank test, p < 0.001). After multivariate adjustment, patients with sleep apnea experienced a 1.20-fold (95% confidence interval 1.10-1.31) increase in incident pneumonia. The risk was even higher among patients who received CPAP therapy. INTERPRETATION: Sleep apnea appeared to confer a higher risk for future pneumonia, possibly in a severity-dependent manner.

One case of complicated crown root fracture of upper anterior teeth managed by multidisciplinary joint approaches.

Complicated crown root fracture is a serious combined fracture of the enamel, dentin, and cementum in dental trauma. The treatment method is complicated. During the procedure, the condition of pulp, periodontal, and tooth body should be thoroughly evaluated, and a multidisciplinary approach combined with sequential treatment is recommended. This case reported the different treatment and repair processes of one case of two affected teeth after complicated crown root fracture of upper anterior teeth, including regrafting of broken crown after flap surgery at the first visit, direct resin repair to remove broken fragments, and pulp treatment and post-crown repair at the second visit. After 18 months of follow-up, the preservation treatment of the affected teeth with complicated crown root fracture was achieved. Therefore, fragment reattachment and post-crown restoration are feasible treatment options for children with complicated crown root fracture.

Involvement of microglial P2X7 receptor in pain modulation.

BACKGROUND: Pain is a rapid response mechanism that compels organisms to retreat from the harmful stimuli and triggers a repair response. Nonetheless, when pain persists for extended periods, it can lead to adverse changes into in the individual's brain, negatively impacting their emotional state and overall quality of life. Microglia, the resident immune cells in the central nervous system (CNS), play a pivotal role in regulating a variety of pain-related disorders. Specifically, recent studies have shed light on the central role that microglial purinergic ligand-gated ion channel 7 receptor (P2X7R) plays in regulating pain. In this respect, the P2X7R on microglial membranes represents a potential therapeutic target. AIMS: To expound on the intricate link between microglial P2X7R and pain, offering insights into potential avenues for future research. METHODS: We reviewed 140 literature and summarized the important role of microglial P2X7R in regulating pain, including the structure and function of P2X7R, the relationship between P2X7R and microglial polarization, P2X7R-related signaling pathways, and the effects of P2X7R antagonists on pain regulation. RESULTS: P2X7R activation is related to M1 polarization of microglia, while suppressing P2X7R can transfer microglia from M1 into M2 phenotype. And targeting the P2X7R-mediated signaling pathways helps to explore new therapy for pain alleviation. P2X7R antagonists also hold potential for translational and clinical applications in pain management. CONCLUSIONS: Microglial P2X7R holds promise as a potential novel pharmacological target for clinical treatments due to its distinctive structure, function, and the development of antagonists.

Combined Transcriptomic and Proteomic Profiling of the Mouse Anterior Cingulate Cortex Identifies Potential Therapeutic Targets for Pulpitis-Induced Pain.

Pulpitis is a common dental emergency that presents with intense pain; there is still no specific medicine to treat pulpitis-induced pain to date. Herein, differentially expressed genes in mouse anterior cingulate cortex (ACC) were investigated 7 days after pulp exposure via a combination of high-throughput transcriptomic and proteomic analyses. We screened 34 key genes associated with 8 critical pathways. Among these, genes (Elovl5, Ikbke, and Nbeal2) involved in immune or inflammatory responses exhibited exclusive regulation at the transcriptomic level, as confirmed by qRT-PCR. We also investigated the comprehensive expression profiles of genes (Erg1, Shank2, Bche, Serinf1, and Pax6) related to synaptic plasticity. Furthermore, the underlying mechanisms for pulpitis-induced pain through immune or inflammatory responses and synaptic plasticity were discussed. Taken together, our findings shed light on the mechanisms underlying pulpitis-induced pain, deepening our understanding of the molecular pathways and providing potential therapeutic and diagnostic targets.

Conservation of root-fractured primary teeth--report of a case.

A 3.5-year-old girl presented to our clinic experiencing pain in her maxillary central incisors following traumatic injury during a fall. Radiographic examination revealed both primary maxillary central incisors with mid-root and apical third horizontal root fractures, respectively. Splinting with orthodontic brackets and stainless steel wire was performed. At 2 weeks, resorption of the apical fragments in both injured teeth was observed, and after 3 months, almost complete resorption was noted on radiographs. Tooth mobility at this point was back to physiologic levels and the splint was removed. After 2.5 years, the primary maxillary incisors were replaced by permanent incisors demonstrating normal tooth color, position, and root development. Although this case illustrated the favorable prognosis of two primary teeth with root fractures and severely mobile coronal fragments by a conservative approach, more scientific evidences are needed and frequent recalls are necessary when primary root fractures are attempted to be managed with splinting.

Treatment for a complicated crown-root fracture with intentional replantation: a case report with a 3.5-year follow up.

Crown-root fractures are always challenging for pediatric dentists because of their complicated treatments and uncertain prognosis. The purpose of this case report was to describe a severe crown-root fracture successfully treated by multidisciplinary approaches including intentional replantation. After a 3.5-year follow up, the patient felt comfortable and satisfied with her tooth, and the prosthesis was functionally and esthetically acceptable. It is recommended that multidisciplinary treatment with intentional replantation is effective and necessary for similar cases to be conservatively managed.

Bilateral Retinal Artery Occlusions and Uveitis as the First Manifestation of Crohn's Disease.

PURPOSE: To present a case of newly diagnosed Crohn's disease, in which retinal artery occlusion (RAO) with uveitis was the first clinical manifestation. CASE DESCRIPTION: A 55-year-old man presented with bilateral blurred vision, with decreased best corrected visual acuity (BCVA) to light perception (right eye, RE) and 20/40 (left eye, LE). Ophthalmological examination revealed bilateral iritis, vitritis, disc edema, and retinal vascular occlusions. Because of concurrent fever and leukocytosis, a systemic infection was highly suspected. However, whole-body imaging was unrevealing. Subsequently, the patient presented with massive bloody stool. Histopathological specimen from emergent hemicolectomy confirmed transmural granulomatous inflammation. Crohn's disease was finally diagnosed. Following treatment, the BCVA recovered to 20/40 (RE) and 20/22 (LE). The systemic condition remained stable after a 3-year follow-up. CONCLUSION: RAO with uveitis is a possible manifestation of Crohn's disease. In complex uveitis cases, clinicians should be aware of inflammatory bowel diseases as an important differential diagnosis.

Real-Time Fluorescence Measurement for Droplet Generation and Signal Detection in a Cylindrical Tube.

This study provides an approach for generating droplets in a cylindrical tube. This creative design utilizes a single tube to generate droplets for the emulsion polymerase chain reaction (PCR). We fabricated the multi-layered tube and detected samples in 1 mm microchannel length for the minimum disposable material used for droplet signal analysis. In this research, we verify the validity of the non-planar droplet chip with a single driving pump by experimentally analyzing the light intensity of the liquids during droplet processing in real time. Experimental observation shows that droplet diameter from 150 to 285 µm was obtained by the cylindrical tube with different dispersed liquid and gas pressure settings. Average size of droplets decreased by approximately 37% as the dispersed phase liquids change at the same flow pressure of 50 mbar. In this study, the effects of the laser site, 6-carboxyfluorescein (6-FAM) dye buffer, DNA reagent, and driving pressure are analyzed directly by the signal recorded during droplet generation in the cylindrical tube. Finally, we have developed a real-time detection method to count exon 19 deletion mutations of epidermal growth factor receptor (EGFR) in a droplet using a cylindrical tube. Two digital droplet PCR methods were compared in measuring the copy numbers of EGFR with the same target DNA concentration of 105 copies/µL.

Anti-Colorectal Cancer Effects of Fucoidan Complex-Based Functional Beverage Through Retarding Proliferation, Cell Cycle and Epithelial-Mesenchymal Transition Signaling Pathways.

BACKGROUND: Fucus vesiculosus-derived fucoidan, a multifunctional bioactive polysaccharide sourced from marine organisms, exhibits a wide range of therapeutic properties, including its anti-tumor effects. While previous research has reported on its anti-cancer potential, limited studies have explored its synergistic capabilities when combined with other natural bioactive ingredients. In this current study, we present the development of an integrative functional beverage, denoted as VMW-FC, which is composed of a fucoidan complex (FC) along with a blend of various herbal components, including vegetables (V), mulberries and fruits (M), and spelt wheat (W). OBJECTIVE: Colorectal cancer (CRC) remains a significant cause of mortality, particularly in metastatic cases. Therefore, the urgent need for novel alternative medicines that comprehensively inhibit CRC persists. In this investigation, we assess the impact of VMW-FC on CRC cell proliferation, cell cycle dynamics, metastasis, in vivo tumorigenesis, and potential side effects. METHODS: Cell growth was assessed using MTT and colony formation assays, while metastatic potential was evaluated through wound healing and transwell migration assays. The underlying signaling mechanisms were elucidated through qPCR and western blot analysis. In vivo tumor formation and potential side effects were evaluated using a subcutaneous tumor-bearing NOD/SCID mouse model. RESULTS: Our findings demonstrate that VMW-FC significantly impedes CRC proliferation and migration in a dose- and time-dependent manner. Furthermore, it induces sub-G1 cell cycle arrest and an increase in apoptotic cell populations, as confirmed through flow-cytometric analysis. Notably, VMW-FC also suppresses xenograft tumor growth in NOD/SCID mice without causing renal or hepatic toxicity. CONCLUSION: The integrative herbal concoction VMW-FC presents a promising approach for inhibiting CRC by slowing proliferation and migration, inducing cell cycle arrest and apoptosis, and suppressing markers associated with proliferation (Ki-67, PCNA, and CDKs) and epithelial-mesenchymal transition (EMT) (Vimentin, N-cadherin, and ß-catenin).

Osteoradionecrosis of the upper cervical spine after radiation therapy for head and neck cancer: differentiation from recurrent or metastatic disease with MR imaging.

PURPOSE: To compare the magnetic resonance (MR) imaging features of upper cervical spine osteoradionecrosis (ORN) with those of recurrent or metastatic disease after the treatment of head and neck malignancies. MATERIALS AND METHODS: This retrospective study was approved by the hospital institutional review board, and the requirement to obtain informed consent was waived. From January 2005 to December 2010, 35 patients who had undergone irradiation of head and neck cancer and who had subsequent C1 or C2 lesions at MR imaging were enrolled. Pathology reports, clinical records, and follow-up MR images were reviewed to classify patients into one of two groups-those with ORN or those with recurrence. The MR imaging characteristics in these patients were evaluated. Statistical significance of intergroup differences was assessed by means of the Pearson χ2 or Fisher exact test for categorical variables and the two-sample t test for continuous variables. RESULTS: ORN was diagnosed in 20 of the 35 patients (57%), and recurrent or metastatic disease was diagnosed in 15 (43%). Ten of the 35 patients (29%) had undergone biopsy of the cervical spine or paraspinal soft tissue. The MR images in the ORN group showed significantly more contiguous involvement of the atlantoaxial or atlanto-occipital bones with intervening joint change (P<.001), more cases of vertebral body collapse (P<.01), more bilateral symmetric involvement of the vertebral body (P<.01), and continuation of vertebral body changes with posterior pharyngeal wall ulceration (P<.01). Posterior arch or other cervical level involvement, paraspinal solid mass, epidural involvement, lateral border cortical destruction, and cervical lymphadenopathy were noted more frequently in the recurrence group than in the ORN group (P=.03, P<.001, P=.02, P<.001, and P<.01, respectively). CONCLUSION: Various MR imaging characteristics can be used to help differentiate between cervical ORN and recurrent disease.

Nicking enzyme-free strand displacement amplification-assisted CRISPR-Cas-based colorimetric detection of prostate-specific antigen in serum samples.

Immunosorbent assay is the gold standard diagnostic technique for the detection of protein biomarkers. However, this technique tends to have low sensitivity and requires laborious manipulation. Although advanced CRISPR-Cas-based biosensors offer advantages of simplicity, low cost and high accuracy, the synergy of using CRISPR-Cas-assisted dual signal amplification system for rapid diagnosis of protein biomarkers remains scarce. In this work, we report a synergetic signal amplification system comprising CRISPR-Cas12a and nicking enzyme-free strand displacement amplification (SDA) technique for accurate detection of prostate-specific antigen (PSA). The presence of PSA will initiate the nicking enzyme-free SDA process, generating amplicons that can be recognized by the CRISPR-Cas12a system. The activated CRISPR-Cas system will then mediate trans-ssDNA cleavage of neighboring linker DNA, which unlocks the gold nanoparticles (AuNPs) signal probes and gives a distance-dependent colorimetric readout. This assay could detect PSA in aqueous buffer sensitively and selectively with a limit of detection (LOD) down to 0.030 ng mL-1. Importantly, this assay was successfully applied for discriminating four blood samples from prostate cancer patients among thirteen blood samples from normal individuals/cancer patients accurately. This work will open an avenue for the development of SDA-CRISPR-AuNPs hybrid sensing systems, offering great potential for the development of non-invasive point-of-care diagnostic tools for prostate cancer.

Spontaneous healing of complicated crown-root fractures in children: Two case reports.

BACKGROUND: Complicated crown-root fracture is considered a severe dental trauma and is unlikely to heal without treatment. Usually, dentists have to remove the loose coronal fragment of the fractured tooth and treat the remaining part with multidisciplinary approaches. However, we observed spontaneous healing of fracture in two pediatric cases with a history of complicated crown-root fractures over 4 years ago. CASE SUMMARY: In case 1, a 12-year-old boy complained of pain at tooth 11 following an accidental fall 1 d ago. Clinical examination showed a crack line on the crown of tooth 11. Cone beam computed tomography (CBCT) images of tooth 11 showed signs of hard tissue deposition between the fractured fragments. The patient recalled that tooth 11 had struck the floor 1 year ago without seeking any other treatment. In case 2, a 10-year-old girl fell down 1 d ago and wanted to have her teeth examined. Clinical examination showed a fracture line on the crown of tooth 21. CBCT images of tooth 21 also showed signs of hard tissue deposition between the fractured fragments. She also had a history of dental trauma 1 year ago and her tooth 11 received dental treatment by another dentist. According to her periapical radiograph at that time, tooth 21 was fractured 1 year ago and the fracture was overlooked by her dentist. Both of these two cases showed spontaneous healing of complicated crown-root fractures. After over 4 years of follow-up, both fractured teeth showed no signs of abnormality. CONCLUSION: These findings may provide new insights and perspectives on the management and treatment of crown-root fractures in children.

Ligand-gated ion channel P2X7 regulates hypoxia-induced factor-1α mediated pain induced by dental pulpitis in the medullary dorsal horn.

Dental pulpitis often induces severe pain, and the molecular immune response is remarkable in both peripheral and central nervous system. Accumulating evidence indicates that activated microglia in the medullary dorsal horn (MDH) contribute to dental pulpitis induced pain. The P2X7 receptor plays an important role in driving pain and inflammatory processes, and its downstream target hypoxia-induced factor-1α (HIF-1α) has a crucial role in maintaining inflammation. However, the relationship between P2X7 and HIF-1α in dental inflammatory pain remains unclear. This study demonstrated that the degree of inflammation in the dental pulp tissue became more severe in a time-dependent manner by establishing a rat dental pulpitis model via pulp exposure. Meanwhile, the expression of P2X7, HIF-1α, IL-1ß, and IL-18 in the MDH increased most on the seventh day when the pain threshold was the lowest in the dental pulpitis model. Furthermore, lipopolysaccharides (LPS) increased P2X7-mediated HIF-1α expression in microglia. Notably, the suppression of P2X7 caused less IL-1ß and IL-18 release and lower HIF-1α expression, and P2X7 antagonist Brilliant Blue G (BBG) could alleviate pain behaviors of the dental pulpitis rats. In conclusion, our results provide further evidence that P2X7 is a key molecule, which regulates HIF-1α expression and inflammation in dental pulpitis-induced pain.