Accuracy of drilling guides for transfer from three‐dimensional CT‐based planning to placement of zygoma implants in human cadavers

Abstract

The accuracy of surgical drilling guides was assessed for placement of zygoma implants. Six zygoma fixtures of length 45 mm (Nobel Biocare, Göteborg, Sweden) were placed in three formalin-fixed human cadavers using surgical drilling guides. The fabrication of these custom-made drilling guides was based on three-dimensional computerized tomography (3D-CT) data for the maxillary-zygomatic complex. The installation of the implants was simulated preoperatively using an adopted 3D-CT planning system. In addition, anatomical measurements of the zygomatic bone were performed on the 3D images. The preoperative CT images were then matched with postoperative ones in order to assess the deviation between the planned and installed implants. The angle between the planned and actually placed implants was < 3 degrees in four out of six cases. The largest deviation found at the exit point of one of the six implants was 2.7 mm. The present study showed that the use of surgical drilling guides should be encouraged for zygoma implant placement because of the lengths of the implants involved and the anatomical intricacies of the region.

Length determination of zygomatic implants using tridimensional computed tomography

“…14,21,22 The deviations from the planning, which occur at surgery, may be explained by factors such as limitations in mouth opening and a more posterior position of the bone structures to be implanted. 4 The internal anatomic reference necessary for the insertion of the fixation (5 mm above the alveolar ridge), as established by the surgeon, differs from the external reference estimated by the radiologist.…”

“…The extra effort is appropriate when weighed against the occasional risk involved when the planning steps are not respected. 6,11,14,22,23 Pre-surgical planning for dental implants is crucial for the success of the treatment in the long term. The imaging examination, which checks the data as close to reality as possible, is an essential element in this process.…”

“…8,9,13,21,23 CT offers bet-ter visualization of the structures than any other radiological method. 6,20,22 It is the aim of this research to evaluate and introduce 3D-CT as a diagnostic instrument in the pre-surgical planning for zygomatic fixation.…”

“…1,2,4,10,12,17,18,22 Osseo-integrated implants are proving to be a successful method for the replacement of lost teeth and this requires accurate diagnostic information to avoid damage to the anatomical vital structures during surgical manipulation. It is essential to have diagnostic resources that reflect the area to be operated on with accuracy in size, volume, and shape as well as the density of the alveolar bone and its corticals.…”

MicroCT-based evaluation of the trabecular bone quality of different implant anchorage sites for masticatory rehabilitation of the maxilla

“…For zygomatic bone, studies on its quantity are available (Uchida et al, 2001;Nkenke et al, 2003;Van Steenberghe et al, 2003;Corvello et al, 2011;Balshi et al, 2012), but data on its quality are still scarce and, except for one histological study by Nkenke et al (2003), are restricted to Japanese populations (Kato et al, 2004(Kato et al, , 2005Yoshino et al, 2007). Possible differences due to ethnicity (Uchida et al, 2001;Nkenke et al, 2003;Liu et al, 2011;Kim et al, 2013b;Putman et al, 2013) and the technique applied for bone analysis (histomorphometry vs. micro-computed tomography (microCT)) (Chappard et al, 2005;Bonnet et al, 2009), and the lack of an intraindividual comparison with the maxilla, triggered the present microCT-based study to assess the trabecular bone quality of the zygomatic bone and compare it with the anterior and posterior maxilla.…”