Effects of polishing press-on force on surface roughness and gloss of CAD-CAM composites.

PURPOSE: The aim of this study was to determine the effect of polishing press-on force on surface roughness and gloss of computer-aided design-computer-aided manufacturing (CAD-CAM) composites. METHODS: The materials evaluated included a CAD-CAM ceramic, a polymer-infiltrated ceramic, and three filler-based CAD-CAM composites. The CAD-CAM blocks were sectioned, embedded in self-cured resin, finished with abrasive papers and ultrasonically cleaned. Specimens were subsequently polished using the Sof-Lex disk system with 0.5, 1.0, 1.5, and 2.0 N press-on force by means of a custom-made apparatus. Contour arithmetic mean deviation (Ra) and gloss value (GU) data were acquired with a profilometer and glossmeter, respectively, and analyzed using ANOVA/Bonferroni post hoc test and Pearson's correlation (α = 0.05). Representative samples of the various materials at baseline and after each polishing step were examined under scanning electron microscope. RESULTS: Mean Ra and GU values ranged from 0.096 ± 0.004 µm to 0.295 ± 0.045 µm and 13.4 ± 1.9 to 67.6 ± 11.3 correspondingly for the various material-force combinations. Surface roughness and gloss were found to be press-on force and material dependent. A moderately strong and negative correlation (rs = -0.69) existed between Ra and GU values. CONCLUSION: For optimal smoothness and gloss, ceramic and polymer-infiltrated ceramic CAD-CAM materials must be polished with a 2.0 N force, while filler-based CAD-CAM composites should, in general, be polished using a 1.0 to 1.5 N force.

Incorporation of Green Capping Agents to Reduce Silver-Mediated Dentine Staining.

Silver diammine fluoride (SDF) is known as a noninvasive, cost-effective, safe, and simple method of dental caries treatment. However, staining and discoloration seem inseparable with SDF and continue as a cosmetic concern. Research is ongoing to overcome these issues, for example, by using glutathione (G) or potassium iodide among others. Therefore, the study aimed to investigate the effects of incorporating different concentrations of capping agents on SDF chemistry and SDF-mediated tooth staining at different time points. Tannic acid (TA), gallic acid (GA), carboxymethyl chitosan (CM), and G at different concentrations (5, 10, and 15% w/v) were incorporated in 30% SDF. FTIR and UV-Vis spectroscopies of the prepared solutions was performed to evaluate chemical changes. Time-dependent color changes (ΔE) in bovine dentine specimens (6 × 6 × 1 ± 0.25 mm3) were measured spectrophotometrically at application/washup, 1 and 3 h, after 1, 2, 4, 7, and 14 days. Results showed suppression of FTIR peaks at 3,358 cm-1 and 1,215 cm-1 in capping agent-modified SDF indicative of a successful capping effect of the silver ions, which was corroborated by UV-Vis blueshift of ∼∆32 nm. The capping effect on SDF increased proportionally with the concentrations of TA, GA, CM, and G used. A more pronounced tooth staining reduction however was shown more in TA- and G- rather than in GA- and CM-modified SDF. At day 14, SDF showed the highest mean ΔE(50.14 ± 2.14), while 15% TA showed the lowest ΔE(30.14 ± 0.81). In conclusion, capping agent incorporation significantly reduced SDF-mediated tooth staining. This reduction in staining is more dependent on the respective capping agent functional groups than concentrations per se. The potential of capping agents to minimize tooth staining of SDF was TA>G>CM>GA.

Increased chemokine RANTES in synovial fluid and its role in early-stage degenerative temporomandibular joint disease.

BACKGROUND: Degenerative joint disease (DJD) of the temporomandibular joints (TMJs) in adolescents and young adults is closely associated with disc displacement without reduction (DDw/oR). OBJECTIVE: This study aimed to determine the pathogenesis of early-stage TMJ DJD induced by DDw/oR. METHODS: 31 female subjects aged 12-30 years were enrolled, comprising 12 patients with DDw/oR without DJD, 13 with DDw/oR and early-stage DJD, and 6 healthy volunteers. The synovial fluid samples of the subjects were screened for 27 inflammatory-related cytokines using multiple cytokine array. Significantly increased cytokines and a key regulator of osteoclastogenesis "receptor activator of nuclear factor-κB ligand" (RANKL) were further determined by sandwich immunoassay. These factors were also assessed for the possible pathophysiologic actions on RAW264.7 cell proliferation, migration, osteoclastogenesis and bone-resorbing activity using Cell Counting Kit-8, Transwell system, tartrate-resistant acid phosphatase staining and osteo assay plates. RESULTS: Macrophage-derived inflammatory protein-1 beta (MIP-1ß) and regulated upon activation normal T cell expressed and secreted (RANTES) were found to vary significantly in relation to the controls. In contrast to an unchanged concentration of RANKL, a strong increase in the level of RANTES was detected in subjects with DDw/oR and early-stage DJD. MIP-1ß concentrations were only elevated in subjects with DDw/oR without DJD. Functionally, both MIP-1ß and RANTES could enhance macrophage migration in a concentration-dependent manner, while only RANTES exhibited a promoting effect on osteoclast formation and bone-resorbing activity. CONCLUSIONS: Chemokine RANTES was significantly upregulated and might be a key regulator of osteoclastogenesis contributing to DDw/oR-induced early-stage TMJ DJD.

Functional, physical and psychosocial impact of Temporomandibular Disorders in adolescents and young adults

BACKGROUND: This community-based study investigated the functional, physical and psychosocial impact of Temporomandibular Disorders (TMDs) in adolescents and young adults. It also determined the discriminative capacity of a TMDs-specific oral health related quality of life (OHRQoL) instrument and compared three formats of appraising OHRQoL data. MATERIAL AND METHODS: Subjects were recruited from a local Polytechnic. The presence of TMDs was established with the Fonseca Anamnestic Index (FAI), whilst TMDs-specific OHRQoL was evaluated with the Oral Health Impact Profile-TMDs (OHIP-TMDs). Demographic information, FAI and OHIP-TMDs responses were gathered with an on-line questionnaire. Data was analysed using Mann-Whitney U-test, chi-square test and Spearman's rho correlation with significance level set at 0.05. RESULTS: Data from a total of 244 participants were compiled and examined. The "no TMDs" (NT) group consisted of 140 subjects (119 females; 21 males) with a mean age of 20.41 ± 3.29 years, while the "with TMDs" (WT) group composed of 104 subjects (88 females; 16 males) aged 19.82 ± 3.04 years. Significant differences in median severity scores were observed between subjects with and without TMDs for all OHIP-TMDs domains and total OHIP (p values < 0.001). For appraisal of extent and prevalence, significant differences were again observed (p values < 0.05) with the exception of the functional limitation and handicap domains. CONCLUSIONS: TMDs impacted physical and psychosocial well-being of adolescents and young adults. OHIP-TMDs, preferably appraised by severity, extent and prevalence, was able to discriminate between subjects with and without TMDs. It holds promise as a TMDs-specific OHRQoL instrument for epidemiological studies

No disponible

Impact of pain-related temporomandibular disorders on jaw functional limitation, psychological distress and quality of life in postoperative class III East Asian patients.

OBJECTIVES: This cross-sectional study determined the prevalence of painful TMD and its impact on jaw function, psychological status and oral health-related quality of life (OHRQoL) in postoperative Chinese patients. It also assessed factors influencing OHRQoL of these patients. MATERIALS AND METHODS: Subjects were recruited from the National Dental Centre Singapore dentofacial deformity registry. Invitations to participate in the study were sent to patients who sought treatment from March 2011 to November 2017. Patients who consented were directed to an online link to complete a series of questionnaires based on the Diagnostic Criteria for TMD (DC-TMD) and the orthognathic quality of life questionnaire (OQLQ). RESULTS: The subjects (n = 99) had a mean age of 25.2 ± 6.0 years and postoperative time of 29.4 ± 22.7 months. 18.2% were found to suffer from pain-related TMD postorthognathic surgery and these patients (n = 18) had significantly higher median JFLS-8 score than those without TMD pain (p = 0.008). Time since surgery was significantly associated with OHRQoL (p = 0.00000026). CONCLUSIONS: Prevalence of painful TMD and psychological distress was low while prevalence of jaw functional limitation was moderately high in postoperative class III Chinese patients. CLINICAL RELEVANCE: Painful TMD impacted jaw function especially when subjects open wide enough to drink, yawn, talk and smile but had no significant consequence on psychological status and OHRQoL.

Quality of life of patients with endodontically treated teeth: A systematic review.

This systematic review aimed to appraise the quality of life of patients with restored endodontically treated teeth. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were employed. The specific PEO question was as follows: population: patients who were healthy individuals ≥18 years old and required endodontic treatment; exposure: endodontic treatment with a coronal restoration with at least 6 months in occlusal function; and outcome: quality of life of patients. Databases were searched in conjunction with hand searching of reference lists of endodontic textbooks, endodontic-related journals, and relevant articles from electronic searching. Six articles met the inclusion criteria. Most studies concluded that non-surgical root canal therapy improved patients' quality of life. The effect of operator type yielded conflicting results. Only one paper compared endodontic treatment with implant placement, and it showed similar patient-centric outcome with a high level of patient satisfaction. Current research is still limited, and further studies are warranted.

Psychometric evaluation of the Chinese version of the Fonseca anamnestic index for temporomandibular disorders.

BACKGROUND: The Fonseca anamnestic index (FAI) offers a simple, low-cost, patient-reported method for screening temporomandibular disorders (TMDs). OBJECTIVES: This study described the development of the Chinese version of the FAI (FAI-C) and examined its reliability and validity when compared to the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD). METHODS: The FAI-C was created by translation and cross-cultural adaptation of the English instrument following international guidelines. Psychometric evaluation of the FAI-C was carried out on a sample of 613 patients with TMDs and 57 controls. Reliability of the FAI-C was determined by means of internal consistency and test-retest methods while validity was ascertained by criterion-related validity. Criterion validity was examined via Cohen's kappa, sensitivity and specificity when compared with DC/TMD Axis I diagnoses. RESULTS: Cronbach's alpha value (internal consistency) for total FAI-C score was 0.669, and intra-class correlation coefficient (ICC) value (test-retest reliability) was 0.823. For criterion validity, kappa coefficient value was 0.633 while sensitivity and specificity was 95.9% and 71.9%, respectively. CONCLUSION: The Chinese version of the FAI demonstrated acceptable reliability and good validity. The FAI-C could thus be used as an instrument for screening TMDs in Chinese literate populations.

Effects of bicuspid extractions and incisor retraction on upper airway of Asian adults and late adolescents: A systematic review.

OBJECTIVES: This systematic review aimed to assess the effects of bicuspid extractions and incisor retraction on airway dimension, hyoid position and breathing of adults and late adolescents. METHODS: The review was conducted according to PRISMA guidelines. Eight databases including PubMed, EMBASE, Web of Science and Scopus were searched to August 2018. Minimum age of participants was 16 years. The intervention was dual-arch bicuspid extractions with incisor retraction. Outcomes were airway dimension, hyoid position and breathing assessment. RESULTS: All nine publications meeting inclusion criteria were from Asia. They were divided into three Asian subregions. All East Asian lateral cephalometric studies reported anteroposterior airway narrowing at the oropharynx and sometimes the hypopharynx. However, the narrowing was small, comparable to measurement errors, and highly variable. Two out of three East Asian computed tomography (CT) studies described reductions in airway dimensions. The single functional breathing study showed increased simulated flow resistance after incisor retraction in East Asians. South Asian studies had mixed findings, with some reporting significant airway narrowing. The single study from West Asia found no significant airway or hyoid changes. CONCLUSIONS: Airway response to bicuspid extractions and incisor retraction varied substantially when assessed with cephalometry. CT measurements present larger effect sizes and smaller variations, providing stronger evidence of airway narrowing. Orthodontic extractions for incisor retraction may be more frequently indicated in Asia, and East Asians seem particularly susceptible to airway narrowing and postero-inferior hyoid movement with incisor retraction. Better designed CT studies are needed for confirmation due to small effect size and large variability.

Condylar repair and regeneration in adolescents/young adults with early-stage degenerative temporomandibular joint disease: A randomised controlled study.

BACKGROUND: Anterior repositioning splint (ARS) can facilitate regenerative condylar remodelling. OBJECTIVE: To determine the effect of ARS on osseous condylar changes in adolescents/young adults with early-stage degenerative joint disease (DJD). METHODS: Sixty-nine patients with early-stage temporomandibular joint (TMJ) DJD based on the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) and cone beam computed tomography (CBCT) imaging were recruited and randomly allocated to two treatment groups: (a) conservative therapy with ARS and (b) conservative therapy without ARS. Subjects with acute TMJ closed-lock had their displaced discs physically reduced by mandibular manipulation prior to ARS therapy. Clinical and CBCT data of 59 patients (86.4% females, mean age 17.95 ± 4.53 years, 67 joints) were attained pre- and at 6 or 12 months post-treatment. Osseous changes after treatment were categorised into (a) progressed, (b) unchanged, (c) repaired (remodelled without new bone formation) and (d) regenerated (remodelled with new bone formation). Statistical analysis including chi-square test, independent samples t test or Mann-Whitney U test was conducted. RESULTS: About 85.5% of patients (59/69) completed the study, with 28 subjects (32 joints) in the splint group and 31 (35 joints) in the control group. The occurrence of condylar repair and regeneration was significantly higher with ARS (78.1%/[25/32] of joints) when compared to control group (48.6%/[17/35]) (P < 0.05). Moreover, condylar regeneration was exclusively observed in 50%/(16/32) of joints with ARS. For the 14 joints in splint group that received physical TMJ closed-lock reduction, 85.7%/(12/14) exhibited condylar regeneration. The splint group (3.1%/[1/32]) also had significantly lower incidence of progressive TMJ degeneration than the control (37.1%/[13/35]) (P < 0.001). CONCLUSION: Condylar repair and regeneration in early-stage TMJ DJD are possible, and ideal spatial disc-condyle relationship appears important. The possibility of restoring TMJ form/structure by ARS therapy presents an attractive area of new basic science and clinical research (Bone defect repair in early osteoarthrosis of temporomandibular joint by joint distraction therapy: A randomized controlled trial/ChiCTR-TRC-14005172).

Effects of non-surgical rapid maxillary expansion on nasal structures and breathing: A systematic review.

OBJECTIVE: This systematic review aims to determine the effects of non-surgical rapid maxillary expansion (RME) on breathing and upper airway structures. MATERIALS AND METHODS: An electronic search of the scientific literature from January 2005 to June 2016 was done using Web of Science, Dentistry & Oral Sciences Source and PubMed databases. A combination of search terms "rapid maxillary expansion", "nasal", "airway" and "breathing" were used. Studies that involved surgical or combined RME-surgical treatments and patients with craniofacial anomalies were excluded. RESULTS: The initial screening yielded a total of 183 articles. After evaluation of the titles, abstracts and accessing the full text, a total of 20 articles fulfilled both inclusion/exclusion criteria and possessed adequate evidence to be incorporated into this review. CONCLUSIONS: Non-surgical RME was found to improve breathing, increase nasal cavity geometry and decrease nasal airway resistance in children and adolescents.

DNA barcoding cannot discriminate between Sardinella tawilis and S. hualiensis (Clupeiformes: Clupeidae).

Sardinella tawilis, the only known freshwater sardinella in the world, is endemic to Taal Lake, Philippines. Previous studies found the Taiwan sardinella, S. hualiensis, to be morphologically very similar to S. tawilis and identified it as the marine sister species of S. tawilis. In this study, DNA barcoding using the mitochondrial cytochrome c oxidase I (COI) gene was carried out to analyze species demarcation in the Sardinella genus, focusing primarily on the relationship between S. tawilis and S. hualiensis. The neighbour-joining (NJ) tree that was constructed using Kimura 2-parameter (K2P) model showed a single clade for the two species with 100% bootstrap support. K2P interspecific genetic divergence ranged from 0% to 0.522%, which is clearly below the suggested 3-3.5% cutoff for species discrimination. Recombination activating gene 1 (RAG1), mitochondrial control region (CR), cytochrome b, 16S rRNA, and S7 markers were used to further validate the results. Sardinella tawilis and S. hualiensis clustered together with a bootstrap support of 99-100% in each of the NJ trees. Low interspecific genetic distances between S. tawilis and S. hualiensis for all the markers except CR could be attributed to incipient allopatric speciation.

Associations between symptoms of temporomandibular disorders, quality of life and psychological states in Asian Military Personnel.

BACKGROUND: Symptoms of Temporomandibular Disorders (TMD) could affect oral health-related quality of life (OHRQoL) and psychological distress. OBJECTIVE: This study aims to determine the prevalence of TMD symptoms, and impact of type and number of TMD symptoms on OHRQoL and psychological states among Asian military personnel. METHOD: The study was conducted across 12 military dental centres using self-administered questionnaire comprising demographical data, DC/TMD symptom questionnaire, OHIP-14 and DASS-21. A total of 3028 personnel, aged between 18-65 years old, were invited to participate with an acceptance rate of 90.5%. Data analysis was done using non-parametric tests, regression analysis and Spearman correlation (P < 0.05). RESULTS: Out of 2043 subjects (1998 males; 45 females, mean age 24.18 ± 7.18 years), 36.32% (n = 742) reported at least one TMD symptom. Significant differences in summary OHIP-14, depression, anxiety and stress scores were observed between subjects with and without TMD symptoms. Significant differences in OHIP-14 and DASS-21 scores were observed between dissimilar type and number of TMD symptoms in the TMD group. Those with headaches and 2-3 symptoms have substantially poorer OHRQoL and greater psychological distress. Associations between number of TMD symptoms, quality of life, depression, anxiety and stress were significant but weak (r = 0.19-0.40). CONCLUSIONS: Symptoms of Temporomandibular Disorders were prevalent among Asian military population. Significant differences in OHRQoL and psychological states were observed between subjects with and without TMD symptoms. Specific type and number of TMD symptoms impacted OHRQoL and psychological states differently. Associations between number of TMD symptoms and quality of life, depression, anxiety and stress were significant but weak.

Prevalence of Sleep Bruxism and Its Association with Obstructive Sleep Apnea in Adult Patients: A Retrospective Polysomnographic Investigation.

AIMS: To determine the prevalence of sleep bruxism (SB) in adult obstructive sleep apnea (OSA) patients, to assess the association between SB and OSA in terms of sleep macrostructure and respiratory parameters, and to determine possible OSA risk factors for SB. METHODS: Type I polysomnographic data of 147 adult OSA patients (mean age 44.6 ± 12.8 years) were evaluated for SB. SB episodes were scored when masseter rhythmic masticatory muscle activity (RMMA) was twice the background electromyography amplitude, and SB was established when patients had more than four SB episodes per hour of sleep. Demographic characteristics, sleep macrostructure, and respiratory parameters, including respiratory-related arousal index (RAI), spontaneous arousal index (SAI), oxygen desaturation index (ODI), and Apnea-Hypopnea Index (AHI), were analyzed for differences between patients with and without SB using independent samples t test and Mann-Whitney U test. Multivariate logistic regression analysis was performed to determine the odds of OSA risk factors for SB. RESULTS: Approximately one-third (33.3%) of the adult OSA patients had concomitant SB. Most of the RMMA observed in OSA-SB patients was phasic in nature. OSA patients with SB demonstrated significantly greater RAI (P = .001) and ODI (P = .005). RAI (odds ratio = 1.05, 95% confidence interval = 1.00 to 1.10) and SAI (odds ratio = 0.89, 95% confidence interval = 0.80 to 0.96) demonstrated marginal effects on the odds of experiencing SB. CONCLUSION: About one-third of adult OSA patients had SB, and these patients demonstrated significantly more respiratory-related arousals and oxygen desaturations. These findings suggest that a phenotypic subtype of OSA patients with predominantly phasic SB exists and allude to a possible protective role of RMMA in respiratory-related arousals.

Association between temporomandibular disorders and pubertal development: A systematic review.

The aim of this systematic review (SR) was to determine the association between temporomandibular disorders (TMDs) and pubertal development. Due to the inadequacy of the conventional PICO (Population, Interventions, Comparisons and Outcome) format used for intervention-based SRs, the Joanna Briggs Institute's guidelines for synthesising evidence related to associations with a focus on aetiology were adopted. A search of the PubMed and LIVIVO databases covering the period from January 1980 to May 2018 yielded four publications, which fulfilled the inclusion criteria. Analysis of articles based on the Pubertal Development Scale showed that TMD prevalence increases with pubertal development. Although no sex difference in TMD prevalence and diagnosis was observed, more females reported TMD anamnestic variables, including accounts of temporomandibular pain during pubertal maturity. The higher prevalence of depression and somatisation during pubertal development may contribute to more TMD symptom reporting in females. More prospective studies incorporating standardised methods for diagnosing TMDs and detecting comorbid psychosocial and somatic problems are desired to further elucidate the relationship between TMDs and pubertal development.

Preparation of Tris-Heteroleptic Iridium(III) Complexes Containing a Cyclometalated Aryl-N-Heterocyclic Carbene Ligand.

A new class of phosphorescent tris-heteroleptic iridium(III) complexes has been discovered. The addition of PhMeImAgI (PhMeIm = 1-phenyl-3-methylimidazolylidene) to the dimer [Ir(µ-Cl)(COD)]2 (1; COD = 1,5-cyclooctadiene) affords IrCl(COD)(PhMeIm) (2), which reacts with 1-phenylisoquinoline, 2-phenylpyridine, and 2-(2,4-difluorophenyl)pyridine to give the respective dimers [Ir(µ-Cl){κ2- C, C-(C6H4-ImMe)}{κ2- C, N-(C6H4-isoqui)}]2 (3), [Ir(µ-Cl){κ2- C, C-(C6H4-ImMe)}{κ2- C, N-(C6H4-py)}]2 (4), and [Ir(µ-Cl){κ2- C, C-(C6H4-ImMe)}{κ2- C, N-(C6F2H2-py)}]2 (5), as a result of the N-heterocyclic carbene (NHC)- and N-heterocycle-supported o-CH bond activation of the aryl substituents and the hydrogenation of a C-C double bond of the coordinated diene. In solution, these dimers exist as a mixture of isomers a (Im trans to N) and b (Im trans to Cl), which lie in a dynamic equilibrium. The treatment of 3-5 with Kacac (acac = acetylacetonate) yields isomers a (Im trans to N) and b (Im trans to O) of Ir{κ2- C, C-(C6H4-ImMe)}{κ2- C, N-(C6H4-isoqui)}(κ2- O, O-acac) (6a and 6b), Ir{κ2- C, C-(C6H4-ImMe)}{κ2- C, N-(C6H4-py)}(κ2- O, O-acac) (7a and 7b), and Ir{κ2- C, C-(C6H4-ImMe)}{κ2- C, N-(C6F2H4-py)}(κ2- O, O-acac) (8a and 8b), which were separated by column chromatography. The treatment of 6a with HX in acetone-water produces the protonation of the acac ligand and the formation of the bis(aquo) complex [Ir{κ2- C, C-(C6H4-ImMe)}{κ2- C, N-(C6H4-isoqui)}(H2O)2]X [X = BF4 (9a[BF4]), OTf (9a[OTf])]. The salt 9a[BF4] reacts with 2-(2-pinacolborylphenyl)-5-methylpyridine in the presence of 40 equiv of K3PO4 to afford Ir{κ2- C, C-(C6H4-ImMe)}{κ2- C, N-(C6H4-isoqui)}{κ2- C, N-(C6H4-Mepy)} (10a). Complexes 6a, 6b, 7a, 7b, 8a, 8b, and 10a are phosphorescent emitters (λem = 465-655 nm), which display short lifetimes in the range of 0.2-5.6 µs. They show high quantum yields both in doped poly(methyl methacrylate) films (0.34-0.87) and in 2-methyltetrahydrofuran at room temperature (0.40-0.93). From the point of view of their applicability to the fabrication of organic-light-emitting-diode devices, a notable improvement with regard to those containing two cyclometalated C,N ligands is achieved. The introduction of the cyclometalated aryl-NHC group allows one to reach a brightness of 1000 cd/m2 at a lower voltage and appears to give rise to higher luminous efficacy and power efficacy.

Bone-borne accelerated sutural expansion: A microcomputed tomography study in rabbits.

INTRODUCTION: In this study, we evaluated the effect of bone-borne accelerated expansion protocols on sutural separation and sutural bone modeling using a microcomputed tomography system. We also determined the optimum instant sutural expansion possible without disruption of bone modeling. METHODS: Sixteen New Zealand white rabbits, 20 to 24 weeks old, were randomly divided into 4 experimental groups. Modified hyrax expanders were placed across their interfrontal sutures and secured with miniscrew implants located bilaterally in the frontal bone. The hyrax appliances were activated as follows: group 1 (control), 0.5-mm per day expansion for 12 days; group 2, 1-mm instant expansion followed by 0.5 mm per day for 10 days; group 3, 2.5-mm instant expansion followed by 0.5 mm per day for 7 days, and group 4, 4-mm instant expansion followed by 0.5 mm per day for 4 days. After 6 weeks of retention, sutural separation and sutural bone modeling were assessed by microcomputed tomography and quantified. Statistical analysis was performed using Kruskal Wallis and Mann-Whitney U tests and the Spearman rho correlation (P <0.05). RESULTS: Median amounts of sutural separation ranged from 2.84 to 4.41 mm for groups 1 and 4, respectively. Median bone volume fraction ranged from 59.96% to 69.15% for groups 4 and 3, respectively. A significant correlation (r = 0.970; P <0.01) was observed between the amounts of instant expansion and sutural separation. CONCLUSIONS: Pending histologic verifications, our findings suggest that the protocol involving 2.5 mm of instant expansion followed by 0.5 mm per day for 7 days is optimal for accelerated sutural expansion. When 4 mm of instant expansion was used, the sutural bone volume fraction was decreased.

Temporomandibular disorder symptoms and their association with quality of life, emotional states and sleep quality in South-East Asian youths.

Population studies on the prevalence of temporomandibular disorders (TMD) and their associations with quality of life (QoL), emotional states and sleep quality in South-East Asian youths are not available. This cross-sectional study assessed the presence of TMD and their relationships to QoL, depression, anxiety, stress and sleep quality in a cohort of South-East Asian adolescents/young adults. Three hundred and sixty-two students from a polytechnic were enrolled in the study and completed an online questionnaire consisting of the Fonesca's Anamnestic Index (FAI), Oral Health Impact Profile for TMD (OHIP-TMD), Depression, Anxiety and Stress Scales-21 (DASS-21) and Pittsburgh Sleep Quality Index. The FAI appraises TMD severity while OHIP-TMD determines the effect of TMD on oral health-related QoL. Statistical analysis was performed using chi-square test for categorical data whilst one-way ANOVA/post hoc Bonferroni's tests were employed for numerical scores (P < 0.05). Of the 244 participants who completed the questionnaires in their entirety (37 males; 207 females, mean age 20.1 ± 3.2 years), 32.4% had mild TMD, 9.4% had moderate TMD and 58.2% were TMD free. The total prevalence of TMD was 41.8% (n = 102) and most OHIP-TMD domains including functional limitation (P = 0.000), physical pain (P = 0.000), handicapped (P = 0.000) and psychological discomfort (P = 0.001) showed significant differences in mean scores depending on TMD severity. A similar trend was observed for DASS-21. The majority of participants with TMD (69.6%; n = 71) had poor sleep quality (P = 0.004). TMD appear to be prevalent in South-East Asian youths with varying severity. Severity of TMD had some bearing on QoL, emotional states as well as sleep quality.

Impact of dietary solvents on flexural properties of bulk-fill composites.

OBJECTIVE: This study investigated the effect of dietary solvents on flexural strength and modulus of bulk-fill composites. MATERIALS AND METHODS: One conventional composite (Filtek Z350 [FZ]), two bulk-fill composites (Filtek Bulk-fill [FB] and Tetric N Ceram [TN]) and a bulk-fill giomer (Beautifil-Bulk Restorative [BB]) were evaluated. Specimens (12 × 2 × 2 mm) were fabricated using customized stainless steel molds. Specimens were light-cured, removed from their molds, finished, measured and randomly divided into six groups. The groups (n = 10) were conditioned in the following mediums for 7 days at 37 °C: air (control), artificial saliva (SAGF), distilled water, 0.02 N citric acid, heptane, 50% ethanol-water solution. After conditioning, the specimens were rinsed, blotted dry, measured and subjected to flexural testing using a universal testing machine. Representative SEM images of the intact surfaces were obtained to appraise the degradation mechanism by dietary solvents. Data was subjected to statistical analysis using ANOVA/Tukey's tests at significance level p < 0.05. RESULTS: Significant differences in flexural properties were observed between materials and conditioning mediums. The highest flexural properties were usually obtained with conditioning in air (control) or heptane. Exposure to aqueous solutions generally reduced flexural properties of bulk-fill composites. CONCLUSION: The effect of dietary solvents on flexural properties of bulk-fill composites was material and medium dependent.

Outcomes of therapeutic TMD interventions on oral health related quality of life: A qualitative systematic review.

OBJECTIVES: This systematic review aims to determine the impact of temporomandibular disorder (TMD) therapeutic interventions on patients' oral health related quality of life (OHRQoL) and to recommend approaches that improve QoL. DATA SOURCES: A systematic search of the literature was performed between January 2007 and October 2017 to identify articles on TMD interventions and OHRQoL. Randomized controlled trials, and retrospective and prospective cohort studies that mentioned dedicated tools for measurement of OHRQoL changes in TMD patients after therapeutic interventions were included. Abstracts of studies that did not mention any form of measurement of OHRQoL in their treatment outcome were excluded. The initial screening yielded 171 articles. After evaluation of abstracts and full text articles, five articles fulfilled all selection criteria and were included. Most TMD treatment interventions seem to improve QoL to some extent, but no single treatment modality can be advocated as the sole approach to managing TMD. CONCLUSION: Psychotherapy, occlusal appliance therapy, arthrocentesis, and orthodontics/orthognathic surgery (in subjects with severe malocclusion) appear to improve OHRQoL of TMD patients. Recommendation on the best TMD intervention for improving QoL could not be made due to the diverse TMD subtypes and non-disease specific OHRQoL instruments employed. More studies incorporating TMD-specific OHRQoL measures and targeting explicit TMD subtypes based on internationally accepted diagnostic criteria are warranted in this area of research.

Is there an optimal initial amount of activation for midpalatal suture expansion? : A histomorphometric and immunohistochemical study in a rabbit model.

OBJECTIVE: Accelerated bone-borne expansion protocols on sutural separation and sutural bone formation were evaluated via histomorphometry and immunohistochemistry to determine the optimal initial activation without disruption of bone formation. MATERIALS AND METHODS: Sixteen New Zealand white rabbits were randomly divided into four groups. Modified Hyrax expanders were placed across the midsagittal sutures and secured with miniscrew implants with the following activations: group 1 (control), 0.5 mm expansion/day for 12 days; group 2, 1 mm instant expansion followed by 0.5 mm expansion/day for 10 days; group 3, 2.5 mm instant expansion followed by 0.5 mm expansion/day for 7 days; and group 4, 4 mm instant expansion followed by 0.5 mm expansion/day for 4 days. After 6 weeks, sutural expansion and new bone formation were evaluated histomorphometrically. Statistical analysis was performed using Kruskal-Wallis/Mann-Whitney U tests and Spearman's rho correlation (p < 0.05). RESULTS: The smallest median sutural separation was observed in group 1 (3.05 mm) and the greatest in group 4 (4.57 mm). The lowest and highest amount of bone formation were observed in group 4 (55.82%) and in group 3 (66.93%), respectively. Immunohistochemical analysis revealed significant differences in median levels of alkaline phosphatase and osteopontin expression between all experimental groups. The highest level of these proteins was attained in group 3, followed by groups 2, 1, and 4, respectively. CONCLUSIONS: Sutural appositional bone formation corresponded with the amount of initial expansion to a point. When initial expansion was increased to 4 mm, sutural bone remodeling was disturbed and new bone formation was decreased. The most effective sutural expansion was achieved with 2.5 mm initial activation followed by 0.5 mm expansion/day for 7 days.