Dental Implant Treatment Planning Research Articles

Deep learning for the identification of ridge deficiency around dental implants.

This study aimed to use a deep learning (DL) approach for the automatic identification of the ridge deficiency around dental implants based on an image slice from cone-beam computerized tomography (CBCT). Single slices crossing the central long-axis of 630 mandibular and 845 maxillary virtually placed implants (4-5 mm diameter, 10 mm length) in 412 patients were used. The ridges were classified based on the intraoral bone-implant support and sinus floor location. The slices were either preprocessed by alveolar ridge homogenizing prior to DL (preprocessed) or left unpreprocessed. A convolutional neural network with ResNet-50 architecture was employed for DL. The model achieved an accuracy of >98.5% on the unpreprocessed image slices and was found to be superior to the accuracy observed on the preprocessed slices. On the mandible, model accuracy was 98.91 ± 1.45%, and F1 score, a measure of a model's accuracy in binary classification tasks, was lowest (97.30%) on the ridge with a combined horizontal-vertical defect. On the maxilla, model accuracy was 98.82 ± 1.11%, and the ridge presenting an implant collar-sinus floor distance of 5-10 mm with a dehiscence defect had the lowest F1 score (95.86%). To achieve >90% model accuracy, ≥441 mandibular slices or ≥592 maxillary slices were required. The ridge deficiency around dental implants can be identified using DL from CBCT image slices without the need for preprocessed homogenization. The model will be further strengthened by implementing more clinical expertise in dental implant treatment planning and incorporating multiple slices to classify 3-dimensional implant-ridge relationships.

Newly Developed Low Dose 180-degree CBCT Protocol Reduces Radiation Dose Without Compromising Diagnostic Value.

To compare the standard 360-degree CBCT acquisition protocol to the low dose 180-degree CBCT protocol for implant planning. Two groups of patients, each consisting of 35 patients, were included in the study. The first group was imaged with the conventional 360-degree CBCT protocol, and the second group was imaged with the low dose 180-degree CBCT protocol. The primary outcome of this study was the number of scans that needed to be repeated due to poor image quality. In addition, six secondary parameters were evaluated quantitatively and qualitatively. The results showed that there was no need to repeat any of the CBCT scans that were obtained in either group, which showed that 360-degree and 180-degree protocols had comparable image quality. As for the secondary parameters, the results showed that the evaluators were able to evaluate the six chosen parameters in a comparable manner. The 180-degree low dose CBCT scan is a viable option for dental implant treatment planning in the posterior mandible as it provides comparable and adequate information regarding accuracy of measurements, identification of critical structures, evaluation of bone quality, and any pathology.

Dental Implant Treatment Planning in the Post-Traumatic Rehabilitation of the Anterior Maxilla: A Report of Three Cases

Evidence-based algorithms guiding treatment of traumatic dentoalveolar injuries prescribe specific interventions in the presence of various sets of historical and clinical cues. However, the staging of dental implant placement in post-traumatic rehabilitation—indeed, whether to consider implant therapy at all—remains more art than science, prior authors cautioning that universal rules do not apply. The purpose of this report is to present treatment approaches applied in three traumatic episodes involving the anterior maxilla. Three patients presented to the Department of Periodontics, Army Postgraduate Dental School, Postgraduate Dental College, Fort Eisenhower, GA, USA, following traumatic injuries to the anterior maxilla with varying degrees of severity. In two cases, central incisors were replaced using immediate implants and immediate provisionalization (IIPP). At one IIPP site, extraction was delayed for eight weeks to permit healing of an alveolar fracture. In the third case, the patient received a non-implant rehabilitation due to severe alveolar destruction. Both patients receiving IIPP expressed satisfaction with immediate esthetics, and in both cases, the provisional restoration prevented extraction-related soft tissue collapse. Trauma adds an element of uncertainty to the technically demanding task of implant placement in the esthetic zone. When appropriate, IIPP in the post-traumatic rehabilitation of the anterior maxilla may mitigate some of the known biopsychosocial consequences of oral trauma and facilitate development of favorable mucosal and osseous architecture at the site. Individualized treatment planning is critically important due to wide variability in site characteristics and injury complexity.

Radiographic alveolar bone assessment in correlation with primary implant stability: A systematic review and meta-analysis.

The radiographic examination of alveolar bone using 3D radiographic examination is essential in dental implant treatment planning. Our study aimed to systematically review and quantitatively analyze the correlation between alveolar bone parameters, specifically bone density and cortical bone thickness, assessed using cone beam computed tomography (CBCT) and/or multidetector computed tomography (MDCT); and primary implant stability (PIS) determined using implant stability quotient (ISQ), Periotest® value (PTV), and insertion torque value (ITV). This review was registered in the PROSPERO database (registration number CRD42022307245). An electronic literature search was conducted on the PubMed, SCOPUS, and Web of Science databases for papers published until February 2022. The Quality Assessment in Prognostic Studies (QUIPS) tool was used to assess risk of bias. Meta-analyses were conducted to calculate the estimated average correlation coefficient based on a multilevel random-effects model, followed by subgroup analysis. Twenty-six studies were included in this review, consisting of 17 prospective cohort studies, eight retrospective cohort studies, and one nonrandomized controlled trial. A total of 3109 implants placed in 1171 subjects were analyzed. Twenty-three studies were evaluated using meta-analysis. The alveolar bone condition was significantly correlated with ISQ (r = 0.60; p < .001), IT (r = 0.52; p < .001), and PTV (r = -0.42; p < .05). Alveolar bone condition is significantly associated with PIS. Low bone density and thin cortical bone can lead to low PIS; therefore, modification of treatment planning and surgical procedures might be needed to avoid poor osseointegration.

Comparative Assessment of Three Different Alveolar Ridge Dimension Measurement Methods before Implant Placement: An In Vivo Study.

The purpose of this study was to compare the three various techniques for measuring the alveolar ridge's dimensions prior to implant insertion. For this study, a total of 36 participants were chosen. To prepare a surgical stent, a study model was created from an alginate impression. A first point (reference point) was marked on the crest of the ridge in relation to the adjacent teeth. Then, one point (point 1) and another point (point 2) were marked at distances of 3 and 6 mm, respectively, from the reference point. Based on the procedure for measuring the size of the alveolar ridge, the study was divided into the following groups. Group I: Cone-beam computed tomography (CBCT) measurement method; Group II: Ridge mapping measurement method; Group III: Direct caliper measurements method. Descriptive statistics were used to estimate the mean and standard deviation (SD). The Student's unpaired t-test was utilized for the statistical analysis. The 5% level of significance was used. There was no significant difference found between CBCT with ridge mapping and direct caliper measurements. However, on comparison of ridge mapping and direct caliper measurements technique, at point 1, the ridge mapping was 3.88 ± 0.12 and the direct caliper measurement was 3.62 ± 0.08. At point 2, the ridge mapping was 6.58 ± 0.06 and the direct caliper measurement was 6.32 ± 0.04. There was a statistically significant difference found between these two measurement methods. Within the limitation, the current study came to the conclusion that when CBCT and ridge mapping measurements were individually compared with the gold standard-the surgical open method, CBCT-demonstrated to be a highly specific and sensitive method for detecting the residual alveolar ridge width in the treatment planning of dental implants. Evaluation of alveolar bone is necessary during treatment planning for dental implant placement. Using simply panoramic and/or periapical radiographs to evaluate the bone may not be sufficient because it only provides two-dimensional information regarding the implant locations. Therefore, for better implant placement, three-dimensional information of the implant site, such as CBCT and ridge mapping technique, should be assessed.

Comparative Evaluation of Different Alveolar Ridge Width Measurement Techniques in Dental Implant Treatment Planning: An in Vivo Observational Non-Interventional Study.

In todays era dental implant has become the dependable therapeutic treatment for the replacement of missing teeth. The success of dental implants depends not only on osteointegration of the implant but also on the surrounding hard and soft tissue. Presurgical evaluation of alveolar ridge width and height is of paramount important for implant placement. There are several methods to evaluate the alveolar ridge width and height such as ridge mapping and CBCT. This study included 30 sites from 8 patients in the age ranging from 30 to 65 years. A stent was prepared and the width of the alveolar ridge was estimated employing the following techniques: Group I: Measurement of alveolar ridge width on cone-beam computed tomography (CBCT) method, group II: Measurement of alveolar ridge width by ridge mapping technique, group III: Measurement of alveolar ridge width by surgical exposure. The minimum value for ridge mapping with caliper is 2 and maximum value is 9 with mean 4.5667 ± 1.63335 with standard error 0.29821. The minimum value for Cone beam computed tomography (CBCT) is 1.80 and maximum value is 9.30 with mean 4.6233 ± 1.67119 with standard error 0.30512. The minimum value for direct intrasurgical measurement with caliper is 2 and maximum value is 9 with mean 4.2000 ± 1.58441 with standard error 0.28927. Cone beam computed tomography could also be used to measure the ridge width accurately. Apart from measurement of alveolar ridge dimensions it had multiple other uses and thus can be advised as per requirement of the clinician.

CBCT Evaluation of Lingual Foramen and its Anatomic Variations in Northeast Indian Population.

The identification of nearby neurovascular structures is a vital part of dental implant treatment planning. Commonly two implants are placed in the mandibular inter foraminal region to support the overdenture. Placing dental implants in this region is considered relatively safe. The purpose of this study was to employ cone beam computed tomography (CBCT) on a representative sample of Northeast Indians to find out the location and distribution of lingual foramen in the anterior mandible. A total of 104 CBCT scans were performed using the Cranex 3D CBCT system. Three Oral and Maxillofacial Radiologists agreed on a visibility grade for assessing the lingual foramen using a 3-point scale. The number and presence of foramina were noted. On cross-sectional pictures, the distance in millimeters between the crest of the alveolar ridge and the superior cortical margin of the foramen was determined. Furthermore, the analysis of the distribution of lingual foramina in terms of frequency and percentages was performed. Scan results showed that the lingual foramen was clearly visible in 65.4% of cases, somewhat visible in 12.5% of scans, and not visible at all in 22.1% of cases. Half of the people in the study had two foramina, whereas 27.9 percent had one and 22.1 percent had none. The mean distance from the crest of the alveolar ridge was 10.84 mm in males whereas 9.91 mm in females. The Northeast Indian population exhibits an unusually high prevalence of lingual foramen in the anterior portion of the mandible. This research will aid in the precise pre-operative identification of the position and number of lingual foramina prior to surgical treatments involving the midline of the mandible.

An irrefutable unambiguous insight into zygomatic air cell defect (ZACD)

Zygomatic air cell defect (ZACD) of the temporal bone, has been characterized as the auxiliary air cells in the zygomatic process and articular eminence of the temporal bone. They present as unresectable findings in the zygomatic process of the temporal bone and articular tubercle. They are crucial, as they signify regions of weak resistance and the spread of disease. Comprehension of the decrepit regions in the zygomatic bones with Cone Beam Computed Tomography (CBCT), and the imaging of choice in maxillofacial disorders for its superior 3D anatomical reconstruction and minimal distortion, are indispensable in the diagnosis, treatment planning and placement of endosseous or basal dental implants to elude complications. 154 CBCT images of subjects aged between18 and 70 years with optimal diagnostic quality and area coverage satisfying the selection criteria without the history of maxillofacial fractures, pathologies, anomalies involving the middle one third of the face were analysed. The overall prevalence of ZACD was in 16 (10.4%) subjects, with 9 in females (56.25%) and in 7 males (43.75%). The men-to-women ratio was 1:1.28. It was also revealed that bilateral incidence of ZACD was more common and the prevalence of ZACD the highest 8 (50%) in the age group of 21- 30 years. This study highlights the importance of research on the prevalence of the ZACD on CBCT, which was exiguous in the past, and compares with similar studies done using panoramic radiographs. This study paves the way for more studies employing CBCT to justify the findings we have expressed.

Surface of a tapered implant

The choice of implant shape and size is an important part of the treatment plan procedure in order to obtain an implant that is sta-ble in masticatory function and aesthetic function. The use of implants with a tapered design and surface modification would improve the ultimate stability in low density bone. A comprehensiveand accurate radiographic examination is also an import-ant aspect of dental implant treatment planning. This article is aimed to present things about taperedinternal implants starting from indications, shape and dimensions, design, surface characteristics of the implant and drilling guide and selection of the appropriate type and radiographic technique to produce appropriate diagnostic information. So, with the limited facilities of modern radiographic images inIndonesia, conventional radiographic examinations with several projections can be used as an option to obtain optimal diagnostic information according to existing cases.&#x0D; Keywords: tapered implant, dental implant, dental implant radiography.

The Learning Curve of Artificial Intelligence for Dental Implant Treatment Planning: A Descriptive Study

Introduction: Cone-beam computed tomography (CBCT) has been applied to implant dentistry. The increasing use of this technology produces a critical number of images that can be used for training artificial intelligence (AI). Objectives: To investigate the learning curve of the developed AI for dental implant planning in the posterior maxillary region. Methods: A total of 184 CBCT image sets of patients receiving posterior maxillary implants were processed with software (DentiPlan Pro version 3.7; NECTEC, NSTDA, Thailand) to acquire 316 implant position images. The planning software image interfaces were anonymously captured with full-screen resolution. Three hundred images were randomly sorted to create six data sets, including 1–50, 1–100, 1–150, 1–200, 1–250, and 1–300. The data sets were used to develop AI for dental implant planning through the IBM PowerAI Vision platform (IBM Thailand Co., Ltd., Bangkok, Thailand) by using a faster R-CNN algorithm. Four data augmentation algorithms, including blur, sharpen, color, and noise, were also integrated to observe the improvement of the model. After the testing process with 16 images that were not included in the training set, the recorded data were analyzed for detection and accuracy to generate the learning curve of the model. Results: The learning curve revealed some similar patterns. The curve trend of the original and blurred augmented models was in a similar pattern in the panoramic image. In the last training set, the blurred augmented model improved the detection by 12.50%, but showed less accuracy than the original model by 18.34%, whereas the other three augmented models had different patterns. They were continuously increasing in both detection and accuracy. However, their detection dropped in the last training set. The colored augmented model demonstrated the best improvement with 40% for the panoramic image and 18.59% for the cross-sectional image. Conclusions: Within the limitation of the study, it may be concluded that the number of images used in AI development is positively related to the AI interpretation. The data augmentation techniques to improve the ability of AI are still questionable.

The use of radiographic imaging technologies by general dentists in Ontario, Canada

The aim of this study was to determine the prevalence of 2-dimensional and 3-dimensional digital imaging technologies, the methods used by general dentists to limit patient exposure to ionizing radiation, and the impact of dentists' education on imaging technologies and patient dose-reducing techniques. A cross-sectional, web-based survey of all general dentists in Ontario was conducted. Responses from 1332 (14.7%) of the 9052 registered general dentists in Ontario were included in the analysis. Approximately 89% reported using digital intraoral technology, 81.1% reported owning panoramic imaging systems, 71.2% reported making referrals for cone beam computed tomography (CBCT), and 9.5% reported including CBCT in their practices. CBCT was most commonly used for dental implant treatment planning (85.8%), followed by endodontics (45.4%), evaluation of pathology (39.6%), and surgical assessment for impacted teeth or difficult extractions (36.8%). Approximately 32.7% used only collimators with a long focal point-receptor distance and 8% used only rectangular collimation; 86.9% reported using a thyroid collar when imaging patients. Differences in educational backgrounds correlated with differences in the use of imaging and dose-reducing techniques. There is widespread adoption of digital imaging technologies by general dentists in Ontario, including CBCT. Greater implementation of long and/or rectangular collimation could markedly reduce the ionizing radiation dose to patients. Changes in dental education curricula and continuing education course offerings may address these issues.

Accuracy of Implant Placement Position Using Nondental Open-Source Software: An In Vitro Study.

To evaluate the accuracy of implant placement position using two different dental implant planning software. A set of Digital Imaging and Communications in Medicine (DICOM) files from a cone beam computed tomography of a patient missing maxillary right first premolar was used. Implant planning was done using two open-source programs: A nondental 3D Slicer/Blender (3DSB) software and a commercial dental implant treatment planning program: Blue Sky Plan 4 (BSP4). An intraoral scan of the same patient was used to create a standard tessellation language (STL) file of the maxillary arch and later printed into 20 identical casts. Ten surgical guides were printed for each group as well. A dental implant (3.8 mm × 12 mm, Biohorizons) was placed into each cast using fully guided surgical protocol. The horizontal displacements at the implant cervical platform and at the implant apex as well as the angulation displacements were measured using digital scanning of the implant scan bodies and were analyzed using a 3D compare software. Statistical analyses were conducted (⍺ = 0.05) using t-test and F-test to examine differences in trueness and precision, respectively. The average horizontal deviations for the platform and the apex, respectively, were 0.33 ± 0.12 mm and 0.76 ± 0.30 mm for 3DSB and 0.44 ± 0.21 mm and 0.98 ± 0.48 mm for BSP4. The average angulation deviations for 3DSB and BSB4 were 2.34 ± 0.93° and 3.07 ± 1.57°, respectively. There were no statistical differences in the means (t-test) of the platform, apex, and angulation deviations (p = 0.16, p = 0.19, and p = 0.18, respectively). There were statistical differences in the variances (F test) of the platform (p = 0.043) and angulation (p = 0.049) deviations but not the apex (p = 0.059) deviations. The combination of nondental open-source software, 3D Slicer/Blender can be used to plan implant guided surgery with an accuracy similar to commercial dental software with slightly higher precision. Open-source nondental software can be considered as an alternative in dental implant treatment planning and guided surgery.

Dental Implant Tedavi Planlamasında Panaromik Radyografinin Farklı Bölgelerdeki Güvenilirliğinin Değerlendirilmesi

Dental Implant Tedavi Planlamasında Panaromik Radyografinin Farklı Bölgelerdeki Güvenilirliğinin Değerlendirilmesi

RELATION OF CONE BEAM COMPUTED TOMOGRAPHY ASSESSMENT OF MANDIBULAR BONE DENSITY TO DUAL ENERGY X-RAY ABSORPTIOMETRY IN TYPE 2 DIABETES MELLITUS PATIENTS

INTRODUCTION: One of the complications associated with diabetes mellitus is decrease in bone mineral density (BMD). Therefore, quantification of BMD for these patients before a dental implant procedure is essential. Cone beam computed tomography (CBCT) is an important tool that can be used for qualitative and quantitative bone assessment for treatment planning of dental implants. OBJECTIVES: Evaluation of mandibular bone mineral density measured by CBCT and its correlation to T-score obtained by dual energy xray absorptiometry (DEXA) in relation to blood glycemic control as detected by glycosylated hemoglobin (HbA1c) in type 2 diabetic patients (T2DM). MATERIALS AND METHODS: The study was conducted clinically on twenty-four patients having T2DM, referred for CBCT examination as a part of implant planning. BMD was measured for each edentulous mandibular space using CBCT scan. The patients were grouped according to the level of HbA1c into 4 groups; control group, well-controlled group, moderately controlled group and poorly controlled group. Additionally, each candidate was examined radio-graphically using DEXA. Then, a statistical correlation between HbA1c values in relation to mandibular BMD values and T-score values was investigated. RESULTS: there was a statistically significant correlation between HbA1c values and BMD variables including: mandibular edentulous quad BMD and T-score values (p <0.001), and a statistically significant correlation between T-score value and Mandibular edentulous quad BMD (p <0.001). CONCLUSIONS: Osteoporosis is a commonly underestimated problem in diabetes patients. Osteoporosis can be predicted using CBCT, so it’s the dentist responsibility to refer osteoporotic patients once being suspected.

Treatment Planning of Dental Implants in the Anterior Maxilla; Risk Assessment and Review of Soft Tissue along with Bone Preservation and Augmentation Techniques for Successful Clinical Outcomes

The anterior maxilla continues to present with high potential risk for esthetic failure, and as a result, there is a clear need for modifications that would allow for natural-looking restorations that are harmonious with the rest of the mouth. A number of changes in protocol for placing implants such as using a restorative-driven protocol, the performance of a risk assessment and addressing factors that could compromise esthetics such as deficiencies in bone and soft tissue using bone and soft tissue grafts to ensure adequate tissue volume are necessary for dental implant overall success in the anterior maxilla. Understanding of timing with regard to implant placement has also contributed to achieving esthetic success in the region. This article reviews modifications made in implant placement in the esthetic zone and how they can contribute to functional and esthetic success in the anterior maxilla.

Comparative evaluation of various methods of assessing residual alveolar ridge width prior to dental implant placement: An in vivo study

Purpose: There is always a slow but steady evolution occurred in dentistry, resulting in use of osseointegrated dental implants which became widely accepted procedure in the rehabilitation of edentulous spaces. Evaluation of the available alveolar bone dimensions is an important prerequisite for dental implant placement and successful outcome. Hence, this vivo study was designed to evaluate the accuracy of cone beam computed tomography (CBCT) and bone mapping for the diagnostic purpose.Materials and Methods: A total of 27 partially edentulous sites in maxilla and/or mandibular arch were selected according to the mentioned criteria. The width of edentulous spaces was measured and compared by three methods: CBCT, bone mapping, and surgical exposure. Later, the obtained data were sent for statistical analysis to check the accuracy of methods for the assessment of residual alveolar ridge width prior to the dental implant placements.Results: Normality check was done before finalizing statistical tests using Kolmogorov–Smirnov and Shapiro–Wilk test and non-parametric tests were applied for final analysis. Variables were compared using the Wilcoxon signed-Rank Test. Spearman's Rank correlation was obtained to check the relationship between variables. Throughout the result, significance level was fixed at 5% and if value of P < 0.05, it shows a significant result. For this study, P < 0.05 and statistically significant, which show that average measurements are significantly differ between the variables.Conclusion: CBCT and ridge mapping measurements when compared individually with the gold standard, surgical open method, CBCT proved to be a highly accurate method detecting the residual alveolar ridge width in the dental implant treatment planning.

Influence of 2D vs 3D imaging and professional experience on dental implant treatment planning.

This study investigated whether professional experience and type of image examination (panoramic radiography (PAN) or cone beam computed tomography (CBCT)) could influence the pre-surgical planning for dental implant treatment. Six dentists, from two different levels of experience (senior (Sr) and junior (Jr)) performed simulated pre-surgical planning by using PANs and after 1month, by using CBCTs, considering implant length (IL), implant width (IW), need for bone graft (BG), and other surgical procedures (OP). Bland-Altman test and Kappa coefficient were used to identify agreements. Bland-Altman test showed good agreement in the plans for inter-professional (i.e., Sr vs Jr) comparisons. Bland-Altman plots displayed intra-observer agreement (i.e., differences between PAN and CBCT), showing discrepancy between imaging modalities for IL and a tendency towards selecting larger dental implant options when using PAN and smaller options with CBCT. Kappa showed almost perfect (0.81-1.0) agreement between Jr and Sr for OP (PAN and CBCT). For BG, agreement was substantial (0.61-0.80) when planning was done with PAN and CBCT. Descriptive statistics showed evidence that when Jrs used CBCT, they no longer indicated the BG they had planned when they used PAN. There were differences in the pre-surgical planning for treatment with dental implants depending on the professional experience and the type of imaging examination used. Variation in dental implant planning can affect treatment time, cost, and morbidity in patients.

Flapless dental implant surgery and use of cone beam computer tomography guided surgery.

Flapless implant surgery is increasing in popularity, particularly due to advances and increased usage of cone beam computed tomography (CBCT) and dental implant treatment planning software allowing three-dimensional assessment of the implant site. It is the aim of the article to provide an overview of flapless implant surgery and CBCT guided flapless implant surgery and summarise the literature with regard to the effectiveness of this surgical technique.

In vitro Evaluation of the Relationship between Gray Scales in Digital Intraoral Radiographs and Hounsfield Units in CT Scans.

Jaw bone quality plays an essential role in treatment planning and prognosis of dental implants. Regarding several available methods for bone density measurements, they are not routinely used before implant surgery due to hard accessibility. An in vitro investigation of correlation between average gray scale in direct digital radiographs and Hounsfield units in CT-Scan provides a feasible method for evaluating alveolar bone quality prior to implant surgery. 26 sheep's mandibles in which a square shape ROI marked by gutta percha, were prepared. Three direct digital radiographs (CCD sensor) from every specimen were taken using 80, 100 and 200 milli-seconds. Then, the average gray levels for ROIs were calculated using a costume-made software. Next, the specimens were scanned using a 16-slice spiral CT and the Hounsfield Unit of each ROI was calculated. Pearson analysis measured the correlation between Hounsfield units and average gray levels. There was a positive correlation between Hounsfield unit and average gray level in the radiographs and the correlation was better in higher exposure times. It is possible to estimate Hounsfield unit and bone density in the jaw bones using average gray scale in a digital radiograph. This approach is easy, simple and available and also results in lower patient exposure comparing other bone densitometric analysis methods.

Accuracy of Cone Beam Computed Tomography for Dental Implant Treatment Planning

Accuracy of Cone Beam Computed Tomography for Dental Implant Treatment Planning