Validation of cone beam computed tomography-based tooth printing using different three-dimensional printing technologies.

OBJECTIVE: Our aim was to determine the accuracy of 3-dimensional reconstructed models of teeth compared with the natural teeth by using 4 different 3-dimensional printers. STUDY DESIGN: This in vitro study was carried out using 2 intact, dry adult human mandibles, which were scanned with cone beam computed tomography. Premolars were selected for this study. Dimensional differences between natural teeth and the printed models were evaluated directly by using volumetric differences and indirectly through optical scanning. Analysis of variance, Pearson correlation, and Bland Altman plots were applied for statistical analysis. RESULTS: Volumetric measurements from natural teeth and fabricated models, either by the direct method (the Archimedes principle) or by the indirect method (optical scanning), showed no statistical differences. The mean volume difference ranged between 3.1 mm(3) (0.7%) and 4.4 mm(3) (1.9%) for the direct measurement, and between -1.3 mm(3) (-0.6%) and 11.9 mm(3) (+5.9%) for the optical scan. A surface part comparison analysis showed that 90% of the values revealed a distance deviation within the interval 0 to 0.25 mm. CONCLUSIONS: Current results showed a high accuracy of all printed models of teeth compared with natural teeth. This outcome opens perspectives for clinical use of cost-effective 3-dimensional printed teeth for surgical procedures, such as tooth autotransplantation.

Comparative assessment of periapical radiography and CBCT imaging for radiodiagnostics in the posterior maxilla.

Close proximity of the maxillary roots and the sinus floor makes a dental disease a probable cause of maxillary sinusitis. The aim of this study was to evaluate the ability of periapical radiography and cone beam computed tomography in defining the topographic relationship of maxillary teeth to the sinus floor and detecting apical periodontitis and other odontogenic causes of the maxillary sinusitis. Out of 145 dental records from subjects (mean age 52 years, range 20-75 years; 89 females) referred to the Oral Imaging Centre, KU Leuven, periapical and CBCT images of the posterior maxilla were selected for further analysis. Anatomical relationship of maxillary teeth to the sinus floor, apical periodontitis and other etiological causes of soft tissue thickening were assessed with both imaging modalities. The results of this study demonstrated that periapical radiographs are not adequate in observing the anatomical relationship between maxillary molars and the sinus floor. CBCT showed an intimate relationship of 1st and 2nd molar with the maxillary sinus in 50 and 45% of the cases, respectively. Periapical radiography could only spot approximately 40% of apical periodontitis on posterior maxillary teeth and 3% of all apical infections extending to the sinus, seen on CBCT.

Comparative assessment of panoramic radiography and CBCT imaging for radiodiagnostics in the posterior maxilla.

OBJECTIVE: The purpose of this study was to assess whether and how the information obtained by means of cone beam computed tomography (CBCT) on maxillary posterior teeth differs from that obtained by panoramic radiography. MATERIALS AND METHOD: From 157 subjects (mean age 48 years, range 19-84 years; 89 females) referred to the oral imaging center, a pair of panoramic and CBCT images was selected for further analysis. Both imaging modalities were analyzed to determine the topographic relationship of maxillary teeth to the sinus floor. Pathologic conditions, apical periodontitis, and presence of soft tissue thickening were also examined with both techniques. RESULTS: CBCT showed an intimate relationship of the first and second molar with the maxillary sinus in 54 and 38%, respectively. Thirty-nine apical periodontitis lesions causing reactive changes in the maxillary sinus were detected by CBCT, while just six of them were diagnosed with panoramic imaging. A total of 26 teeth with apical extension to the maxillary sinus were detected with CBCT, from which two could be identified with panoramic radiography. CONCLUSION: This study emphasizes that anatomical and pathological involvement of the maxillary sinus in relation to posterior teeth is considerably high. It is of clinical importance that the 3D nature of CBCT imaging allowed a better assessment of the relationship between the maxillary sinus and posterior root apices compared to the low detection on panoramic radiographs. CLINICAL RELEVANCE: CBCT imaging can be a valuable adjunct in radioanatomical and radiodiagnostic observations in the posterior maxilla. It may better visualize maxillary sinus involvement for posterior upper teeth than panoramic radiography.

Validation of the cone beam computed tomography-based stereolithographic surgical guide aiding autotransplantation of teeth: clinical case-control study.

OBJECTIVE: To compare the outcome of cone beam computed tomography (CBCT)-based surgical planning and transfer technique for tooth autotransplantation versus conventional autotransplantation. STUDY DESIGN: The study material comprised 40 pediatric subjects in whom 48 teeth were transplanted following a case-control design. While the study group (mean age 11 years) underwent CBCT imaging for surgical planning and transfer via stereolithographic tooth replica fabrication, the historical control group (mean age 12 years) was subjected to conventional autotransplantation. RESULTS: The CBCT-based preoperative planning and the use of a tooth replica decreased the extra-alveolar time and reduced the number of positioning trials with the donor tooth. In the control group, 6 patients showed 1 or more complications, while this was noticed for only 2 study patients. CONCLUSION: CBCT-based surgical planning of tooth autotransplantation may benefit from a shorter surgical time, while being a less invasive technique, causing fewer failures than a conventional approach.

Importance of root development in autotransplantations: a retrospective study of 137 teeth with a follow-up period varying from 1 week to 14 years.

The aim of the present study was to perform a retrospective study of autotransplanted teeth with a variable but individually maximized follow-up period in order to provide information on the long-term clinical outcome. The sample was obtained from patients who were treated at the University Hospitals KU-Leuven, Belgium, during the period 1996-2010. Of the total of 109 subjects (137 teeth), 98 patients were invited for recall, of whom 68 patients (87 teeth) responded positively. Eleven out of the 109 patients were excluded due to loss of the transplanted tooth. Although 41 patients had no re-examination visit, clinical and radiological data from all 109 subjects were included in the sample. The follow-up period varied from 1 week of 14.8 years, with a mean of 4.9 years. Transplanted teeth receiving orthodontic treatment had a lower risk of ankylosis and were less likely to fail. The risk of root resorption was lower for teeth with stages one-half to three-quarters of root length at the time of transplantation. Molars were more susceptible to ankylosis. Almost all teeth showed partial or full obliteration of the pulp. Absence of further root development was higher in donor teeth with root length stage less than one-half. Trans-alveolar transplantation was less successful. Autotransplantation can be a valid alternative method in young adolescents for replacing missing teeth because of agenesis or trauma. The optimal time to transplant is when the root has reached two-thirds to three-quarters of the final root length.

Spiral computed tomography based maxillary sinus imaging in relation to tooth loss, implant placement and potential grafting procedure.

OBJECTIVES: The purpose of the present study was to explore the maxillary sinus anatomy, its variations and volume in patients with a need for maxillary implant placement. MATERIAL AND METHODS: Maxillary sinus data of 101 consecutive patients who underwent spiral computed tomography (CT) scans for preoperative implant planning in the maxilla at the Department of Periodontology, University Hospital, Catholic University of Leuven, Leuven, Belgium were retrospectively evaluated. The alveolar bone height was measured on serial cross-sectional images between alveolar crest and sinus floor, parallel to the tooth axis. In order to describe the size of the maxillary sinus anteroposterior (AP) and mediolateral (ML) diameters of the sinus were measured. RESULTS: The results indicated that the alveolar bone height was significantly higher in the premolar regions in comparison to the molar region (n = 46, P < 0.01). The age showed negative relation to bone dimension (r = - 0.32, P = 0.04). Anterior and posterior border of the maxillary sinuses were mostly located in the first premolar (49%) and second molar (84%) regions, respectively. Maxillary sinus septa were indentified in 47% of the maxillary antra. Almost 2/3 (66%) of the patients showed major (> 4 mm) mucosal thickening mostly at the level of the sinus floor. The present sample did not allow revealing any significant difference (P > 0.05) in maxillary sinus dimensions for partially dentate and edentulous subjects. CONCLUSIONS: Cross-sectional imaging can be used in order to obtain more accurate information on the morphology, variation, and the amount of maxillary bone adjacent to the maxillary sinus.

A comparative evaluation of Cone Beam Computed Tomography (CBCT) and Multi-Slice CT (MSCT) Part I. On subjective image quality.

AIMS: To compare image quality and visibility of anatomical structures in the mandible between five Cone Beam Computed Tomography (CBCT) scanners and one Multi-Slice CT (MSCT) system. MATERIALS AND METHODS: One dry mandible was scanned with five CBCT scanners (Accuitomo 3D, i-CAT, NewTom 3G, Galileos, Scanora 3D) and one MSCT system (Somatom Sensation 16) using 13 different scan protocols. Visibility of 11 anatomical structures and overall image noise were compared between CBCT and MSCT. Five independent observers reviewed the CBCT and the MSCT images in the three orthographic planes (axial, sagittal and coronal) and assessed image quality on a five-point scale. RESULTS: Significant differences were found in the visibility of the different anatomical structures and image noise level between MSCT and CBCT and among the five CBCT systems (p=0.0001). Delicate structures such as trabecular bone and periodontal ligament were significantly less visible and more variable among the systems in comparison with other anatomical structures (p=0.0001). Visibility of relatively large structures such as mandibular canal and mental foramen was satisfactory for all devices. The Accuitomo system was superior to MSCT and all other CBCT systems in depicting anatomical structures while MSCT was superior to all other CBCT systems in terms of reduced image noise. CONCLUSIONS: CBCT image quality is comparable or even superior to MSCT even though some variability exists among the different CBCT systems in depicting delicate structures. Considering the low radiation dose and high-resolution imaging, CBCT could be beneficial for dentomaxillofacial radiology.