211 research outputs found

    Bone regeneration at the distal aspect of the adjacent second molar after lower third molar coronectomy: a long-term analysis

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    Abstract. A residual bone defect at the distal aspect of the adjacent second molar may occur after total removal of the lower third molar. Lower third molar coronectomy has been proved to be a safe alternative to total removal, but the extent of bone regeneration at the adjacent tooth after coronectomy is not well reported. The aim of this prospective study was to investigate the long-term bone regeneration at the distal aspect of the adjacent second molar after lower third molar coronectomy. Preoperative and postoperative cone beam computed tomography scans were measured to assess bone regeneration at the distobuccal (DB), mid-distal (MD), and distolingual (DL) aspects of the lower second molar. Forty-eight coronectomies in 37 patients (23 female) with a mean ďż˝(standard deviation) age of 29.1 (7.2) years were assessed. The mean follow-up was 93.2 (8.7) months. The mean bone level increase at DB, MD, and DL aspects was 3.2 (1.6) mm, 3.5 (1.5) mm, and 3.2 (1.6) mm, respectively; the bone levels were significantly higher than the preoperative measurements (P < 0.001). Age and impaction patterns were not factors affecting bone regeneration. Based on this study, it appears that coronectomy of the lower third molar brings favourable bone regeneration at the distal aspect of the adjacent second molar

    Anatomical variations of the ethmoid sinuses and their association with health or pathology of the ethmoid and maxillary sinuses in a Southern Chinese population: An analysis using cone-beam computed tomography.

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    Purpose The aim of this study was to evaluate the prevalence of clinically relevant anatomical variations of the ethmoid sinuses and their potential association with ethmoid and maxillary sinus pathologies on cone-beam computed tomography (CBCT) scans. Additionally, potential associations with different sides and demographic factors, including age and sex, were evaluated. Materials and Methods In total, 273 CBCT scans with complete ethmoid and maxillary sinuses were analyzed to determine the prevalence of Agger nasi cell, supraorbital ethmoid cell, Haller cell, Onodi cell, and ethmomaxillary sinus. In addition, the health or pathology of the ethmoid and maxillary sinuses was also recorded to assess correlations with the aforementioned variations. Results The prevalence of Agger nasi cell was found to be the highest (95.6%) in this study, followed by Onodi cell (60.4%), Haller cell (29.3%), and supraorbital ethmoid cell (19.4%). Ethmomaxillary sinus was the least common finding (16.5%). Males and persons above 61 years of age had a significantly higher frequency of supraorbital ethmoid cell and Onodi cell, respectively. However, no significant relationships were noted between anatomical variations of the ethmoid sinus and pathologies of the ethmoid or maxillary sinus. Conclusion There was a high prevalence of ethmoid sinus variations in this Southern Chinese population. The prevalence of Agger nasi cell and Onodi cell was higher than that of other anatomical variations of the ethmoid sinuses. Anatomical variations of the ethmoid sinuses were not associated with ethmoid or maxillary sinus pathologies in this patient cohort

    Adverse childhood experiences and dental anxiety among Chinese adults in Hong Kong: a cross-sectional study

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    IntroductionThis study aimed to investigate the relationship between adverse childhood experiences (ACEs) and dental anxiety among Chinese adults in Hong Kong.MethodsA cross-sectional survey was conducted at a university in Hong Kong. The recruiting period and data collection started in January 2023 and ended in June 2023. Participants completed an online questionnaire that assessed ACEs (using the Adverse Childhood Experiences International Questionnaire – ACE-IQ) and dental anxiety (using the Modified Dental Anxiety Scale – MDAS and Dental Fear Survey – DFS). The study examined the impacts of both cumulative (i.e., total number) and independent ACE components on dental anxiety. To explore the relationships between cumulative ACEs, individual ACE components and dental anxiety (MDAS and DFS score), Pearson correlations, linear regression and logistic regression were conducted.ResultsSignificant associations were observed between ACEs and dental anxiety among 171 subjects. Cumulative ACEs were positively correlated with MDAS scores (r = 0.169, p = 0.027) and DFS scores (r = 0.253, p &lt; 0.001). The odds of an individual having high dental anxiety increased by 26–43% for every additional increase in the number of ACEs. Individual types of ACEs, such as emotional and physical neglect, sexual abuse, and household substance abuse, significantly influenced the likelihood of having high dental anxiety.DiscussionThe results showed a positive association between ACEs and dental anxiety, highlighting the impact of ACEs on dental anxiety. Dental practitioners should consider inquiring about a patient’s ACE history to develop personalized treatment plans

    Entrainment of chaotic activities in brain and heart during MBSR mindfulness training

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    AbstractThe activities of the brain and the heart are dynamic, chaotic, and possibly intrinsically coordinated. This study aims to investigate the effect of Mindfulness-Based Stress Reduction (MBSR) program on the chaoticity of electronic activities of the brain and the heart, and to explore their potential correlation. Electroencephalogram (EEG) and electrocardiogram (ECG) were recorded at the beginning of an 8-week standard MBSR training course and after the course. EEG spectrum analysis was carried out, wavelet entropies (WE) of EEG (together with reconstructed cortical sources) and heart rate were calculated, and their correlation was investigated. We found enhancement of EEG power of alpha and beta waves and lowering of delta waves power during MBSR training state as compared to normal resting state. Wavelet entropy analysis indicated that MBSR mindfulness meditation could reduce the chaotic activities of both EEG and heart rate as a change of state. However, longitudinal change of trait may need more long-term training. For the first time, our data demonstrated that the chaotic activities of the brain and the heart became more coordinated during MBSR training, suggesting that mindfulness training may increase the entrainment between mind and body. The 3D brain regions involved in the change in mental states were identified

    Common Bile Duct Dilatations in Asymptomatic Neonates: Incidence and Prognosis

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    Background. This retrospective study reviewed 213 asymptomatic neonates with common bile duct (CBD) dilatations diagnosed via ultrasound to evaluate their incidence and outcomes. Materials and Methods. From August 2001 to July 2010, 18,230 abdominal ultrasound scans were performed as newborn screening. There were 213 (1.17%) cases of CBD dilatation. Dilatation of neonatal CBD was defined when its diameter was ≥2 mm. The neonates’ birth history, CBD size, and follow-up results were analyzed. Results. In the 213 infants, four cystic dilatations (1.88%, 4/213) that were eventually diagnosed as choledochal cysts (CC). Among 209 neonates with fusiform dilatations (size 2.0–6.7 mm), 77 had ultrasound follow-up and 87% of them resolved spontaneously which were diagnosed as transient CBD dilatation (TCBDD). Eighty percent of TCBDDs resolved within 6 months. Patients with initial CBD size ≥3 mm had significantly lower resolution rate and neonates whose mothers are older than 35 years took longer time to resolve. Conclusion. The incidence of CBD dilatation in asymptomatic neonates was 1.17%. Eighty percent of TCBDDs resolved within 6 months. Regular ultrasound follow-up every 6 months may be appropriate for asymptomatic neonates with fusiform CBD dilatations to ensure resolution or progression

    The impact of the ClearRT™ upgrade on target motion tracking accuracy in Radixact® Synchrony® lung treatments

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    Background: The objective was to investigate the change in segmentation error of Radixact® Synchrony® lung treatment after its kV imaging system was upgraded from Generation 1 to Generation 2 in the ClearRT™ installation. Materials and methods: Radixact® Lung Synchrony® plans were created for the Model 18023 Xsight® Lung Tracking “XLT” Phantom combined with different lung target inserts with densities of 0.280, 0.500, 0.943 and 1.093 g/cc. After Radixact® Synchrony® treatment delivery using the Generation 1 and Generation 2 kV systems according to each plan, the tracking performance of the two kV systems on each density insert was compared by calculating the root mean square (RMS) error (δRMS) between the Synchrony-predicted motion in the log file and the known phantom motion and by calculating δ95%, the maximum error within a 95% probability threshold. Results: The δRMS and δ95% of Radixact® Synchrony® treatment for Gen1 kV systems deteriorated as the density of the target insert decreased, from 1.673 ± 0.064 mm and 3.049 ± 0.089 mm, respectively, for the 1.093 g/cc insert to 8.355 ± 5.873 mm and 15.297 ± 10.470 mm, respectively, for the 0.280 g/cc insert. In contrast, no such trend was observed in the δRMS or δ95% of Synchrony® treatment using the Gen2 kV system. The δRMS and δ95%, respectively, fluctuated slightly from 1.586 to 1.687 mm and from 2.874 to 2.971 mm when different target inserts were tracked by the Gen2 kV system. Conclusion: With improved image contrast in kV radiographs, the Gen2 kV imaging system can enhance the ability to track targets accurately in Radixact® Lung Synchrony® treatment and reduce the segmentation error. Our study showed that lung targets with density values as low as 0.280 cc/g could be tracked correctly in Synchrony treatment with the Gen2 kV imaging system
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