A computed tomographic evaluation of effect of mandibular advancement device at two different horizontal jaw positions in patients with obstructive sleep apnea.

Statement of problem: Studies pertaining to the objective assessments of the efficacy of mandibular advancement device in patients with obstructive sleep apnea are scarce. Purpose: The purpose of this clinical study was to evaluate the effect of MAD at two different horizontal positions of mandible on upper airway dimensions through computed tomography. Material and methods: Twenty-nine consenting participants satisfying predetermined inclusion and exclusion criteria were enrolled and an adjustable two-piece MAD was fabricated at 50% maximum mandibular protrusion and after 4 weeks was adjusted to 70% protrusion. CT scans were obtained at baseline, 4 weeks after delivering MAD with 50% mandibular protrusion, and then after 4 weeks with 70% mandibular protrusion. Cross sectional area with diameters (lateral and anteroposterior) of upper airway was measured at three specific anatomic levels (retropalatal-RP, retroglossal-RG, and epiglottal-EG). Data were analyzed using the Student t-test for parametric analysis. Results: Intragroup comparison revealed a statistically significant increase in lateral & anteroposterior dimensions as well as cross sectional area at all three anatomical levels at 4 weeks after MAD with 50% mandibular protrusion compared with baseline and 4 weeks after MAD with 70% mandibular protrusion compared with baseline. However, the difference between lateral and anteroposterior dimensions with MAD at 70% protrusion compared with MAD at 50% protrusion was not statistically significant. The difference between cross-sectional area was found to be statistically significant. Conclusion: Mandibular advancement device at 70% mandibular protrusion is more effective compared with the device at 50% protrusion in relieving oropharyngeal obstruction seen in OSA.

To compare different non-surgical treatment modalities on treatment of obstructive sleep apnea: A systematic review and meta-analysis.

The study aimed to assess the effect of mandibular advancement device (MAD) in patients with obstructive sleep apnea for reduction in 24-h mean blood pressure, sleep quality, Apnea Hypopnea Index (AHI), and patient compliance, compared to continuous positive airway pressure (CPAP), other interventions, or no treatment. Three different databases such as PubMed, EMBASE, and CENTRAL were searched using different search terms till July 2021 as per the inclusion and exclusion criteria. After inclusion of studies, data extraction including risk of bias assessment was done. For each study, we used odds ratio, mean difference, and 95% confidence interval to assess and synthesize the outcomes. The quality of evidence was evaluated as per the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE). Twenty-one randomized controlled trials were included: 497 patients in the MAD group, 239 patients in the CPAP group, and 274 patients in the sham group. In MAD-CPAP comparison, the results favored CPAP in the reduction of AHI of 3.48 (1.76-5.19). However, unclear results were found for sleep quality measured as Epworth Sleepiness Scale (ESS), patient compliance, and 24-h mean blood pressure. In MAD-sham comparison, the results favored MAD in the reduction of AHI of - 8.39 (-10.90--5.88] and ESS of - 0.91 (-1.70--0.12) and favored sham in terms of patient compliance while, unclear results for 24-h mean blood pressure. The GRADE score indicated that the quality of evidence is very low, low, and moderate for different outcomes. CPAP in comparison to MAD and MAD in comparison to sham showed a significant AHI reduction. However, patient compliance and 24-h mean blood pressure were not significantly different in MAD-CPAP or MAD-sham. Quality of evidence is very low and low when MAD was compared with CPAP and sham, respectively, for AHI.

Empirical assessment of allele frequencies of genome wide association study variants associated with obstructive sleep apnea.

OBJECTIVE: Obstructive Sleep Apnea (OSA) is a heterogeneous disorder with a complex interplay of genetic and environmental factors. Over the years, with advancement in genotyping and sequencing techniques, various loci have shown an association with OSA. It is pertinent to understand the status of these associated variants in different ethnic groups. The aim of the study was to assess the genetic affinity among different population groups by evaluating the risk allele frequencies of variants associated with OSA. METHOD: The variants associated with OSA were obtained from the GWAS catalog with a significant p value of <5 × 10-7; 95 variants were obtained (www.ebi.ac.uk/gwas). Further, the variants were narrowed down on the basis of risk allele frequencies (>5%). The fst was calculated to assess the genetic affinity between super population groups and among the sub-population groups present in the 1000 genome project. RESULT: The fst values observed indicated all super populations were genetically related (SAS, AMR, EAS and EUR) except in the African (AFR) population group. Further, the closely related super population i.e., SAS, AMR, EAS and EUR when bifurcated on the basis of sub-population groups shows population stratification and SAS population groups form separate clusters on the MDS plot. CONCLUSION: The study highlights genetic heterogeneity among different population groups that gets diluted and results are biased when the samples are pooled irrespective of their endogamous groups. Our results provide insight to researchers to target specific endogamous groups for future studies on OSA.

An in vitro Evaluation of Fracture Resistance of endodontically treated Teeth with Different Restorative Materials.

AIMS: The aim of the present study is to compare and assess the fracture resistance of root canal treated teeth with different restorative materials. MATERIALS AND METHODS: The present in vitro study was carried out on seventy-five freshly extracted, noncarious, single-canal human lower-first premolars with similar anatomic characteristics. Teeth were randomly assigned to five groups with 15 teeth being present in each group. Group I is control group (no alteration done), group II is restored with silver amalgam after endodontic therapy, group III is restored with posterior composite after end-odontic therapy, group IV is restored with posterior glass ionomer cement (GIC) after endodontic therapy, and group V is restored with miracle mix after endodontic therapy. Universal testing machine was used to assess the fracture strength. Analysis of variance (ANOVA) test followed by Tukey's post hoc test were used to determine the significant difference between each group. A p-value of < 0.05 was considered as statistically significant. RESULTS: The mean fracture resistance of control group showed highest fracture resistance with a mean Newton of 1083.33 ± 136.78. Among the restorative material, the highest fracture resistance was shown by teeth restored by composite (845.46 ± 47.36), followed by silver amalgam (845.46 ± 47.36). There was statistically significant difference among all the restorative materials compared with the control group (p < 0.05). However, among the teeth restored with silver amalgam and miracle mix, there was no statistical significance (p > 0.05). CONCLUSION: The present study concludes that composites are found to be having more fracture resistance followed by silver amalgam on endodontically treated premolar teeth. CLINICAL SIGNIFICANCE: Restoring nonvital teeth represents a major challenge for clinicians as they are extensively damaged due to caries and endodontic access preparations. With various restorative materials in the market, it becomes difficult for the clinician to choose the better restorative material for postendodontic restoration.