[A study on the hearing protection and intervention effects of silicone earplug usage among manufacturing workers].

Objective: To assess the efficacy of silicone earplugs in protecting workers exposed to noise in a typical manufacturing environment, and to provide training interventions for workers who do not achieve the anticipated noise reduction levels, as well as examining the spectral characteristics of earplug attenuation. Methods: From June to August 2022, a total of 294 noise-exposed workers in two manufacturing enterprises equipped with the same type of earplug were studied by cluster sampling method, by conducting questionnaire surveys, collecting data, fitting tests, and providing trainings, the current noise exposure levels of workers in the industry as well as the perception about the earplug were understood. Additionally, the attenuation before and after intervention in workplace were measured, the spectral characteristics of noise reduction were were described and compared. Results: The percentage of workers with Personal Attenuation Rating (PAR) of 0 is 32.7% (96/294), and the baseline pass rates are all below 60%. There were no significant differences in pass rates based on gender, age, noise exposure, education level, or cognition of earplug effectiveness. After adjusting the way that earplugs are worn or changing the type of earplugs, all workers were able to meet their noise reduction requirements. The median PAR improvement for both companies is above 10 dB. The noise attenuation of the earplug vary with frequency, with lower attenuation at 4 000 Hz and higher attenuation at 8 000 Hz, showing some deviation from the nominal values. Conclusion: The difference between the actual sound attenuation value of earplugs and the nominal value is related to the noise frequency. When using silicone earplugs, attention should be paid to the spectral composition of the noise in the workplace.

Expression of 20 SCPP genes during tooth and bone mineralization in Senegal bichir.

The African bichir (Polypterus senegalus) is a living representative of Polypteriformes. P. senegalus possesses teeth composed of dentin covered by an enameloid cap and a layer of collar enamel on the tooth shaft, as in lepisosteids. A thin layer of enamel matrix can also be found covering the cap enameloid after its maturation and during the collar enamel formation. Teleosts fish do not possess enamel; teeth are protected by cap and collar enameloid, and inversely in sarcopterygians, where teeth are only covered by enamel, with the exception of the cap enameloid in teeth of larval urodeles. The presence of enameloid and enamel in the teeth of the same organism is an opportunity to solve the evolutionary history of the presence of enamel/enameloid in basal actinopterygians. In silico analyses of the jaw transcriptome of a juvenile bichir provided twenty SCPP transcripts. They included enamel, dentin, and bone-specific SCPPs known in sarcopterygians and several actinopterygian-specific SCPPs. The expression of these 20 genes was investigated by in situ hybridizations on jaw sections during tooth and dentary bone formation. A spatiotemporal expression patterns were established and compared with previous studies of SCPP gene expression during enamel/enameloid and bone formation. Similarities and differences were highlighted, and several SCPP transcripts were found specifically expressed during tooth or bone formation suggesting either conserved or new functions of these SCPPs.

Mandibular condylar process remodeling in rats with different bite-altering devices.

The objective was to compare different dental splint models and materials for inducing abnormal loading on the gross morphology and histological appearance of the mandibular condylar processes of Sprague Dawley rats. Three different types of dental splints (resin molar, aluminum incisor, stainless-steel incisor) were placed unilaterally to induce occlusal perturbation for 4 weeks. At that time, mandibular condylar processes were assessed by gross appearance and histology. Quantitative measurements were also conducted on the hematoxylin and eosin images for condyle shape. The results showed that although the condylar cartilage was affected by all splint types, the resin molar splint was associated with the most extensive mandibular condylar process remodeling, which was primarily a slant (skewness) of the lateral aspect of the condylar process. Additionally, quantitative measurements on the histological specimens demonstrated that the split and tilt angle of the left (ipsilateral) condylar processes in the resin molar group (124.8 ± 12.7° and 104.1 ± 12.7°, respectively) increased significantly (p < 0.05) when compared to right (contralateral) condylar processes (104.7 ± 5.8°and 91.6 ± 4.4°, respectively). However, no changes were noted on the thickness of the fibrocartilage layer at medial, central, and lateral regions of the condylar process. Another major finding is the high variability of morphology of the naïve animals. Future studies will assess the impact of longer durations of splinting, age, and sex on the remodeling of the mandibular condylar process, allowing for the development of diagnostics and therapies.

Association between sleep-disordered breathing and periodontitis: a meta-analysis.

BACKGROUND: Systemic inflammation is a feature of sleep-disordered breathing (SDB) as well as periodontitis. The association between SDB and periodontitis, however, has been inconsistent in previous studies. In order to fully evaluate the above association, we conducted a meta-analysis. MATERIAL AND METHODS: Observational studies related to the aim of the meta-analysis were identified by search of PubMed, Embase, Web of Science, Wanfang, and CNKI databases. Only studies with SDB diagnosed with the objective polysomnography examination were included. The results were analyzed using a random-effects model that incorporated potential heterogeneity between studies. RESULTS: Ten cross-sectional or case-control studies with 43,296 participants contributed to the meta-analysis. Pooled results showed that SDB was significantly associated with periodontitis (odds ratio [OR]: 1.83, 95% confidence interval [CI]: 1.52 to 2.20, I2 = 40%, p < 0.001). Sensitivity analysis showed consistent association for severe periodontitis (OR: 1.39, 95% CI: 1.20 to 1.61, I2 = 0%, p < 0.001). Subgroup analyses showed consistent results in patients with mild (OR: 1.66, p < 0.001), moderate (OR: 2.23, p = 0.009), and severe SDB (OR: 2.66, p < 0.001). Moreover, the association between SDB and periodontitis was consistent in Asian and non-Asian studies, in cross-sectional and case-control studies, in studies with univariate and multivariate regression models, and in studies with different quality scores (p for subgroup effects all < 0.05). CONCLUSIONS: Polysomnography confirmed diagnosis of SDB is associated with periodontitis in adult population.

[Effect of alar base cinch suture based on anatomic landmarks on the morphology of nasolabial region in patients after orthognathic surgery].

OBJECTIVE: To study the effect of a modified alar base cinch suture (ABCS) based on nasal musculature anatomy on the three-dimensional morphology of nasolabial region in patients after Le Fort Ⅰ osteotomy. METHODS: In the study, 30 patients[11 males and 19 females, with an average age of (23.23±2.98) years]with skeletal Class Ⅲ malocclusion underwent orthognathic surgery between August, 2019 and January, 2020 to have the maxilla advanced no more than 4 mm in the Department of Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology were involved and were divided into the test and control groups based on the random number table.In the test group, the nasal musculature was identified and labeled before dissection and the ABCS was according to the label, while in the control group, the nasal musculature was directly sutured and knotted in the midline of nose without prepend labeling.All the patients underwent three-dimensional facial photos preoperatively and 6 months postoperatively by using 3dMD face system.On the three dimensional image, soft tissue landmarks of nasolabial region was identified by the same examiner.Fourteen measurements including straight distance, curve distance, angle and ratio were measured.Statistical analysis was done by using SPSS 22.0. RESULTS: There were significant differences between the two groups in cutaneous height of upper lip (P=0.023) and in nasal tip protrusion-alar width (P=0.012).The increase rate of cutaneous height of upper lip and the decrease rate of nasal tip protrusion-alar width in the control group were significantly higher than that in the test group.The alar width and alar base width of the both groups were significantly increased compared with the preoperative level (P < 0.05).The nasolabial angle in the control group was significantly higher compared with the normal value, while there was no significant difference between the test group and the normal value. CONCLUSION: Compared with the conventional suture method, this modified alar base cinch suture is more favorable for the postoperative nasal coordination and nasolabial morphology in patients who need mild to moderate maxillary advancement, and it has certain advantages in operability and objective accuracy.So it could become a modified and accurate method of alar base cinch suture and be widely applied in clinical practice.

[Diagnostic value of F wave changes in patients with Charcot-Marie-Tooth1A and chronic inflammatory demyelinating polyneuropathy].

OBJECTIVE: To analyze and compare the characteristics and causes of F wave changes in patients with Charcot-Marie-Tooth1A (CMT1A) and chronic inflammatory demyelinating polyneuropathy (CIDP). METHODS: Thirty patients with CMT1A and 30 patients with CIDP were enrolled in Peking University Third Hospital from January 2012 to December 2018. Their clinical data, electrophysiological data(nerve conduction velocity, F wave and H reflex) and neurological function scores were recorded. Some patients underwent magnetic resonance imaging of brachial plexus and lumbar plexus, and the results were analyzed and compared. RESULTS: The average motor conduction velocity (MCV) of median nerve was (21.10±10.60) m/s in CMT1A and (31.52±12.46) m/s in CIDP. There was a significant difference between the two groups (t=-6.75, P < 0.001). About 43.3% (13/30) of the patients with CMT1A did not elicit F wave in ulnar nerve, which was significantly higher than that of the patients with CIDP (4/30, 13.3%), χ2=6.65, P=0.010. Among the patients who could elicit F wave, the latency of F wave in CMT1A group was (52.40±17.56) ms and that in CIDP group was (42.20±12.73) ms. There was a significant difference between the two groups (t=2.96, P=0.006). The occurrence rate of F wave in CMT1A group was 34.6%±39%, and that in CIDP group was 70.7%±15.2%. There was a significant difference between the two groups (t=-5.13, P < 0.001). The MCV of median nerve in a patient with anti neurofascin 155 (NF155) was 23.22 m/s, the latency of F wave was 62.9-70.7 ms, and the occurrence rate was 85%-95%. The proportion of brachial plexus and lumbar plexus thickening in CMT1A was 83.3% (5/6) and 85.7% (6/7), respectively. The proportion of brachial plexus and lumbar plexus thickening in the CIDP patients was only 25.0% (1/4, 2/8). The nerve roots of brachial plexus and lumbar plexus were significantly thickened in a patient with anti NF155 antibody. CONCLUSION: The prolonged latency of F wave in patients with CMT1A reflects the homogenous changes in both proximal and distal peripheral nerves, which can be used as a method to differentiate the CIDP patients characterized by focal demyelinating pathology. Moreover, attention should be paid to differentiate it from the peripheral neuropathy caused by anti NF155 CIDP. Although F wave is often used as an indicator of proximal nerve injury, motor neuron excitability, anterior horn cells, and motor nerve myelin sheath lesions can affect its latency and occurrence rate. F wave abnormalities need to be comprehensively analyzed in combination with the etiology, other electrophysiological results, and MRI imaging.

[Clinicopathological study in 28 cases of oral basaloid squamous cell carcinomas].

OBJECTIVE: To investigate the clinicopathologic features and prognostic factors in oral basaloid squamous cell carcinoma. METHODS: Retrospective analysis of oral basaloid squamous cell carcinomas patients who underwent tumor resection during the period from January 2002 to December 2020 in the authors' hospital, especially the clinicopathologic characteristics of 28 cases with confirmed diagnosis and follow-up data. Immunohistochemistry was performed to define the helpful markers for differentiation diagnosis. The factors influencing the prognosis were evaluated based on Kaplan-Meier method. RESULTS: The tongue and mouth floor (11 cases, 39.3%) were the most frequently involved sites, followed by gingiva (6 cases, 21.4%), buccal (5 cases, 17.9%), palate (4 cases, 14.3%), and oropharynx (2 cases, 7.1%). The majority of basaloid squamous cell carcinomas were in advanced stage, with 12 cases in stage Ⅱ and 16 cases in stages Ⅲ-Ⅳ. Twelve of 28 patients were identified to have cervical lymph node metastasis, which was confirmed by histopathological examination. The incidence rate of lymph node metastasis was 42.9% (12/28). Nine tumors recurred, with one metastasized to the lung. At the meantime, the 28 conventional squamous cell carcinomas were matched with the same stage, among which 13 cases were identified with cervical lymph node metastasis. The incidence rate of lymph node metastasis was 46.4% (13/28). Five cases recurred, with two cases that metastasized to the lung and one to the brain. The 5-year overall survival rates of the basaloid squamous cell carcinoma and conventional squamous cell carcinoma patients were 54.6% and 53.8%, respectively. Histopathologically, basaloid cells consisted of tumor islands without evident keratinization but frequently with comedo-like necrosis within the tumor islands. CK5/6 and P63 exhibited strongly positive in all the 28 cases, whereas neuroendocrine markers, CgA and Syn, were negative. Eight cases positively expressed P16; one case showed focal SOX10 positive but CK7 negative. CONCLUSION: The majority of oral basaloid squamous cell carcinomas present in advanced stage with a high tendency to lymph node metastasis, but the overall survival rates are not significantly different from conventional squamous cell carcinomas matched with the same stage. The human papilloma virus (HPV), as HPV-positivity rate is high, correlates to good prognosis. In addition, CK7 & SOX10 immunohistochemistry could contribute to differential diagnosis for basaloid squamous cell carcinoma with solid adenoid cystic carcinoma.

[Marginal features of CAD/CAM laminate veneers with different materials and thicknesses].

OBJECTIVE: To analyze the marginal roughness and marginal fitness of chairside computer-aided design and computer-aided manufacturing (CAD/CAM) laminate veneers with different materials and thicknesses, and to provide a reference for the clinical application of laminate veneers. METHODS: The butt-to-butt type laminate veneers were prepared on resin typodonts, the preparations were scanned, and the laminate veneers were manufactured by chairside CAD/CAM equipment. The laminate veneers were divided into four groups (n=9) according to the materials (glass-matrix ceramics and resin-matrix ceramics) and thickness (0.3 mm and 0.5 mm) of the veneers, with a total of 36. The marginal topo-graphies of each laminate veneer were digitally recorded by stereomicroscope, and the marginal rough-nesses of the laminate veneers were determined by ImageJ software. The marginal fitness of the laminate veneers was measured by a fit checker and digital scanning and measuring method. At the same time, the mechanical properties of glass-matrix ceramic and resin-matrix ceramic bars (n=20) were tested by a universal testing device. RESULTS: The marginal roughness of 0.3 mm and 0.5 mm glass-matrix ceramic laminate veneers was (24.48±5.55) µm and (19.06±5.75) µm, respectively, with a statistically significant difference (P < 0.001). The marginal roughness of 0.3 mm and 0.5 mm resin-matrix ceramic laminate veneers was (6.13±1.27) µm and (6.84±2.19) µm, respectively, without a statistically significant difference (P>0.05). The marginal roughness of the glass-matrix ceramic laminate veneers was higher than that of the resin-matrix ceramic laminate veneers with a statistically significant difference (P < 0.001). The marginal fitness of 0.3 mm and 0.5 mm glass-matrix ceramic laminate veneers were (66.30±26.71) µm and (85.48±30.44) µm, respectively. The marginal fitness of 0.3 mm and 0.5 mm resin-matrix ceramic laminate veneers were (56.42±19.27) µm and (58.36±8.33) µm, respectively. There was no statistically significant difference among the 4 groups (P>0.05). For glass-matrix ceramics, the flexural strength was (327.40±54.25) MPa, the flexural modulus was (44.40±4.39) GPa, and the modulus of resilience was (1.24±0.37) MPa. For resin-matrix ceramics, the flexural strength was (173.71±16.61) MPa, the flexural modulus was (11.88±0.51) GPa, and the modulus of resilience was (1.29±0.27) MPa. The flexural strength and modulus of glass-matrix ceramics were significantly higher than those of resin-matrix ceramics (P < 0.001), but there was no statistically significant difference in the modulus of resilience between the two materials (P>0.05). CONCLUSION: The marginal roughness of CAD/CAM glass-matrix ceramic laminate veneers is greater than that of resin-matrix ceramic laminate veneers, but there was no statistically significant difference in marginal fitness among them. Increasing the thickness can reduce the marginal roughness of glass-matrix ceramic laminate veneers, but has no effect on the marginal roughness of resin-matrix ceramic laminate veneers.

[Genetic distribution in Chinese patients with hereditary peripheral neuropathy].

OBJECTIVE: To analyze the distribution characteristics of hereditary peripheral neuropathy (HPN) pathogenic genes in Chinese Han population, and to explore the potential pathogenesis and treatment prospects of HPN and related diseases. METHODS: Six hundred and fifty-six index patients with HPN were enrolled in Peking University Third Hospital and China-Japan Friendship Hospital from January 2007 to May 2022. The PMP22 duplication and deletion mutations were screened and validated by multiplex ligation probe amplification technique. The next-generation sequencing gene panel or whole exome sequencing was used, and the suspected genes were validated by Sanger sequencing. RESULTS: Charcot-Marie-Tooth (CMT) accounted for 74.3% (495/666) of the patients with HPN, of whom 69.1% (342/495) were genetically confirmed. The most common genes of CMT were PMP22 duplication, MFN2 and GJB1 mutations, which accounted for 71.3% (244/342) of the patients with genetically confirmed CMT. Hereditary motor neuropathy (HMN) accounted for 16.1% (107/666) of HPN, and 43% (46/107) of HPN was genetically confirmed. The most common genes of HMN were HSPB1, aminoacyl tRNA synthetases and SORD mutations, which accounted for 56.5% (26/46) of the patients with genetically confirmed HMN. Most genes associated with HMN could cause different phenotypes. HMN and CMT shared many genes (e.g. HSPB1, GARS, IGHMBP2). Some genes associated with dHMN-plus shared genes associated with amyotrophic lateral sclerosis (KIF5A, FIG4, DCTN1, SETX, VRK1), hereditary spastic paraplegia (KIF5A, ZFYVE26, BSCL2) and spinal muscular atrophy (MORC2, IGHMBP, DNAJB2), suggesting that HMN was a continuum rather than a distinct entity. Hereditary sensor and autosomal neuropathy (HSAN) accounted for a small proportion of 2.6% (17/666) in HPN. The most common pathogenic gene was SPTLC1 mutation. TTR was the main gene causing hereditary amyloid peripheral neuropathy. The most common types of gene mutations were p.A117S and p.V50M. The symptoms were characterized by late-onset and prominent autonomic nerve involvement. CONCLUSION: CMT and HMN are the most common diseases of HPN. There is a large overlap between HMN and motor-CMT2 pathogenic genes, and some HMN pathogenic genes overlap with amyotrophic lateral sclerosis, hereditary spastic hemiplegia and spinal muscular atrophy, suggesting that there may be a potential common pathogenic pathway between different diseases.

Eleutheroside K isolated from Acanthopanax henryi (Oliv.) Harms suppresses methicillin resistance of Staphylococcus aureus.

Acanthopanax (A.) henryi (Oliv.) Harms contain many bioactive compounds commonly used in traditional Chinese medicine. The objective of the present study was to investigate the antibacterial activity of the single constituent, Eleutheroside K (ETSK) isolated from the leaves of A. henryi (Oliv.) Harms, against methicillin-resistant Staphylococcus (S.) aureus (MRSA). Broth microdilution assay was used to measure the minimal inhibitory concentration (MIC) and the MIC values of ETSK against eight clinical S. aureus strains were all 50 µg ml-1 . At sub-inhibitory concentrations, a synergistic effect between oxacillin (OXA) and ETSK was confirmed using checkerboard dilution assay and time-kill curve analysis. The bacteriostatic effect became more pronounced when ETSK was used in combination with detergent (Triton X-100) or ATPase inhibitor (N, N'-dicyclohexylcarbodiimide). According to western blot analysis, the down-regulated expression of Penicillin-binding protein 2a (PBP2a) further validated that the bacterial activity was inhibited when treated with ETSK in a dose-dependent manner. Results based on our study verified that ETSK significantly suppressed MRSA infections and emphasized the potential application of ETSK as a novel anti-MRSA natural drug.

Forehead Widening in Nonsyndromic Scaphocephaly Operated After 12 Months of Age.

AIM AND SCOPE: Our standard management is to operate isolated sagittal synostosis around 4 months of age because of morphological and cognitive outcomes. However, some patients present late and the likelihood of spontaneous remodeling is low in isolated sagittal craniosynostosis operated on after 12 months of age with a limited technique. The preliminary result of a modified technique for forehead remodeling and subtotal calvarial remodeling in nonsyndromic scaphocephalic children with late presentation is presented. PATIENTS AND METHODS: All patients older than 1 with isolated sagittal synostosis assessed between 2011 and 2015, over 1 year of age at the time of surgery, with available pre and postoperative computed tomography-scans, were retrospectively included into the study. The following parameters were collected: (1) age at surgery, (2) duration of the procedure, (3) surgical technique, (4) fronto-nasal angle before and after surgery and (5) forehead width before and after surgery. RESULTS: Ten patients aged between 15 months and 6 years were retrospectively included. Delayed surgery was due to late presentation or initial parental reluctance. All patients presented with a transversal narrowing of the forehead and an anterior bulge. Mean age at surgery was 28 months and mean follow up was 23 months (1-4 years). Measurements showed significant improvement of both the fronto-nasal angle and the width of the forehead. CONCLUSIONS: Late-presenting scaphocephalic patients operated on after 12 months of age require forehead remodeling to achieve satisfactory aesthetic results. Modified forehead remodeling by splitting the forehead sagittally into 2 symmetrical halves and adding a midline bone strip is a safe and feasible way to widen the forehead. Long term follow-up is needed to assess this modified technique.

[Three-dimensional movement of posterior teeth after losing the interproximal and occlusal contacts in adults].

OBJECTIVE: To observe the movement of posterior teeth after losing the interproximal and occlusal contacts in adults from the amount and speed of mesial-distal, buccal-lingual, occlusal-gingival and three-dimensional movements. METHODS: Twenty cases of metal post-core restoration from the Department of Prosthodontics, Peking University School and Hospital of Stomatology were recruited into this study, which was an observational study. The restored teeth had complete mesial, distal, and occlusal contacts before treatment. All the interproximal and occlusal contacts were removed during the preparation for the post-core. The three-dimensional positions of the post-core preparation were obtained by the intraoral scanner at the day of tooth preparation and that of post-core placement. The amounts of mesial-distal, buccal-lingual and occlusal-gingival tooth movement were measured in the software. On this basis, the amount of three-dimensional tooth movement was calculated. The speed of tooth movement was calculated based on the elapsed time between the two scans. RESULTS: Ten females and ten males with an average age of (29.5±4.9) years were recruited. The average elapsed time was (10.9±2.7) days. The amount of the mesial-distal tooth movement was (134.8±61.2) µm, of the buccal-lingual tooth movement was (110.3±39.5) µm, of the occlusal-gingival tooth movement was (104.8±57.5) µm, and of the three-dimensional tooth movement was (211.4±71.0) µm, respectively. The amounts of mesial-distal, buccal-lingual and three-dimensional tooth movements were larger in female than in male (P < 0.05). The speed of the mesial-distal tooth movement was (13.1±7.8) µm/d, of the buccal-lingual tooth movement was (10.6±4.5) µm/d, of the occlusal-gingival tooth movement was (10.1±6.8) µm/d, and of the three-dimensional tooth movement was (20.5±9.7) µm/d, respectively. The speed of mesial-distal and buccal-lingual tooth movements were larger in female than in male (P < 0.05). The speed of three-dimensional tooth movement was slightly larger in female than in male, while there was no significant difference between different genders (P>0.05). CONCLUSION: The three-dimensional position of posterior teeth changed after losing the interproximal and occlusal contacts in adults. The female had more significant and faster tooth movement than the male.

[The application of scales and characteristics of disability in the common genotypes of Charcot-Marie-Tooth disease].

Objective: To analyze the correlations among different common scales for evaluating the severity of the first-visit Charcot-Marie-Tooth disease (CMT), and explore the cross-sectional characteristics of neurological dysfunction in patients with four common genotypes (CMT1A, CMT1X, CMT2A and MPZ-related CMT) at their first visits. Methods: A total of 117 genetically confirmed CMT patients (aged ≥10 years) from the Department of Neurology of the Third Xiangya Hospital from 2009 to 2019 were included in the study, which consisted of 45 CMT1A, 41 CMT1X, 19 CMT2A, and 12 MPZ-related CMT patients. Clinical data of these patients at first visits were collected and neurological deficits were evaluated by Charcot-Marie-Tooth Neuropathy Score (CMTNS), Charcot-Marie-Tooth Examination Score (CMTES), Overall Neuropathy Limitation Scale (ONLS) and Functional Disability Scale (FDS). Spearman's correlation was performed to analyze the relationship between CMTNS, CMTES, ONLS and FDS. The age of onset, duration of disease, scores of CMTNS, CMTES, ONLS and FDS were compared among four genotypes. Results: In the 117 CMT patients, the male to female ratio was 1.79/1, and the age of onset was (19±13) years. The duration of disease was 10(3, 15) years, and the scores of CMTNS, CMTES, ONLS and FDS were 11.4±6.2, 8.8±5.7, 2.7±1.4 and 2.6±1.3, respectively. There was a significant correlation between CMTES, ONLS, FDS and CMTNS in the overall CMT patients and four subtypes respectively (r≥0.40, P<0.05). CMTNS, CMTES and ONLS scores of four subtypes showed positive correlations with duration of disease (P<0.05), but FDS scores of CMT1A, CMT1X and MPZ-related CMT patients exhibited no correlation with duration of disease (P>0.05) at their first visits. The age of onset in CMT2A patients was younger than that of the patients with the other three genotypes (P<0.05), furthermore, the scores of four scales in early-onset CMT2A patients were higher than those of adult-onset type CMT2A patients (CMTNS: P=0.031, CMTES: P=0.048, ONLS: P=0.042, FDS: P=0.047). In CMT1X patients, the males had higher scores than those of females for all four scales (CMTNS: P=0.028, CMTES: P=0.014, ONLS: P=0.023, FDS: P=0.002). Conclusions: CMTNS, CMTES and ONLS could be used in natural history studies and clinical trials according to the different clinical situations. In the four genotypes, CMT2A patients have younger age of onset, and the earlier the age of onset, the severer the dysfunction. Moreover, male CMT1X patients relatively have severer neurological dysfunction than female patients.

Molecular analysis and clinical diversity of distal hereditary motor neuropathy.

BACKGROUND AND PURPOSE: Distal hereditary motor neuropathies (dHMNs) are a clinically and genetically heterogeneous group of disorders. The purpose of this study was to identify the genetic distribution of dHMNs in a large cohort of Chinese patients and provide insight into the underlying common pathophysiology of dHMNs. METHODS: Multi-gene panel testing or whole-exome sequencing was performed in 70 index patients with clinically diagnosed dHMN between January 2007 and December 2018. The clinical features, Charcot-Marie-Tooth (CMT) neuropathy scores and electrophysiological data at diagnosis were recorded. RESULTS: Twenty-four causative mutations were identified in 70 index patients with dHMN (34.3%). Mutation in the HSPB1 gene was the most common cause of dHMN. Some CMT genes (MPZ, SH3TC2, GDAP1) were found to be related to dHMN with minor sensory involvement. Patients with a dHMN-plus phenotype (distal motor neuropathy and additional neurological deficits) carried variants in genes related to hereditary spastic paraplegia, amyotrophic lateral sclerosis and spinal muscular atrophy (FUS, KIF5A, KIF1B, ZFYVE26, DNAJB2). CONCLUSIONS: Comprehensive genetic testing of dHMN patients allows for identification of the pathogenic mutation in one-third of cases. Pure motor neuropathies and motor neuropathies with minor sensory involvement share many genes with CMT disease. Causes for dHMN-plus phenotypes overlap with motor neuron disease.

Cell migration and osteo/odontogenesis stimulation of iRoot FS as a potential apical barrier material in apexification.

AIM: To investigate the in vitro biological effects of a nanoparticle bioceramic material, iRoot Fast Set root repair material (iRoot FS), on the proliferation, migration and osteo/odontogenic differentiation of human stem cells from the apical papilla (hSCAP), and to further explore the mechanism involved in osteo/odontogenic induction of iRoot FS. METHODOLOGY: hSCAP were isolated and characterized in vitro. iRoot FS conditioned medium were prepared and used to treat hSCAP, while using mineral trioxide aggregate (MTA) conditioned medium as the positive control and regular medium as the negative control. MTT assay and BrdU labelling assay were performed to determine cell proliferation. Wound healing assay and transwell assay were conducted to evaluate cell migration. The osteo/odontogenic differentiation of hSCAP was evaluated by qPCR, Western blot and Alizarin red S staining. Wnt inhibitor was used for downregulating the expression level of ß-catenin of hSCAP. RESULTS: The cell proliferation of hSACP in the iRoot FS group was not significantly different compared with the control groups. The cell migration of hSCAP in the iRoot FS group was significantly increased than the MTA and negative control groups (P < 0.01). The expression levels of osteo/odontogenic markers and mineralization nodule formation of hSCAP in the iRoot FS group were significantly elevated (P < 0.01). Furthermore, iRoot FS enhanced the osteo/odontogenic differentiation of hSCAP by activating Wnt/ß-catenin signalling. CONCLUSIONS: iRoot FS promoted the cell migration of hSCAP and enhanced their oseto/odontogenesis potential via the Wnt/ß-catenin pathway without cytotoxicity. iRoot FS had satisfactory biological properties and has potential to be used as an apical barrier in apexification or as a coronal sealing material in regenerative endodontic treatment.

[Esthetic proportions of maxillary anterior teeth of 120 Chinese adults].

OBJECTIVE: To analyze the esthetic proportions of maxillary anterior teeth in term of the apparent widths proportion of the adjacent teeth and width/height ratio of the clinical crown in 120 Chinese adults. METHODS: Maxillary gypsum casts were obtained from the dental laboratories of stomatological hospitals in North China, Southeast China, and Southwest China, according to the inclusion criteria and exclusion criteria. Standardized digital photographs of each cast were recorded. The apparent widths and actual widths and heights of the central incisors, lateral incisors and canines were determined by ImageJ software for the calculation of apparent widths proportion of the adjacent teeth and width/height ratio of the clinical crown. The ideal apparent widths proportion (Golden proportion and Preston proportion) and width/height ratio (0.80) were tested. The gender, arch side, and regional differences were investigated. RESULTS: The apparent widths proportion of the lateral/central incisor was 0.724±0.047, of the canine/lateral incisor was 0.814±0.092. The width/height ratio of the central incisor was 0.848±0.072, of the lateral incisor was 0.834±0.094, of the canine was 0.883±0.098. The esthetic proportions were different from the predicted ideal ratio (P < 0.001). The apparent widths proportion of lateral/central incisor was significantly larger in the right side than that in the left side (0.730± 0.044 vs. 0.718±0.050), and was significantly smaller in North China than that in Southwest China (0.711±0.051 vs. 0.731±0.044). The width/height ratio of the central incisor was significantly larger in the female than that in the male (0.855±0.074 vs. 0.835±0.068), and in the right side than that in the left side (0.855±0.073 vs. 0.842±0.072). The width/height ratio of the lateral incisor was significantly larger in the female than that in the male (0.843±0.097 vs. 0.817±0.084). CONCLUSION: The apparent widths proportion of adjacent teeth and the width/height ratio of the clinical crown in Chinese adults are different from the foreigner's. The esthetic proportion parameters have significant population specificity, and the measurements cannot be generalized as well as it should be applied with caution.

[Cervical lymph node metastasis in adenoid cystic carcinoma of the salivary glands: A clinicopathologic study].

OBJECTIVE: To investigate the incidence and clinicopathologic features of cervical lymph node metastasis in salivary gland adenoid cystic carcinoma (AdCC). METHODS: Retrospective analysis was made in 798 AdCC patients who underwent tumor resection during January, 2001 to January, 2019 in Peking University School and Hospital of Stomatology, especially the clincopathologic characteristics of 82 cases with lymph node metastasis. RESULTS: In the study, 82 of the 798 patients were identified with cervical lymph node metastasis, which was confirmed by histopathological examination. The palate, the region of sublingual gland and mouth floor, and the parotid were the frequently involved primary sites for AdCCs. The general incidence rate of lymph node metastasis was approximately 10%. The submandibular gland, the region of sublingual gland and mouth floor, and the mobile tongue were the most frequent sites of lymph node metastasis with the incidence rates of 20.8%, 16.1%, and 15.1%, respectively; while lymph node metastasis was uncommon in the tumors which were the origin from the palate and parotid, with incidence rates of 6.1% and 3.4%, respectively. Most AdCC cases (70.7%) showed the classic "tunnel-style" metastatic pattern of occurrence, and the level I and II regions were the most frequently involved areas. The 5-year and 10-year overall survival rates of the patients with lymph node metastasis were 77.4% and 20.6% respectively, while the 5-year and 10-year overall survival rates of the patients with no lymph node metastasis were 83.5% and 57.6%, respectively. The univariate analysis demonstrated that statistically significant differences in the overall survival for the presence of lymph node metastasis (P<0.001). In the meantime, the 5-year disease-free survival rate of the patients with lymph node metastasis also showed statistically significant differences to that of the AdCC patients with no lymph node metastasis. In addition, the primary site and histological grade were significantly associated with lymph node metastasis, and the high-grade solid growth pattern was identified as a strong predictor for the occurrence of lymph node metastasis. CONCLUSION: Cervical lymph node metastasis has a high tendency of occurrence in submandibular gland and tongue-mouth floor complex, and the high-grade solid growth pattern could be taken as a strong predictor for the occurrence of lymph node metastasis, which correlates to poor prognosis of AdCC patients. A selective neck dissection should be considered as a management in such patients.

[Evaluation of mandibular stability and condylar volume after orthognathic surgery in patients with severe temporomandibular joint osteoarthrosis].

OBJECTIVE: To investigate the effect of preoperative condylar condition for mandible retrognathism deformities with severe temporomandibular joint osteoarthrosis on the stability of the jaw after orthognathic surgery and on the postoperative condylar volume changes. METHODS: In this retrospective study, from 2014 to 2019, 37 patients including 1 male and 36 female, aged between 21 to 34 years old with an average age of (28.03±6.52) years, were diagnosed with mandible retrognathism deformities with severe temporomandibular joint osteoarthrosis by Peking University School and Hospital of Stomatology and received orthognathic surgery, meeting the inclusion criteria were included. According to the preoperative condylar condition. There were divided into smooth group and non-smooth group, the lateral cephalometric films 1 week (T0), 3 months (T1), 6 months (T2) and 1 year (T3) after surgery were used to establish the coordinate system and cephalometric analysis to determine the stability of the jaw after operation. The three-dimensional model of the condyle was segmented by cone beam computed tomography (CBCT) 1 week (T0), 3 months (T1), 6 months (T2) and 1 year (T3) after surgery and the volume was obtained to evaluate the change of the condyle volume after surgery. CBCT image data was used to evaluate the changes of the condylar condition after surgery, and to clarify the correlation between the postoperative condylar condition and jaw stability. SPSS 20.0 statistical software was used for statistical analysis, Fisher's exact probability methods were used to compare whether there were statistically significant differences in the stability of the mandibular joint at stages T1, T2 and T3 with different preoperative condylar condition.Spearman correlation coefficient analysis and Mann-Whitney test were used to compare whether there were statistically significant differences in the volume changes at stages T1, T2 and T3 after surgery between the two groups. RESULTS: The recurrence rates of the mandible in the condylar smooth group were T1 36.85%, T2 47.37% and T3 42.11%, respectively. The recurrence rates in the non-smooth condylar group were T1 27.78%, T2 44.44% and T3 55.56%, respectively. There was no statistical difference in the recurrence rates between the two groups at different time points. There was no significant difference in the condylar volume change between smooth group and non-smooth group. CONCLUSION: For patients with mandible retrognathism deformities with severe temporomandibular joint osteoarthrosis and no significant changes in the condyle observed for one year before surgery, there is no difference in the influence of the preoperative condylar condition on the stability of jaw after operation, and no definite influence on the volume of the condyle after operation. Condylar resorption 3 months after surgery can cause instability of the jaw after orthognathic surgery.

[Blood pressure and heart rate changes of 640 single dental implant surgeries].

OBJECTIVE: To investigate the blood pressure and heart rate changes and influencing factors during single dental implant surgery. METHODS: A retrospective cohort study was conducted. Six hundred and forty cases underwent single dental implant placement in Department of Prosthodontics, Peking University School and Hospital of Stomatology from January 2016 to December 2016 were recruited in this study according to the inclusion and exclusion criteria. They were divided into different groups according to the exposure factors which were patient characteristics (gender, age) and surgical procedures (immediate placement, flap elevation, bone grafting). The correlation between blood pressure and heart rate variability during single dental implant surgery and the patient characteristics and surgical procedures were analyzed. RESULTS: The average systolic blood pressure variability was 9.47%±6.45% (maximum 46.04%), the average diastolic blood pressure variability was 12.18%±9.39% (maximum 88.00%), and the average heart rate variability was 10.59%±7.68% (maximum 49.12%). The effects of age and bone grafting on blood pressure variability, and of gender and immediate placement on heart rate variability, were statistically significant (P < 0.05), respectively. The incidence of abnormal intraoperative blood pressure rise was 4.69%, of which there were 4 cases (0.63%) of systolic blood pressure ≥180 mmHg and/or diastolic blood pressure ≥110 mmHg. The incidence of abnormal intraoperative heart rate rise was 6.72%. Hierarchical analysis showed a higher risk of abnormal intraoperative blood pressure rise in the elderly (≥60 years) male patients [P < 0.05, RR=3.409 (95%CI: 1.155-10.062) ] and flap elevation with bone grafting cases [P < 0.05, RR=2.382 (95%CI: 1.126-5.040)], respectively. There was no statistically significant association between abnormal heart rate rise and patient characteristics or surgical procedures (P>0.05). CONCLUSION: There was a certain risk of blood pressure and heart rate variability during dental implant surgery. Elderly male patients and flap elevation with bone grafting were risk factors of abnormal intraoperative blood pressure rise.

[Effects of loupes and microscope on the prosthodontist's posture from ergonomic aspects].

OBJECTIVE: To assess the effects of loupes and microscope on the posture of prosthodontists when preparing the laminate veneer, and to assess the clinical value of loupes and microscope from the ergonomic aspects. METHODS: Twenty young prosthodontists from Department of Prosthodontics, Peking University School and Hospital of Stomatology were recruited into this study, which was a prospective, single blind, self-control trials. The research hypothesis was concealed and the participants were deceived about the precise purpose of the study to counterbalance the lack of direct blinding. The prosthodontists prepared laminate veneers of open window type in the artificial dental model, under routine visual field (control group), 2.5× headwear loupes (loupes group), and 8× operating microscope (microscopic group) by turning. The participants were photographed from profile view and front view. Thereafter, the subjective assessment was performed by themselves using the visual analogue score (VAS). The expert assessment was performed by two professors using modified-dental operator posture assessment instrument on the basis of photographs of the profile view and front view. RESULTS: The subjective assessment scores for the control group, loupes group and microscopic group were 4.55±1.96, 7.90±1.12, and 9.00±0.92, respectively. There was significant difference between the three groups' subjective scores (P < 0.05). The expert assessment scores for the control group, loupes group and microscopic group were 16.38±1.52, 15.15±1.30, and 13.60±0.88, respectively. There was significant difference between the three groups' expert assessment scores (P < 0.05). Specifically, the three groups' expert assessment scores were significantly different (P < 0.05) in trunk position (front to back) (1.33±0.41, 1.03±0.11, 1.00±0.00), head and neck position (front to back) (2.75±0.38, 2.13±0.36, 1.23±0.38), elbows level (1.38±0.43, 1.40±0.45, 1.13±0.22), and shoulders level (1.43±0.41, 1.23±0.34, 1.13±0.28). Thereinto, the microscopic group was better than loupes group in head and neck position (front to back) and elbows level (P < 0.05). CONCLUSION: Loupes and microscope improve the posture of the prosthodontist when preparing the laminate veneer, in which the microscope is better than loupes. Therefore, the magnification devices have clinical value from the ergonomic aspects.