Tooth eruption is a localised event whereby the signals for eruption for a given tooth are synthesised in the dental follicle of that tooth with a possible cross talk of signals coming from the adjacent stellate reticulum. The eruption process requires alveolar bone resorption that is primarily regulated by the dental follicle. This is reflected by the fact that failures of eruption often can be traced to either osteoclast deficiencies or to dental follicle abnormalities. Recent advances in application of molecular techniques to animal models allowed for better understanding of gene regulatory events involved in the physiology of tooth eruption. This article attempts to consolidate and organise the facts that offshoot from animal studies.
Tooth Eruption ; Dental Sac ; Molecular Biology

OBJECTIVE: To observe the clinical efficacy of auricular electroacupuncture for post-stroke dysphagia in the pharyngeal phase. METHODS: Eighty-two patients with post-stroke dysphagia in the pharyngeal phase were randomized into an auricular electroacupuncture group (41 cases) and a swallowing electrical stimulation group (41 cases, 1 case dropped out). In the auricular electroacupuncture group, electroacupuncture was applied at auricular points, i.e. Xin (CO₁₅) and Yanhou (TG₃), using disperse-dense wave, in frequency of 2 Hz/10 Hz, 30 min a time. In the swallowing electrical stimulation group, swallowing electrical stimulation was delivered for 30 min a time. Both groups were treated once daily for 4 weeks. The functional oral intake scale (FOIS) grade, as well as the hyolaryngeal complex displacement, the pharyngeal constriction rate (PCR) and the pharyngeal delay time (PDT) under video fluoroscopic study of swallowing (VFSS) were observed before and after treatment, and the clinical efficacy was evaluated in the two groups. RESULTS: Compared before treatment, the FOIS grade was improved (P<0.01), the forward and upward displacement amplitude of hyoid bone and thyroid cartilage was increased (P<0.05), and the PCR and PDT were decreased (P<0.05) after treatment in the two groups. After treatment, compared with the swallowing electrical stimulation group, the FOIS grade was superior (P<0.01), the upward displacement amplitude of hyoid bone and thyroid cartilage was larger (P<0.05) and the PCR and PDT were lower (P<0.05) in the auricular electroacupuncture group. The total effective rate was 85.4% (35/41) in the auricular electroacupuncture group, which was higher than 62.5% (25/40) in the swallowing electrical stimulation group (P<0.05). CONCLUSION Auricular electroacupuncture can effectively trigger pharyngeal initiation and improve post-stroke dysphagia in the pharyngeal phase.
Humans ; Electroacupuncture ; Male ; Deglutition Disorders/etiology* ; Female ; Middle Aged ; Aged ; Stroke/physiopathology* ; Pharynx/physiopathology* ; Acupuncture, Ear ; Acupuncture Points ; Deglutition ; Treatment Outcome ; Adult

INTRODUCTION: Antimicrobial resistance (AMR) poses a critical global health threat, with millions of deaths attributed to it annually. Antibiotic stewardship to combat AMR is the responsibility of all healthcare professionals. Despite evidence suggesting that it is unnecessary, dentists routinely prescribe prophylactic antibiotics following third molar (3M) surgeries. METHOD: This mixed-methods study examined the behavioural barriers influencing antibiotic prescribing practices within the Division of Oral and Maxillofacial Surgery at the National University Centre for Oral Health Singapore. This study used the capability, opportunity and motivation for behavioural change or COM-B framework to implement interventions targeting the behavioural barriers. RESULTS: Pre- and post-intervention data over 6 months showed a significant reduction in antibiotic prescriptions from 84.45% to 20.89%, following the implementation of COM-B strategies (P<0.001). Qualitative feedback from focus group discussions highlighted a positive shift in clinicians' attitudes towards antibiotic reduction, acknowledging the minimal infection risk associated with non-prescribing practices. Notably, complication rates remained stable throughout the study period, indicating no adverse effects from reduced antibiotic usage. CONCLUSION These findings demonstrated that the COM-B model can be successfully applied to modify deeply ingrained prescription habits, and underscored the effectiveness of a structured behavioural change intervention in enhancing compliance with antibiotic stewardship guidelines. The study advocates continuation of initiatives to sustain this positive trend and mitigate AMR in clinical practice.
Humans ; Molar, Third/surgery* ; Anti-Bacterial Agents/therapeutic use* ; Singapore ; Antimicrobial Stewardship/methods* ; Practice Patterns, Dentists'/statistics & numerical data* ; Antibiotic Prophylaxis ; Female ; Attitude of Health Personnel ; Male ; Tooth Extraction ; Adult ; Focus Groups ; Practice Patterns, Physicians'

PURPOSE: Orotracheal intubation is one of the most frequently used techniques in emergency procedures and especially in anesthesia and resuscitation. Teeth may be "victims" of the orotracheal intubation. Several factors may predispose to these accidents. The aim of this study is to determine the incidence of oral trauma that occurs during scheduled and urgent oral tracheal intubation, and identify the risk factors, the types and locations of these dental injuries. METHODS: It is a cross-sectional study that lasted 6 months from June to November 2022. This study was carried out in several departments. An examination of the dental and periodontal status of patients who will undergo surgery under general anesthesia was performed before the operation according to the surgical program. Yet, in emergency settings, this examination was not possible. Patients with anterior edentation and patients refusing participation in the study were excluded. After the surgery, included patients were examined to detect eventual dental trauma such as fracture, luxation, and contusion. Collected data were entered and analyzed using SPSS version 18 software. The Wilcoxon Mann-Whitney U test was used to compare quantitative variables. The Chi-square test was used to compare qualitative variables with a statistical significance level of 5% (p < 0.05). RESULTS: There were 43 patients included in the study, and dental trauma was noted in 11 patients (25.6%). Their mean age was (59.8 ± 15.4) years. The statistical analysis shows that there is a significant relationship between age (over 40 years old) and trauma (p = 0.004). Among the traumatized group, orotracheal intubation was undergone for 8 cases according to the surgical program whereas it was performed, for 3 cases, in emergency settings. The difference between the 2 types of intervention is statistically significant (p = 0.045). The odds ratio was 0.086 (95% CI: 0.008 - 0.942). A Mallampati score of 1 was rated for 6 injured (54.5%). The difference between the difficulty of the intubation evaluated by the Mallampati score and the occurrence of trauma was statistically insignificant (p = 0.278). The dental partial dislocation was the most frequent trauma (6 cases, 54.5%). The maxillary teeth were the most affected (n = 13, 72.2%). CONCLUSION According to the present study, the incidence of orotracheal intubation dental traumas is relatively high. The age of the patient is one of the factors predisposing to these traumas. In scheduled surgery, orotracheal intubation is quietly performed during general anesthesia, and the risk of incidence of dental trauma is reduced than in emergency settings.
Humans ; Intubation, Intratracheal/adverse effects* ; Male ; Female ; Prospective Studies ; Tooth Injuries/epidemiology* ; Cross-Sectional Studies ; Adult ; Middle Aged ; Risk Factors ; Aged ; Adolescent ; Young Adult ; Incidence

Complex crown-root fractures in the esthetic zone refer to a type of dental trauma occurring in the anterior region, characterized by concurrent fractures involving both the crown and the root, with associated pulp exposure and periodontal tissue injury. These injuries consistently exhibit critical anatomical features, including a fixed palatal fracture location below the alveolar crest, compromised residual tooth structure, and frequent encroachment of the biological width. To predict treatment outcomes, a risk assessment framework based on the restoration-tooth-periodontium interface was developed. Resistance risk was evaluated by assessing the type of residual dentin ferrule and the length of the root within the alveolar bone, while periodontal risk was assessed according to gingival phenotype and alveolar bone morphology. Based on these risk dimensions and the principles of aesthetics, stability, and minimally invasive treatment, a diagnostic classification system was established to categorize fractures into three types: favorable, intervention and high-risk. Type-specific management strategies were proposed: for favorable cases, crown lengthening combined with deep margin elevation to reduce periodontal risk is recommended; for intervention cases, orthodontic extrusion or surgical extrusion is applied to simultaneously address both ferrule deficiency and biological width violation; for high-risk cases, extraction followed by implant restoration is advised due to limited root preservation value. The presented classification enables clinicians to adopt a scientific and structured approach to treatment planning for these complex crown-root fractures in the aesthetic zone.
Humans ; Tooth Fractures/therapy* ; Tooth Root/injuries* ; Risk Assessment ; Tooth Crown/injuries* ; Periodontium ; Esthetics, Dental ; Dental Restoration, Permanent/methods*

BACKGROUND: An increased prevalence of cleft lip and/or palate (CL/P), a major congenital anomaly, has been observed in the offspring of women with elevated body mass index (BMI) before pregnancy. Likewise, gestational comorbidities, such as hypertension and diabetes mellitus, also increase the risk of CL/P; however, the risk linked to the coexistence of these conditions in women with higher BMI on birth prevalence of CL/P remains unclear. This study focused on the combined effects of a high BMI before pregnancy and gestational comorbidities on the birth prevalence of CL/P. METHODS: Among 98,373 live births from the Japan Environment and Children's Study (JECS), a nationwide birth cohort, 255 mothers of infants with CL/P (74, 112, and 69 infants born with cleft lip, cleft lip and palate, and isolated cleft palate, respectively) were included in the analyses. The association of CL/P birth prevalence with pre-pregnancy BMI and gestational comorbidities (hypertension and diabetes) was examined using multivariate logistic regression analyses after multiple imputations, with adjustments for several maternal (age at delivery, smoking habits, and alcohol intake) and child-related (sex and prevalence of other congenital diseases) variables, obtained through medical record transcriptions and self-reports on JECS transcription forms. RESULTS: Higher prevalence rates of overweight, gestational hypertension, and gestational diabetes mellitus were found in mothers of infants with CL/P (16.1%, 6.3%, and 4.7%, respectively) than in the control group (10.4%, 3.1%, and 3.1%, respectively). The odds ratio [95% confidence interval] for childbirth with CL/P was increased in mothers with high BMI before pregnancy (1.58 [1.11-2.24]). Furthermore, gestational hypertension and diabetes coexisting with high BMI additionally increased the odds ratios for childbirth with CL/P (2.91 [1.28-6.61] and 2.12 [0.87-5.19], respectively). CONCLUSION High maternal BMI, particularly when accompanied by gestational hypertension, was significantly associated with an increased prevalence of childbirth with CL/P.
Humans ; Female ; Cleft Lip/etiology* ; Cleft Palate/etiology* ; Pregnancy ; Japan/epidemiology* ; Prevalence ; Body Mass Index ; Adult ; Male ; Infant, Newborn ; Comorbidity ; Diabetes, Gestational/epidemiology* ; Risk Factors ; Young Adult ; Birth Cohort

BACKGROUND: Dental caries is a chronic childhood disease and one of the most prevalent public health problems worldwide. Lead is a heavy metal that is taken up by the teeth and bones. However, the association between lead exposure during pregnancy, when the tooth germs are formed, and the prevalence of dental caries in the primary dentition remains unclear. This study aimed to examine the association between maternal blood lead levels and the prevalence of dental caries in the primary dentition of children. METHODS: This cross-sectional study was conducted as an Adjunct Study to the Japan Environment and Children's Study (JECS), which is an ongoing nationwide birth-cohort study. Among children participating in the JECS at the University of Occupational and Environmental Health Sub-Regional Center, those aged 7-8 years underwent oral examination and questionnaire administration. The dft (i.e., sum of the number of decayed and filled primary teeth) was then determined. The dft numerically expresses the dental caries prevalence in the primary dentition (larger value indicates more prevalent dental caries). Poisson regression analyses with robust standard errors were performed to evaluate the association between maternal blood lead levels during pregnancy, measured using frozen samples, and the dft. RESULTS: The study included 139 children, of whom 54.7% were girls, and 89.2% were 7 years old. The median maternal blood lead level was 6.1 ng/g (25-75 percentile, 5.0-7.3). The median dft was 0 (25-75 percentile, 0-4). After adjusting for covariates including age, sex, and oral health status and behavior, maternal blood lead levels were significantly associated with increased dft (prevalence ratio, 1.6; 95% confidence interval, 1.3-1.8; per one standard deviation increase in natural log-transformed maternal blood lead levels). CONCLUSIONS This study found an association between maternal blood lead levels and the prevalence of dental caries in the primary dentition of children aged 7-8 years. Maternal exposure to lead during mid- to late-term pregnancy may affect the caries susceptibility of children after birth.
Humans ; Lead/blood* ; Female ; Dental Caries/epidemiology* ; Prevalence ; Tooth, Deciduous ; Male ; Japan/epidemiology* ; Child ; Cross-Sectional Studies ; Pregnancy ; Adult ; Maternal Exposure/adverse effects* ; Environmental Pollutants/blood* ; Prenatal Exposure Delayed Effects/epidemiology*

OBJECTIVE: To evaluate the clinical and radiographic efficacy of micro crestal flap-alveolar ridge preservation following extraction of mandibular molars with severe periodontitis compared with natural healing, and to preliminarily propose the surgical indication. METHODS: A retrospective analysis was conducted on clinical data from patients with mandibular molars with severe periodontitis either receiving micro crestal flap-alveolar ridge preservation (MCF-ARP group) or undergoing natural healing in department of periodontology, Peking University School and Hospital of Stomatology from September 2013 to June 2021. Cone-beam computed tomography scannings performed before/immediately after extraction (as baseline) and repeated before implantation (after the extraction socket healing) were used to measure the ridge width, height and volumetric changes of the sockets, and the proportion of guided bone regeneration (GBR) during implant therapy were compared between the two groups. RESULTS: Between baseline and healing, significant differences in changes of MCF-ARP group [(8.34±2.81) mm] and natural healing group [(3.82±3.58) mm] in the distances from mandibular canal to center of the tooth socket were recorded (P < 0.001). The ridge width at 1 mm below the most coronal aspect of the crest increased by (3.50±4.88) mm in the MCF-ARP group but decreased by (0.16±5.70) mm in the natural healing group, respectively (P=0.019). After healing, the MCF-ARP group showed the distances from mandibular canal to center of the tooth socket >8 mm in all the cases, with 97.1% exceeding 10 mm. Natural healing group displayed 23.1% of the cases with center bone height < 8 mm and 61.5% exceeding 10 mm. Volume changes at the buccal and lingual aspect as well as the total socket were significantly greater in the MCF-ARP group compared with natural healing group (P < 0.001).At the time of implantation, GBR was performed in 5 out of 68 subjects (8.3%) in the MCF-ARP group, whereas 8 out of 26 subjects (30.8%) in the natural healing group required GBR, reflecting significant difference (P=0.003). CONCLUSION In the sites of mandibular molars with severe periodontitis, when the distances from mandibular canal to center of the tooth socket was not enough (less than 7 mm), clinicians could consider performing the micro crestal flap-alveolar ridge preservation to achieve augmentation for alveolar ridge and reduce the proportion of guided bone regeneration during implant therapy to reduce the difficulty and risk of injuries during implant therapy.
Humans ; Tooth Extraction ; Retrospective Studies ; Surgical Flaps ; Molar/surgery* ; Mandible/surgery* ; Female ; Periodontitis/surgery* ; Male ; Adult ; Middle Aged ; Cone-Beam Computed Tomography ; Alveolar Ridge Augmentation/methods* ; Alveolar Process/surgery* ; Tooth Socket/diagnostic imaging* ; Dental Implantation, Endosseous/methods*

OBJECTIVE: To evaluate the clinical efficacy of clear aligner therapy in patients with severe periodontitis accompanied by pathological tooth displacement in the anterior region. METHODS: This retrospective study analyzed patients diagnosed with severe periodontitis and pathological displacement in the anterior region, who visited both the Periodontics and Orthodontics Departments at Peking University School and Hospital of Stomatology between 2019 and 2022. A total of 26 eligible cases were included in this study. All the patients underwent regular periodontal maintenance throughout the treatment process, and clear aligners were used for orthodontic treatment. Intraoral scans were analyzed by dedicated software to measure and compare occlusal distribution and proximal contact scores before and after orthodontic treatment. Periodontal clinical indicators were assessed at three key time points: before periodontal treatment (T0), before orthodontic treatment (T1), and after orthodontic treatment (T2). All the cases were treated with clear aligner. RESULTS: A total of 217 pathologically displaced anterior teeth from 26 patients were analyzed. Among these, 105 teeth exhibited periodontal pockets [probing depth (PD) ≥5 mm] before periodontal treatment. After clear aligner therapy, the occlusal score improved significantly from 10.35±8.61 to 23.62±9.73 (P < 0.001), and the proximal contact score increased from 13.62±4.73 to 31.62±10.37 (P < 0.001). The median PD decreased significantly from 3.33 mm [interquartile range (IQR)=0.92] at T0 to 2.50 mm (IQR=0.67, P < 0.001) at T1 and remained stable at 2.50 mm (IQR=0.50) after treatment (T2). A significant reduction in PD was observed between T0 and T2 (P < 0.001), but no significant difference was found between T1 and T2 (P=0.948). CONCLUSION Clear aligner therapy demonstrates favorable clinical efficacy in patients with severe periodontitis and pathological anterior tooth displacement. It effectively improves occlusal distribution and proximal contact while maintaining periodontal health in these patients. However, further large-scale prospective controlled studies are needed to verify its long-term clinical outcomes.
Humans ; Retrospective Studies ; Periodontitis/therapy* ; Female ; Male ; Adult ; Tooth Migration/therapy* ; Tooth Movement Techniques/methods* ; Treatment Outcome ; Middle Aged ; Young Adult ; Orthodontic Appliances, Removable

OBJECTIVE: To evaluate the wound healing of recipient and donor sites following keratinized mucosa augmentation (KMA) around implants in reconstructed jaw areas and to compare these outcomes with gingival grafts in native jawbone, so as to provide clinical guidance for postoperative maintenance, and to investigate the impact of clinical experience on the evaluation of KMA postoperative healing through subgroup comparisons. METHODS: This study included patients who underwent resection of maxillofacial tumors, fibular or iliac flap reconstruction, and implant placement at Peking University Dental Hospital from October 2020 to April 2023. Three months post-implant placement, the patients were referred for KMA procedures. Clinical photographs of the reconstructed area were taken preoperatively, immediately postoperatively, and 3 weeks and 3 months post-surgery. Additionally, photographs of the palatal donor site were obtained preoperatively and 3 weeks later. Wound healing was assessed by four junior and three senior clinicians utilizing the early healing index (EHI), early wound healing score (EHS), and pink esthetic score (PES).And senior clinicians evaluated the healing effect compared with gingival transplantation on natural jawbone using a 10-point scale. RESULTS: A total of 26 patients with jawbone reconstruction were included, with an average age of (34.2±10.2) years, 11 males (42.3%) and 15 females (57.7%). Among them, 13 cases (50.0%) underwent fibula flap reconstruction, and 13 cases (50.0%) underwent iliac flap reconstruction. The average number of implants per patient was 3.2±0.7. In the recipient area, 3 weeks postoperatively, the EHS was 7.0 (4.0, 9.0), with sub-item scores as follows: Clinical signs of re-epithelialization (CSR) 6.0 (3.0, 6.0), clinical signs of haemostasis (CSH) 1.5 (1.0, 2.0), and clinical signs of inflammation (CSI) 1.0 (0.0, 1.0), indicating that the average appearance of the wound in the recipient area was characterized by generally well-approximated wound edges with minimal fibrin lines and mild erythema and swelling. The EHI for the recipient area was 2.0 (1.5, 2.5), suggesting that the incision was mostly closed with some fibrin lines 3 weeks postoperatively. The long-term healing evaluation system, PES, was 2.5 (2.0, 3.0), with sub-scores for color [1.0 (1.0, 1.5)] and texture [1.5 (1.0, 2.0)], which were slightly different from the reference values.In the palatal donor area, 3 weeks postoperatively, the EHI score was lower at 1.3 (1.0, 2.5), while the EHS score was higher at 8.5 (6.0, 10.0), indicating better soft tissue healing in the donor area compared with the recipient area. Among the clinicians with different levels of experience, the assessment of wound healing revealed that except for the CSI sub-item, where the junior group scored higher than the senior group, all other sub-items showed significantly higher scores in the senior group compared with the junior group. In the EHS evaluation system, the CSH sub-item demonstrated no significant differences between the groups with varying levels of experience. Experienced clinicians' evaluation outcomes of healing effect compared with gum graft on natural alveolar bone was 8.5 (7.5, 9.5), showing high consistency [intraclass correlation coefficient (ICC): 0.892; 95% confidence interval (CI): 0.791－0.949], suggesting slightly suboptimal healing results after KMA surgery. CONCLUSION The healing process following KMA in the context of jawbone reconstruction is relatively protracted, emphasizing the necessity for comprehensive postoperative management. Moreover, clinician experience plays a significant role in the assessment of wound healing outcomes for KMA in maxillofacial reconstruction.
Humans ; Wound Healing ; Adult ; Male ; Female ; Gingiva/transplantation* ; Plastic Surgery Procedures/methods* ; Middle Aged ; Surgical Flaps ; Keratins