Development and evaluation of a surgical 3D simulation model on submental flap surgery training.

OBJECTIVES: The purpose of the present study was to design and assess a 3D simulation model for submental flap surgery in training oral and maxillofacial surgery (OMFS) residents. METHODS: This quasi-experimental study involved a total of 20 OMFS residents attending and was conducted from September 2023 to December 2023. A 3D submental flap surgical phantom was designed using Mimics V.21 software and printed using fused deposition modeling technology. Participants were first tested on their knowledge of submental flap surgery before being randomly assigned to experimental or control groups. The experimental group received a lecture and demonstration using the developed phantom, while the control group had traditional lecture education only. Afterward, the same test was administered to all participants post-training. Pre- and post-test scores were calculated and compared between the two groups. p-Value < 0.05 was considered statistically significant. RESULTS: The average pre-intervention test scores in the control and experimental group, were 2.5 ± 1.43 and 3 ± 0.816, respectively (p = 0.35). Post-intervention, the experimental group exhibited significantly higher exam scores compared to the group who had only received academic lecture training (6.9 ± 0.87 vs. 4.9 ± 0.99) (p < 0.001). Irrespective of the applied teaching method, both groups showed a significant increase in exam scores after receiving submental flap training (p < 0.001 for both groups, paired-sample t-test). CONCLUSION: The use of the developed submental flap phantom model significantly improved OMFS residents' test scores and knowledge of the surgical technique, suggesting its potential integration into the conventional resident training curriculum.

Evaluating malocclusion patterns in children with autism spectrum disorder using the index of complexity, outcome and need: a cross-sectional study.

BACKGROUND: The purpose of this study was to evaluate the complexity of malocclusion and existing patterns in children with autism spectrum disorders (ASD) using the index of complexity, outcome and need (ICON). METHODS: This cross-sectional study included children diagnosed with ASD, aged 9-15 years. A group of healthy children with the same demographic characteristics was randomly selected as the control group. Malocclusion was assessed according to ICON scoring protocol. The following parameters were recorded: dental aesthetics, upper arch crowding/spacing, presence of crossbite, anterior-vertical relationship (open and deep bite) and buccal segment anterior-posterior relationship. Finally, an overall ICON score was derived and reported for each patient. Descriptive analysis was performed for all investigated variables. Significance level was set at p < 0.05. RESULTS: A total of 324 children, divided into ASD (162) and control (162) groups, comprised the study population. Our results demonstrated that the average overall ICON score was significantly higher in the ASD group compared to the control group (38.77 vs. 27.43, p < 0.001). ASD children also obtained significantly higher scores regarding the dental aesthetics component (3.84 vs 2.78, p < 0.001). Study groups were significantly different in terms of the prevalence of incisor overbite and open bite (p = 0.002 and p < 0.001, respectively). Patients in the ASD group showed a higher prevalence of Class II and Class III malocclusions (p < 0.001). CONCLUSION: ASD children obtained significantly higher overall ICON scores, indicating more complex and severe malocclusions. These children also exhibited a greater tendency towards Class II and III malocclusions.

Evaluation and comparison of the effects of a new paste containing 8% L-Arginine and CaCO3 plus KNO3 on dentinal tubules occlusion and dental sensitivity: a randomized, triple blinded clinical trial study.

BACKGROUND: Dentin hypersensitivity, often occurring after dental treatments or from erosive lesions, is a prevalent patient complaint. This study introduces a paste combining 8% L-arginine, calcium carbonate, and potassium nitrate to evaluate its impact on dentinal tubules occlusion, dentin permeability, and tooth sensitivity. METHODS: Dentin surfaces from 24 third molars (thickness: 2 mm) were divided into two groups of 12. One received the experimental paste, while the other received a placebo without desensitizer. Permeability and sealing ability were assessed through scanning electron microscopy (SEM) and dentin permeability measurement. The pastes' effects on hypersensitivity were then examined in a triple-blind, randomized parallel-armed clinical trial with 16 eligible patients. Sensitivity to cold, touch, and spontaneous stimuli was recorded using the VAS scale at various intervals post-treatment. Statistical analysis was conducted using Shapiro-Wilk, Mann-Whitney U, Friedman, and Wilcoxon tests (α = 0.05). RESULTS: The permeability test demonstrated a significant reduction in dentin permeability in the experimental group (P = 0.002) compared to the control (P = 0.178). SEM images revealed most dentinal tubules in the intervention samples to be occluded. Clinically, both groups showed a significant decrease in the three types of evaluated sensitivity throughout the study. However, no significant difference in sensitivities between the two groups was observed, with the exception of cold sensitivity at three months post-treatment (P = 0.054). CONCLUSION: The innovative desensitizing paste featuring 8% L-arginine, calcium carbonate, and potassium nitrate effectively occluded dentinal tubules and reduced dentin permeability. It mitigated immediate and prolonged dentin hypersensitivity to various stimuli, supporting its potential role in managing dentin hypersensitivity. TRIAL REGISTRATION: http://irct.ir : IRCT20220829055822N1, September 9th, 2022.

Effect of preheating nano-hybrid and bulk-fill composites with warm airstream on their microtensile bond strength to dentin.

Aims: This study assessed the effect of preheating nano-hybrid and bulk-fill composites with warm airstream on their microtensile bond strength (MTBS) to dentin. Materials and Methods: In this in vitro study, dentin was exposed in 42 extracted premolars that were assigned to two groups (n = 21) for bonding to EverX Posterior bulk-fill and Grandio nano-hybrid posterior composite. Each group was subdivided into three subgroups for preheating of composite to 50°C by a commercial composite warmer (Subgroup 1), a warm airstream by a hair dryer for 10 s (Subgroup 2), and no heating (room temperature; Subgroup 3). Composite cylinders with a 4-mm height were bonded to the tooth surface with a 5th-generation bonding agent using the incremental technique and cured (each increment for 30 s). The MTBS to dentin was measured, and the bonding interface was evaluated under a stereomicroscope and a scanning electron microscope (SEM). Data were analyzed using one-way and two-way ANOVA, Tukey's test, and independent t-test (α =0.05). Results: In both composite groups, the mean MTBS of the warm airstream subgroup was significantly higher than that of warmer (P < 0.001) and control (P < 0.001) subgroups. The mean MTBS of the warmer subgroup was significantly lower than that of control subgroup (P = 0.01). The MTBS of the EverX composite was significantly higher than that of the Grandio composite only in the warmer group (P < 0.05). Adhesive failure occurred more frequently in all groups with the highest frequency in airstream subgroup of both composite types. Conclusion: Preheating with a warm airstream significantly increased the MTBS of both composite types to dentin.