Using cone beam computed tomography to determine safe regions for implant placement

This study sought to identify and follow the course of the incisive canal in the mental interforaminal region of the human mandible and to describe other anatomical landmarks present in this region. Cone beam computerized tomography (CBCT) studies for 40 patients were collected from the database at the Department of Oral & Maxillofacial Radiology, School of Dentistry, Lebanese University. Ten patients had edentulous mandibles; the other 30 had partially or completely dentate mandibles. Axial native images and panoramic and cross-sectional reconstructions were examined to assess the anatomical landmarks in the anterior mandible. Multiple neurovascular canals and foramina were clearly detected on CBCT studies of the mandible. Numerous foramina were seen on the internal surface of the mandible, even distant from the midline. The incisive canal was identified in 97.5% of the images. These anatomical landmarks should be evaluated carefully during preoperative planning.     

Influence of maxillomandibular positioning in cone beam computed tomography for implant planning

The aim of this study was to evaluate the influence of changes in maxillomandibular positioning during cone beam computed tomography (CBCT) imaging on the planning of dental implants. Ten skulls were marked bilaterally with metal spheres in four regions: incisors, canine, premolars, and molars. CBCT scans were obtained in seven positions: standard position (SP), displacements of 10° and 20° above and below the SP, and lateral displacements of 10° and 20° from the SP. Subsequently, bilateral measurements of the height and width of the maxilla and mandible were performed on all images. The results showed that the position with a displacement of 20° above the SP presented the greatest differences in the measurements of bone height and width. In the bilateral comparisons, the maxillary bone width showed the greatest differences, especially for the regions of the premolars and molars. It is concluded that alterations of positioning during the acquisition of CBCT images can lead to alterations in the measurements of bone height and width, which may result in errors in implant planning and cause damage to anatomical structures.     

Dental cone beam computed tomography analyses of postoperative labial bone thickness in maxillary anterior implants: comparing immediate and delayed implant placement

This study aimed to evaluate the influence of labial alveolar bone thickness and the corresponding vertical bone loss on postoperative gingival recessions around anterior maxillary dental implants. Using cone beam computed tomography (CBCT) scanning, the temporal changes of three-dimensional images of alveolar bone were monitored to determine hard and soft tissue outcomes of two different implant placement techniques: delayed two-stage and immediate placement. Furthermore, for the delayed two-stage placement, guided bone regeneration was applied using either nonresorbable or resorbable membranes combined with anorganic bovine bone matrix. The comparative results suggested that gingival recessions were significantly lower in delayed two-stage placement, especially when using a nonresorbable membrane, compared to immediate placement, and labial bone thickness, measured by CBCT, offered an effectual indicator to assess gingival recession in the anterior region.     

Registration accuracy of three-dimensional surface and cone beam computed tomography data for virtual implant planning

Objective: Virtual wax‐ups based on three‐dimensional (3D) surface models can be matched (i.e. registered) to cone beam computed tomography (CBCT) data of the same patient for dental implant planning. Thereby, implant planning software can visualize anatomical and prosthetic information simultaneously. The aim of this study is to assess the accuracy of a newly developed registration process. Material and methods: Data pairs of CBCT and 3D surface data of 16 patients for dental implant planning were registered and the discrepancy between the visualized 3D surface data and the corresponding CBCT data were measured on 64 teeth at seven points by two investigators in two iterations with a total of 1792 measurements. Results: All data pairs were matched successfully and mean distances between CBCT and 3D surface data were between 0.03(±0.33) and 0.14(±0.18) mm. At two of seven measuring points, statistically significant correlations were determined between the measured error and the presence and type of restorations. Registration errors in maxilla and mandible were not statistically significantly different. Conclusion: According to the results of this study, registration of 3D surface data and CBCT data works reliably and is sufficiently accurate for dental implant planning. Thereby, barium‐sulfate scanning templates can be avoided and dental implant planning can be accomplished fully virtual. To cite this article:
Ritter L, Reiz SD, Rothamel D, Dreiseidler T, Karapetian V, Scheer M, Zöller JE. Registration accuracy of three‐dimensional surface and cone beam computed tomography data for virtual implant planning.
Clin. Oral Impl. Res. 23 , 2012 447–452.
doi: 10.1111/j.1600‐0501.2011.02159.x     

State-of-the-art on cone beam CT imaging for preoperative planning of implant placement

Orofacial diagnostic imaging has grown dramatically in recent years. As the use of endosseous implants has revolutionized oral rehabilitation, a specialized technique has become available for the preoperative planning of oral implant placement: cone beam computed tomography (CT). This imaging technology provides 3D and cross-sectional views of the jaws. It is obvious that this hardware is not in the same class as CT machines in cost, size, weight, complexity, and radiation dose. It is thus considered to be the examination of choice when making a risk–benefit assessment. The present review deals with imaging modalities available for preoperative planning purposes with a specific focus on the use of the cone beam CT and software for planning of oral implant surgery. It is apparent that cone beam CT is the medium of the future, thus, many changes will be performed to improve these. Any adaptation of the future systems should go hand in hand with a further dose optimalization.     

Horizontal alteration of anterior alveolar ridge after immediate implant placement: A retrospective cone beam computed tomography analysis

PURPOSEThe aim of this study was to evaluate the labio-lingual alterations of the alveolar bone where the implant was placed immediately after tooth extraction.MATERIALS AND METHODSImplants were placed immediately after tooth extraction on anterior alveolar ridges in the maxilla and mandible. The pin-guide system was used to help determine the location and path of implants during the surgical process. The horizontal distance from implants to the outer border of alveolar bone was measured at the rim and middle of the implants in the cone beam computed tomography images. The alteration of alveolar bone was evaluated comparing the horizontal distances measured immediately after surgery and 3 months after surgery.RESULTSThe results show that more resorption occurred towards the labial bone than the lingual bone in the maxilla. A similar amount of labial and lingual bone resorption was observed in the mandible.CONCLUSIONConsidering the horizontal alteration of alveolar bone, labio-lingual positioning of the implant towards the lingual bone in the maxilla and at the center of the alveolar ridge in the mandible is recommended when it is placed immediately after tooth extraction.     

Application of cone beam computed tomography in oral and maxillofacial surgery

In the past decade, the utility of cone beam computed tomography (CBCT) images in oral and maxillofacial surgery has seen continuous increase. However, CBCT images are not always able to replace other imaging modalities. Based on the current published knowledge, this paper discusses advantages and limitations of CBCT images in the diagnosis and surgical planning of dentoalveolar procedures, odontogenic cysts, benign and malignant tumours, inflammatory changes, orthognathic surgery, maxillofacial trauma, sinus disorders, and systemic and osseous conditions that manifest in the maxillofacial area. This paper also suggests alternative imaging modalities when CBCT images are not adequate for surgical planning.     

Applications of cone beam computed tomography in dental and oral medicine

Cone beam computed tomography (CBCT) is a radiological technique available since 1998 in dental and oral medicine in which a cylindrical volume is acquired with a conical x-ray beam during one rotation around the head of the patient (cone beam computed tomography, cone beam CT). This technique is increasingly replacing conventional radiological procedures due to the possibility of arbitrary reconstructions and views free of superimposition. CBCT focuses on the display of the bones of the jaw, so that its use concentrates on problems in implantology, before surgical removal of impacted and displaced teeth, in traumatology, and in craniofacial malformations. The objective of this overview was to emphasize the advantages of cone beam computed tomography in the individual disciplines. However, schematization of examinations should be avoided for reasons of radiation protection and for avoiding forensic pressure. The limits of CBCT and thus an indication for computed tomography exist where there is suspicion of bone tumors with soft tissue participation as well as in extensive fractures with suspicion of craniocerebral trauma. In the case of tumors in the soft tissues and of functional temporomandibular joint symptoms, magnetic resonance tomography is preferable to CBCT.     

Texture analysis of cone beam computed tomography images reveals dental implant stability

The aim of this study was to characterize the alveolar bone of edentulous maxillary sites using texture analysis (TA) of cone beam computed tomography (CBCT) images and to correlate the results to the insertion torque, thus verifying whether TA is a predictive tool of final implant treatment. This study was conducted on patients who had received single implants in the maxilla (46 implants) 1 year earlier and whose torque values were properly recorded. Three cross-sections of the sites were selected on CBCT scans. Two regions of interest (ROIs) corresponding to the implant bone site and peri-implant bone were also outlined, according to virtual planning. The CBCT scans were exported to MaZda software, where the two ROIs were delimited following the previously demarcated contours. Values for the co-occurrence matrix were calculated for TA. With regard to the insertion torque value, there was a direct correlation with the contrast of the peri-implant bone (P < 0.001) and an inverse correlation with the entropy of the implant bone site (P = 0.006). A greater contrast indicates a greater torque value for insertion of the implants, and there is a possible association with a lower entropy value of the implant–bone interface.     

锥形束CT的特点及其在正畸专业中的应用

在正畸治疗中,X线检查对明确患者的错袷类型、制定错[牙合]畸形患者的矫治计划等具有重要的价值。长期以来,医生使用的曲面断层片和头颅侧位片,均为二维影像,且存在着重叠、图像放大等缺点。传统的扇形CT,因其占地面积大、设备价格高、操作复杂、射线量大、费用昂贵等因素,无法成为正畸患者常规的检查方法。近年来,随着锥形束CT（CBCT）的引入,对正畸患者的诊断和治疗,以及在医患沟通方面均带来了很大的帮助。本文就CBCT的起源和技术特点及其在正畸专业中的应用作一综述。     

应用锥形束CT评估腭部种植体的植入部位

Objective To investigate the vertical bone height and the bone density of the palate for implants placement using cone beam CT(CBCT)and to provide references to the safe and stable placement of palatal implants.Methods Three-dimensional reformatting images were reconstructed with the selected CBCT scanning data of 34 patients aged 18 to 35 yeras,by means of EZ implant software.The vertical bone height was measured at 20 interesting sites of palate.Bone density was measured at 10 sites that could support 3.0mm long implants.The data of the vertical bone height and bone density were analyzed by Kmeans cluster analysis.Results According to the cluster analysis results,the 10 sites were classified into 3 clusters.There were statistical differences among these three clusters in bone height and bone density(P＜0.05).The ISD result showed that the greatest mean value of vertical bone height was obtained in cluster 2,followed by cluster 1 and cluster 3;the highest bone density was founded in cluster 3,followed by cluster 1 and cluster 2.Conclusions Evaluation of the sites for palatal implant placement with cone beam CT would be helpful in safe and stable implantation.     

应用锥形束CT评估腭部种植体的植入部位

目的 对腭部种植体支抗植入部位的骨厚度和骨密度进行定量研究,为临床安全、稳定地植入腭部种植体提供参考依据.方法 测量34例正畸患者(18～35岁)腭部20个兴趣区的骨厚度、种植体可植入率高的10个部位的骨密度,将34例患者的头颅锥形束CT扫描数据导入EZ种植分析软件获得三维重建图像,以骨厚度、骨密度为指标的数据进行K均值聚类分析.结果 将可植入率高的10个部位分为3类(Ⅰ～Ⅲ类),骨厚度:Ⅱ类(8.3±0.4 mm)>Ⅰ类(6.2±0.5 mm)、Ⅲ类(5.4±0.4 mm);骨密度:Ⅲ类(638.6±42.5 HU)>Ⅰ类(514.6±63.6 HU)>Ⅱ类(414.8±11.1 HU):3类骨厚度、骨密度比较,差异有统计学意义(P<0.05).结论 应用锥形束CT评估腭部种植体支抗的植入部位,在一定程度上有助于种植体安全、稳定.     

应用锥形束CT评估腭部种植体的植入部位

Objective To investigate the vertical bone height and the bone density of the palate for implants placement using cone beam CT(CBCT)and to provide references to the safe and stable placement of palatal implants.Methods Three-dimensional reformatting images were reconstructed with the selected CBCT scanning data of 34 patients aged 18 to 35 yeras,by means of EZ implant software.The vertical bone height was measured at 20 interesting sites of palate.Bone density was measured at 10 sites that could support 3.0mm long implants.The data of the vertical bone height and bone density were analyzed by Kmeans cluster analysis.Results According to the cluster analysis results,the 10 sites were classified into 3 clusters.There were statistical differences among these three clusters in bone height and bone density(P＜0.05).The ISD result showed that the greatest mean value of vertical bone height was obtained in cluster 2,followed by cluster 1 and cluster 3;the highest bone density was founded in cluster 3,followed by cluster 1 and cluster 2.Conclusions Evaluation of the sites for palatal implant placement with cone beam CT would be helpful in safe and stable implantation.     

应用锥形束CT评估腭部种植体的植入部位

Objective To investigate the vertical bone height and the bone density of the palate for implants placement using cone beam CT(CBCT)and to provide references to the safe and stable placement of palatal implants.Methods Three-dimensional reformatting images were reconstructed with the selected CBCT scanning data of 34 patients aged 18 to 35 yeras,by means of EZ implant software.The vertical bone height was measured at 20 interesting sites of palate.Bone density was measured at 10 sites that could support 3.0mm long implants.The data of the vertical bone height and bone density were analyzed by Kmeans cluster analysis.Results According to the cluster analysis results,the 10 sites were classified into 3 clusters.There were statistical differences among these three clusters in bone height and bone density(P＜0.05).The ISD result showed that the greatest mean value of vertical bone height was obtained in cluster 2,followed by cluster 1 and cluster 3;the highest bone density was founded in cluster 3,followed by cluster 1 and cluster 2.Conclusions Evaluation of the sites for palatal implant placement with cone beam CT would be helpful in safe and stable implantation.     

应用锥形束CT评估腭部种植体的植入部位

Objective To investigate the vertical bone height and the bone density of the palate for implants placement using cone beam CT(CBCT)and to provide references to the safe and stable placement of palatal implants.Methods Three-dimensional reformatting images were reconstructed with the selected CBCT scanning data of 34 patients aged 18 to 35 yeras,by means of EZ implant software.The vertical bone height was measured at 20 interesting sites of palate.Bone density was measured at 10 sites that could support 3.0mm long implants.The data of the vertical bone height and bone density were analyzed by Kmeans cluster analysis.Results According to the cluster analysis results,the 10 sites were classified into 3 clusters.There were statistical differences among these three clusters in bone height and bone density(P＜0.05).The ISD result showed that the greatest mean value of vertical bone height was obtained in cluster 2,followed by cluster 1 and cluster 3;the highest bone density was founded in cluster 3,followed by cluster 1 and cluster 2.Conclusions Evaluation of the sites for palatal implant placement with cone beam CT would be helpful in safe and stable implantation.     

应用锥形束CT评估腭部种植体的植入部位

Objective To investigate the vertical bone height and the bone density of the palate for implants placement using cone beam CT(CBCT)and to provide references to the safe and stable placement of palatal implants.Methods Three-dimensional reformatting images were reconstructed with the selected CBCT scanning data of 34 patients aged 18 to 35 yeras,by means of EZ implant software.The vertical bone height was measured at 20 interesting sites of palate.Bone density was measured at 10 sites that could support 3.0mm long implants.The data of the vertical bone height and bone density were analyzed by Kmeans cluster analysis.Results According to the cluster analysis results,the 10 sites were classified into 3 clusters.There were statistical differences among these three clusters in bone height and bone density(P＜0.05).The ISD result showed that the greatest mean value of vertical bone height was obtained in cluster 2,followed by cluster 1 and cluster 3;the highest bone density was founded in cluster 3,followed by cluster 1 and cluster 2.Conclusions Evaluation of the sites for palatal implant placement with cone beam CT would be helpful in safe and stable implantation.     

The use of cone beam computed tomography as an aid in evaluating and treatment planning for mandibular cancer.

PURPOSE: The workup for oral malignancy involving the mandible typically involves a head and neck exam, laboratory studies, a panoramic radiograph, and computed tomography (CT) or magnetic resonance imaging of the head and neck to evaluate the primary lesion and cervical lymph nodes. Panoramic plain film radiography of the mandible is often unreliable for detecting bony invasion; therefore, other imaging studies are necessary before staging is complete. Bony invasion is typically imaged with the use of conventional CT scanners. In this article we relate the use of cone beam computed tomography (CBCT) to image the mandible with less cost and morbidity to the patient and its use in the evaluation and treatment planning of mandibular cancer. MATERIALS AND METHODS: A retrospective review of 3 patients with mandibular malignancies was performed. All patients had a panoramic radiograph, magnetic resonance imaging, and chest radiograph, in addition to laboratory studies. CBCT scans were ordered, after bony involvement was suspected, and compared with the other imaging studies. RESULTS: Two patients with squamous cell carcinoma of anterior mandible and 1 patient with osteogenic sarcoma were reviewed. In all cases CBCT aided the evaluation of the mandible. The cone beam panoramic view, as part of the CBCT, was used to determine extent of resection. CONCLUSION: CBCT can accurately aid in evaluating and treatment planning for malignant tumors of the mandible with less cost and decreased radiation to the patient relative to conventional CT.