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Pittayapat P.,University of Leuven and Oral and Maxillofacial Surgery | Pittayapat P.,Chulalongkorn University | Jacobs R.,University of Leuven and Oral and Maxillofacial Surgery | Odri G.A.,Center hospitalier regional dOrleans | And 3 more authors.
Imaging Science in Dentistry | Year: 2015

Purpose: This study was performed to assess the reproducibility of identifying the sella turcica landmark in a threedimensional (3D) model by using a new sella-specific landmark reference system. Materials and Methods: Thirty-two cone-beam computed tomographic scans (3D Accuitomo® 170, J. Morita, Kyoto, Japan) were retrospectively collected. The 3D data were exported into the Digital Imaging and Communications in Medicine standard and then imported into the Maxilim® software (Medicim NV, Sint-Niklaas, Belgium) to create 3D surface models. Five observers identified four osseous landmarks in order to create the reference frame and then identified two sella landmarks. The x, y, and z coordinates of each landmark were exported. The observations were repeated after four weeks. Statistical analysis was performed using the multiple paired t-test with Bonferroni correction (intraobserver precision: p<0.005, interobserver precision: p<0.0011). Results: The intraobserver mean precision of all landmarks was <1 mm. Significant differences were found when comparing the intraobserver precision of each observer (p<0.005). For the sella landmarks, the intraobserver mean precision ranged from 0.43±0.34 mm to 0.51±0.46 mm. The intraobserver reproducibility was generally good. The overall interobserver mean precision was <1 mm. Significant differences between each pair of observers for all anatomical landmarks were found (p<0.0011). The interobserver reproducibility of sella landmarks was good, with >50% precision in locating the landmark within 1 mm. Conclusion: A newly developed reference system offers high precision and reproducibility for sella turcica identification in a 3D model without being based on two-dimensional images derived from 3D data. © 2015 by Korean Academy of Oral and Maxillofacial Radiology.

Pittayapat P.,University of Leuven and Oral and Maxillofacial Surgery | Pittayapat P.,Chulalongkorn University | Bornstein M.M.,University of Leuven and Oral and Maxillofacial Surgery | Bornstein M.M.,University of Bern | And 4 more authors.
European Journal of Orthodontics | Year: 2014

Background: The aim of this study was to evaluate the accuracy of linear measurements on three imaging modalities: lateral cephalograms from a cephalometric machine with a 3 m source-to-mid-sagittal-plane distance (SMD), from a machine with 1.5 m SMD and 3D models from cone-beam computed tomography (CBCT) data. Methods: Twenty-one dry human skulls were used. Lateral cephalograms were taken, using two cephalometric devices: one with a 3 m SMD and one with a 1.5 m SMD. CBCT scans were taken by 3D Accuitomo® 170, and 3D surface models were created in Maxilim® software. Thirteen linear measurements were completed twice by two observers with a 4 week interval. Direct physical measurements by a digital calliper were defined as the gold standard. Statistical analysis was performed. Results: Nasion-Point A was significantly different from the gold standard in all methods. More statistically significant differences were found on the measurements of the 3 m SMD cephalograms in comparison to the other methods. Intra- and inter-observer agreement based on 3D measurements was slightly better than others. Limitations: Dry human skulls without soft tissues were used. Therefore, the results have to be interpreted with caution, as they do not fully represent clinical conditions. Conclusions: 3D measurements resulted in a better observer agreement. The accuracy of the measurements based on CBCT and 1.5 m SMD cephalogram was better than a 3 m SMD cephalogram. These findings demonstrated the linear measurements accuracy and reliability of 3D measurements based on CBCT data when compared to 2D techniques. Future studies should focus on the implementation of 3D cephalometry in clinical practice. © 2014 The Author.

Guerrero M.F.,University of Leuven and Oral and Maxillofacial Surgery | Beltran J.,Post University | de Laat A.,Stomatology and Maxillofacial Surgery | Jacobs R.,University of Leuven and Oral and Maxillofacial Surgery
Imaging Science in Dentistry | Year: 2015

Purpose: This study was performed to evaluate the relationship between pterygoid plate asymmetry and temporomandibular joint disorders. Materials and Methods: Cone-beam computed tomography (CBCT) images of 60 patients with temporomandibular disorders (TMD) involving pain were analyzed and compared with images of 60 age- and gender-matched controls. Three observers performed linear measurements of the lateral pterygoid plates. Results: Statistically significant differences were found between measurements of the lateral pterygoid plates on the site that had pain and the contralateral site (p<0.05). The average length of the lateral pterygoid plates (LPPs) in patients with TMD was 17.01±3.64 mm on the right side and 16.21±3.51 mm on the left side, and in patients without TMD, it was 11.86±1.97 mm on the right side and 11.98±1.85 mm on the left side. Statistically significant differences in the LPP length, measured on CBCT, were found between patients with and without TMD (p<0.05). The inter-examiner reliability obtained in this study was very high for all the examiners (0.99, 95% confidence interval: 0.98-0.99). Conclusion: Within the limits of the present study, CBCT lateral pterygoid plate measurements at the side with TMD were found to be significantly different from those on the side without TMD. More research is needed to explore potential etiological correlations and implications for treatment. © 2015 by Korean Academy of Oral and Maxillofacial Radiology.

Miclotte A.,Catholic University of Leuven | Franco A.,Pontifical Catholic University of Parana | Guerrero M.E.,University of Leuven and Oral and Maxillofacial Surgery | Guerrero M.E.,Scientific University of the South | And 2 more authors.
Surgical and Radiologic Anatomy | Year: 2015

Purpose: The present study aims to compare mandibular third molar position in relation to the mandibular ramus, mandibular third molar angulation, potential impaction and nerve involvement in orthodontic treated versus untreated subjects. Methods: The sample consisted of 300 panoramic radiographs 119 males (mean age 16.9 years); 181 females (mean age 16.8 years), contrasting an orthodontically treated (n = 150) to an untreated group (n = 150). Only patients with a full mandibular dentition were included. Pell and Gregory (Dent Digest 39: 330–338, 1933), Winter (Principles of exodontia as applied to the impacted third molars, 1926) and Félez-Gutierrez modified by Gomes (Study of nerve lesion following mandibular third molar surgery, 2011) classifications were used. Radiological information was used to predict eruption. Data was analyzed using frequency analysis and Chi-square testing. Results: 220 lower wisdom teeth (73.3 %) were impacted in the treated group, opposed to 236 impacted lower wisdom teeth (78.7 %) in the untreated group. A close relation with the mandibular nerve was observed 125 times (41.7 %) in the treated group, opposed to an incidence of 112 (37.3 %) in the untreated group. The differences were not statistically significant. A partial eruption was predicted for 153 (51 %) lower wisdom teeth in the treated group, opposed to 106 (35 %) in the untreated group and an impossible eruption in 67 (22 %) in the treated group, opposed to 130 (43 %). These differences were statistically significant (p < 0.05). Conclusions: The significant outcomes indicate that orthodontically treated patients may develop a higher likeliness to partially erupted third molars, which potentially leads to local clinical morbidities, such as pericoronitis and caries on adjacent teeth. In this context, it may support third molar extractions at an earlier stage in particular cases. © 2014, Springer-Verlag France.

Sun Y.,University of Leuven and Oral and Maxillofacial Surgery | Luebbers H.-T.,Brigham and Womens Hospital | Agbaje J.O.,University of Leuven and Oral and Maxillofacial Surgery | Kong L.,PLA Fourth Military Medical University | And 5 more authors.
Journal of Healthcare Engineering | Year: 2015

The aim of this study is to evaluate feasibility and accuracy of dental implant placement utilizing a dedicated bone-supported surgical template. Thirty-eight implants (sixteen in maxilla, twentytwo in mandible) were placed in seven fully edentulous jaws (three maxillae, four mandibles) guided by the designed bone-supported surgical template. A voxel-based registration technique was applied to match pre-and post-operative CBCT scans. T he mean angular deviation and mean linear deviation at the implant hex and apex were 6.4 ± 3.7 ° (0.7 °-14.8 °), 1.47 ± 0.64 mm (0.5-2.56 mm) and 1.70 ± 1.01 mm (0.71-4.39 mm), respectively. The presented bonesupported surgical template showed acceptable accuracy for clinical use. In return for reduced accuracy, clinicians gain accessibility when using this type of surgical template for both the maxilla and the mandible. This is particularly important in patients with reduced mouth opening.

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