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Background/purpose: The nature of susceptibility to condylar resorption after orthognathic surgery can be different between skeletal Class II and Class III populations, which was addressed by few in the past. The aim of the present study was to use cone-beam computed tomographic (CBCT) images to investigate the displacement and morphological changes of temporomandibular joints (TMJs) in patients received orthodontic treatment combined with orthognathic surgery. Methods: Both Class III (n = 34) and Class II (n = 17) patients were compared through overall and regional superimpositions of the initial and posttreatment CBCTs. Two-sample t-test was used to identify significance between group differences. Pearson's correlation coefficient was used to address changes of TMJ and the amount of setback or advancement. Results: The axial ramal angle increased significantly in Class III group and decreased in Class II groups after orthognathic surgery (p

Introduction Mandibular advancement device (MAD) is designed to pull the mandible and the tongue forward anteriorly to increase the cross-sectional airway dimension and thus possibly reduce airway obstructions during sleep. The effectiveness of a MAD may be affected by the pre-treatment OSA severity, BMI, and degree of changes in pharyngeal dimensions resulting from the device in situ. In this study, 3D submental ultrasound imaging is applied to evaluate the difference in the tongue and airway configurations between the responders and non-responders of the MAD treatment. Methods In this retrospective study, 31 subjects (25 males, median age/BMI/baseline AHI of 56/24.5/25.3) diagnosed with sleep apnea and underwent tongue-backing-MAD (t-MAD) treatment were consented from the Department of dentistry of National Taiwan University Hospital between April and December 2022 (IRB 202108078RIPD). Changes in the severity of OSA were assessed with polysomnographic studies. Success of t-MAD treatment was defined by an AHI of less than 10 events/hour and at least 50% decrease in AHI from baseline. There were no significant differences in age, BMI, gender and baseline AHI between responders (17) and non-responders (14). While awake and lying in supine position, the tongue and airway configurations at retropalatal and retroglossal regions without and with t-MAD in situ were assessed with standardized 3D submental ultrasound imaging (AmCAD BioMed Corp., Taiwan). Statistical comparisons were performed using t-tests, chi-square tests and nonparametric Mann-Whitney tests. Results The anteroposterior location of the tongue-airway interface at retroglossal region, relative to the superior-inferior location of the soft-palate-airway interface, was found significantly reduced in responders when t-MAD is in situ (p = 0.0078). 13 responders (76.5%) and 9 non-responders (64.3%) were observed with airway width increase in the retroglossal region with t-MAD in situ. However, the difference in airway width changes between responders and non-responders was not statistically significant possibly due to the limited sample size. Conclusion With the real-time visualization and quantitative characterization of the tongue and airway configurations, the 3D submental ultrasound with standardized imaging protocol is able to differentiate the responders from non-responders of the t-MAD treatment and could be a potential tool for treatment response evaluation. Support (if any)

Introduction The association of mandibular advancement device (MAD) treatment response and polysomnographic phenotype in patients with obstructive sleep apnea (OSA) has not been fully elucidated. We hypothesized MAD response would be associated with two polysomnographic phenotypes, including sleep stage and positional dependency in treatment-naïve patients with moderate-severe obstructive OSA. Methods This retrospective study recruited OSA patients with AHI ≥15/h, aged 20 to 80, treatment naïve, and received MAD treatment for more than three months. Positional phenotype included supine predominant (supine-p) and non-positional OSA. Sleep stage phenotype included REM-predominant (REM-p), NREM-predominant (NREM-p), and stage-independent (SI) OSA. MAD response was defined as criterion 1: residual AHI< 5/h with >50% reduction, and criterion 2: residual AHI< 10/h with >50% reduction. Outcomes included the change in PSG parameters, habitual latency of sleep onset and sleep hour, Epworth sleepiness scale, excessive daytime sleepiness, depression, physical, vitality and mental health domain of SF-36, and in-lab bedtime and wake blood pressure (BP). Results 379 patients with median age of 52.2 years, BMI of 26 kg/m2, 78.1% of men, and AHI of 28.2/h were recruited. Supine-p and REM-p OSA had lower baseline AHI and desaturation. The overall response rate were 34.7% (criterion 1 ) and 56% (Criterion 2). Supine-p OSA had higher response rate than non-positional OSA (criterion 1: 42.2% vs. 20.3%; criterion 2: 64.3% vs. 32.5%), while NREM-p OSA had lower response rate than REM-p and SI (REM-p vs. NREM-p vs. SI: criterion 1: 43.9% vs. 9.7% vs. 34.2%; criterion 2: 54.5% vs. 41.9% vs. 53.3%). Despite the more reduction in AHI, desaturaiotn, and arousal in responders, there was no differences in change of ESS, EDS, sleep pattern, depression, SF 36 domain, and BP between responders and non-responders which remained unchanged after stratified with sleep stage and position phenotypes. Conclusion Non-positional and NREM-predominant OSA had lower responses rate to MAD treatment. There were no differences in non-breathing outcomes between responders and nonresponders regardless of sleep stage and positional phenotype. Support (if any) The work was supported by grants from the National Science and Technology Council, Taiwan (NSTC 111-2314-B-002-293); Ministry of Science and Technology, Taiwan (MOST 109-2314-B-002-252); National Taiwan University Hospital (NTUH 107-19, 111-X0033, 111-S0298)

Chien-Feng Lee,1,* Yunn-Jy Chen,2,* Wen-Chi Huang,3 Jen-Wen Hou,4 Yu-Ting Liu,5 Tiffany Ting-Fang Shih,6 Pei-Lin Lee,7– 10 Chong-Jen Yu1,8,9 1Department of Internal Medicine, National Taiwan University Hospital Hsin-Chu Branch, Hsin-Chu, Taiwan; 2Department of Dentistry, School of Dentistry, National Taiwan University Hospital, Taipei, Taiwan; 3Department of Computer Science and Information Engineering, National Taiwan University, Taipei, Taiwan; 4Graduate Institute of Electronics Engineering, National Taiwan University, Taipei, Taiwan; 5MediaTek Inc., Hsinchu, Taiwan; 6Department of Radiology and Medical Imaging, National Taiwan University Hospital, Taipei, Taiwan; 7Center of Sleep Disorder, National Taiwan University Hospital, Taipei, Taiwan; 8Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan; 9School of Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan; 10Center for Electronics Technology Integration, National Taiwan University, Taipei, Taiwan*These authors contributed equally to this workCorrespondence: Pei-Lin Lee, Tel +886-2-2356-2755, Fax +886-2-2358-2867, Email leepeilin@ntu.edu.twObjective: Both continuous positive airway pressure (CPAP) pressure and polysomnographic phenotypes have been associated with mandibular advancement device (MAD) treatment response, but the precise relationship has not been fully elucidated. We hypothesized that utilizing CPAP pressure would predict the MAD response in treatment-naïve patients with moderate-severe obstructive sleep apnea (OSA), and the MAD response would be associated with two polysomnographic phenotypes, including sleep stage dependency and positional dependency.Methods: OSA treatment-naïve patients with an apnea-hypopnea index (AHI) ≥ 15/h who declined CPAP treatment and received MAD treatment for 3– 6 months were enrolled. The MAD treatment response was defined as 1) residual AHI under MAD (AHIMAD) < 5/h and 2) AHIMAD < 10/h. Logistic regression was applied to identify the association between CPAP pressure and MAD treatment responders. The predictability of the MAD responder status utilizing CPAP pressure was assessed with the area under the receiver operating characteristic (AUROC).Results: A total of 128 enrolled patients (AHI ≥ 30/h in 74.2%) were recruited, of whom 119 patients and 80 patients were included for analysis of sleep stage and positional dependency, respectively. REM-predominant OSA had lower AHI than stage-independent OSA, while the supine-predominant phenotype had lower anthropometrics than the nonpositional-dependent phenotype. The response rates for AHIMAD < 5/h and AHIMAD < 10/h were 25.8% and 48.4%, respectively. Lower anthropometrics, baseline AHI, and supine predominance were associated with the responder status, while CPAP pressure was an independent predictor. The AUROCs for the prediction of AHIMAD < 5/h and AHIMAD < 10/h responders were 0.635 and 0.664, respectively. Utilizing a CPAP level > 14 cmH2O as the cutoff to predict criterion 1 and 2 nonresponders, the sensitivity was 93.9% and 95.2%, respectively.Conclusion: In treatment-naïve patients with moderate-severe OSA, the supine-predominant phenotype and lower CPAP pressure were associated with the MAD response, while the sleep stage dependency phenotype was not. Utilization of a CPAP level > 14 cmH2O could be a sensitive measure to identify nonresponders.Keywords: continuous positive airway pressure, mandibular advancement device, polysomnography, phenotype, sleep apnea, obstructive

To assess the craniofacial morphology in children with sleep-disordered breathing (SDB) using nonradiation and readily accessible photogrammetry technique.Included children aged 3-18 years with SDB-related symptoms from April 2019 to February 2020 in a tertiary center. All participants underwent craniofacial photogrammetry and overnight polysomnography (PSG). Participants were stratified into 2 groups (obstructive sleep apnea [OSA] group: apnea-hypopnea index [AHI] ≥ 1 and non-OSA group: AHI1). Craniofacial photogrammetry was performed to derive variables of craniofacial features in standardized frontal and profile views. The 2 groups were propensity score matched based on age, sex, and body mass index (BMI) percentiles. Associations between craniofacial feature variables and OSA (AHI ≥1) likelihood were examined using logistic regression test. intraclass correlation coefficient (ICC) was used to evaluate the intrarater and interrater reliability.In total, 58 children were enrolled for the analysis after matching. All 3 variables representing the mandibular plane angle in the profile view were increased in the OSA group (mego-tn: 34.85 ± 5.99 vs 31.65 ± 5.96°, odds ratio [OR]: 1.10, 95% CI:1.02 to 1.18, P = .01; tn-gogn: 28.65 ± 6.38 vs 25.91 ± 5.38°, OR: 1.08, 95% CI:1.02 to 1.15, P = .012; and gome-tsup: 26.71 ± 6.13 vs 22.20 ± 5.89°, OR: 1.13, 95% CI:1.04 to 1.23, P = .003).Craniofacial photogrammetry revealed increased mandibular inclination in children with OSA. A steep mandibular plane with craniofacial photogrammetry is considered a potential predictor of pediatric OSA. Further investigation with a large sample size is required to clarify the validity of photogrammetry in evaluating pediatric OSA.

IMPORTANCE: Early intervention using cone-beam computed tomography (CBCT) and adenotonsillectomy for children with obstructive sleep apnea (OSA) may prevent impaired growth, adverse cardiovascular consequences, learning deficits, and poor quality of life. OBJECTIVE: To assess changes in CBCT airway measurements and polysomnography (PSG) parameters that occur after adenotonsillectomy in children with OSA and to determine whether CBCT changes are correlated with apnea-hypopnea index (AHI) reduction. DESIGN, SETTING, AND PARTICIPANTS: This prospective cohort study was conducted at a tertiary medical center from 2013 to 2016. Children aged 7 to 13 years with PSG-confirmed OSA (ie, AHI ≥1) were recruited. Data analysis was performed from March to July 2021. EXPOSURES: All participants underwent CBCT and PSG before and after adenotonsillectomy. MAIN OUTCOMES AND MEASURES: Changes in PSG and CBCT parameters after adenotonsillectomy were analyzed. RESULTS: A total of 49 children (mean [SD] age, 9.5 [1.8] years; 34 boys [69.4%]) were recruited. Eighteen participants (36.7%) had obesity. After adenotonsillectomy, AHI significantly decreased from 11.4 to 1.2 events per hour (mean difference, −10.24 events per hour; 95% CI, −13.84 to −6.64 events per hour). The following CBCT parameters significantly increased: total airway volume (from 11 265 to 15 161 mm(3); mean difference, 3896.6 mm(3); 95% CI, 2788.0 to 5005.2 mm(3)), nasopharyngeal volume (from 2366 to 3826 mm(3); mean difference, 1459.7 mm(3); 95% CI, 1122.9 to 1796.5 mm(3)), minimal nasopharyngeal airway area (from 128 to 191 mm(2); mean difference, 63.1 mm(2); 95% CI, 47.4 to 78.8 mm(2)), mean nasopharyngeal airway area (from 144 to 231 mm(2); mean difference, 86.8 mm(2); 95% CI, 67.0 to 106.5 mm(2)), oropharyngeal volume (from 8898 to 11 335 mm(3); mean difference, 2436.9 mm(3); 95% CI, 1477.0 to 3396.8 mm(3)), minimal oropharyngeal airway area (from 82 to 158 mm(2); mean difference, 76.2 mm(2); 95% CI, 57.0 to 95.4 mm(2)), and mean oropharyngeal airway area (from 182 to 234 mm(2); mean difference, 52.5 mm(2); 95% CI, 33.6 to 71.4 mm(2)). Among all parameters, only body mass index percentile showed large effect size between the group with residual OSA (postoperative AHI ≥1) and the group with resolved disease, with the residual OSA group having a higher body mass index percentile (87.8 vs 61.4; mean difference, 26.33; 95% CI, 10.00 to 42.66). A quantile regression model revealed that total airway volume and minimal oropharyngeal airway area were significantly correlated with reductions in AHI. CONCLUSIONS AND RELEVANCE: These findings suggest that in children undergoing adenotonsillectomy, improvements in total airway volume and oropharyngeal minimal airway area were correlated with reduction of AHI. Future studies are needed to assess whether CBCT has a role in the evaluation of children with OSA who are being considered for adenotonsillectomy.

Objectives: To measure in vivo three-dimensional kinematics of the mandible and associated end-point trajectories and to quantify their relationships during temporomandibular joint activities using 3D fluoroscopy. Methods: A novel fluoroscopy-based 3D measurement method was used to measure motions of the mandible and the associated end points (i.e. incisors and lateral poles of both condyles) during open close, lateral gliding and protrusion-retraction movements in healthy young individuals. The contributions of each of the rotational and translational components of the mandible to the end-point trajectories were quantified through experiment-based computer simulations. Results: The mandibular rotation was found to account for 91% of the maximal mouth-opening-capacity and 73% of the maximal lateral incisor movement, while the condylar translation contributed to 99% of the anterior protrusion distance. Incisor trajectories were nearly vertical within the first 60% of the maximal opening during the open-close movement. Conclusions: Similar condylar downward rotation paths but with bilaterally asymmetrical ranges were used to perform basic mandibular movements of different targeted TI trajectories in three dimensions, that is, open-close, lateral-gliding and protrusion-retraction. Mandibular rotations contributed to the majority of the principal displacement components of the incisor, that is, vertical during open-close and towards the working-side-during lateral-gliding, while mandibular translation contributed mainly to the forward movement of the incisor during protrusion-retraction. Owing to the anatomical constraints, the freedom of mandibular translation is limited and mainly in the anteroposterior direction, which is considered helpful for the control and stability of the TMJ during oral activities.

Masticatory muscle thickness provides objective measurements of the oral motor function, which may change in patients with oral myofascial pain. In this study, we aimed to establish a reliable ultrasound (US) protocol for imaging the superficial and deep masticatory muscles and to identify the potential influencers of the measurements. Forty-eight healthy participants without orofacial pain were enrolled. The intra-and inter-rater reliabilities of US measurements for masseter, temporalis, and lateral pterygoid muscles were assessed. Intraclass correlation coefficients for all muscles were greater than 0.6. The generalised estimating equation was used to analyse the impact of age, gender, laterality, and body mass index on the measurements, whereby age and body mass index were likely to be associated with an increase in masticatory muscle thickness. The thickness tended to be lesser in females. Laterality seemed to exert minimal influence on masticatory muscle thickness. Our study shows acceptable reliability of US in the evaluation of superficial and deep masticatory muscle thickness. Future studies are warranted to validate the usefulness of US imaging in patients with oral myofascial pain syndrome.

OBJECTIVE Cone-beam computed tomography (CBCT) offers three-dimensional structures in assessing upper airway of patients. This study aims to compare the cone-beam computerized tomography scan measurements between children with obstructive sleep apnea (OSA) and primary snoring. STUDY DESIGN Case-control study. METHODS This prospective study was conducted in a tertiary referral center. Thirty-six children with moderate-to-severe OSA (with apnea-hypopnea index [AHI] > 5 events/hour) and 36 age-, gender-, and obesity-matched children with primary snoring (AHI

Introduction Mandibular advancement device (MAD) responder phenotype are not well understood in patients with obstructive sleep apnea (OSA). Recent studies have reported the association between MAD treatment response and polysomnographic phenotypes using positional and sleep stage dependency, but with inconsistent findings. Thus, the study aims to investigate the relationship between the two phenotypes and MAD response. Methods This retrospective study recruited patients with OSA (apnea-hypopnea index [AHI] >10/h), who were 20 to 80 years old, treatment naïve, and received MAD treatment for more than three months from 2009 to 2017. AHIsupine/AHInon-supine ≥2 and 50% reduction; criterion 2: residual AHI 50% reduction; criterion 3: reduction >50%). The association between the two phenotypes and the three treatment criteria was identified using multivariable logistic regression. Results A total of 218 patients with a median age of 52.5 years, body mass index (BMI) of 25.4 kg/m2, and AHI of 28.2/h were recruited. Supine-p OSA had lower waist circumferences than non-positional OSA. The REM-p group had lower AHI and more female than the NREM-p and SI group. Supine-p OSA had better response than non-positional OSA (criterion 1: 43.2% vs 34.1%; criterion 2: 63.6% vs 34.1%; criterion 3: 77.3% vs 51.2%). NREM-p OSA had lower response across all three criteria (REM-p vs NREM-p vs SI: criterion 1: 57.6% vs 0% vs 42.0%; criterion 2: 75.8% vs 16.7% vs 56.5%; criterion 3: 75.8% vs 33.3% vs 77.1%). The odds of MAD response for supine-p OSA was 3.78 (95% CI = 1.44–9.93) to 3.98 (95% CI = 1.58–9.99)-fold than non-positional OSA while the odds for NREM-p OSA were 0.06 (95% CI = 0.01–0.58) to 0.15 (95% CI = 0.03–0.67)-fold than SI OSA after adjusting demographics and clinical features affecting MAD response. Conclusion Positional and sleep stage dependency were associated with MAD response and could be indicators for personal-tailored OSA treatment. Support (if any) The Ministry of Science and Technology, Taiwan (MOST 109-2314-B-002-252)

A system integrating temperature, pressure and voice sensors is proposed for a smart oral appliance for use in diagnosing and alleviating obstructive sleep apnea (OSA). Using sealed bio-compatible packaging for intraoral use, this system is also capable of wireless charging and data transmission. This proposed design aims to enhance the effectiveness and convenience of OSA treatment.

Dynamic magnetic resonance imaging (MRI) allows real-time characterization of upper airway collapse in sleeping subjects with obstructive sleep apnea (OSA). The aim of our study was to use sleep MRI to compare differences in upper airway collapse sites between BMI-matched subjects with mild OSA and severe OSA. This is a prospective, nested case–control study using dynamic sleep MRI to compare 15 severe OSA subjects (AHI >40) and 15 mild OSA (AHI

Objectives Using sleep MRI, we aimed to identify static craniofacial measurements and dynamic upper airway collapse patterns associated with severe obstructive sleep apnoea (OSA) during natural sleep in age and BMI-matched patients. Design Nested case–control study. Setting Sleep MRI images (3.0 Tesla scanner) and synchronised acoustic recording were used to observe patterns of dynamic airway collapse in subjects with mild and severe OSA. Midsagittal images were also used for static craniofacial measurements. Participants Fifteen male subjects with severe OSA (mean AHI 70.3 ± 23 events/h) were matched by age and BMI to 15 subjects with mild OSA (mean AHI 7.8 ± 1.4 events/h). Subjects were selected from a consecutive sleep MRI study cohort. Main outcome measures Static craniofacial measurements selected a priori included measurements that represent maxillomandibular relationships and airway morphology. Axial, sagittal and coronal views of the airway were rated for dynamic collapse at retropalatal, retroglossal and lateral pharyngeal wall regions by blinded reviewers. Bivariate analysis was used to correlate measures associated with severity of OSA using AHI. Statistical significance was set at P

Butyric acid as a histone deacetylase (HDAC) inhibitor is produced by a number of periodontal and root canal microorganisms (such as Porphyromonas, Fusobacterium, etc.). Butyric acid may affect the biological activities of periodontal/periapical cells such as osteoblasts, periodontal ligament cells, etc., and thus affect periodontal/periapical tissue destruction and healing. The purposes of this study were to study the toxic effects of butyrate on the matrix and mineralization marker expression in MG-63 osteoblasts. Cell viability was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. Cellular apoptosis and necrosis were analyzed by propidium iodide/annexin V flow cytometry. The protein and mRNA expression of osteoprotegerin (OPG) and receptor activator of nuclear factor kappa-B ligand (RANKL) were analyzed by Western blotting and reverse transcriptase-polymerase chain reaction (RT-PCR). OPG, soluble RANKL (sRANKL), 8-isoprostane, pro-collagen I, matrix metalloproteinase-2 (MMP-2), osteonectin (SPARC), osteocalcin and osteopontin (OPN) secretion into culture medium were measured by enzyme-linked immunosorbant assay. Alkaline phosphatase (ALP) activity was checked by ALP staining. Histone H3 acetylation levels were evaluated by immunofluorescent staining (IF) and Western blot. We found that butyrate activated the histone H3 acetylation of MG-63 cells. Exposure of MG-63 cells to butyrate partly decreased cell viability with no marked increase in apoptosis and necrosis. Twenty-four hours of exposure to butyrate stimulated RANKL protein expression, whereas it inhibited OPG protein expression. Butyrate also inhibited the secretion of OPG in MG-63 cells, whereas the sRANKL level was below the detection limit. However, 3 days of exposure to butyrate (1 to 8 mM) or other HDAC inhibitors such as phenylbutyrate, valproic acid and trichostatin stimulated OPG secretion. Butyrate stimulated 8-isoprostane, MMP-2 and OPN secretion, but not procollagen I, or osteocalcin in MG-63 cells. Exposure to butyrate (2&ndash, 4 mM) for 3 days markedly stimulated osteonectin secretion and ALP activity. In conclusion, higher concentrations of butyric acid generated by periodontal and root canal microorganisms may potentially induce bone destruction and impair bone repair by the alteration of OPG/RANKL expression/secretion, 8-isoprostane, MMP-2 and OPN secretion, and affect cell viability. However, lower concentrations of butyrate (1&ndash, 4 mM) may stimulate ALP, osteonectin and OPG. These effects are possibly related to increased histone acetylation. These events are important in the pathogenesis and repair of periodontal and periapical destruction.

Butyric acid as a histone deacetylase (HDAC) inhibitor was produced by a number of periodontal and root canal microorganisms (such as Porphyromonas, Fusobacterium etc.). Butyric acid may affect the biological activities of periodontal/periapical cells such as osteoblasts, periodontal ligament cells etc., and thus affect periodontal/periapical tissue destruction and healing. The purposes of this study were to study the toxic effects of butyrate on matrix and mineralization markers’ expression of MG-63 osteoblasts. Cell viability and proliferation were determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. Cellular apoptosis and necrosis were analyzed by propidium iodide/Annexin V flow cytometry. Protein and mRNA expression of OPG, and RANKL were analyzed by western blotting and RT-PCR. OPG, soluble RANKL (sRANKL), 8-isoprostane, pro-collagen I, MMP-2, osteonectin (SPARC), osteocalcin and osteopontin secretion into culture medium were measured by enzyme-linked immunosorbant assay. Histone H3 acetylation levels were evaluated by immunofluorescent staining (IF) and western blot. We found that butyrate induced morphologic changes of growing MG-63 cells, with bigger and flattened in appearance. Butyrate activated histone H3 acetylation of MG-63 cells. Exposure of MG-63 cells to butyrate partly decreased cell number with no marked increase in apoptosis and necrosis. Butyrate stimulated RANKL protein expression, whereas it inhibited OPG protein expression. Butyrate also inhibited the secretion of OPG in MG-63 cells, whereas sRANKL level was below detection limit. Butyrate stimulated 8-isoprostane, MMP-2 and osteopontin secretion, but not procollagen I, osteonectin, osteocalcin in MG-63 cells. In conclusion, butyric acid generated by periodontal and root canal microorganisms may potentially induce bony destruction and impair bone repair by alteration of OPG/RANKL expression/secretion, 8-isoprostane, MMP-2, and osteopontin secretion, and affect cell proliferation. These effects are possibly related to increased histone acetylation. These events are important in the pathogenesis of periodontal and periapical destruction.

OBJECTIVE The aim of this study was to analyse morphological changes in the upper airways in patients with anterior open bite treated with temporary anchorage devices for intrusion of upper posterior teeth. MATERIALS AND METHODS Twelve nonobese (body mass index

In this work, a mandibular advancement device integrated with a highly-sensitive pressure sensing array and a system-on-a-chip (SoC) is presented. The device is designed for monitoring the tongue pressure distributions of patients for treating orofacial disorders such as obstructive sleep apnea syndrome and snoring. The pressure sensing array consists of a conductive polymer assembled with interdigital electrodes, and the SoC chip possesses the capabilities of array scanning and RF transmission. Microdome structures were patterned on the conductive polymer for enhancing the sensitivity of pressure sensing. The proposed device exhibit excellent sensitivity and rapid response. The pressure patterns induced by the tongue positions before and after the tongue drop during sleep were also presented.

Background/PurposeCone-beam computed tomography (CBCT) can provide valuable data for root canal systems of human teeth in vivo. This study used CBCT to evaluate the number of roots and canals of 300 mandibular first premolars in 150 northern Taiwanese patients.MethodsThe root canal systems of 300 mandibular first premolars in 150 northern Taiwanese patients with bilateral premolars were analyzed by CBCT.ResultsOf the 300 mandibular first premolars, 197 (65.7%) had one root with one canal (1R1C), 49 (16.3%) had one root with two canals (1R2C), 51 (17.0%) had two roots with one canal in each root (2R2C), and three (1.0%) had three roots with one canal in each root (3R3C). Statistical analyses showed that women had a significantly higher incidence of 1R1C mandibular first premolars (71.4%) than men (58.8%, p = 0.031), and men had a significantly higher incidence of 2R2C mandibular first premolars (27.2%) than women (8.5%, p

Background/purpose The current study aimed to determine the intra- and inter-rater, and intersession reliability of the determination of the morphological parameters of the human mandible using cone-beam computed tomography (CBCT)-synthesized cephalometric radiographs. Materials and methods CBCT data of 12 mandibles were obtained and used to generate synthetic cephalograms via a digitally reconstructed radiography (DRR) technique. Eleven landmarks describing the key morphological features of the mandible on each DRR-synthesized cephalogram were identified manually six times by one senior and one junior dentist. The operation was repeated 5 days later. Twelve parameters based on interlandmark line segments and their angles were calculated. Test–retest reliability was assessed in terms of intraclass correlation coefficient (ICC) and coefficient of variation (CV) using a two-way mixed-effects model. The paired-sample t-test was used to compare differences between examiners and sessions. A one-sample t-test was employed to assess whether the difference between the examiners was significantly different from zero. Results Very good intrarater (senior: ICC > 0.93; junior: ICC = 0.78 for CdP-GoP, ICC > 0.91 for other parameters), inter-rater (ICC = 0.62 for CdP-GoP, ICC > 0.84 for other parameters) and intersession reliability (ICC > 0.84 for all parameters and examiners; ICC = 0.74 for CdP-GoP for junior examiner) in measuring mandibular morphological parameters were found. Conclusion These results suggest that very good reliability could be achieved via manual identification of the anatomical landmarks without the effects of factors such as malpositioning of the head during imaging. Further investigations using the current DRR-based approach will be needed to evaluate the individual effects of these other factors on the morphological measurements.

Background Cephalometric radiography has been used for orthodontic and surgical treatment planning and assessment, and for quantifying mandibular growth. However, it remains unclear how head positioning errors and the level of examiner experience affect the reliability of such morphometric measurements. The current study aimed to bridge the gap by determining the intra-, inter-rater, and inter-session reliability of measurements of mandibular morphology with random head positioning errors as measured by a junior and a senior dentist. Methods Cone-beam computed tomography data of twelve mandibles were obtained with each rotated randomly away from the neutral position within the range of +3 and −3° along each of the anatomical axes to simulate six imaging trials. A synthetic cephalogram for each trial was obtained via a digitally reconstructed radiography (DRR) technique and eleven landmarks for twelve morphological parameters on the cephalogram were identified manually six times by a junior and a senior dentist. The procedure was repeated on another day within 5 days. Test–retest reliability was assessed in terms of an intra-class correlation coefficient (ICC) using a two-way mixed-effects model. Results Good to very good intra-rater (senior: ICC > 0.92; junior: ICC > 0.78), inter-rater (ICC > 0.70 for most parameters) and inter-session reliability (senior: ICC > 0.84; junior: ICC > 0.62) were found. Bland & Altman plots of inter-rater comparisons show that there were systematical biases between the examiners on most parameters, except for the distance between Gonion and Pogonion. Conclusions The current results suggest that good to very good intra-rater, inter-rater and inter-session reliability can be achieved for most parameters with randomized head positioning errors; higher inter-session reliability can be achieved by more experienced examiners; and that long-term monitoring of mandibular growth based on cephalographic measurements should be made by the same more experienced examiner. The current DRR-based approach can be used to evaluate individual factors that affect the morphological measurements.

Obstructive sleep apnea (OSA), which is caused by obstructions of the upper airway, is a syndrome with rising prevalence. Mandibular advancement splints (MAS) are oral appliances for potential treatment of OSA. This work proposes a highly-sensitive pressure sensing array integrated with a system-on-chip (SoC) embedded in a MAS. The device aims to measure tongue pressure distribution in order to determine the efficacy of the MAS for treating OSA. The flexible sensing array consists of an interdigital electrode pair array assembled with conductive polymer films and an SoC capable of retrieving/storing data during sleep, and transmitting data for analysis after sleep monitoring. The surfaces of the conductive polymer films were patterned with microdomed structures, which effectively increased the sensitivity and reduced the pressure sensing response time. The measured results also show that the crosstalk effect between the sensing elements of the array was negligible. The sensitivity of the sensing array changed minimally after the device was submerged in water for up to 100 h.

The purpose of this study was to measure the long-term growth of the mandible in miniature pigs using 3D Cone-Beam Computerized Tomography (CBCT). The mandibles of the pigs were scanned monthly over 12 months using CBCT and the 3D mandibular models were reconstructed from the data. Seventeen anatomical landmarks were identified and classified into four groups of line segments, namely anteroposterior, superoinferior, mediolateral and anteroinferior. The inter-marker distances, inter-segmental angles, volume, monthly distance changes and percentage of changes were calculated to describe mandibular growth. The total changes of inter-marker distances were normalized to the initial values. All inter-marker distances increased over time, with the greatest mean normalized total changes in the superoinferior and anteroposterior groups (p0.05). Monthly distance changes were greatest during the first four months and then reduced over time. Percentages of inter-marker distance changes were similar among the groups, reaching half of the overall growth around the 4th month. The mandibular volume growth increased non-linearly with time, accelerating during the first five months and slowing during the remaining months. The growth of the mandible was found to be anisotropic and non-homogeneous within the bone and non-linear over time, with faster growth in the ramus than in the body. These growth patterns appeared to be related to the development of the dentition, providing necessary space for the teeth to grow upward for occlusion and for the posterior teeth to erupt.

Introduction This study aimed to determine the effect of combining positive airway pressure (PAP) therapy and mandibular advancement device (MAD) in patients with severe obstructive sleep apnea (OSA) who were pressure intolerant for PAP and were unresponsive to MAD. Methods This retrospective study reviewed the medical records of severe OSA patients with apnea-hypopnea index (AHI) ≥ 30/hr who were diagnosed between October 1, 2008 and June 30, 2014. Patients were initially treated with 2 weeks of PAP, and those who were intolerant to high-pressure PAP (≥15 cm H2O) were switched to 12 weeks of MAD, which is a monobloc designed at 75% of maximum protrusion. Patients who had high residual AHI (≥15/hr) on MAD underwent 12 weeks of combination therapy (CT) with MAD and CPAP and were enrolled in the present study. Enrolled subjects who completed the 12-week CT were followed-up until June 30, 2016. Results A total of 14 male patients were included. All three treatments effectively reduced AHI, oxygen desaturation index (ODI), and total sleep time with SpO2

Sleep apnea is a serious sleep disorder, and the most common type is obstructive sleep apnea (OSA). Untreated OSA will cause lots of potential health problems. Oral appliance therapy is an effective and popular approach for OSA treatment, but making a perfect fit for each patient is time-consuming and decreases its efficiency considerably. This paper proposes a System-on-a-Chip (SoC) enabled sleep monitoring system in a smart oral appliance, which is capable of intelligently collecting the physiological data about tongue movement through the whole therapy. A tunneling sensor array with an ultra-high sensitivity is incorporated to accurately detect the subtle pressure from the tongue. When the device is placed on the wireless platform, the temporary stored data will be retrieved and wirelessly transmitted to personal computers and cloud storages. The battery will be recharged by harvesting external RF power from the platform. A compact prototype module, whose size is 4.5 × 2.5 × 0.9 cm3, is implemented and embedded inside the oral appliance to demonstrate the tongue movement detection in continuous time frames. The functions of this design are verified by the presented measurement results. This design aims to increase efficiency and make it a total solution for OSA treatment.