The Importance of Three-Dimensional Imaging from CBCT in Elucidating a Well-Defined Radiolucency Image within the Maxillary Sinus: A Case Report

This study describes a case of antral septum with alveolar process extension that is identified using cone-beam computed tomography (CBCT). Periapical radiolucency was observed in the maxillary sinus, and clinical and radiographic examinations ruled out the possibility of odontogenic lesions. CBCT was performed to elucidate the radiolucency identified using periapical radiography. A 3-D image indicated that the maxillary sinus extended into the alveolar process toward the palatal cortical bone in the region of the maxillary right first molar, as well as an antral septum extending from the inferior and lateral wall of the right maxillary sinus. CBCT is an important tool for use in dental practice because CBCT images reveal the entire volume of the maxillary sinus and allow for identification of patient anatomy and anatomical variations, which is essential for planning appropriate surgical interventions.

Morphometric analysis of the relationships between the maxillary first molar and maxillary sinus floor

Objectives: To assess the relationships between the maxillary first molar and the maxillary sinus floor in a group of patients referred to a dental clinic. Methods: Ninety-seven patients were recruited for this study. The distances between the examined roots (mesio-buccal, disto-buccal and palatal) as well as furcations, and the sinus floor, were evaluated using cone beam computed tomography, and grouped as follows: class 0: distance = 0 mm;class 1: 0 mm < distance < 2 mm;class 2: 2 mm ≤ distance < 4 mm;class 3: 4 mm ≤ distance < 6 mm;class 4: 6 mm ≤ distance. The Spearman’s Rank Correlation coefficient was used to test the univariate associations between furca-tion-sinus floor distance and each root class. Results: The prevalence of class 0 was the highest for the palatal root (44.33%), followed in descending order by mesio-buccal (40.21%), and disto-buccal (38.14%) roots. The highest correlation coefficient was recorded when assessing the relationship between furcation-sinus floor distance and palatal root classes (rho = 0.66, p < 0.001, n = 97). Conclusions: Altogether, the results suggest that the palatal root of the maxillary first molar not only had the closest relationship with the sinus floor, but also proved to be the best predictor for the furcation-sinus floor distance. The clinician should be aware of the anatomical and morphological details of this root, especially when taking surgical decisions.

Asymmetric outcomes in bilateral maxillary impacted tooth extractions:A case report

BACKGROUND The extraction of maxillary impacted teeth is a common procedure in oral surgery,frequently complicated by oroantral communications.For less-experienced clinicians,accurately assessing the difficulty and associated risks of maxillary third molar extractions remain a significant challenge.CASE SUMMARY We present a case involving disparate outcomes following bilateral extraction of maxillary third molars.Using cone-beam computed tomography and three-dimensional software,we conducted a digital assessment of the factors contributing to extraction difficulty and risk,controlling for potential confounders.Key variables analyzed included alveolar bone volume,bone quality,crown-root angulation,and maxillary sinus mucosal thickness.Additionally,we introduce the novel concept of"tegmen bone"to quantitatively evaluate the bone mass between the teeth and the maxillary sinus.This unique case,with differing outcomes on opposite sides of the same patient,provided an opportunity to minimize extraneous variables and focus on the local anatomical factors influencing the procedures,thereby improving the precision of our analysis.CONCLUSION This case highlights the potential utility of predictive analysis in guiding the management of complex tooth extractions.

Root canal morphology and configuration of 123 maxillary second molars by means of micro-CT

The aim of this study was to investigate the root canal configuration, accessory canals and number of main foramina of 123 maxillary second molars by means of micro-computed tomography. The teeth were scanned and reproduced with 3D software imaging. The root canal configuration and number of main foramina were evaluated by means of a four-digit system. The morphological complexity of human maxillary second molars is depicted by the number of accessory and connecting canals. The most frequently observed root canal configurations in the mesiobuccal root were 2-2-2/2 （19.5%）, 2-2-1/1 （14.6%） and 2-1-1/1 （13.0%）. A 1-1-1/1 configuration was observed in 93.5% and in 96.7% in the distobuccal and palatal roots, respectively. The MB1 mot canal had one accessory canal （18.7%）, and 8.9% of the MB2 root canal had one or two accessory canals. The distobuccal （11.3%） and palatal （14.6%） root canals had at least one accessory canal, and connecting canals were observed in 16.3% of mesiobuccal roots. The MB1, MB2, distobuccal and palatal root canals had one main foramen in 99.2%, 43.1%, 98.4% and 99.2% of samples, respectively. In the mesiobuccal root, one accessory foramen was detected in 14.6%, two were detected in 7.3%, and three were detected in 5.7%. The distobuccal root showed one or two accessory foramina in 9.1% of samples. The root canal configuration of maxillary second molars is quite heterogeneous; the mesiobuccal root has predominantly two root canal entrances （58.4%, 1 in 41.1%） with one main foramen （54.4%）. Two main foramina were observed in 43.0%. Morphological variations, connecting and accessory canals were observed in all apical thirds.

Concrescence of maxillary second molar and impacted third molar:A case report

BACKGROUND Morphological anomalies of teeth,including talon cusp,dens evaginatus,gemination,fusion,concrescence,root dilaceration,and taurodontism,always involve changes in the enamel,cementum and dentin.Diagnosing concrescent teeth through routine clinical examination alone is difficult,and most cases of concrescence are found accidentally during extraction.A definite preoperative diagnosis of concrescence would contribute to a better treatment plan and fewer undesirable complications CASE SUMMARY A 47-year-old woman who complained of left maxillary first molar loss for half a year presented to our department seeking treatment by dental implant restoration.Panoramic radiography and cone-beam computed tomography(CBCT)showed an unclear boundary between the distal root of the second molar and the mesial root of the third molar.The teeth were extracted under local anesthesia,and a definite diagnosis of concrescence was made by histopathological examination.CONCLUSION CBCT is a useful tool for diagnosing and planning the management of tooth concrescence and may be beneficial for reducing unnecessary complications.

Maxillary first molar with an O-shaped root morphology:report of a case

This case report is to present a maxillary first molar with one O-shaped root, which is an extended C-shaped canal system. Patient with chronic apical periodontitis in maxillary left first molar underwent replantation because of difficulty in negotiating all canals. Periapical radiographs and cone-beam computed tomography （CBCT） were taken. All roots were connected and fused to one root, and all canals seemed to be connected to form an O-shape. The apical 3 mm of the root were resected and retrograde filled with resin-modified glass ionomer. Intentional replantation as an alternative treatment could be considered in a maxillary first molar having an unusual O-shaped root.

Bilateral maxillary fused second and third molars:a rare occurrence

This case report describes the diagnosis and endodontic therapy of maxillary fused second and third molars, using cone-beam computed tomography （CBCT）. A 31-year-old Chinese male, with no contributory medical or family/social history, presented with throbbing pain in the maxillary right molar area following an unsuccessful attempted tooth extraction. Clinical examination revealed what appeared initially to be a damaged large extra cusp on the buccal aspect of the distobuccal cusp of the second molar. However, CBCT revealed that a third molar was fused to the second molar. Unexpectedly, the maxillary left third molar also was fused to the second molar, and the crown of an unerupted supernumerary fourth molar was possibly also fused to the apical root region of the second molar. Operative procedures should not be attempted without adequate radiographic investigation. CBCT allowed the precise location of the root canals of the right maxillary fused molar teeth to permit successful endodontic therapy, confirmed after 6 months.

Endodontic management of a fused left maxillary second molar and two paramolars using cone beam computed tomography: A case report

BACKGROUND Fused teeth usually involve several complications,such as the development of caries in the groove between fused crowns,tooth impaction,diastemas,aesthetic and periodontal problems,and pulpal pathosis,due to the complex anatomical structure of fused teeth.A thorough diagnosis is paramount to forming an accurate treatment plan and obtaining a favourable prognosis.With the advent of cone-beam computed tomography(CBCT),accurate 3-dimensional images of teeth and their surrounding dentoalveolar structures can now be readily obtained,and the technology can accurately provide a minimally invasive approach to acquire detailed diagnostic information.Therefore,we utilize CBCT data herein to generate a digital model for the infected region in a patient,and this model enables us to better plan the management of his case.CASE SUMMARY This report details the diagnosis and endodontic treatment of a rare case involving a fused maxillary second molar and two paramolars with apical periodontitis.The patient experienced pain upon biting and cold sensitivity in the area of the maxillary left molar.No caries or other defects were identified in these teeth,and a normal response to a pulp electric viability test was observed.With the aid of CBCT and digital model technology,we initially suspected that the infection originated from the isthmus between the maxillary second molar and two paramolars.Therefore,we only treated the isthmus by an endodontic approach and did not destroy the original tooth structure;furthermore,the vital pulp was retained,and good treatment outcomes were observed at the 24-month follow-up.CONCLUSION This finding may provide new insights and perspectives on the diagnosis and treatment of fused teeth.

CT在上颌窦囊肿切除术式选择中的应用评价

目的评价鼻窦薄层CT在上颌窦囊肿切除手术策略选择中的应用效果。方法回顾性分析2018年3月~2021年3月上颌窦囊肿患者80例(90窦)病历资料,术前均行鼻窦CT检查并判读,按囊肿不同的起源分类后,采用相应的手术径路切除病变。结果分析鼻窦CT,囊肿起源于上颌窦前壁21窦,上壁8窦,底壁1窦,内侧壁25窦,外侧壁17窦。行扩大自然窦口径路26窦,下鼻道开窗径路20窦,泪前隐窝径路44窦。手术均实现全切,无术后出血,溢泪,前鼻孔狭窄等并发症。随访期间无复发。结论术前鼻窦CT对囊肿起源位置的确定可以为合适的手术径路选择提供重要依据。

CBCT评价526颗上颌第二磨牙牙根根管形态及其与上颌窦的关系

目的研究上颌第二磨牙(MSM)的牙根、根管系统的解剖学特征以及根尖与上颌窦的关系。方法回顾性分析了263例患者526颗MSM的CBCT成像资料。记录并分析患者的年龄、牙根及根管数量、融合根数量、根管弯曲类型以及牙根与窦底的解剖关系。结果大多数上颌第二磨牙有3个根(59.1%)。三根三管的发生率最高(47.3%)。有192颗(36.5%)的牙齿出现牙根融合。两根两管和三根三管MSM的腭根管在颊舌方向的弯曲度大于近远中向。三根MSM的近中颊根有向上颌窦内延伸的趋势,腭根有远离上颌窦的倾向。MSM牙根到上颌窦底的距离随年龄增长而增加(P<0.05)。结论MSM的牙根和根管形状差异较大。

锥形束CT测量成人上颌前磨牙根尖与上颌窦位置关系及其对即刻种植的影响

目的分析上颌前磨牙牙根与上颌窦空间位置关系,为该位点即刻种植时机、方案、术式及种植体选择等提供解剖依据。方法本研究已通过单位伦理委员会审查批准,并获得患者知情同意。收集2017年1月⁃2023年3月瑞华口腔门诊部就诊的264例患者(年龄20~65岁)口腔锥形束CT(cone beam CT,CBCT)影像,选取冠状面测量上颌前磨牙根尖到上颌窦下壁的最短距离,对牙根与上颌窦下壁的垂直关系分类,并就双侧、性别及不同年龄组进行比较。结果上颌前磨牙根尖至上颌窦下壁最短距离:上颌第一前磨牙单根型中位数为7.34 mm,双根型颊根中位数为7.80 mm,腭根中位数为7.36 mm;上颌第二前磨牙单根型中位数为2.56 mm,双根型中颊根中位数为1.73 mm,腭根中位数为1.23 mm。上颌第二前磨牙右侧单根型根尖至上颌窦下壁间最短距离在各年龄组间有统计学差异(P<0.05),20~29岁组最小(中位数1.52 mm),≥40岁组最大(中位数4.44 mm)。性别和左右侧对根尖到窦下壁距离的影响无统计学差异(P>0.05)。上颌前磨牙根尖与上颌窦垂直关系中,根尖不与上颌窦下壁接触的情况占比最高,垂直关系分类在单根型和双根型间无统计学差异(P>0.05)。结论上颌第一前磨牙根方大多可为即刻种植提供足够高度骨量,较易实现即刻种植;上颌第二前磨牙根方骨量不足常见,需充分利用拔牙窝骨壁或窦底皮质骨实现初期稳定性;根尖与窦下壁垂直关系分型分布受年龄及牙位影响,青年组较其他年龄组更易出现骨高度不足,需谨慎选择即刻种植适应证;牙根数量对牙根与上颌窦垂直关系影响不大,双根型因牙根直径小及根间骨性分隔,可为即刻种植提供更多骨支持。

锥形束CT测量不同上颌第二磨牙萌出阶段的青少年颧牙槽嵴区骨厚度

目的探究不同上颌第二磨牙萌出阶段的青少年颧牙槽嵴区(infrazygomatic crest,IZC)骨厚度分布规律与差异,为微种植支抗植入提供参考。方法回顾性分析110名正常颌青少年颌面部锥形束CT影像资料,根据上颌第二磨牙萌出阶段由早至晚分为S1(44例)、S2(30例)、S3(36例)3组。将过左侧上颌第一磨牙近中颊尖的水平横断面定义为水平基准面(horizontal base plane,HB)。选取左侧上颌第一磨牙近中颊根与远中颊根两个冠状截面,分别在HB上方13(HB13)、15(HB15)、17(HB17)mm高度,呈龈向60°角测量颊侧牙槽骨骨厚度。分别比较近、远中根与不同高度下的骨厚度,并比较3组在各植入路径的骨厚度差异。使用色彩映射图展示3组骨厚度分布。结果3组骨厚度测量结果在HB13与HB15高度上均表现为远中颊根骨厚度大于近中颊根。随着高度的增加,骨厚度逐渐减小(P<0.05)。组间分析显示骨厚度在HB13与HB15高度上表现为S1>S2>S3。骨厚度最大值在S1组的远中颊根HB13高度上(5.20 mm),最小值在S2组远中颊根HB17高度上(1.90 mm)。结论3组青少年的IZC骨厚度均表现为在上颌第一磨牙远中颊根的HB13高度处最大,随着高度增加,骨厚度减少。上颌第二磨牙处于的萌出阶段越晚,IZC骨厚度越少,微种植支抗植入难度增加。

苏南地区成年人上颌窦分隔的锥形束CT分析

目的探讨锥形束CT(CBCT)在苏南地区成年人上颌窦分隔发生情况中的应用价值。方法选取2021年1月至2023年9月苏南地区的江苏大学附属人民医院收治的308例(616侧上颌窦)患者作为研究对象。患者均行CBCT检查,统计上颌窦间隔的分布位置、发生率,比较不同性别、牙缺失和非缺牙、不同年龄段患者上颌窦间隔发生率。结果上颌窦分隔以中部居多,占47.95%;前部次之,占35.62%;后部最少,占16.43%。308例患者(616侧)中,以上颌窦为对象,上颌窦发生率为11.53%(71/616);以患者为对象,上颌窦分隔发生率为18.18%(56/308)。不同性别患者上颌窦分隔发生率比较差异无统计学意义。牙缺失与非缺牙患者的上颌窦分隔发生率比较差异无统计学意义。18~44、45~59、≥60岁患者上颌窦分隔发生率比较差异无统计学意义。结论上颌窦分隔有一定的发生率,位于牙槽骨中部居多,不受年龄、性别、牙缺失的影响。CBCT能准确地评估上颌窦的相关解剖结构,可为临床工作提供有利数据分析。

上颌第一磨牙解剖结构的锥形束CT研究

目的应用锥形束计算机断层扫描法(CBCT)研究上颌第一磨牙的牙体及根管解剖结构,为上颌第一磨牙的临床诊疗提供数据支持。方法根据纳入及排除标准,选择上颌第一磨牙完整的18~25岁健康人群共计401(男196,女205)例为研究对象,拍摄CBCT影像,使用SmartVPro软件测量分析牙体形态、根管形态,采用SPSS 26.0软件对数据进行统计学处理。结果右侧上颌第一磨牙平均全长为(20.22±1.72)mm,左侧上颌第一磨牙平均全长为(20.24±1.74)mm;全长、冠宽、颈宽在左右侧上颌第一磨牙间无明显差异(P>0.05),左侧上颌第一磨牙冠长、根长、冠厚、颈厚显著大于右侧上颌第一磨牙(P<0.05);男性全长、根长、冠厚、颈厚、冠宽、颈宽等显著大于女性(P<0.05)。左右侧上颌第一磨牙根管形态对称,三根型牙根最常见,发生率为98.75%,双根型牙根的发生率为1.25%;根管数目最常见为四根管,发生率为63.47%,其次为三根管,发生率为35.78%;近颊第二根管发生率为63.84%。近颊根管分型以VertucciⅣ型根管为主,在左右侧上颌第一磨牙中分别占比为62.59%、64.59%,远颊根及腭根则以VertucciⅠ型根管为主,远颊根VertucciⅠ型根管占比为97.00%,左右侧上颌第一磨牙腭根VertucciⅠ型根管占比则分别为98.75%、98.50%。结论上颌第一磨牙牙体形态在性别间存在显著差异,且根管系统复杂多变,相关数据有望为上颌第一磨牙牙体牙髓病的防治提供指导。

与上颌窦底提升术相关的腭鼻隐窝的CBCT研究

目的:腭鼻隐窝(palatonasal recess,PNR)是上颌窦内侧壁的凹陷性结构,熟悉腭鼻隐窝的解剖特点有利于评估上颌窦底提升术的难度,降低黏膜穿孔的风险。本研究通过锥形束CT(CBCT)分析了PNR的解剖特点,为上颌窦底提升手术提供参考。方法:选取于解放军总医院第一医学中心口腔科就诊的189例上颌后牙缺失患者(223个缺牙位点)的CBCT影像资料,测量缺失牙位的PNR的检出率、PNR的角度以及PNR与牙槽嵴顶、上颌窦侧壁的距离,并进一步统计PNR角度<90°且距离牙槽嵴顶<15 mm的风险位点的发生率。结果:共有176位(93.12%)患者观察到PNR,总计PNR位点为202个(90.58%)。PNR角度为(123.81±25.15)°,从第一前磨牙到第二磨牙位点角度逐渐增大。PNR与牙槽嵴顶距离是(12.89±2.85)mm,第二前磨牙处与牙槽嵴顶的距离最远,第二磨牙处最近。PNR与上颌窦外侧壁的距离是(16.93±4.57)mm,第一磨牙处的PNR距离上颌窦外侧壁最远。PNR风险位点在第一前磨牙处发生率最高。结论:PNR是上颌窦内壁的常见解剖结构,在上颌窦底提升术前应通过CBCT仔细了解PNR的解剖特点,降低上颌窦黏膜穿孔的发生率。

CBCT测量上颌后牙根尖与上颌窦底距离的应用价值

目的通过CBCT资料分析吉林地区正常人群上颌后牙根尖与上颌窦底的距离,为上颌磨牙区的牙种植术和疾病诊断以及治疗计划等临床口腔外科提供解剖学基础。方法从吉林大学口腔医院放射科留存的CBCT资料中,选择上颌后牙健康,没有经过外科手术和正畸等处理的CBCT资料27例(其中男13例,女14例),利用CBCT配套软件进行三维重建,并用软件内置测量工具逐一测量上颌第二前磨牙、第一磨牙和第二磨牙根尖与上颌窦底的距离。结果上颌后牙各个牙根与上颌窦底距离在左右两侧和男女之间无差异(P>0.05)。27名试验人员(54侧)CBCT中,上颌第二前磨牙牙根、第一磨牙的近中根、腭根、远中根、第二磨牙的近中根、腭根、远中根的根尖与上颌窦底的距离分别为:(4.13±3.71)mm、(3.12±3.76)mm、(3.50±3.58)mm、(2.62±3.32)mm、(1.81±2.55)mm、(3.14±3.08)mm、(2.67±3.27)mm。结论上颌第二磨牙近中根根尖距离上颌窦底最近,上颌第二前磨牙根尖距离上颌窦底最远(P<0.05)。

上颌窦底与上颌磨牙牙根关系的锥形束CT研究

目的:应用锥形束CT分析上颌窦底与上颌磨牙牙根的关系,为临床治疗提供参考。方法:收集具备上颌后部锥形束CT扫描数据的患者资料,应用CT配套软件观察上颌窦底与上颌磨牙牙根的关系并测量上颌磨牙牙根与上颌窦底间距离。结果:共收集40例,男26名,女14名,平均年龄35.5岁(19～55岁)。12例牙根根尖与上颌窦底在同一水平;16例牙根根尖水平高于上颌窦底水平,平均距离为(3.62±0.52)mm;12例牙根根尖水平低于上颌窦底水平,平均距离(3.16±0.42)mm。在距离上颌窦底最近的牙根方面,上颌第一磨牙腭根最为多见(20/40)。结论:锥形束CT在判断上颌窦底与上颌磨牙牙根关系方面有较高应用价值。上颌窦底与上颌磨牙牙根关系密切,其中,与第一磨牙腭根关系最为密切,临床治疗中应预防上颌窦穿孔或上颌窦炎的发生。

螺旋CT在上颌窦底壁分型及内提升术风险评估中的应用

目的通过上颌窦螺旋CT扫描,初步对上颌窦底壁进行分型,并为种植牙上颌窦内提升术的风险评估提供理论依据。方法选取55例(110侧)健康成人的鼻窦CT影象,对上颌窦进行螺旋CT连续容积扫描、三维重建,在选取的截面上观察上颌窦底的形态。结果 110侧上颌窦底中,平坦型、凹面型、凸面型各有50侧、53侧、7侧,所占比例分别为45.5%、48.2%、6.3%。其中平坦型与凹面型之间无显著性差异(P<0.05),而凸面型与另两种分型之间有显著性差异(P>0.05)。性别、左右侧以及不同年龄之间均无显著性差异(P<0.05)。结论上颌窦内提升术前,进行螺旋CT扫描,观察窦底形态对评估手术风险有重要的临床指导意义。

青海地区成人上颌窦间隔锥形束CT的研究分析

目的:通过锥形束CT(CBCT)结合测量软件,研究青海地区成人上颌窦间隔的解剖学变化。方法:选取300例成人研究对象的CBCT影像资料,测量分析上颌窦间隔的发生、位置、高度、方向及形态学变化。用SPSS17.0软件对数据进行统计学分析。结果:300例研究对象中,有80例出现上颌窦间隔,发生率为26.7%;窦间隔的发生与性别、年龄及牙缺失无关。窦间隔主要出现在上颌窦中部(41.4%);平均高度右侧(6.60±4.08)mm,左侧(6.81±4.24)mm;平均长度右侧(9.28±2.99)mm,左侧(9.00±3.00)mm;颊腭向多见(85.2%),完全性为主(80.5%)。结论:青海地区成人中有26.7%出现上颌窦间隔,在上颌窦底提升术时应予以重视,采取适当的对策。

陕西汉中人群上颌第一恒磨牙根管系统的CBCT研究

目的：了解陕西汉中人群上颌第一恒磨牙根管解剖形态。方法：选择陕西汉中人群上颌第一恒磨牙526个,CBCT影像分析每个磨牙的牙根数目、根管形态,采用Vertucci分类法对根管构型进行分类描述。并按年龄段分组,对上颌第一恒磨牙根管口间距、MB2检出率进行分析。结果：526个上颌第一恒磨牙中,0.76%有2个独立牙根,98.66%有3个牙根,0.57%有4个牙根;在有3个牙根的519个上颌第一恒磨牙中,Ⅰ型为43.93%,Ⅱ型为36.22%;汉中地区人群上颌第一恒磨牙MB2检出率在20~30年龄组最高（65%）,随着年龄增大,MB2检出率逐渐降低,61~70年龄组最低（25%）。结论：陕西汉中人群上颌第一恒磨牙的根管形态复杂,根管治疗时要防止遗漏根管的发生。