[Contribution of 3D imaging using 3DNEO(®) software in surgical-orthodontic treatment of impacted teeth]. / Apport de la reconstruction tridimensionnelle à l'aide du logiciel 3DNEO(®) dans le traitement chirurgico-orthodontique des dents incluses.

OBJECTIVES: The aim of this investigation was to present and evaluate an original method of mini-invasive oral surgery and orthodontics based on 3D images from a computed tomography software (3DNEO(®), 3DNEOVISION). MATERIALS AND METHODS: Three patients with impacted teeth were examined and their data were analyzed with this software based on the "region growing" method. RESULTS: Several clinical interests emerge : locate and visualize precisely the relationships of the impacted tooth with the adjacent anatomical elements under the desired angle, associate/dissociate the different elements of the 3D scene, measure the distances, calculate the axes of traction, materialize the way of traction and the optimal point for bonding, prepare virtually the surgical exposure and orthodontic treatment plan. CONCLUSION: This 3D method might provide information for improved diagnosis and treatment plans in order to ultimately result in more successful treatment outcomes and better care for patients.

Dentinogenesis imperfecta: long-term rehabilitation in a child.

The treatment of dentinogenesis imperfecta represents a challenge for the dental practitioner. The aim of this case report was to describe the chronology and problems encountered in the long-term rehabilitation of a young girl suffering from dentinogenesis imperfecta with severe attrition. A 2-stage treatment over a period of 9 years is described and discussed. This treatment comprised an initial treatment to restore esthetic appearance and function during primary and mixed dentitions and a complete prosthetic rehabilitation in a second stage to protect permanent teeth with low-fusion ceramicmetal individual crowns. Discovery of a follicular cyst is also reported and its treatment is described.

Contributions of reformatted computed tomography and panoramic radiography in the localization of third molars relative to the maxillary sinus.

OBJECTIVE: The aim of this clinical study was to seek an answer to the question of whether CT gives better qualitative and quantitative information as compared to panoramic radiograph when deciding on extraction of upper impacted third molars. STUDY: The study concerned 34 third molars appearing in direct relation with the sinus on the panoramic radiograph for which a CT scan had been recommended. For each case, the panoramic radiograph was compared with the CT scan for 5 evaluation criteria. RESULTS: The CT scan was more precise than the panoramic radiograph by 1.67 mm for measurement of the level of impaction of the third molar, by 12.44 degrees for measurement of the third molar displacement, by 0.74 mm for bone height separating the third molar roots and the sinus, and by 2.26 mm for the length of roots in the sinus. The CT scan was equally accurate for measurement of the distance separating the crowns of second and third molars in 34 cases. CONCLUSIONS: This study confirms the gain in precision for the CT scan as compared with conventional techniques. The CT scan therefore presents advantages when considering the extraction of upper third molars by providing both qualitative and quantitative information liable to bear on the diagnosis and therapeutic management.

An image-guided system-drilled surgical template and trephine guide pin to make treatment of completely edentulous patients easier: a clinical report on immediate loading.

PURPOSE: An image-guided system has been developed to drill a conventional surgical guide following a preoperative three-dimensional plan for accurate placement of implant on bone. The aim of this study is to illustrate how this system facilitates treatment of completely edentulous patients by modifying both surgical and prosthetic protocols, thereby making flapless surgery possible as well as the preparation of the transitional prosthesis before surgery. MATERIALS AND METHODS: This system was tested on 10 consecutive patients, placing all planned implants without raising the mucoperiosteal flap and with the connection of all implants to pre-angulated abutments. RESULTS: A 1-year follow-up demonstrated stable and properly functioning prostheses in all cases. CONCLUSIONS: This technique can be expected to flourish because implantology makes the highest demands on comfort, precision, and safety.

Reliability of preoperative planning of an image-guided system for oral implant placement based on 3-dimensional images: an in vivo study.

PURPOSE: The purpose of this study was to assess the reliability of the planning software of an image-guided implant placement system based on a mechanical device coupled with a template stabilized on soft tissue during surgery. MATERIALS AND METHODS: Thirty consecutive partially or completely edentulous patients were treated with the image-guided system. For each patient, a study prosthesis was fabricated and duplicated in acrylic resin and served as a scanning template. Axial images were obtained from a computerized tomographic scan and transferred to planning software that provides real 3-dimensional information to plan implant position. Once the final position of the implant was defined, preoperative data such as the size of implants and anatomic complications were recorded using the planning software. The scanning template was then drilled in that exact position by a drilling machine. During surgery, the drilled template was used as a drill guide. After implant placement, intraoperative data were recorded and statistically compared with the preoperative data using the Kendall correlation coefficient for qualitative data and the Kappa concordance coefficient for quantitative data. RESULTS: Agreement between the preoperative and intraoperative data was high for both implant size and anatomic complications. The Kendall correlation coefficient was 0.8 for the diameter and 0.82 for the length. The Kappa concordance coefficient was 0.87 for both dehiscence and bone graft, 0.88 for osteotomy, and 1.0 for fenestration. DISCUSSION: In the few instances where planning was not perfect, implant placement was completed in a clinically acceptable manner. CONCLUSION: The results suggest that the image-guided system presented is reliable for the preoperative assessment of implant size and anatomic complications. It may also be reliable for flapless surgery.

Precision of transfer of preoperative planning for oral implants based on cone-beam CT-scan images through a robotic drilling machine.

In this study, an image-guided system for oral implant placement was assessed. A specially designed mechanical tool has been elaborated to transfer the preoperative implant axis planned on 3-dimensional imagery into a surgical template by a numerically controlled drilling machine. The main drawback of image-guiding systems is the use of preoperative computed tomography, which is expensive and delivers high radiation doses. Therefore, in this study the image-guiding system was coupled with a cone-beam tomograph that significantly decreased both cost and radiation doses. Three edentulous models were used. To determine the accuracy of the system, the ability of a 1.8-mm diameter drill to enter a 2.0-mm diameter, 10-mm-long titanium tube inserted on the model with no contact was verified. Because the drill entered the tubes with no contact and went beyond the end of the tube, the transfer error was less than 0.2 mm for translation and less than 1.1 degrees for rotation. The method presented here is low cost and high precision compared to other technological solutions such as tracking. Further assessment in the surgical field should lead to daily use of this system for flapless surgery, to prepare a prosthesis prior to surgery for immediate loading, to reduce risk of injuring critical anatomical structures and to eliminate manual placement error.