A Case Report of Kissing Molars Class II

Kissing molars (KMs) is a condition of occlusal molar surfaces in a single follicular space with roots extending in opposite directions. Here, we have reported a case of KMs in a 58-year-old woman. The patient complained of pain in the right mandibular molar region and was diagnosed with KMs consisting of the right mandibular second and third molars. Because of the patient’s pain having subsided at the time of the visit and her unwillingness to undergo tooth extraction, the patient was followed up. KMs is classified into three classes (I-III) and is either true-KMs or pseudo-KMs and presents with or without cystic variants of dental follicles. The presents as true-KMs class II without a cystic variant. With reference to the literature and based on our analysis, the mean age of patients affected by this specific case of KMs is 31.7 years and unilateral KMs is relatively more common (85.7%). Histopathological findings of dentigerous cysts are more often indicated (42.9%). The treatment policy for KMs should therefore be based on the classification of KMs. Importantly, the focus should be on preserving the first and second molars as much as possible. The treatment approach, such as the employment of surgical removal or orthodontics, should be determined by considering the associated factors such as the crowns, tissues, and age of the patient.

Two-stage extraction by partial grinding of impacted mandibular third molar in close proximity to the inferior alveolar nerve

BACKGROUND Extraction of impacted third molars often leads to severe complications caused by damage to the inferior alveolar nerve(IAN).AIM To proposes a method for the partial grinding of an impacted mandibular third molar(IMM3)near the IAN to prevent IAN injury during IMM3 extraction.METHODS Between January 1996 and March 2022,25 patients with IMM3 roots near the IAN were enrolled.The first stage of the operation consisted of grinding a major part of the IMM3 crown with a high-speed turbine dental drill to achieve sufficient space between the mandibular second molar and IMM3.After 6 months,when the root tips were observed to be away from the IAN on X-ray examination,the remaining part of the IMM3 was completely removed.RESULTS All IMM3s were extracted easily without symptoms of IAN injury after extraction.CONCLUSION Partial IMM3 grinding may be a good alternative treatment option to avoid IAN injury in high-risk cases.

Ectopic Molar Pregnancy with Coexistent Normal Intrauterine Pregnancy: A Report of an Unusual Diagnosis managed in Yaoundé Gyneco-Obstetric and Pediatric Hospital, Cameroon

Background: Heterotopic pregnancy is a very rare event in a natural cycle. Its incidence is rising mostly due to induction of ovulation or Assisted Reproductive Technique. Most ectopic in heterotopic pregnancies are localized in the fallopian tubes. The occurrence of molar tubal ectopic pregnancy coexisting with intrauterine pregnancy is uncommon and consequently not often considered a diagnostic possibility. Case Report: We report the case of a 25-year-old woman, gravida 4 para 1, who complained of vaginal spotting and lower abdominal pain after 6 weeks of amenorrhea following clomiphene citrate ovarian stimulation. Transvaginal Ultrasonography revealed an intrauterine pregnancy and an unruptured left tubal ectopic pregnancy. She underwent successful laparoscopic salpingectomy while the intra-uterine pregnancy was allowed to continue. The ectopic pregnancy tissue histology reported an ectopic partial molar pregnancy. She subsequently had a normal vaginal delivery at 39 weeks and 3 days and her follow-up was uneventful. Conclusion: Heterotopic pregnancy is a rare but life-threatening condition. It should be suspected in a pregnant woman with a risk factor of multiple gestations who presents vaginal bleeding and lower abdominal pain in the context of early pregnancy. Laparoscopic surgery is effective for confirming the diagnosis and treating the ectopic component. Routine histological examination of tubal specimens must be taken very seriously because some findings like molar pregnancies may require specific management.

Root Canal System Variation in Mandibular Second Molar: Middle-Mesial Canal

Middle-mesial canals in mandibular molars are present in the population depending on age, sex and ethnicity. However, limited literature alludes to its prevalence. Troughing procedures may enhance identification, cleaning and shaping. This case report expresses the recognition and management of middle-mesial canal in a mandibular second molar of 24 years old Hispanic-Latino male.

Five-year outcomes of immediate implant placement for mandibular molars with and without chronic apical periodontitis:A retrospective study

BACKGROUND Most physicians consider molars with chronic apical periodontitis(CAP)lesions as contraindications for immediate implant placement.At the patient’s request,we perform immediate implant placement of the mandibular molars with CAP in clinical practice.AIM To retrospectively analyze and compare the 5-year outcomes of immediate implant placement of the mandibular molars with CAP and those without obvious inflammation.METHODS The clinical data of patients with immediate implant placement of the mandibular molars in the Department of Oral and Maxillofacial Surgery,the Affiliated Hospital of Qingdao University,from June 2015 to June 2017 were collected.The patients were divided into CAP(n=52)and no-CAP(n=45)groups.Changes in bone mineral density and bone mass around implants were analyzed 5 years after implant restoration.RESULTS At 5 years after implantation,the peri-implant bone mineral density was 528.2±78.8 Hounsfield unit(HU)in the CAP group and 562.6±82.9 HU in the no-CAP group(P=0.126).Marginal bone resorption around implants did not differ significantly between the two groups,including buccal(P=0.268)or lingual(P=0.526)resorption in the vertical direction or buccal(P=0.428)or lingual(P=0.560)resorption in the horizontal direction.Changes in the peri-implant jump space did not differ significantly between the two groups,including the buccal(P=0.247)or lingual(P=0.604)space in the vertical direction or buccal(P=0.527)or lingual(P=0.707)space in the horizontal direction.The gray value of cone-beam computed tomography measured using Image J software can reflect the bone mineral density.In the CAP area,the gray values of the bone tissue immediately and 5 years after implant placement differed significantly from those of the surrounding bone tissue(P<0.01).CONCLUSION The results of this study suggest that immediate implant placement of the mandibular molars with CAP can achieve satisfactory 5-year clinical results,without significant differences in the complications,survival rate,or bone tissue condition from the no-CAP mandibular molars.

Transfer learning-based super-resolution in panoramic models for predicting mandibular third molar extraction difficulty: a multi-center study

Background:This study aims to predict the extraction difficulty of mandibular third molars based on panoramic images using transfer learning while employing super-resolution(SR)technology to enhance the feasibility and validity of the prediction.Methods:We reviewed a total of 608 preoperative mandibular third molar panoramic radiographs from two medical facilities:the First Affiliated Hospital of Zhengzhou University(n=509;456 in the training set and 53 in the test set)and the Henan Provincial Dental Hospital(n=99 in the validation set).We conducted a deep-transfer learning network on high-resolution(HR)panoramic radiographs to improve the longitudinal resolution of the images and obtained the SR images.Subsequently,we constructed models named Model-HR and Model-SR using high-dimensional quantitative features extracted through the Least Absolute Shrinkage and Selection Operator method.The models’performances were evaluated using the receiver operating characteristic curve(ROC).To assess the reliability of the model,we compared the results from the test set with those of three dentists.Results:Model-SR outperformed Model-HR(area under the curve(AUC):0.779,sensitivity:85.5%,specificity:60.9%,and accuracy:79.8%vs.AUC:0.753,sensitivity:73.7%,specificity:73.9%,and accuracy:73.7%)in predicting the difficulty of extracting mandibular third molars.Both Model-HR(AUC=0.821,95%CI 0.687–0.956)and Model-SR(AUC=0.963,95%CI 0.921–0.999)demonstrated superior performance compared to expert dentists(highest AUC=0.799,95%CI 0.671–0.927).Conclusions:Model-SR yielded superior predictive performance in determining the difficulty of extracting mandibular third molars when compared with Model-HR and expert dentists’visual assessments.

改良前方牵引矫治器治疗骨性Ⅲ类错[牙合]伴拥挤的疗效评价

目的:评价改良前方牵引矫治器治疗骨性Ⅲ类错[牙合]伴拥挤的疗效。方法:将40例骨性Ⅲ类错[牙合]患者,按磨牙关系分为2组,每组20例,试验组磨牙中性或远中关系,应用改良前方牵引矫治器;对照组磨牙近中关系,应用传统前方牵引矫治器。2组患者治疗前后分别拍摄头颅侧位片进行比较,采用SPSS 22.0软件包对数据进行统计学分析。结果:2组患者治疗前后角度测量中,SNA、ANB、SN-MP、U4-SN显著增加(P<0.01),SNB显著减小(P<0.01);SN-OL在试验组治疗前后变化有显著差异(P<0.05)。2组患者治疗前后矢状向测量指标中,除对照组上颌牙弓长度外,其余指标均有显著改变(P<0.05);垂直向测量指标中,U1-PP、L1-MP、U4-SN、U6-SN、ANS-Me显著增加(P<0.05);U4-PP、U6-PP在对照组治疗前后的变化有显著差异(P<0.05)。2组患者治疗前后头影测量值变化量与对照组相比,试验组治疗后上颌牙弓长度显著增加,U6位置更偏远中,磨牙关系变化更小(P<0.01)。结论:改良前方牵引矫治器对磨牙中性或远中关系的骨性Ⅲ类错[牙合]伴拥挤患者具有良好的前方牵引和推磨牙向远中的效果。

改进和优化黑果枸杞及其制品中花青素测定的pH示差法

建立一种基于美国官方分析化学师协会(Association of Official Analytical Chemists,AOAC)方法检测黑果枸杞及其制品中花青素含量的改进pH示差法。考察了黑果枸杞及其制品中花青素的最佳提取和检测条件,通过液相色谱-三重四级杆串联质谱法鉴别出黑果枸杞中花青素的具体化学结构,并计算出混合花青素的平均摩尔质量。通过分光光度法测得混合花青素的平均摩尔消光系数,对改进后的pH示差法进行方法学验证和花青素的含量测定。结果显示,最佳提取和检测条件如下:黑果枸杞花青素提取溶剂为盐酸-80%(体积分数)乙醇(3∶97,体积比),料液比为1∶100(g∶mL),提取温度为50℃,提取时间为30 min,缓冲溶液稀释5倍后静置平衡20 min。液相色谱-三重四级杆串联质谱法鉴别黑果枸杞中主要以矮牵牛素类花青素为主(占97.96%),黑果枸杞特有的混合花青素平均摩尔质量为912.7 g/mol,平均摩尔消光系数为29591 L/(mol·cm)。pH示差法改进后能够满足方法学验证要求,固体样品和液体样品最低检出限分别为28.2 mg/100 g、0.282 mg/100 mL。方法改进后花青素提取增长率均大于20%,静置平衡20 min后单次检测结果精密度小于0.3%。以矮牵牛素类花青素代替矢车菊素-3-O-葡萄糖苷计算花青素含量平均提高了2.41倍,能真实地反映黑果枸杞及其制品中花青素的含量。

海南石碌铁矿石氢基矿相转化——磁选试验研究

海南石碌铁矿石铁品位为52.45%,铁主要以赤(褐)铁矿形式存在,分布率达86.18%,少量以磁铁矿形式存在。为高效回收利用该矿石,采用氢基矿相转化(HMPT)—磁选工艺流程开展了系统的试验研究,并对适宜条件下的产品进行了化学成分、XRD和VSM分析。结果表明:试样在给矿粒度-0.074mm占89.41%、HMPT温度525℃、HMPT时间10min、总气体流量500m L/min、H_(2)浓度20%、HMPT产品磨矿细度-0.045mm占69.68%的适宜条件下,经磁选获得铁品位65.26%、铁回收率95.39%的铁精矿。试验所获铁精矿较原重磁联合工艺铁精矿品位提高了2.7个百分点,铁回收率增加了30个百分点。研究不仅为海南石碌铁矿氢基矿相转化—高效分选工业应用提供技术支撑,还为其他复杂难选铁矿资源的绿色高效分选提供了参考依据。

二氧化锆髓腔固位冠修复低牙合龈距磨牙的临床效果

目的 评估二氧化锆髓腔固位冠修复低牙合龈距磨牙的临床效果。方法 对2020年1月—2022年1月就诊的46例(50颗)根管治疗后的低牙合龈距磨牙采用二氧化锆髓腔固位冠修复。分别于修复完成后1、6、12个月复查,对修复体完整性、邻接紧密度、边缘密合情况、基牙情况、牙周状况及修复体松动或脱落情况进行评估。结果 1个月复查,50颗磨牙修复后各项评价指标均达到临床可接受水平。6个月复查,6颗患牙牙龈轻度充血,修复体及基牙牙体无异常。12个月复查,仅2颗患牙修复体邻接关系欠佳;2颗患牙牙龈轻度充血,未发现修复体及基牙牙体问题。结论 对根管治疗后的低牙合龈距磨牙采用二氧化锆髓腔固位冠修复既可保护牙体避免折裂,又可提升黏结效果且兼具美观,临床应用效果良好。

磨牙根管治疗后锂基玻璃陶瓷髓腔固位冠修复的回顾性分析

目的:了解根管治疗后磨牙采用锂基玻璃陶瓷髓腔固位冠(endocrown)修复的临床效果。方法:选择根管治疗后的磨牙,经同一医师评估为大面积牙体缺损或者临床冠较短常规修复无法获得足够的固位力。所有预备体肩台均采用端对端的预备方式,保证至少1.0 mm的瓷厚度;髓腔深度大于4.0 mm时采用玻璃离子垫底。采用CAD/CAM制作锂基玻璃陶瓷髓腔固位冠后粘接。临床随访并观察和记录相关临床指标。结果:纳入观察的234个患者249个髓腔固位冠在4-9年的观察中,继发龋32颗;修复体折断5颗;脱粘接25颗,脱粘接的25颗中除5颗拔除外其余重新再粘接或重新修复;患根尖周炎8颗,其中7颗拔除;14颗患牙拔除,其中5颗因为预备体折断,1颗因为牙周牙髓联合病变,7颗因根尖周炎,7颗中有3颗合并预备体折断;4颗因继发龋后缺损太大。髓腔固位冠修复4-9年患牙总保存率可达94.38%。性别、年龄、牙位、预备体边缘位置对预备体是否会发生折裂以及是否会产生根尖周炎无明显关系;髓腔垫底会降低患牙根尖周炎及以及最终拔除的风险。第二磨牙脱粘接和患龋率明显高于第一磨牙。预备体边缘位于龈下与患龋、脱粘接以及修复体损坏的风险相关。随着年龄的增加,修复体脱粘接风险增高。结论:锂基玻璃陶瓷瓷髓腔固位冠可满足临床修复效果,是临床冠短患牙修复的理想选择,是大面积牙体缺损需要桩核冠修复患牙的有益补充。对于根管治疗后的患牙采用髓腔固位冠修复时应考虑垫底及避免预备体边缘位于龈下。

iRoot BP Plus冠髓切断术治疗乳磨牙部分不可复性牙髓炎的回顾性研究

目的 回顾性观察iRoot BP Plus冠髓切断术治疗乳磨牙部分不可复性牙髓炎的临床疗效。方法 收集2019年1月—2023年8月行乳磨牙iRoot BP Plus冠髓切断术治疗且随访24~47个月的部分不可复性牙髓炎病例102例,根据术前有无不可复性牙髓炎症状将纳入病例分为无症状组(n=53)和有症状组(n=49),观察两组的临床和影像学成功率。结果 无症状组和有症状组的临床成功率分别为96.2%和97.9%,影像学成功率分别为96.2%和93.9%。结论 在高抗菌等级前提下,iRoot BP Plus冠髓切断术可以尝试用于治疗乳磨牙部分不可复性冠髓炎。

复杂根管上颌磨牙的根管治疗3例

根管的清创与消毒是影响根管治疗成功率的关键因素[1],根管系统内的感染成分即残留的牙髓组织和细菌是根管治疗失败的主要原因[2],而遗漏根管则会造成感染清除不全,并可能导致患牙症状的开始或持续存在[3],因此熟悉和了解患牙根管解剖是去除根管系统感染、取得根管治疗成功的必要条件。上颌第一磨牙和第二磨牙多为三牙根,其中近中颊根的根管变异较多.

Hall技术治疗孤独症儿童乳磨牙龋齿的临床研究

目的:观察Hall技术用于孤独症儿童乳磨牙龋齿的临床疗效。方法:纳入4~8岁乳磨牙龋齿的患儿80例,正常儿童和孤独症儿童各40例,共153颗乳磨牙,随机数字法分别分组,正常儿童分为树脂充填组(CR)38颗和Hall技术治疗组(CH)39颗,孤独症儿童分为树脂充填组(AR)37颗和Hall技术治疗组(AH)38颗,给予相应治疗,记录操作时间、Frankl评分、Houpt评分、家长满意率,6、12、18和24月复查效果。结果:CH组与AH组从操作时间、依从性、Houpt评分和6、12、18和24月复查效果方面比较均无统计学差异(P>0.05)。AR组家长满意度最低(P<0.05)。24月复查HALL技术治疗组成功率高于树脂充填组(P<0.05)。结论:Hall技术是一种有效且优于传统树脂充填用于治疗孤独症儿童乳磨牙龋齿的方法。

重庆市12岁儿童第一恒磨牙龋患率及相关因素研究

目的了解重庆市12岁儿童第一恒磨牙龋患率及相关因素,为开展儿童口腔疾病综合干预提供建议。方法采用随机整群抽样的方法在重庆市6个区县抽取12岁儿童进行问卷调查与口腔健康检查,采用SPSS 25.0进行统计分析,第一恒磨牙龋患率相关因素采用多因素Logistic回归分析。结果共计调查12岁儿童3770人,其中男生与女生分别为1953人(51.80%)与1817人(48.20%);城市与农村儿童分别占49.97%与50.03%;正确刷牙率为26.37%;口腔健康知识知晓率为2.23%;对口腔健康持正确态度的儿童比例为67.88%;牙龈出血和牙石检出率分别为33.69%与4.62%,接受过窝沟封闭的占42.86%。12岁儿童第一恒磨牙龋患率为33.69%,龋均为1.47。多因素Logistic回归分析结果提示,农村居住(OR=1.38,95%CI:1.20~1.59)、每天饮用碳酸饮料或含糖饮料(OR=1.38,95%CI:1.05~1.82)、每天摄入甜点或糖果(OR=1.30,95%CI:1.07~1.58)、牙龈出血(OR=0.70,95%CI:0.60~0.81)、牙石(OR=2.17,95%CI:1.58~2.96)、接受过窝沟封闭(OR=0.61,95%CI:0.53~0.70)是重庆市12岁儿童第一恒磨牙龋患率的影响因素。结论重庆市12岁儿童龋患率高,正确刷牙率低,窝沟封闭率低,应针对龋患率的影响因素开展有针对性的干预,扩大窝沟封闭的覆盖率,降低儿童龋患率。

活髓切断术与间接盖髓术对乳磨牙深龋患儿治疗效果及预后的影响比较

目的:对比分析活髓切断术与间接盖髓术对乳磨牙深龋患儿治疗效果及预后的影响。方法:对2019年1月-2023年2月笔者医院收治的152例乳磨牙深龋患儿的临床资料进行回顾性分析,按治疗方法的不同分为A组(n=78,96颗患牙)和B组(n=74,96颗患牙),A组予以活髓切断术治疗,B组予以间接盖髓术治疗,治疗后均随访12个月。比较两组治疗效果、牙本质桥形成率、牙齿咀嚼功能、并发症发生情况和学龄前儿童口腔健康影响量表(ECOHIS)的差异。结果:治疗后12个月,A组患牙的修复成功率高于B组(P<0.05);治疗后6、12个月,A组患牙的牙本质桥形成率均高于B组(P<0.05);治疗后12个月,两组牙齿咀嚼功能各维度评分均高于同组治疗前,且A组均高于B组(P<0.05);A组的并发症发生率低于B组(P<0.05);两组ECOHIS量表口腔症状、口腔功能、心理状态、社会交往评分均低于同组治疗前,且A组低于B组(P<0.05)。结论:活髓切断术相较间接盖髓术对乳磨牙深龋患儿的疗效更加显著,能有效提高修复成功率,促进牙本质桥形成,改善牙齿咀嚼功能,提高生存质量,减少并发症的发生。

MTA与iRoot BP Plus行直接盖髓术治疗龋源性露髓恒磨牙临床疗效分析

目的:观察成熟恒磨牙去龋未净时露髓使用无机三氧化物聚合体(Mineral trioxide aggregate,MTA)和生物陶瓷类材料(iRoot BP Plus)行直接盖髓术的临床疗效,探讨此类术式的可行性及其影响因素,比较两种盖髓剂疗效的差异。方法:选取2018年4月-2019年10月就诊于笔者科室符合纳入标准的53例患者,共53颗患牙,随机分为M组和B组,分别使用MTA与iRoot BP Plus行直接盖髓术,术后定期复查,比较两组的临床疗效。结果:共计45例患者(45颗患牙)完成2年随访,总体成功率84.4%;M组和B组分别为85.7%、83.3%,两组比较差异无统计学意义(P>0.05)。性别、年龄、露髓孔大小等因素对疗效均无显著影响(P>0.05)。结论:成熟恒磨牙术中露髓时使用MTA或iRoot BP Plus行直接盖髓术均可获得良好疗效;相较于性别、年龄、露髓孔大小等因素,如何简单准确评判牙髓状态及避免龈下微渗漏更加值得关注。

双波长激光联合生物陶瓷材料iRoot SP辅助磨牙根管治疗效果分析

目的:探讨双波长激光联合生物陶瓷材料iRoot SP辅助磨牙根管治疗的效果。方法:选择2020年1月—2023年6月收治的104例磨牙根管治疗患者,按照随机数字表法分为对照组与试验组,每组52例。对照组采用iRoot SP糊剂进行根管充填,试验组以双波长激光(Nd:YAG和Er:YAG)联合iRoot SP糊剂进行治疗。比较2组总有效率、疼痛程度及并发症,观察治疗前、治疗后6周及12周的血清白细胞介素6(IL-6)、白细胞介素17(IL-17)、肿瘤坏死因子α(TNF-α)、出血指数(bleeding index,BI)、牙周探诊深度(depth of periodontal probing,PD)和临床附着水平(clinical attachment level,CAL)。采用SPSS 22.0软件包对数据进行统计学分析。结果:试验组总有效率显著高于对照组,根管填充后疼痛程度显著低于对照组(P<0.05);试验组治疗后6、12周的IL-6、IL-17、TNF-α、BI、PD和CAL显著低于对照组(P<0.05)。结论:双波长激光联合生物陶瓷材料iRoot SP辅助磨牙根管治疗效果较为理想,有利于减轻牙周炎症和疼痛程度。

重度牙周破坏对下颌第一磨牙拔牙后种植手术方式影响的回顾性研究

目的:对下颌第一磨牙拔除后行种植修复的病例进行回顾性研究,探索重度牙周破坏(advanced periodontal defect,APD)对拔牙后种植手术方式的影响。方法:纳入下颌第一磨牙拔除后自然愈合3~12个月行种植手术的患者176例,共179个种植位点,进行回顾性分析,记录患者年龄、性别、缺牙时间以及拔牙时是否有APD。采用多因素Logistic回归,分析拔牙前APD是否是种植时行引导性骨再生(guided bone regeneration,GBR)的风险因素。结果:对年龄、性别、缺牙时间等因素校正后,结果显示,有APD的下颌第一磨牙,种植时行GBR的风险是无APD位点的4.738倍(95%可信区间:1.650~13.609,P<0.05)。结论:APD的下颌第一磨牙拔除后,种植手术时行GBR的可能性更大。

牙髓切断术与牙髓摘除术治疗深龋露髓乳磨牙的临床效果分析

目的对深龋露髓乳磨牙患儿采取牙髓切断术、牙髓摘除术治疗的效果进行分析。方法选取单颗牙深龋露髓乳磨牙患儿78例,按治疗方式不同分为研究组和对照组,各39例。研究组使用牙髓切断术进行治疗,对照组使用牙髓摘除术进行治疗。比较两组临床疗效,术后3、6个月牙本质桥成形情况,并发症发生情况。结果术后,研究组总有效率与对照组比较,差异无统计学意义(P>0.05)。术后3、6个月,研究组患儿牙本质桥成形率与对照组比较,差异无统计学意义(P>0.05)。术后,研究组患儿并发症发生率7.69%低于对照组的25.64%,差异具统计学意义(P<0.05)。结论深龋露髓乳磨牙患儿采取牙髓切断术、牙髓摘除术治疗均有较好的效果,但牙髓切断术能减少患儿术后并发症发生率,可帮助患儿更好地恢复口腔健康。