A comparative study of microbial changes in dental plaque before and after single- and multiappointment treatments in patients with severe early childhood caries.

BACKGROUND: The status of dental caries is closely related to changes in the oral microbiome. In this study, we compared the diversity and structure of the dental plaque microbiome in children with severe early childhood caries (S-ECC) before and after general anaesthesia and outpatient treatment. METHODS: Forty children aged 3 to 5 years with S-ECC who had completed whole-mouth dental treatment under general anaesthesia (C1) or in outpatient settings (C2) were selected, 20 in each group. The basic information and oral health status of the children were recorded, and the microbial community structure and diversity of dental plaque before treatment (C1, C2), the day after treatment(C2_0D), 7 days after treatment (C1_7D, C2_7D), 1 month after treatment (C1_1M, C2_1M), and 3 months after treatment (C1_3M, C2_3M) were analysed via 16 S rRNA high-throughput sequencing technology. RESULTS: (1) The alpha diversity test showed that the flora richness in the multiappointment group was significantly greater at posttreatment than at pretreatment (P < 0.05), and the remaining alpha diversity index did not significantly differ between the 2 groups (P > 0.05). The beta diversity analysis revealed that the flora structures of the C1_7D group and the C2_3M group were significantly different from those of the other time points within the respective groups (P < 0.05). (2) The core flora existed in both the pre- and posttreatment groups, and the proportion of their flora abundance could be altered depending on the caries status of the children in both groups. Leptotrichia abundance was significantly (P < 0.05) lower at 7 days posttreatment in both the single- and multiappointment groups. Corynebacterium and Corynebacterium_matruchotii were significantly more abundant in the C1_1M and C1_3M groups than in the C1 and C1_7D groups (P < 0.05). Streptococcus, Haemophilus and Haemophilus_parainfluenzae were significantly more abundant in the C1_7D group than in the other groups (P < 0.05). CONCLUSION: A single session of treatment under general anaesthesia can cause dramatic changes in the microbial community structure and composition within 7 days after treatment, whereas treatment over multiple appointments may cause slow changes in oral flora diversity.

[Clinical analysis of 182 cases with facial nerve injury].

OBJECTIVE: To investigate the recovery patterns and the influencing factors of facial nerve injury in maxillofacial surgery by retrospective analysis of a serial clinical data. METHODS: A total of 182 patients with facial nerve injury were reviewed. The cause of injury, the initial facial nerve function after trauma, the treatment, the initial recovery time of facial nerve function and the total recovery time were recorded. The factors that influenced the outcome of facial nerve function were analyzed. RESULTS: The facial nerve branch injury was common in maxillofacial injury. The injury pattern, location, age and reconstruction time all had effects on the function recovery of the facial nerve. Within 6 months, 45 of 49 (92%) anatomic injured patients completely recovered in 6 months; 53 of 59 patients (90%) began to recover when nerve had been ruptured. In 12 months, 33 of 35 patients (94%) after nerve anastomosed and 5 of 8 patients (62%) with nerve transplantation got complete recovery. CONCLUSIONS: Preserving the facial nerve during surgery is very important. If the facial nerve is injured, reconstructive surgery should be applied as soon as possible.