[Clinical analysis of patients with oral and maxillofacial infections in oral emergency].

OBJECTIVE: To analyze the composition, incidence and clinical characteristics of oral and maxillofacial infections in oral emergency. METHODS: A retrospective study on patients with oral and maxillofacial infections who visited the Department of Oral Emergency in Peking University School and Hospital of Stomatology from January 2017 to December 2019 was conducted. General characteristics, such as disease composition, gender, age distribution and position of involved teeth were analyzed. RESULTS: A total of 8 277 patients with oral and maxillofacial infections were finally collected, including 4 378 male patients (52.9%) and 3 899 female patients (47.1%), with gender ratio of 1.12:1. The common diseases were periodontal abscess (3 826 cases, 46.2%), alveolar abscess (3 537 cases, 42.7%), maxillofacial space infection (740 cases, 9.0%), sialadenitis (108 cases, 1.3%), furuncle & carbuncle (56 cases, 0.7%) and osteomyelitis (10 cases, 0.1%). Male patients were more easily affected by periodontal abscess, space infection and furuncle & carbuncle than female patients with the gender ratios 1.24:1, 1.26:1, 2.50:1 individually, while the incidence of alveolar abscess, sialadenitis, furuncle & carbuncle had no significant gender difference. Different diseases were prone to occur at different ages. The peak ages of alveolar abscess were 5-9 and 27-67 years, while the peak age of periodontal abscess was 30-64 years. Space infection tended to occur between 21-67 years. There were 7 363 patients with oral abscess (3 826 patients with periodontal abscess and 3 537 patients with alveolar abscess), accounting for 88.9% of all the patients with oral and maxillofacial infections, involving 7 999 teeth, including 717 deciduous teeth and 7 282 permanent teeth. Periodontal abscess usually occurred in permanent teeth, especially the molar teeth. Alveolar abscess may occur in both primary teeth and permanent teeth. In primary teeth, the most vulnerable sites were primary molar teeth and maxillary central incisors while in permanent teeth the most vulnerable sites were first molar teeth. CONCLUSION: Understanding the incidence of oral and maxillofacial infection was conducive to the correct diagnosis and effective treatment of clinical diseases, as well as targeted education for patients of different ages and genders to prevent the occurrence of diseases.

[Clinical analysis of children and adolescents emergency dental trauma cases].

OBJECTIVE: To analyze the etiological and clinical characteristics of oral emergency patients under 18 years with dental trauma, and to provide guidance on the prevention and treatment in children and adolescents. METHODS: A retrospective study on the intact data of the dental trauma patients under 18 years from January 2016 to December 2018 in the Department of Oral Emergency in Peking University School of Stomatology was conducted, and the distribution of the patients' gender, age and visiting time, as well as the number and position of traumatic teeth, diagnostic classification, and multiple injury with dental trauma were analyzed. RESULTS: During the period, 54.2% of the first visit dental trauma patients (10 164) were children or adolescents (5 506). The two peak ages were 3-4 and 7-9 years. The incidence of the male was higher than the female in every age group (Wilcoxon test, P < 0.001). From May to June and September to November, there were more cases of dental trauma. The peak time of daily dental trauma cases was from 19:00 to 20:00 (Jonckheere-Terpstra test, P < 0.001). The positions of traumatic teeth in both sides were approximate symmetrical, and maxillary central incisors were the most affected. 52.3% of the patients suffered multiple teeth injuries. Among the permanent teeth trauma, enamel and dentin fracture was the most common (24.7%), followed by concussion (20.5%), sub-luxation (17.9%) and complicated crown fracture (14.4%). And among the primary teeth trauma, subluxation was the most common (31.1%), followed by concussion (14.5%) and lateral luxation (9.5%). 19.7% of the children and adolescent dental trauma patients were also suffered maxillofacial soft or hard tissue injury. CONCLUSION: The incidence of dental trauma in children and adolescents is higher than that in adults. There were two age peaks among the children and adolescents patients. Primary teeth and young permanent teeth were usually suffered. Clinical treatment should be considered along with the characteristics of child tooth growth. In order to prevent the occurrence of dental trauma, early orthodontic intervention should be carried out in children with severe overjet. Families, schools and nursery institutions should strengthen the protection against dental trauma.

Early spectra of the gravitational wave source GW170817: Evolution of a neutron star merger.

On 17 August 2017, Swope Supernova Survey 2017a (SSS17a) was discovered as the optical counterpart of the binary neutron star gravitational wave event GW170817. We report time-series spectroscopy of SSS17a from 11.75 hours until 8.5 days after the merger. Over the first hour of observations, the ejecta rapidly expanded and cooled. Applying blackbody fits to the spectra, we measured the photosphere cooling from [Formula: see text] to [Formula: see text] kelvin, and determined a photospheric velocity of roughly 30% of the speed of light. The spectra of SSS17a began displaying broad features after 1.46 days and evolved qualitatively over each subsequent day, with distinct blue (early-time) and red (late-time) components. The late-time component is consistent with theoretical models of r-process-enriched neutron star ejecta, whereas the blue component requires high-velocity, lanthanide-free material.

Light curves of the neutron star merger GW170817/SSS17a: Implications for r-process nucleosynthesis.

On 17 August 2017, gravitational waves (GWs) were detected from a binary neutron star merger, GW170817, along with a coincident short gamma-ray burst, GRB 170817A. An optical transient source, Swope Supernova Survey 17a (SSS17a), was subsequently identified as the counterpart of this event. We present ultraviolet, optical, and infrared light curves of SSS17a extending from 10.9 hours to 18 days postmerger. We constrain the radioactively powered transient resulting from the ejection of neutron-rich material. The fast rise of the light curves, subsequent decay, and rapid color evolution are consistent with multiple ejecta components of differing lanthanide abundance. The late-time light curve indicates that SSS17a produced at least ~0.05 solar masses of heavy elements, demonstrating that neutron star mergers play a role in rapid neutron capture (r-process) nucleosynthesis in the universe.

Chemical removal of necrotic periodontal ligament on delayed replanted teeth by sodium hypochlorite: morphological analysis and microhardness indentation test of cementum.

AIM: To compare the efficacy of sodium hypochlorite (NaOCl) used at different concentrations and working times for removing necrotic periodontal ligament (PDL) from delayed replanted teeth and to observe the effects of NaOCl on surface structure and microhardness of cementum. METHODOLOGY: A total of 88 healthy premolars with a single root extracted for orthodontic purposes were selected and kept dry at room temperature for 1 h. The teeth were divided into 11 groups: group 1 (control): roots were untreated; group 2: necrotic PDL was removed with gauze; groups 3-11: teeth were immersed in NaOCl at different concentrations (1, 2.5 and 5.25%) and for different working times (5, 10 and 15 min). The specimens in each group were inspected separately for cementum integrity and the presence of PDL remnants by histomorphometric analysis, confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM). Another 14 healthy premolars with roots divided into two pieces were selected for Vickers microhardness indentation tests before and after NaOCl treatment. The data were analysed statistically using Wilcoxon signed-rank test of two-related samples (P = 0.05). RESULTS: In teeth treated with 1% NaOCl for 15 min or 5.25% NaOCl for 5 min, the cementum remained morphologically intact without cracks, and PDL remnants were absent. In the 1% NaOCl for 15 min group, the microstructure of cementum was arranged more regularly, as observed ×8000 magnification by SEM. Teeth in each of the other groups displayed cementum damage and/or the presence of PDL remnants. Microhardness tests revealed that treatment with 1% NaOCl for 15 min or 5.25% NaOCl for 5 min significantly decreased microhardness of root cementum (P < 0.05). CONCLUSIONS: Use of either 1% NaOCl for 15 min or 5.25% NaOCl for 5 min was effective at removing necrotic PDL from the delayed replanted teeth whilst having a minimal influence on cementum integrity. However, 1% NaOCl for 15 min was less damaging to cementum.

[Clinical analysis for systemic complications of patients in the dental emergency room].

OBJECTIVE: To analyze the clinical features of oral emergency patients in general health, and to guide the oral emergency patients in the treatment, and prevention of accidents. METHODS: The retrospective study was performed on the day visits to the emergency department in Peking University School and Hospital of Stomatology from February to November 2013.The basic information of the newly diagnosed adult, their overall health status, American society of anesthesiologists(ASA) classification and oral diagnosis information were analyzed and summarized. RESULTS: The cardiovascular and cerebrovascular diseases(6.4%), hypertension(13.4%), endocrine system diseases(4.2%)were most common in the patients. With the increase of age, the associated systemic diseases had increased in number and in ASA classification. Periapical disease(24.6%), dental pulp disease(24.4%), and periodontal disease(18.0%) accounted for about 2/3. CONCLUSION: The general health status of patients with oral emergency worsened with the increase of age. Oral surgeons should make risk assessment before treatment. ASA classification system can help doctors predict the patient risk, take corresponding measures in advance, and help to reduce the occurrence of accidents.

Submental cutaneous sinus tract of mandibular second molar origin.

AIM: To report a case in which a submental cutaneous sinus tract resulted from apical periodontitis associated with a mandibular second molar. SUMMARY: A 53-year-old man presented with a chronic cutaneous sinus tract in the submental region, which had previously been misdiagnosed as a thyroglossal fistula. The origin of the sinus tract was shown by sinus tract angiography to be the left mandibular second molar (tooth 37), which had apical periodontitis. The sinus tract healed after extraction of the tooth and partial excision of the lesion from an extraoral approach. Histological examination confirmed that the tract was lined with granulation tissue and not with epithelial tissue. A submental sinus tract drainage pathway was observed. Prompt dental evaluation, especially of all mandibular teeth, should be considered when assessing cases of submental cutaneous sinus tracts. KEY LEARNING POINTS: An odontogenic origin should be part of the differential diagnosis for orofacial skin lesions. Cutaneous sinus tracts of mandibular molar origin are complex and thus a comprehensive examination should be stressed. It is necessary to examine all mandibular teeth in cases of odontogenic submental cutaneous sinus tracts. Sinus tract angiography can be used to identify the sinus tract pathway and to confirm the associated teeth. The treatment of an odontogenic cutaneous sinus tract requires the elimination of the source of infection.

[Further studies on the mongolian jird model of Giardia lamblia].

Seventy-seven Meriones unguiculatus were inoculated intra-esophageal with Giardia lamblia cysts isolated from the stool of a Giardia infected child. Correlation between oral dosage, course of infection, trophozoite distribution and the pathological changes in the small intestine of the infected jirds were studied. One (12.5%) of eight animals became infected with only 5 cysts. 10(4) cysts/jird or more was infective to nearly all the animals. Most of the infected animals (83%) excreted cysts and/or trophozoites intermittently. The extent of trophozoite colonization and their distribution in the small intestine varied with the time of infection, but not with the number of Giardia found in the feces. There was no direct correlation between the size of inoculum and the course of infection, the fecal output of cysts and/or trophozoites, or the intensity of pathological changes in the small intestine. The histopathological lesions induced by G. lamblia included cellular infiltration of the mucosa of the small bowel, nodular lymphoid hyperplasia, edema of the lamina propria and increase in mucous secretion. Necrobiosis and shedding of the epithelium was evident, and the mitotic figures of intestinal crypt increased significantly. The reduction of the villi to crypts ratio may indicate that the villi of small intestine were covered by relatively immature enterocytes, which may, partially, account for the malabsorption in giardiasis (Figs. 1-3).