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Key words: guided surgery, navigation, transtomography Frederic Bousquet, Marion Joyard, 82 avenued’Assas, Montpellier, France.
Objectives: To present a new guidance technique using transtomography in the operating room and to test the accuracy of this surgical protocol.
Material: A new concept of operating room, integrating when necessary this imagery to secure flapless procedures by intraoperative control, is described. This operating room Tel.: þ 33 (0)467-633-999e-mail: [email protected] concept, including X ray protection of the operators, is explained in addition to the transport system of the panoramic machine for its transfer to the patient who remains Methods: Twenty-five single-tooth edentulous patients were treated by implant placement with a flapless or a minimally invasive procedure using transtomographic navigation. The surgical protocol is explained: after the first limited drill through mucosa and bone, intraoperative transtomography is performed with a custom-made titanium guide inserted into the bone. Images show the drilling axis in three dimensions. This form of navigation allows rectifying the drill axis. We explain how this protocol respects asepsis.
Results: The mean angular deviation was 2.041 in the mesiodistal direction (range: 01–4.81, variance: 2.88) and 2.711 in the buccal or the palatolingual direction (range: 01–5.41; variance: 2.63). Implant tip deviation was calculated: the mean mesiodistal tip deviation was 0.42 mm, and the mean buccal or palatolingual tip deviation was 0.5 mm. The maximum tip mesiodistal deviation was 1.08 mm and the maximum vestibular or palatolingual tip deviation was 1.22 mm.
Conclusion: This protocol appears to be as accurate as other guided or navigation systems.
The advantages and limitations of this technique are explained, followed by future prospects with the new 3D cone beam computed tomography developed with the same For implant placement, examination of the bone ridge contour before surgery is parti- sive surgical procedure has to be performed.
Campelo & Camara 2002; Becker et al.
2005), or require image assistance to ensure accuracy: use of a template or bur tracking Bousquet F, Joyard M. Surgical navigation for implantplacement using transtomography.
Clin. Oral Impl. Res. 19, 2008; 724–730doi: 10.1111/j.1600-0501.2008.01528.x bone. Flapless procedures are restricted by bone ridge contour for implant planning.
 2008 The Authors. Journal compilation c Bousquet & Joyard . Surgical navigation for implant placement using transtomography be used separately for classical surgery.
X-ray protection is secured by the leaded needs a transtomographic verification, the digital detector and image treatment, the effects of superpositions are reduced.
navigation, the surgeon is protected behind Overlapping of the operating room and the the closed dividing wall. The assistant uses of conventional tomography (Welander et al.
starter r and supervises the radiographic The radiology room and the operating room 2004): images are provided with a panoramic examination through the leaded glass.
are separated by a leaded dividing wall that The patient remains seated on the operat- can slide laterally to create an opening.
narrow beam, using a detector as a receptor.
Translation system of the panoramic machine on the screen, we decided to install it in (Fig. 2a and b) is performed by a kart. A the operating room. The aim was to use it fixed on the lateral wall. Hence, the ma- chine can move along the lateral wall up to tient, for tissue healing and preservation of the operating chair in a linear way without tissue volume (Ramfjord & Costich 1968; any rotation of the kart during translation.
Wood et al. 1972; Tarnow et al. 1992). Inthis way, the operating room concept al- lows intraoperative drilling axis control, Twenty-five single-tooth edentulous patients using a metallic guide temporarily inserted into the drilled bone during radiographic flapless or a minimally invasive procedure tortion assessment related to this kind ofimagery was performed by taking measure- ments of the metallic guides on the screen The preoperative planning included clinical tions: panoramic and transtomographic ex- radiographic investigations were conducted tortion (0–6%) (Kobayashi et al. 2004) and bone contour and quality of alveolar bone The purpose of this article is to introduce this new guidance technique using transto- The first part of this paper explains this calculated. With the Promax machine, it is part describes to the translation system of possible to combine one longitudinal slice and one cross-sectional slice on one com- patient who remains seated on the operat- ing chair. In the third part, the surgical tial 66 kVp, tube current 1 mA, with anexposure time of 8 s. The implant planning Fig. 1. (a) The radiology room and the operating room are separated by a leaded dividing wall that can slide laterally.(b) Panoramic machine can be An individualized silicon occlusal regis- moved to the operating room. The leaded dividing tration key was used for patient positioning wall is closed after shifting.(c) During navigation, The operating room concept integrates the during transtomography. For each patient, assistant 1 uses starter r. The surgeon supervises the radiographic examination through leaded glasses.
the same silicon key was used for preopera-  2008 The Authors. Journal compilation c 725 | Clin. Oral Impl. Res. 19, 2008 / 724–730 Bousquet & Joyard . Surgical navigation for implant placement using transtomography els), enhanced resolution (one picture pixelequals three physical pixels) and high re-solution (one picture pixel equals two phy-sical pixels). The size of the physical pixelis 33 mm. After picture calibration (1.4magnification coefficient in case of trans-tomography), measurements are then ta-ken with a 132 mm (33 Â 4) measurementunit in the normal resolution mode. Thisexplains why all the measurements (dis-tance and angle) of this study appear withinabout one-hundredth of a millimetre.
Surgical protocolLimited first drilling length: On pre-operative transtomography, full drilling Fig. 3. Custom-made titanium reference guides(6 and 10 mm long): the intrabony part may have was chosen according to implant length.
notches to facilitate measurements on the images.
Nevertheless, a first drilling length waschosen (through mucosa and bone) depend-ing on the distance from the top of the ridge to the nearest critical anatomic structures trajectory. Thus, the drill’s axis could be (cortical plates, undercuts, concavities or zones–the first drilling length through the just after transtomographic navigation. In distance to these critical zones (Fig. 4a).
6/25 sites, a crestal incision was made to Similar to this, for this blind first drilling, optimize the buccal presence of keratinized the distance maintained from the critical tissue. Hence, at this time, the thickness of zones provided protection. The axis could the mucosa could be confirmed. Then, full be corrected during full drilling after the pilot drilling was performed in the bone, considering the height of mucosa and axis first blind limited drill (through mucosa placement were carried out: 23 implants of radiographic reference guide made of tita- Fig. 2. (a) Surgery begins by a first drill through themucosa. Then, axis control is carried out using transtomography.(b) Travelling system of the pa- consists of a 2 mm section intrabony part of noramic machine: a metallic arm connects the kart 6 or 10 mm length. The intrabony part has composite also–(Fig. 4c) was performed to and the panoramic machine to a track roller linear check implant axis and distance to critical system. A radiographic control can be performed images easier (Fig. 3). The extrabony part of zones. Implants’ positioning could be con- tive, intra operative and postoperative in- the mucosa. The guide fills the entire the first drilling cavity (Fig. 6). Thus, during needed. Hence, rectification was estimated intra operative transtomography, the risk of and carried out. Postoperative control in- difference was found between the real im- At each implant site, cross-sectional and plant position and rectification planning surement program (Planmeca Dimaxis).
(angle deviation and tip deviation).
This program allows the calibration of the grams – composite image – (Fig. 4b) were If no rectification was needed, a compar- taken with the radiopaque reference guide mic and tomographic digital unit presents securely sutured to the adjacent teeth or to axis and the guide axis (angle deviation and three picture-grabbing modes. These three (one picture pixel equals four physical pix- 726 | Clin. Oral Impl. Res. 19, 2008 / 724–730  2008 The Authors. Journal compilation c Bousquet & Joyard . Surgical navigation for implant placement using transtomography Fig. 5. (a) Case 5–intraoperative control–a 151 palatalrectification has to be carried out.(b) Case 5–post-operative control: effective rectification is 10.91.
Buccal deviation is 4.11. Implant length is 13 mm.
Tip buccal deviation is calculated (0.92 mm).
surgeon. In 11/25 sites, no correction wasneeded (Table 1). When transtomographic Fig. 4. (a)Case 3––preoperative transtomography–a 6 mm first drill is decided upon to avoid any risk ofinterference with critical zones.(b) Case 3–intraoperative transtomography–a 151 buccal rectification has to be navigation revealed that the axis had to be carried out to avoid a lingual undercut.(c) Case 3–postoperative control–effective rectification is 17.71: buccal altered (14/25 sites), angle adjustment was deviation is 2.71 and distal deviation is 0.41.
calculated on the image in the buccal/lingual direction and/or in the mesial/dis-tal direction (Table 2). A postoperative antibiotic prophylaxis (–4.5 M UI Spiramy- day, Avensis Laboratory, Paris, France).
No complication appeared after these flap- real implant position and rectification plan- less/minimally invasive procedures or dur- ning. If navigation revealed that no rectifi- 7 days after surgery. The patient was in- ing the implant healing period. Patients did cation was needed, we evaluated the angle structed to rinse with 0.12% chlorexhidine not require medication other than antibio- difference between the real implant posi- tics because pain was minimal. No failure tion and the guide axis (Table 3). Devia- results in all sites. The mean angular de- viation was 2.041 in the mesiodistal direc- tion (range: 01–4,81, variance: 2.88) and Intraoperative images (Fig 4b and Fig 5a) direction (range: 01–5.41; variance: 2.61).
France) and he was informed that he could of the 25 sites with the reference guides inserted into the bone gave provided infor- lated, considering the length of each im- mation regarding the drilling axis to the plant placed: tip deviation ¼ sin angle   2008 The Authors. Journal compilation c 727 | Clin. Oral Impl. Res. 19, 2008 / 724–730 Bousquet & Joyard . Surgical navigation for implant placement using transtomography Table 1. Intraoperative and postoperative axis measurements–cases without drill axis rectification Table 2. Intraoperative and postoperative axis measurements – cases necessiting a rectification in one or two space dimensions M, mesial; D, distal; L/P, lingual palatal; V, vestibular.
length. The mean mesiodistal tip deviation perative transtomography, with a titanium This surgical protocol, including transto- guide inserted temporarily into the drilled zone, allows axis control and evaluation of the distance to anatomical structures. Axis assistants. The operating zone is designed rectification can be performed if necessary.
for X-ray protection of the operators.
Hence, with this protocol, it is possible to Leaded glass allows the operators to super- vise their patients during transtomographic sufficient height of keratinized tissue on the through mucosa even for the 6/25 gingival vestibular side was observed after healing.
remodelling cases. In these cases, a crestal navigation. During the navigation phase in techniques use a template for drilling: these all cases, total obturation of the drilled site with the body of the metallic guide prevents Tardieu et al. 2003; Casap et al. 2004).
This surgical protocol begins with a first Some allow for flexibility in the implant limited drill calculated in the preplanning reference guide is temporarily sutured to location during the operation with a real- to avoid any risk of interference with cor- the surrounding soft tissues to avoid any tical plates or critical zones. Then, intrao- movement during radiographic examination.
728 | Clin. Oral Impl. Res. 19, 2008 / 724–730  2008 The Authors. Journal compilation c Bousquet & Joyard . Surgical navigation for implant placement using transtomography Table 3. Deviation between checked implant axis and real implant position M, mesial; D, distal; L/P, lingual palatal; V, vestibular protocol allowing axis rectification beforeimplant placement.
tip deviation of 0.42 mm in the mesiodistal direction and 0.54 mm in the buccal/pala- tolingual direction). These results seem to be comparable to accuracy studies of other (314 mSv) should be restricted to large eden- tulisms (Dula et al. 2001). Currently, se- the doses delivered and the image quality for a composite image (one longitudinal sliceand one transversal slice) is 6–8mSv–one slice alone: 3–4 mSv–(information given by absorbed doses can be superposed to Lecom- ber et al. (2001) as he found 2 mSv for one linear cross-sectional tomogram slice, much resource demands, surgical templates–the less than a CT scan (314 mSv). Other pre-  2008 The Authors. Journal compilation c 729 | Clin. Oral Impl. Res. 19, 2008 / 724–730 Bousquet & Joyard . Surgical navigation for implant placement using transtomography Table 5. Deviation analysis – Statistics Minimal value Maximal value Mean value Ecartype that this procedure is as accurate as other guidance systems, more flexible than tem-plate systems and has a favourable cost/ This technique appears to be suitable only benefit ratio if we consider that the panora- for small sectorial edentulism because of the mic machine is also used for preplanning.
images when there are several nearby.
image-guided implantology: ‘the most im- portant challenges of the next generation next to each other, it is necessary to perform one transtomography for each implant site lower price, smaller size, good performance with only one metallic guide in the bone.
and reliability and ease of use. This kind of This is the limitation of this navigation image guided system should allow for pre- planning of implant locations, and guided insertion by minimal invasive procedure.
Fig. 6. A radiographic reference guide inserted into the bone fills and obturates the entire drilled zone chine), there is no artefact when several that this kind of navigation using transto- metallic guides are on the same image.
vious works showed from 44 to 117 mSv for a conventional spiral cross-sectional tomo- have interesting prospects for navigation graphy and 3 mSv for one slice of conven- tional tomography (Ekestubbe et al. 2004).
Becker, W., Goldstein, M., Becker, B.E. & Sen- bone using surgical guides in conjunction with Schulze, D., Heiland, M., Thurmann, H. & Adam, nerby, L. (2005) Minimally invasive flapless im- medical imaging techniques. Journal of Oral Im- G. (2004) Radiation exposure during midfacial plant surgery: a prospective multicenter study.
imaging using 4- and 16-slice computed tomogra- Clinical Implant Dentistry & Related Research Hahn, J. (2000) Single-stage, immediate loading, and phy, cone beam computed tomography systems flapless surgery. Journal of Oral Implantology 26: and conventional radiography. Dentomaxillofa- Bousquet, F., Bousquet, P. & Vazquez, L. (2007) Transtomography for implant placement guidance Kan, J.Y., Rungcharassaeng, K., Ojano, M. & Good- Shohat, M. & Tal, C. (2005) Image guided implan- in non invasive surgical procedures. Dentomax- tology. Refuat Hapeh Vehashinayim 22: 60–64.
surgery: a surgical and prosthodontic rationale.
Tardieu, P., Vrielinck, L. & Escolano, E. (2003) Campelo, L.D. & Camara, J.R. (2002) Flapless Practical Periodontics & Aesthetic Dentistry Computer-assisted implant placement. A case implant surgery: a 10-year clinical retrospective report: treatment of the mandible. International analysis. International Journal of Oral & Max- Kobayashi, K., Shimoda, S., Nakagawa, Y. & Ya- Journal of Oral & Maxillofacial Implants 18: mamoto, A. (2004) Accuracy in measurement of Casap, N., Wexler, A., Persky, N., Schneider, A. & distance using limited cone-beam computerized Tarnow, D.P., Magner, A.W. & Fletcher, P. (1992) Lustmann, J. (2004) Navigation surgery for dental tomography. International Journal of Oral & The effect of the distance from the contact point implants: assessment of accuracy of the image Maxillofacial Implants 19: 228–231.
to the crest of bone on the presence or absence of guided implantology system. Journal of Oral & Lecomber, A.R., Yoneyama, Y., Lovelock, D.J., the interproximal dental papilla. Journal of Perio- Maxillofacial Surgery 62: 116–119.
Hosoi, T. & Adams, A.M. (2001) Comparison of Dula, K., Mini, R., Van der Stelt, P.F. & Buser, D.
patient dose from imaging protocols for dental Welander, U., Li, G., McDavid, W.D. & Tronje, G.
(2001) A radiographic assessment of implant pa- implant planning using conventional radiography (2004) Transtomography: a new tomographic tients: decision-making criteria. International and computed tomography. Dentomaxillofacial scanning technique. Dentomaxillofacial Radiol- Journal of Oral & Maxillofacial Implants 16: Mischkowski, R.A., Zinser, M.J., Neugebauer, J., Widmann, G. & Bale, R.J. (2006) Accuracy in Ekestubbe, A., Thilander-Klang, A., Lith, A. & Kubler, A.C. & Zoller, J.E. (2006) Comparison of computer-aided implant surgery: a review. Inter- Gro¨ndahl, H.G. (2004) Effective and organ doses static and dynamic computer-assisted guidance national Journal of Oral & Maxillofacial Im- from scanography and zonography: a comparison methods in implantology. International Journal with periapical radiography. Dentomaxillofacial of Computerized Dentistry 9: 23–35.
Wood, D.L., Hoag, P.M., Donnenfeld, O.W. & Ramfjord, S.F. & Costich, E.R. (1968) Healing after Rosenfeld, L.D. (1972) Alveolar crest reduction Fortin, T., Champleboux, G., Lorme´e, J. & Coudert, exposure of periosteum on the alveolar process.
following full and partial thickness flaps. Journal J.L. (2000) Precise dental implant placement in Journal of Periodontology 39: 199–207.
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