BMC Oral Health最新文献

Background: Establishing accurate, reliable, and convenient methods for enamel segmentation and analysis is crucial for effectively planning endodontic, orthodontic, and restorative treatments, as well as exploring the evolutionary patterns of mammals. However, no mature, non-destructive method currently exists in clinical dentistry to quickly, accurately, and comprehensively assess the integrity and thickness of enamel chair-side. This study aims to develop a deep learning work, 2.5D Attention U-Net, trained on small sample datasets, for the automatical, efficient, and accurate segmentation of enamel across all teeth in clinical settings.

Methods: We propose a fully automated computer-aided enamel segmentation model based on an instance segmentation network, 2.5D Attention U-Net. After data annotation and augmentation, the model is trained using manually annotated segmented enamel data, and its performance is evaluated using the Dice similarity coefficient metrics. A satisfactory image segmentation model is applied to generate a 3D enamel model for each tooth and to calculate the thickness value of individual enclosed 3D enamel meshes using a normal ray-tracing directional method.

Results: The model achieves the Dice score on the enamel segmentation task of 96.6%. This study provides an intuitive visualization of irregular enamel morphology and a quantitative analysis of three-dimensional enamel thickness variations. The results indicate that enamel is thickest at the incisal edges of anterior teeth and the cusps of posterior teeth, thinning towards the roots. For posterior teeth, the enamel is thinnest at the central fossae area, with mandibular molars having thicker enamel in the central fossae compared to maxillary molars. The average enamel thickness of maxillary incisors, canines, and premolars is greater than that of mandibular incisors, while the opposite is true for molars. Although there are individual variations in enamel thickness, the average enamel thickness graduallly increases from the incisors to the molars among all teeth within the same quadrant.

Conclusions: This study introduces an automatic, efficient, and accurate 2.5D Attention U-Net system to enhance precise and efficient chair-side diagnosis and treatment of enamel-related diseases in clinical settings, marking a significant advancement in automated diagnostics for enamel-related conditions.

Background: Examining stress distributions in abutment teeth with periapical lesions is essential for understanding their biomechanical impact on dental structures and tissues. This study uses finite element analysis (FEA) to evaluate these stress patterns under occlusal forces, aiming to enhance treatment strategies and prosthetic designs.

Methods: Three FEA models were created: a healthy mandibular premolar (Model 1), a premolar with a single crown and a lesion repaired using a fiber-post (Model 2), and 3) a premolar with a lesion repaired using fiber-post to support a four-member bridge (Model 3). A 300 N occlusal static stress was given to each model at a 45° angle to the long axis of the tooth, namely at the lingual inclination of the buccal-cusp. Deformation behaviour and maximum equivalent stress distributions were simulated on the all components, including the bony structure for each model.

Results: The study showed a reduction in equivalent stress levels in trabecular and cortical bone, crown, cementum, and PDL under occlusal force, from Model 1 to Model 3. The Von Mises yield criteria values of the tooth models differed depending on the prosthetic restorations, with the highest value seen in Model 2 (133.87 MPa). Similar locations in all models showed concentrated equivalent stresses for all components. The periapical lesion area exhibited relatively low stress values for Models 2 and 3, at 0.061 MPa and 0.039 MPa, respectively. The largest level of stress was seen in the cervicobuccal areas of the tooth in all models.

Conclusion: Prosthetic restorations on teeth with periapical lesions resulted in varying stress and biomechanical responses in the tooth and surrounding bone tissue. These teeth can serve as abutments in a four-unit bridge when subjected to optimal occlusal stresses, based on the findings.

Background: To evaluate the prognostic role of the preoperative pan-immune-inflammation value (PIV) index in patients with oral squamous cell carcinoma (OSCC) after undergoing radical resection and to develop a prognostic prediction model for these patients.

Methods: A large cohort study was conducted between January 2015 and March 2022. Univariate and multivariate Cox regression was used to assess the prognostic value of PIV, and propensity score matching (PSM) analysis was used to adjust for potential confounders. Randomized survival forest (RSF) was used to assess the relative importance of preoperative PIV in prognostic prediction. Finally, a Nomogram model was plotted to predict the prognosis of oral cancer patients.

Results: A total of 779 patients were enrolled and followed up (mean follow-up time 34.14 ± 24.39). High PIV was significantly associated with worse survival in OSCC patients (hazard ratio [HR] = 1.62, 95% confidence interval [CI]: 1.15-2.29, P = 0.006). The same trend was observed in PSM (HR = 1.55,95% CI: 1.03-2.23, P = 0.035). RSF showed that PIV ranked third in the importance ranking of all prognostic factors. The calibration curves indicated that the Nomogram model was superior in predicting the prognostic 1-, 3-, and 5-year survival of oral cancer patients.

Conclusions: PIV is an independent predictor of prognosis in patients with oral squamous cell carcinoma, and a column-line graphical model based on PIV can effectively predict prognosis.

Background: This study aims to evaluate the clinical outcome of biofluorescent imaging system (BIS) guided MRONJ surgery through analyzing 3D volumetric changes in CBCT data of bone structure.

Methods: BIS-guided surgery for MRONJ surgery was performed by grinding red-fluorescent area from remained residual bone detected by Qray-pen. CBCT data was collected preoperatively, postoperatively, and at last follow-up more than 3 months of each patient. Healing ratio per month was calculated through measuring difference between postoperative defect and last follow-up defect volume by analyzing CBCT.

Results: With mean follow-up period of 7.8 ± 4.8 months, twelve MRONJ surgeries of 11 patients (2 males, 9 females, mean 72.8 ± 13.7 years old) showed bone healing tendency without recurrence in average healing ratio of 5.49 ± 2.22% per month, with complete soft tissue closure. It was observed that the healing ratio per month did not show statistically significant differences based on location of MRONJ, size of post-operative defect volume, nor duration of bisphosphonate intake before surgery.

Conclusions: Based on three-dimensional bone analysis, efficacy of BIS-based MRONJ surgery was proved through the recovery pattern of underlying bone structure and no recurrence sign showing.

Clinical trial registration: Not applicable.

Background: Understanding the interactions among predictors of dental trust in children is important for designing effective interventions in pediatric dental care.

Aim: This study aimed to develop and validate a conceptual model to evaluate factors influencing dental trust in children.

Design: This cross-sectional study included 267 parent-child dyads. Data collection tools included a sociodemographic data form, the Turkish Oral Health Literacy Assessment Task (TOHLAT-P), the Dental Trust Scale (DTS), the Children's Fear Survey Schedule-Dental Subscale (CFSS-DS), and the Early Childhood Oral Health Impact Scale (ECOHIS). The conceptual model explored the factors influencing dental trust in children by incorporating endogenous and exogenous variables. Path analysis was conducted to test model fit.

Results: Dental trust was significantly associated with parental oral health literacy (β = -0.20; P < 0.001), dental anxiety (β = -0.18; P < 0.001), and oral health-related quality of life (β = -0.15; P < 0.001). The path analysis confirmed the validity of the proposed model, showing significant pathways between these variables and dental trust in children.

Conclusions: This study presents a validated model illustrating the relationships between parental and child-related factors and dental trust in children. These findings underscore the importance of addressing these factors in clinical strategies to enhance dental trust and improve pediatric dental outcomes.

Objectives: The objective of this study was to examine the effects of modeling liquid application on the color stability and surface roughness of single-shade composites.

Materials and methods: Single-shade composites were divided into 4 main groups according to their contents. A total of 64 disc-shaped samples (8 × 2 mm) were prepared, 16 in each group, by using Teflon molds. The samples were divided into two subgroups on the basis of the application of a modeling liquid. After the initial color and roughness measurements, the samples were immersed in coffee for 12 days. Color changes were assessed via a spectrophotometer and ΔE values were calculated via the CIELAB formula. The surface roughness (Ra) was measured via a profilometer. The data were subjected to statistical analysis via two-way analysis of variance and Tukey's test to examine pairwise differences at a significance level of 0.05.

Results: The application of modeling liquid reduced discoloration in Charisma Diamond One (CDO) and Vittra APS Unique (VUA), whereas it slightly increased discoloration in Omnichroma (OMN) and Zenchroma (ZNC). However, only the changes in CDO were statistically significant (p < 0.05). Among the composite control groups baseline and after the coloring procedures, the highest surface roughness degree was observed in the CDO group, while the lowest surface roughness degree was observed in the OMN and ZNC groups (p < 0.05), and the differences between them were found to be significant (p > 0.05). The surface roughness and color changes approached the mean values in the subgroups where the modeling liquid was applied, and there was no significant difference between them (p > 0.05). The application of modeling liquid was observed to reduce the variation in initial roughness among the composites, bringing their roughness values closer to an average range (0.26-0.34).

Conclusion: Modeling liquid application increased roughness and discoloration in composites with initially low surface roughness (OMN and ZNC) while reducing roughness and discoloration in composites with initially high surface roughness (VUA and CDO).

Clinical relevance: Modeling liquid application should be approached more cautiously in composites with high polishability, despite contributing to clinical use in composites with high roughness values.

Background: Early childhood caries (ECC) is a highly prevalent oral disease among children worldwide, arising from multiple contributing factors. This study aimed to investigate the sociodemographic and clinical factors associated with ECC in preschool children attending a hospital in Ica, Peru.

Methods: This observational cross-sectional study involved 186 children evaluated during two dental health campaigns organised by a hospital in Ica, Peru. Oral examinations were conducted by two trained paediatric dentists, while haemoglobin levels were measured by two nurses. Mothers or caregivers completed questionnaires to provide relevant sociodemographic and behavioural data. Multiple logistic regression analyses were conducted to identify variables significantly associated with ECC (p < 0.05). The maximum likelihood method was used to assess the contribution of demographic, clinical and other factors-such as oral hygiene and cariogenic diet-using odds ratios (ORs) and regression coefficients to indicate the magnitude and direction of their effects.

Results: The prevalence of ECC was 76.88%. Among the children, 50.54% were male, with a mean age of 4.44 ± 0.87 years. Most participants had poor oral hygiene (63.98%), while 82.26% of children with anaemia had reduced haemoglobin levels. The mean monthly family income was USD 376.35 ± 168.96. Mothers or caregivers reported brushing their children's teeth twice daily (56.99%) and giving sweets one to two times daily (79.03%). Factors significantly associated with ECC included the child's age (OR = 3.32; 95% CI, 1.68-6.58), haemoglobin level (OR = 0.43; 95% CI, 0.25-0.72), monthly family income (OR = 0.99; 95% CI, 0.9972-0.9998) and mother/caregiver education (OR = 0.13; 95% CI, 0.03-0.52). Additionally, dental brushing frequency (OR = 0.13; 95% CI, 0.02-0.65) and sweet consumption (OR = 4.98; 95% CI, 1.05-23.56) were identified as associated behaviours.

Conclusion: The findings demonstrate that ECC is associated with a child's age, monthly family income, mother/caregiver education level, haemoglobin level, brushing frequency and sweet consumption.

Objective: With altered sense of taste being a common symptom of coronavirus disease 2019 (COVID-19), the main objective was to investigate the presence and distribution of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) within the tongue over the course of infection.

Methods: Golden Syrian hamsters were inoculated intranasally with SARS-CoV-2 and tongues were collected at 2, 3, 5, 8, 17, 21, 35, and 42 days post-infection (dpi) for analysis. In order to test for gross changes in the tongue, the papillae of the tongue were counted. Paraffin-embedded thin sections of the tongues were labeled for the presence of SARS-CoV-2 antigen.

Results: There was no difference in fungiform or filiform papillae density throughout the course of infection. SARS-CoV-2 antigen was observed in the vallate papillae taste buds (3-35 dpi) and autonomic ganglia (5-35 dpi), as well as in the serous and mucous salivary glands of the posterior tongue (2-42 dpi).

Conclusion: The presence and distribution of SARS-CoV-2 suggest that the virus could cause taste disturbance by infecting the vallate papillae taste buds. This effect could be exacerbated by a diminished secretion of saliva caused by infection of the serous salivary glands and the autonomic ganglia which innervate them.

Background: Sex estimation is the first stage in the identification of an individual in the forensic context, and can be carried out from bone structures like the mandible. The aim of this study was to estimate sex from metric analysis of the mandible in cone beam computed tomography images (CBCT) of adult Chilean individuals.

Methods: Six mandibular measurements were analysed, five linear and one angular, in CBCT of adult Chilean individuals of both sexes. ROC Curve analysis was performed, with cut-off points, and of the overall model quality. Univariate discriminant function analysis was used to determine the accuracy of each measurement for sex estimation. Multivariate discriminant function analysis, both directly and by steps, was used to obtain the predictive value of the mandible including all the measurements.

Results: The data included were 155 CBCT, 105 of females and 50 of males. The mandible presented great sexual dimorphism, with the mandibular ramus presenting greater predictive power than the mandibular body. When each mandibular measurement was analysed separately, the maximum height of the mandibular ramus presented the greatest predictive power (76.5%), while the mandibular angle was the least accurate parameter for sex estimation (58.1%). Direct method analysis presented 87.1% accuracy for sex identification of adult Chilean individuals, and joint analysis of maximum mandibular ramus height (MRH), corono-condylar distance and bigonial breadth presented 86.5% accuracy. In ROC Curve analysis the MRH was the variable with the greatest discriminating capacity (AUC = 0.833), MA was the only variable which presented no discriminating capacity (AUC = 0.386) and also presented low quality in model quality analysis.

Conclusion: Metric analysis of the mandible in CBCT images presents an acceptable accuracy for sex estimation in Chilean individuals, and its use for that purpose in forensic practice is recommended.

Background: To improve the success rate of mini-implants, some surgical guides have been developed through digital technologies to achieve three-dimensional (3D) guided mini-implants insertion. However, there is no a surgical guide which can be applied for the insertion of infrazygomatic mini-implant. In this study, we introduced a two-trajectories surgical guide and investigated the success rate of infrazygomatic mini-implants under the guidance of the template.

Methods: An individualized surgical guide was fabricated based on the cone-beam computed tomography images, digital intraoral scanning images and the predesigned insertion plans. In the surgical guide group, 62 mini-implants were inserted between the maxillary first and second molars under the guidance of surgical guides (n = 62). In the historical control group, 54 mini-implants were placed by the direct manual method at the same site (n = 54). Then the mini-implant success rate in these two groups was compared.

Results: After implantation, 2 out of the 62 mini-implants fell off and a success rate of 96.8% was indicated in the surgical guide group. In the historical control group, 11 of 54 mini-implants fell off and the success rate was 79.6%. There was statistically significant difference between the success rate of two groups (P = 0.003).

Conclusions: The two-trajectories surgical guide is advantageous for the insertion of infrazygomatic mini-implant. Both the success rate and stability of infrazygomatic mini-implant were improved significantly with the use of the guide. But further studies with enlarged sample are needed to evaluate the accuracy and stability of the mini-implant placement.