BACKGROUND Odontogenic keratocyst (OKC) is a common odontogenic cyst, and it occurs more frequently in the mandible, with the posterior region of the dental arch, the angle, or the ramus being the most commonly affected sites. Odontogenic keratocyst occurring within the maxillary sinus is extremely rare, accounting for only about 1% of cases. CASE REPORT A 20-year-old female patient without any clinical symptoms underwent an oral examination, during which a dense dental shadow was identified within the maxillary sinus, surrounded by a low-density shadow. Physical examination revealed absence of the left maxillary third molar, with intact mucosa. The patient reported no history of tooth extraction. X-ray and cone-beam computed tomography revealed a high-density image within the left maxillary sinus, resembling a tooth and surrounded by a soft-tissue shadow, which exhibited a greater density in comparison to conventional odontogenic cysts. The initial diagnosis was odontogenic keratocyst in the maxillary sinus with an ectopic maxillary third molar. Surgical enucleation of the cyst and extraction of the impacted tooth were carried out utilizing the Caldwell-Luc approach. Histopathological analysis confirmed the presence of OKC. No significant recurrence was noted during the 6 months of follow-up. CONCLUSIONS Odontogenic keratocysts in the maxillary sinus with ectopic third molar are rare and may not have any symptoms in the early stage. Surgery can be performed using the Caroler-Luke approach to achieve ideal treatment results. In view of the high recurrence rate of OKC, close follow-up should be conducted after surgery.

Most of the maxillary impacted third molars are located in the maxillary tuberosity, where the vision and operation space are limited. This paper reports a case of surgical extraction of the left maxillary horizontal superhigh impacted third molar, which is located between the roots of the adjacent teeth and is closely related to the maxillary sinus. The digital simulation technology was used to reconstruct a three-dimensional visual image of the patient\'s maxilla, related teeth, and other adjacent anatomical structures to assist in finding the optimal surgical method accurately. Root dislocation before the crown not only protects the roots of the adjacent tooth, but also reduces the risk of maxillary sinus lining damage or perforation during operative procedures, improves the efficiency of the operation, and reduces surgical trauma, which conforms to the concept of minimally invasive surgery and provides a new idea and experience for the clinical extraction of such maxillary impacted third molars.
上颌阻生第三磨牙多位于上颌结节区，此区域手术操作空间小、视野差。本文报道1例牙冠位于邻牙两牙根之间、与上颌窦关系密切的上颌水平超高位阻生第三磨牙的拔除。利用数字化模拟技术三维重建患者部分上颌骨、相关牙齿等毗邻解剖结构，精准制定最佳手术方案，采用牙根先脱位、牙冠后脱位法拔除阻生牙。该法既保护了邻牙牙根，也降低了上颌窦黏膜损伤以及穿孔的风险，提高了手术效率，减小了手术创伤，符合微创牙槽外科理念，为临床上拔除此类埋伏阻生牙提供了新思路和经验。.

OBJECTIVE: This study aims to compare the sedative effects of remimazolam and midazolam during impacted tooth extraction to provide a comfortable sedation treatment for patients with dental anxiety.
METHODS: A prospective randomized controlled trial was conducted, in which 60 patients undergoing intravenous sedation for mandibular impacted third molar extraction were evenly divided into either the remimazolam or midazolam group. Prior to receiving a nerve blocker, the patients were sedated with remimazolam or midazolam. Various parameters were recorded and analyzed, including onset time, awakening time, recovery time, modified dental anxiety scale (MDAS) scores before and after surgery, patient-doctor satisfaction levels, postoperative side effects within 24 hours, heart rate (HR), and mean arterial pressure (MAP) at different time points.
RESULTS: Compared with the midazolam group, patients in the remimazolam group demonstrated significantly shorter onset, awakening, and recovery times as well as lower postoperative MDAS scores and higher levels of patient-doctor satisfaction. Fewer postoperative side effects were reported in the remimazolam group, although the differences were not statistically significant.
CONCLUSIONS: The use of remimazolam demonstrates faster onset and recovery, superior efficacy in reducing dental anxiety, and enhanced satisfaction among patients and doctors, thereby presenting distinct advantages for sedation treatment for patients with dental anxiety.
目的: 比较瑞马唑仑和咪达唑仑在阻生牙拔除术中的镇静效果，以期为牙科焦虑患者提供更加舒适的镇静治疗。方法: 采用前瞻性随机对照试验设计，将60例接受静脉镇静下颌阻生第三磨牙拔除术的患者平均分配到瑞马唑仑组或咪达唑仑组。患者在行神经阻滞麻醉前使用瑞马唑仑或咪达唑仑进行预先镇静，记录并分析镇静起效、术后苏醒及完全恢复时间，手术前后改良牙科焦虑量表（MDAS）评分，医患满意度，术后24 h不良反应发生率，不同时间点心率（HR）和平均动脉压（MAP）的变化趋势。结果: 与咪达唑仑组相比，瑞马唑仑组患者的镇静起效、术后苏醒及完全恢复时间显著缩短，术后MDAS评分显著降低，医患满意度显著提高，术后不良反应发生率降低，但差异无统计学意义。结论: 瑞马唑仑起效和恢复更快，缓解牙科焦虑效果更好，医患满意度更高，在牙科焦虑患者镇静治疗时具有明显的优势。.

BACKGROUND: The distal aspect of the second molar (d-M2) often exhibits infrabony defects due to the adjacent third molar. Although the defects can be treated by guided tissue regeneration (GTR) after removing the third molar, the optimal timing remains uncertain following third molar removal in clinical decision-making. This study aimed to compare delayed and immediate GTR treatments to assist in clinical decision-making.
METHODS: D-M2 infrabony defects with a minimum 1-year follow-up were collected and divided into three groups: Immediate GTR group, which underwent third molar extraction and received GTR simultaneously; Delayed GTR group, which underwent delayed GTR at least 3 months after third molar extraction; and Control group, which underwent only scaling and root planing during third molar extraction. The clinical and radiographic parameters related to the infrabony defect before GTR and post-surgery were evaluated using the Kruskal-Wallis test or one-way ANOVA, followed by post-hoc Dunn\'s test or the Bonferroni test for pairwise comparisons.
RESULTS: A total of 109 d-M2 infrabony defects were assessed. No significant differences were found between the two GTR groups, although both of them showed significant reductions in infrabony defect depth: the immediate GTR group (2.77 ± 1.97 mm vs. 0.68 ± 1.03 mm, p < 0.001) and the delayed GTR group (2.98 ± 1.08 mm vs. 0.68 ± 1.03 mm, p < 0.001) compared to the control group.
CONCLUSIONS: GTR can effectively improve d-M2 infrabony defects when the third molar is removed, whether simultaneously or delayed. Patients may experience less discomfort with immediate GTR treatment as it requires only one surgery.

OBJECTIVE: To conduct a finite element analysis of the impact of different variables on tooth sectioning efficiency and trauma to surrounding tissues when utilizing high-speed surgical handpieces and elevators.
METHODS: CBCT data from the horizontally impacted third mandibular molar (M3M) of a patient were utilized to establish digital models of the M3M, adjacent M2M, and surrounding bone. To simulate tooth sectioning, a 3D finite element model was established with the following variables: remaining tooth tissue thickness (1-5 mm), tooth section fissure width (1-3 mm), elevator depth in fissure (2-6 mm), elevator position (buccal, lingual, central), elevator width (2-5 mm), and application of force (rotating, levering). Using this model, the distribution of stress on the M3M and the surrounding tissue was assessed while measuring tooth sectioning efficiency and trauma to the surrounding tissue.
RESULTS: Factors associated with uniform stress at the site of sectioning included thin (≤ 3 mm) remaining tooth tissue, appropriate fissure width (~ 2 mm), a wide (≥ 4 mm) elevator, and central elevator positioning. Levering the elevator yielded greater stress on the M3M than rotating force. Greater sectioning efficiency was associated with increased stress placed on the distobuccal side of M2M.
CONCLUSIONS: Tooth sectioning efficiency can be improved by adjusting the high-speed surgical handpiece and elevator. However, it is important to remain attentive to the trauma to which adjacent teeth are exposed during this process.
CONCLUSIONS: These results offer guidance for approaches to improving operator efficiency and reducing trauma to surrounding tissues during tooth sectioning.

It is urgently necessary to clarify the effect of extraction of impacted mandibular third molar (IMTM) on the periodontal tissue of adjacent second molars (ASMs). In this study, the ASM periodontal condition and pathogenic microbes were assessed before IMTM extraction and at 1, 4, 8 and 12 weeks postoperatively. Based on the inclusion and exclusion criteria, our study revealed that IMTM extractions adversely affected distal － periodontal probing depth (dPPD), attachment loss (dAL), plaque index (dPLI) and bleeding on probing (dBOP) within 8 weeks, but these indices gradually normalize after 12 weeks. The subgingival pathogens near the ASMs distal surface, Porphyromonas and Pseudomonas, were significantly increased postoperatively. Moreover, relevance of ASMs clinical indices and subgingival microbes after IMTM extractions was found. In contrast to the situation in chronic periodontitis, the effects of IMTM extraction on dPPD, dAL, dPLI and dBOP of ASMs were mainly correlated with Pseudomonas. Additionally, while the IMTM extractions have adverse distal periodontal indices of ASMs within 8 weeks and increase subgingival pathogens, the modified triangular flap (MTF) had fewer distal periodontal indices and less Pseudomonas. Compared to the traditional envelope flap and triangular flap, the MTF benefits the periodontal health, which could be considered as the priority option for IMTM extractions.

OBJECTIVE: The aim of this study was to explore inflammation of soft tissue around the upper third molar as a prevalent cause of limited mouth opening, identify the clinical and radiographic features, and summarize the therapeutic effectiveness of tooth extraction.
METHODS: A retrospective analysis of data from 264 patients with limited mouth opening over the last five years was performed.
RESULTS: Among the 264 patients, 24 (9.1%) had inflammation of the soft tissue around the upper third molar, which was the second most common cause of limited mouth opening. Twenty-one of the twenty-four affected patients, with an average mouth opening of 19.1 ± 7.6 mm, underwent upper third molar extraction. Gingival tenderness around the upper third molar or maxillary tuberosity mucosa was a characteristic clinical manifestation (p < 0.05). The characteristic features on maxillofacial CT included soft tissue swelling around the upper third molar and gap narrowing between the maxillary nodules and the mandibular ascending branch. Post extraction, the average mouth opening increased to 31.4 ± 4.9 mm (p < 0.05), and follow-up CT demonstrated regression of the inflammatory soft tissue around the upper third molar.
CONCLUSIONS: Inflammation of soft tissue around the upper third molar is a common cause of limited mouth opening. Symptoms of pain associated with the upper third molar and distinctive findings on enhanced maxillofacial CT scans are crucial for diagnosis. Upper third molar extraction yields favorable therapeutic outcomes.
CONCLUSIONS: Inflammation of the soft tissue around the maxillary third molar commonly causes limited mouth opening, but this phenomenon has long been overlooked. Clarifying this etiology can reduce the number of misdiagnosed patients with restricted mouth opening and enable more efficient treatment for patients.

BACKGROUND: This study investigated the effect of carbodiimide (EDC) combined with Clearfil SE self-etch adhesive on the shear bond strength (SBS), crosslinking degree, denaturation temperature, and enzyme activity of dentin in vitro.
METHODS: Collected human sound third molars were randomly divided into different groups with or without EDC treatment (0.01-1 M). The specimens (n = 16)were stored for 24 h (immediate) or 12 months (aging) before testing the SBS. Fine dentin powder was obtained and treated with the same solutions. Then the crosslinking degree, denaturation temperature (Td), and enzyme activity were tested. Statistical analysis was performed using a one-way analysis of variance (ANOVA) to compare the differences of data between groups (α = 0.05).
RESULTS: There was a significant drop in immediate SBS and more adhesive fracture of 1.0 M EDC group, while there were no significant differences among the other groups. SEM showed a homogeneous interface under all treatments. After 12 months of aging, the SBS significantly decreased. Less decreases of SBS in the 0.3 and 0.5 M groups were found. Due to thermal and enzymatical properties consideration, the 0.3 and 0.5 M treatments also showed higher cross-link degree and Td with lower enzyme activity.
CONCLUSIONS: 0.3 and 0.5 M EDC may be favorable for delaying the aging of self-etch bond strength for 12 months. But it is still needed thoroughly study.

OBJECTIVE: To investigate the age-related changes of the mandibular third molar root pulp visibility in individuals in East China, and to explore the feasibility of applying this method to determine whether an individual is 18 years or older.
METHODS: A total of 1 280 oral panoramic images were collected from the 15-30 years old East China population, and the mandibular third molar root pulp visibility in all oral panoramic images was evaluated using OLZE 0-3 four-stage method, and the age distribution of the samples at each stage was analyzed using descriptive statistics.
RESULTS: Stages 0, 1, 2 and 3 first appeared in 16.88, 19.18, 21.91 and 25.44 years for males and in 17.47, 20.91, 22.01 and 26.01 years for females. In all samples, individuals at stages 1 to 3 were over 18 years old.
CONCLUSIONS: It is feasible to determine whether an individual in East China is 18 years or older based on the mandibular third molar root pulp visibility on oral panoramic images.
目的: 研究华东地区个体下颌第三磨牙根管可见度的增龄性变化，探讨应用其判断个体是否年满18周岁的可行性。方法: 共收集1 280例华东地区15~30周岁人群的口腔全景片，应用OLZE等提出的方法（0~3 4个阶段）评估所有口腔全景片中下颌第三磨牙根管可见度，对各阶段的样本年龄分布进行描述性统计分析。结果: 男性首次出现阶段0、1、2、3的年龄分别为16.88、19.18、21.91、25.44岁，女性分别为17.47、20.91、22.01、26.01岁。所有样本中，阶段1~3的个体年龄均超过18周岁。结论: 基于口腔全景片中下颌第三磨牙根管可见度判断华东地区个体是否年满18周岁的方法具有一定的可行性。.

OBJECTIVE: To explore the preventive efficacy of antibiotics following surgical removal of the impacted mandibular third molars and screen the potential risk factors.
METHODS: A cohort trial. Place and Duration of the Study: Department of Oral and Maxillofacial Surgery, Zhejiang University School of Medicine, Stomatology Hospital, Hangzhou, China, from August 2021 to 2022.
METHODS: Cases with impacted mandibular third molar were divided into two groups based on antibiotics use. The primary outcome variable post-operative infection, secondary clinical parameter analgesics intake, and other variables (the operative time, the history of pericoronitis, and wound closure) were documented.
RESULTS: The post-operative infections occurred in 3.64% (n = 12) of the 330 cases (n = 330); 3.01% in the antibiotic group (n = 166) and 4.27% in the control group (n = 164, OR = 1.44, 95% CI: 0.49 to 4.06; p = 0.54). Concerning secondary outcome measures, the analgesics that the antibiotic group took was 5.40, and the control group took was 5.95 (95% CI = -0.21 to 1.30; p = 0.16). For those with post-operative infections, the average operative time was 22.83 minutes, whereas for those without post-operative infections it was 14.87 minutes (95% CI = -0.26 to 15.67; p = 0.04). When the operative time was greater than or equal to 15 minutes, it was related to more analgesics use (95% CI: -0.43 to 1.93; p <0.05), also was the history of pericoronitis (95% CI = 0.04 to 1.54; p = 0.04).
CONCLUSIONS: Antibiotics are unnecessary for preventing post-operative infections or minimising analgesic requirements following extraction of the impacted mandibular third molars; operative time and pericoronitis showed a suppressive influence on post-operative recovery.
BACKGROUND: Impacted molars, Antibiotics, Analgesics, Operative time, Pericoronitis.