Prevalence of canalis sinuosus and accessory canals of canalis sinuosus on cone beam computed tomography: a systematic review and meta-analysis

The aim of this systematic review was to determine the prevalence of the canalis sinuosus (CS) and accessory canals of the canalis sinuosus (ACCS) as identified on cone beam computed tomography (CBCT). Online searches were conducted in the MEDLINE (via PubMed), Scopus, LILACS, Cochrane CENTRAL, Web of Science, and SIGLE (via OpenGrey) databases. Primary studies that determined the prevalence of canalis sinuosus and/or its anatomical variations using CBCT were included. The risk of bias assessment was performed using the AQUA tool. The quality effects model using double arcsine transformation was used for the meta-analysis of prevalence. Heterogeneity, publication bias, and sensitivity analyses were performed. Of 3237 initial results, 17 papers were included for systematic review. The meta-analysis comprising 1994 patients showed a pooled prevalence of CS of 0.80 (95% confidence interval (CI) 0.51–0.99; P = 0.001; I² = 99%). Publication bias analysis revealed minor asymmetry (LFK index 1.84). The meta-analysis of 4605 patients showed a pooled prevalence of ACCS of 0.54 (95% CI 0.38–0.69; P = 0.001; I² = 99%). The sensitivity analysis showed a pooled prevalence of ACCS of 0.53 (95% CI 0.32–0.74; P = 0.001; I² = 99%) for studies with ≥ 1000 patients and 0.55 (95% CI 0.33–0.76; P = 0.001; I² = 98%) for studies with< 1000 patients. Canalis sinuosus showed a pooled prevalence of 0.80 and ACCS showed a pooled prevalence of 0.54; hence both should be considered as anatomical structures, which means that they are present in most people. Surgeons must be aware of the CS and ACCS on CBCT analysis during pre-surgical planning.PROSPERO registration numberCRD42020154195     

基于锥形束CT对上颌窦分隔分布的影像学分析

目的：运用InVivo Dental软件对北京第二炮兵总医院口腔科锥形束CT（CBCT）影像学资料进行回顾性分析,研究2012年7月至2013年10月期间就诊于我院口腔科成人人群中上颌窦底壁分隔与年龄,性别以及缺牙情况的关系,以期为上颌窦底提升术提供解剖学依据和手术指导。方法：选取538例研究对象的上颌窦CBCT影像资料,其中上颌后牙区缺失牙与不缺牙组各269例,分别按照性别、年龄分组。将所有数据导入In-VivoDental软件中,通过三维重建,测量记录上颌底壁分隔的发生率,位置,高度,方向及形态学变化,采用SPSS18．0软件包对数据进行统计学分析。结果：538例研究对象中,89例有窦分隔,发生率16．54％;29例出现多个窦分隔（5．39％）,25例双侧同时出现分隔（4．64％）;在测得的1076个上颌窦中,116个出现窦分隔,发生率为10．78％;男性中年不缺牙组的窦分隔出现率最高;原发性分隔出现率远远超出继发性分隔出现率;窦分隔的发生与性别、年龄及牙缺失无关。窦分隔主要出现在上颌窦中部,占51．720／0;平均高度左侧为（6．17±3．35）mm,右侧为（6．50±4．22）mm,平均长度右侧为（10．87±2．96）mm,左侧为（10．05±4．27）mm。结论：北京第二炮兵总医院口腔科2012年7月至2013年10月期间就诊患者成人人群中,16．54％出现窦分隔;上颌窦分隔出现率与缺失牙,不考虑年龄及性别。     

Maxillary sinus septa and anatomical correlation with the dentition type of sinus region: a cone beam computed tomographic study

Maxillary sinus septa increase the risk of membrane perforation during sinus floor elevation and grafting operations. This study was designed to evaluate the prevalence, morphology, localisation, aetiology, and orientation of maxillary sinus septa in dentate, completely edentulous, and partially edentulous sinus regions using cone beam computed tomography (CBCT), and possible patient-related factors were also assessed. Data from 300 patients (600 sinuses), 160 women and 140 men, with a mean (SD) age of 50.72 (13.99) years (range 20–83), who were undergoing treatment planning for implant-supported restorations in posterior maxillae, were analysed from reformatted CBCT scans. Sinus septa were detected in 132 (44%) patients. A total of 208 septa were found, and 187 (31.17%) single maxillary sinuses presented septa in 600 sinuses. Unilateral septa were found in 77 patients (58.3%) and bilateral septa in 55 patients (41.7%). Out of the 208 septa, 42 (20.19%) were in the anterior third, 124 (59.62%) were in the middle third, and 42 (20.19%) were in the posterior third. Further, 106 (50.96%) septa were in completely edentulous regions, 64 (30.77%) were in partially edentulous regions, and 38 (18.27%) were in dentate regions. The prevalence of septa was significantly higher in the middle third area of the completely edentulous sinus regions. The mean (SD) height of septa was 6.34 (3.05) mm, and the mean orientation was buccopalatal in 204 patients (98.08%). Maxillary sinus septa are common anatomical structures. To avoid possible complications during sinus augmentation, a detailed radiographic identification of anatomical structures in maxillary sinuses is needed.     

Location of posterior superior alveolar artery and evaluation of maxillary sinus anatomy with computerized tomography: a clinical study

Objectives: Knowledge and evaluation of the maxillary sinus anatomy before sinus augmentation are essential for avoiding surgical complications. Posterior superior alveolar artery (PSAA) is the branch of maxillary artery that supplies lateral sinus wall and overlying membrane. The aims of this study were to examine the prevalence, diameter, and location of the PSAA and its relationship to the alveolar ridge and to study the prevalence of the sinus pathology and septum using computerized tomography (CT) scans. Materials and methods: One hundred and twenty‐one CT scans (242 sinuses) from patients undergoing sinus augmentation procedure and/or implant therapy were included. Lower border of the artery to the alveolar crest, bone height below the sinus floor to the ridge crest, distance of the artery to the medial sinus wall, diameter of the artery, and position of the artery were measured; presence of septa and pathology were recorded from CT sections. Results: Prevalence of sinus septa and sinus pathology was 16.1% and 24.8%, respectively. Artery was seen in 64.5% of all sinuses and was mostly intraosseous (68.2%). Mean diameter of PSAA was found 1.3 ± 0.5 mm. No significant correlation between the diameter of the artery and age was observed. Conclusions: The results from this study suggested that CT scan is a valuable tool in evaluating presence of sinus pathology, septa, and arteries before maxillary sinus surgery. Although variations exist in every patient, the findings from this study suggest limiting the superior border of the lateral window up to 18 mm from the ridge to avoid any potential vascular damage. To cite this article:
Güncü GN, Yildirim YD, Wang H‐L, Tözüm TF. Location of posterior superior alveolar artery and evaluation of maxillary sinus anatomy with computerized tomography: a clinical study.
Clin. Oral Impl. Res. 22 , 2011; 1164–1167.
doi: 10.1111/j.1600‐0501.2010.02071.x     

Complications of total temporomandibular joint replacement: a systematic review and meta-analysis

The aim of this systematic review was to determine the most prevalent complications resulting from total temporomandibular joint (TMJ) replacement. An electronic search was performed using the Embase, LILACS, MEDLINE (via PubMed), SciELO, Scopus, and Web of Science databases up to June 2022. Prospective and retrospective clinical studies on patients who underwent TMJ replacement were included. Two reviewers performed the study selection, data extraction, and individual risk of bias assessment using the Joanna Briggs Institute Critical Appraisal Tools. The pooled prevalence of each complication was calculated through a proportion meta-analysis using the random-effects model. Twenty-eight studies met the eligibility criteria and were included in the review. All of the eligible studies had a low risk of bias. The results of the meta-analysis revealed that the most prevalent complication was paresis or paralysis of the facial nerve branches (7.8%; 95% confidence interval (CI) 2.6–15.1%, I² = 94.5%), followed by sensory alterations (1.8%; 95% CI 0.6–4.9%, I² = 88.8%), heterotopic bone formation (1.0%; 95% CI 0.1–2.5%, I² = 75.8%), and infection (0.7%; 95% CI 0.1–1.6%, I² = 22.7%). In conclusion, TMJ replacement has a low prevalence of complications, and most of them can be managed successfully.     

A retrospective analysis of maxillary sinus septa on reformatted computerised tomography scans

Objectives: This study analysed 200 consecutive computerised tomography (CT) scans, reformatted with specialised software for the identification of maxillary sinus septa. All patients were routine implant patients who had undergone CT scans for dental implant planning.
Materials and methods: The data of two hundred consecutive patients (400 maxillary sinuses) who had been sent for CT scan, were reformatted with CT software. The group consisted of 115 edentulous and 85 dentate (below sinuses) patients. Septa were identified using three-dimensional (3D) reconstruction and panoramic views. No septa were included unless they were clearly visible on the 3D reconstruction. The prevalence, height and number of septa were analysed for both groups of patients.
Results: The prevalence of sinus septa was found to be 69% (138 patients), with a significant number of these patients showing multiple septa (89/138). The mean age of the patients was 54 (±14). The prevalence of edentulous patients with septa (71%) was not statistically different from the dentate patients (66%) ( P =0.7).
Discussion: This study found a higher prevalence of patients with maxillary sinus septa than what has been reported previously. This may be due to the exact nature of the CT software and the ease of use of the 3D reconstruction for identification of septa. Another explanation could be that all septa that were visible on the 3D reconstruction were included and there was no minimum cut-off height. No significant differences were found between edentulous and dentate patients.     

Assessment of Maxillary Sinus Septa Using Cone-Beam Computed Tomography: Etiological Consideration

Background: Septum presence in the maxillary sinus complicates sinus floor elevation surgery, and so it is important that septa are accurately diagnosed on preoperative imaging.
Purpose: Septa were observed regarding their relationship with the bony palate using cone-beam computed tomography (CT).
Materials and Methods: Thirty maxillary sinuses with dentate jaws of 15 dry skulls and a cone-beam CT unit were used. A septum was defined as a pointed bone structure, and an exostosis was defined as a rounded bone structure. The occurrence and locations of maxillary sinus septa and exostoses of more than 2 mm in height were evaluated. Also, angles between the direction of septum and median palatine suture were measured on axial images.
Results: Twelve septa of 11 maxillary sinuses (37%) and nine exostoses of nine maxillary sinuses (30%) were observed. Also, 42% of septa and 67% of exostoses were antero-posteriorly aligned according to the transverse palatine suture. Moreover, the mean septum angle was 57.9 degrees in the anterior maxillary sinus region, and 101.8 degrees in the transverse palatine suture region, and significant differences were noted between them.
Conclusion: Maxillary sinus septa and exostoses could be clarified regarding their relationship with the bony palate using cone-beam CT.     

上颌磨牙缺失患者上颌窦的CBCT影像学特点

目的 :观察上颌磨牙缺失患者上颌窦生理及病理CBCT影像学表现,并分析各类异常的发生率,为种植术前评估提供参考。方法:选择复旦大学附属中山医院口腔科及静安区牙病防治所,2014-01-01—2015-05-01期间,收治的上颌磨牙缺失患者CBCT影像学资料202例,共404侧上颌窦。由2名研究人员对资料进行研究分析,观察项目分为3类:正常上颌窦、上颌窦炎、上颌窦囊肿。测量3种类型病例缺牙区窦嵴距、上颌窦的宽度、外侧骨壁厚度、外侧骨壁血管位置与直径,采用SPSS17.0软件进行统计分析。结果:404侧上颌窦中,正常上颌窦185侧(45.80%);上颌窦炎118侧(29.20%);上颌窦囊肿101侧(25.00%)。结论:上颌窦异常影像诊断发生率最高者为上颌窦炎,其次为上颌窦囊肿;不同上颌窦影像诊断类型间窦嵴距、上颌窦的宽度、外侧骨壁厚度、外侧骨壁血管位置与直径差异均无统计学意义(P>0.05)。     

Detection of the Accessory Mental Foramina on Human Mandibles Using Cone-beam Computed Tomography: A Systematic Review and Meta-analysis

IntroductionThis study aimed to perform a systematic review and meta-analysis on accessory mental foramen (AMF) research using cone-beam computed tomographic (CBCT) imaging.MethodsA systematic review was performed in PubMed, Embase, Thomas Reuter's Web of Science, Scopus, and ScienceDirect databases according to the Preferred Reporting Items for Systematic Reviews and Meta-analysis statement. Articles focusing on AMF prevalence and location using CBCT imaging were selected without language restrictions. Studies reporting pooled results only or presenting any pathology in the area surrounding the mental foramen (MF) were excluded. A meta-analysis using random effects was performed.ResultsThe present meta-analysis included a total of 46 articles involving 21,761 subjects. The overall pooled AMF prevalence was 7.87% (95% confidence interval [CI], 6.69–9.24) in subjects and 4.75% (95% CI, 3.79–5.95) in hemimandibles (n = 31,158). AMF presence was most commonly unilateral, reaching 90.15% (95% CI, 82.98–94.49). AMFs were significantly more frequent in right hemimandibles (χ² = 5.20, P < .05) and were most commonly located posterior and inferior to the MF. However, AMFs superior to the MF were also observed in 47.43% (95% CI, 38.45-56.58) of cases. The studies conducted over the last 3 years showed significantly higher AMF prevalence levels (χ² = 5.12, P < .05).ConclusionsOur meta-analysis demonstrates that AMF prevalence is considerable and should not be underestimated. AMFs are most frequently located in right hemimandibles. The presence of AMFs superior to the MF is frequent. Around 3% of people present superior AMFs. This fact puts those patients at greater risk for injury when performing periapical surgery in this area.     

Prevalence and location of maxillary sinus septa in the Taiwanese population and relationship to the absence of molars

Objectives: Understanding the septum structure of the sinus is necessary for correct implant placement in the maxilla if sinus encroachment is required. The exact mechanism that controls septum development is unclear, although a role for the irregular pneumatization of the sinus floor following tooth loss has been suggested. The aims of this study were to examine the prevalence and location of sinus septa in the Taiwanese population and to determine whether there is a relationship between the presence of septa and the absence of molars. Materials and methods: Using computed tomography (CT) scans of sinuses obtained from 423 subjects (216 women and 207 men, mean age 53.65 years), septum morphology and its correlation with the presence of molars was examined. Results: About 30% of subjects (124/423) had sinus septa, corresponding to 20.45% of all sinus segments detected (173/846). Fifty‐nine patients had multiple septa, giving a prevalence of septa of 22.93%. Septa were located most frequently in the regions of the first and second molars. The prevalence was not related to tooth loss (edentulous, partially edentulous, or dentate maxillary segments). Logistic regression analysis showed that men were significantly more likely to have septa than were women (OR=1.67; P=0.019). Conclusions: In the 423 Taiwanese subjects tested, the prevalence of septum was 29.31% according to the subjects and 22.93% according to the sinus segments. The most frequent location of septa was in the region of the first and secondary molars. No correlation was observed between the presence of septa and the absence of molars.     

Anatomical characteristics of maxillary sinus septa visualized by cone beam computed tomography

Proper implant positioning in the posterior region of the edentulous maxilla commonly requires sinus floor elevation. Maxillary sinus septa increase the risk of membrane perforation during sinus floor elevation. The purpose of this retrospective, cone beam computed tomography (CBCT)-based study was to examine the frequency, number, location, and orientation of antral septa in the maxillary sinus. Further, possible associated factors were assessed. Measurements were performed on CBCT scans of 301 patients (602 sinuses). The data were analysed statistically with respect to patient age, sex, and dentition type. One or more septa were detected in 117 patients (38.9%). A total of 188 septa were found in the 602 sinuses (31.2%). Septa were most often coronally oriented (53.2%), followed by sagittal (24.5%) and transverse (22.3%) orientations. Septa were most often found in the region of the first and second molar (37.2%), followed by the posterior region of the third molar (33.0%) and the anterior region of the premolars and canines (29.8%). A significant association was found between edentulism and the presence of septa. For edentulous patients, the septa were most often transversally oriented. Maxillary sinus septa are encountered in every third patient. This may have an influence on the performance of sinus floor elevation.     

The prevalence and location of the posterior superior alveolar artery in the maxillary sinus wall: A preliminary computed-cone beam study

The lateral wall of the maxillary sinus is supplied by the posterior superior alveolar artery (PSAA). It may be affected by trauma, pathology, or surgery performed to access or correct any fracture involving the maxillary sinus. This study analysed the prevalence and distance of the PSAA from the floor of the maxillary sinus in selected Southeast Asian patients. Methods: This is a cross sectional study conducted using cone-beam computed tomographic images of 83 dentate patients with a mean age of 38.3 years. Results: One hundred sixty-six maxillary sinuses of 54 males and 29 females were evaluated, with PSAA observed in 91.6 % of sinuses. Of the PSAA identified (n = 152), 64.5 % were intraosseous (n = 98), 25.7 % were beneath the sinus membrane (n = 39), and the remaining 15 (9.9 %) were on the external cortex of the lateral sinus wall. The mean distance between PSAA and the lowest point of the sinus floor was 11.44 mm (SD, 3.36). Sixty-four maxillary sinus walls (38.6 %) presented with 2 PSAA branches. The inferior and superior branches were located 6.42 mm (SD, 2.68) and 8.48 mm (SD, 3.56) from the floor of the maxillary sinus, respectively. The mean difference between these 2 branches was 2.25 mm (SD, 1.90). Conclusion: This study confirms the different locations of the PSAA in relation to the lateral wall of the maxillary sinus with no gender influence. Branching of PSAA occurs, and should be highlighted to surgeons.     

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。     

Volumetric changes of the graft after maxillary sinus floor augmentation with Bio-Oss and autogenous bone in different ratios: a radiographic study in minipigs

Objective: The objective of the present study was to learn about the volumetric changes of the graft after maxillary sinus floor augmentation with Bio‐Oss and autogenous bone from the iliac crest or the mandible in different ratios in minipigs. Material and methods: Bilateral maxillary sinus floor augmentation was performed in 40 minipigs with: (A) 100% autogenous bone, (B) 75% autogenous bone and 25% Bio‐Oss, (C) 50% autogenous bone and 50% Bio‐Oss, (D) 25% autogenous bone and 75% Bio‐Oss, and (E) 100% Bio‐Oss. The autogenous bone graft was harvested from the iliac crest or the mandible and the graft composition was selected at random and placed concomitant with implant placement. Computed tomographies of the maxillary sinuses were obtained preoperatively, immediately postoperatively, and at euthanasia after 12 weeks. The volumetric changes of the graft were estimated using the Cavalieri principle and expressed as mean percentage with a 95% confidence interval (CI). Results: The mean volume of the graft was reduced by (A) 65% (95% CI: 60–70%), (B) 38% (95% CI: 35–41%), (C) 23% (95% CI: 21–25%), (D) 16% (95% CI: 12–21%), and (E) 6% (95% CI: 4–8%). The volumetric reduction was significantly influenced by the ratio of Bio‐Oss and autogenous bone (P<0.001), but not by the origin of the autogenous bone graft (P=0.2). Conclusions: The volume of autogenous bone grafts from the iliac crest and the mandible is reduced significantly after maxillary sinus floor augmentation in minipigs. The graft volume is better preserved after the addition of Bio‐Oss and the volumetric reduction is significantly influenced by the ratio of Bio‐Oss and autogenous bone. However, further studies are needed addressing the amount of new bone formation and bone‐to‐implant contact before the final conclusion can be made about the optimal ratio of Bio‐Oss and autogenous bone. To cite this article:
Jensen T, Schou S, Svendsen PA, Forman JL, Gundersen HJG, Terheyden H, Holmstrup P. Volumetric changes of the graft after maxillary sinus floor augmentation with Bio‐Oss and autogenous bone in different ratios: a radiographic study in minipigs.
Clin. Oral Impl. Res. 23 , 2012; 902–910
doi: 10.1111/j.1600‐0501.2011.02245.x     

Retrospective analysis of maxillary sinus septa – A cone beam computed tomography study

BackgroundSinus lift procedures have become a routine and reliable way to gain bone volume in the posterior maxilla for implant placement. The presence of an antral septum in the maxillary sinus increases the risk of complications and subsequent implant failure. This study was designed to estimate the prevalence of maxillary sinus septa and its correlation with age, sex, dentition status and the risk of perforating the Schneiderian membrane using cone beam computed tomography (CBCT).MethodsThis retrospective, cross-sectional study consisted of a total of 178 CBCT images (100 male, 78 female), 63.0% were dentate, 36.0% partially dentate and 1.1% edentate subjects with a mean age of 35 ± 45 years was analyzed to determine the prevalence, height, location, and orientation of maxillary sinus septa. The septa were classified according to the modified Al-Faraje’s classification into VII septal patterns, and the risk of perforation of the Schneiderian membrane was estimated. The chi-square test was used to compare categorical variables, and Student’s t-test and the Kruskal-Wallis test were used to compare continuous variables.ResultsSepta were present in 25.6% of the sinus segments (37.64% of the subjects). The mean septum height was 5.22 mm ± 2.06 in males and 6.27 mm ± 3.55 in females. The majority of septa were located in the middle 76.92%, while 4.40% were anterior, and 18.68% were posterior; 76.92% were in a buccopalatal direction, whereas 23.08% were in an anteroposterior direction. Class III was the most prevalent type. Overall, 60.4% had a moderate risk of membrane perforation, 30.8% had a low risk, and only 8.8% had a high risk.ConclusionThree-dimensional CBCT image analyses can be used as a diagnostic tool to provide accurate information that can help avoid unnecessary intra- and postoperative complications during sinus augmentation procedures by identifying the anatomic structures inherent to the maxillary sinus.     

Resolution of maxillary sinus mucositis after endodontic treatment of maxillary teeth with apical periodontitis: a cone-beam computed tomography pilot study

Introduction

Apical periodontitis (AP) is an inflammatory response that can affect the maxillary sinus. This study characterized maxillary sinus mucositis adjacent to teeth with AP and assessed its resolution after endodontic treatment.

Methods

Thirty maxillary sinuses in subjects (n = 29) who had AP associated with maxillary posterior teeth were imaged with cone-beam computed tomography (CBCT). When mucositis was detected, its resolution was assessed with CBCT scanning 3 months after treatment, and periapical healing was assessed using the periapical index (PAI) after 6 months.

Results

Excluding 5 sinuses obscured by sinusitis, mucositis was detected in 14 of 25 sinuses (56%). Nonsignificant inverse association was observed between the mucosal lining thickness and the distance from the sinus to root apices with AP. Four noncompliant subjects were discontinued. Three months after treatment, mucositis was fully resolved in 3 of 10 subjects (30%), partially resolved in 3 of 10 subjects (30%), unchanged in 3 of 10 subjects (30%), and worsened in 1 subject (10%). Six months after treatment, 6 of 10 subjects (60%) had reduced PAI scores classified as healed or healing. The subject with expanded mucositis at 3 months was not healing at 6 months.

Conclusions

Within the limited sample of this pilot study, CBCT imaging revealed a lower-than-expected prevalence of mucositis adjacent to teeth with AP. Fully resolved mucositis was not common 3 months after endodontic treatment, suggesting that in specific cases it might linger beyond 3 months after the elimination of the endodontic infection. Because of the low statistical power, the association between the resolution of mucositis and periapical healing could not be explored.     

Relationship among Schneiderian Membrane,Underwood's Septa,and the Maxillary Sinus Inferior Border

Background: Osseo‐integrated implants are increasingly being used to restore functional dentition; however, in the posterior region, implant placement can be problematic because of inadequate bone height. In this condition, maxillary sinus floor elevation surgery has become the treatment of choice. The presence of anatomic variations within the maxillary sinus such as Underwood's septa and thin schneiderian membrane decreases the success of the sinus floor elevation. Purpose: In this study, we tried to determine the relationship between the anatomic variations of the maxillary sinus: Underwood's septa, schneiderian membrane thickness, and the cortical thickness of the inferior border of the maxillary sinus. Material and Methods: The left and right maxillary sinus images of 74 patients were obtained by using dental computed tomography (CT). The schneiderian membrane and the cortical thickness of the inferior border of the maxillary sinus were measured on the coronal images of dental CT scans at the deepest portion of the sinus cavity. The presence of Underwood's septa was identified on the axial images. The correlations between these variables were assessed. Results: We found that there was only a negative correlation between the schneiderian membrane thickness and the presence of Underwood's septa (r = –0.168 p = .042). Conclusion: It is suggested that Underwood's septa may be the reason for the thinness of the schneiderian membrane. However, future studies among larger groups are necessary for confirming the finding by using well‐designed clinical studies.     

CBCT对上颌后牙游离缺失患者的上颌窦底壁骨分嵴分布的评估

目的评估上颌后牙游离缺失患者上颌窦底壁骨分嵴的分布情况。方法纳入2011年1月至2013年12月在四川省人民医院就诊的上颌后牙游离缺失患者,对其CBCT资料进行统计分析,评估在上颌后牙游离缺失情况下上颌窦底壁骨分嵴的分布情况。结果符合纳入标准的患者共计253例(男132例,女121例),上颌窦共计289个。骨分嵴的检出率约为26.09%,其中上颌前磨牙区12例(18.18%),显著高于低于磨牙区54例(81.82%),骨分嵴的平均高度为(3.87±1.10)mm,不同年龄和性别差异无统计学意义。骨分嵴走向分布中颊腭向为59个(89.39%),近远中向为7个(10.61%)。结论上颌窦底壁骨分嵴发生率高,走向复杂,拟行上颌窦提升手术前对上颌窦底骨分嵴进行评估是必不可少的,CBCT不失为评估上颌窦底骨分嵴的好方法。     

上颌窦气化及其相关解剖特征的锥形束CT分析

目的    应用锥形束CT（cone beam computed tomography,CBCT）分析上颌窦不同气化分型的发生率及相关解剖特征的差异性。方法    选择2020年1—6月就诊于南昌大学附属口腔医院并拍摄CBCT影像患者200例,对其CBCT图像进行重建分析。依据上颌窦底与上颌后牙的位置关系将上颌窦气化类型分为正常气化和过度气化,统计各分型的发生率。根据上颌窦气化程度,将纳入研究的上颌窦分为正常气化组和过度气化组,评估每组以下与上颌窦气化相关解剖学特征：上颌窦气化度（amount of maxillary sinus pneumatization,MSPA）;牙槽骨高度（height of alveolar bone,BH）;上颌窦外侧骨壁厚度（maxillary sinus lateral wall thickness,LWT）;上颌窦间隔（maxillary sinus septa,SS）;上颌窦副口（accessory maxillary ostia,AMO）;上颌窦口直径（diameter of the ostium,OD）。结果    因7侧上颌窦存在明显炎症而被排除,最终纳入研究的是200例患者的393侧上颌窦。200例患者的上颌窦正常气化发生率为50.0%（100/200）,共发生于163侧上颌窦中（41.5%）;过度气化发生率为67.0%（134/200）,共发生于230侧上颌窦中（58.5%）。MSPA、BH、LWT在过度气化组中分别为（5.48 ± 2.36）、（5.10 ± 1.62）、（1.80 ± 0.75）mm,在正常气化组中分别为（-0.07 ± 4.07）、（11.12 ± 3.76）、（2.80 ± 1.51）mm,组间差异有统计学意义（P < 0.05）;过度气化组的SS、AMO发生率分别为48.26%和18.26%,而正常气化组发生率分别为11.04%和4.29%,组间差异有统计学意义（P < 0.05）;OD在两组间的差异无统计学意义（P > 0.05）。结论    上颌窦过度气化的发生率较高,这类气化现象会导致MSPA的增加、LWT和BH的降低,更易出现SS、AMO,提醒口腔医生在上颌后牙区种植手术前和正畸加力过程中应关注上颌窦的气化程度及其相关的解剖特征,防止并发症的发生。