Résumé
The purpose of this study was to investigate the cortical bone thickness of the inter-dental area of both jaws for orthodontic miniscrew placement. The cone-beam computerized tomography images of 32 non-orthodontic adults with normal occlusion were taken to measure the cortical bone thickness in both jaws. One-way analysis of variance (ANOVA) was used to analyze the differences in cortical bone thickness. Buccal cortical bone in the mandible was thicker than that in the maxilla. In the maxilla, cortical bone thickness was thicker in the buccal side than in the palatal side. Buccal cortical bone thickness in the mandible was thickest at the site distal to the first molar, and in the maxilla it was thickest at the site mesial to the first molar, while in the palatal side of maxilla it was thickest at the site mesial to the second premolar. The changing pattern of cortical bone thickness varies at different sites. In the buccal side of maxilla, the thinnest cortical bone thickness was found to be at 4 mm level from the alveolar crest, while the thickest was at 10 mm level (except for the site mesial to the first premolar). The buccal cortical bone thickness at the sites mesial or distal to the first molar in the mandible and palatal cortical bone thickness of maxilla tended to increase with increasing distance from the alveolar bone.
Résumé
The purpose of this study was to investigate the cortical bone thickness of the inter-dental area of both jaws for orthodontic miniscrew placement. The cone-beam computerized tomography images of 32 non-orthodontic adults with normal occlusion were taken to measure the cortical bone thickness in both jaws. One-way analysis of variance (ANOVA) was used to analyze the differences in cortical bone thickness. Buccal cortical bone in the mandible was thicker than that in the maxilla. In the maxilla, cortical bone thickness was thicker in the buccal side than in the palatal side. Buccal cortical bone thickness in the mandible was thickest at the site distal to the first molar, and in the maxilla it was thickest at the site mesial to the first molar, while in the palatal side of maxilla it was thickest at the site mesial to the second premolar. The changing pattern of cortical bone thickness varies at different sites. In the buccal side of maxilla, the thinnest cortical bone thickness was found to be at 4 mm level from the alveolar crest, while the thickest was at 10 mm level (except for the site mesial to the first premolar). The buccal cortical bone thickness at the sites mesial or distal to the first molar in the mandible and palatal cortical bone thickness of maxilla tended to increase with increasing distance from the alveolar bone.
Sujets)
Adulte , Femelle , Humains , Mâle , Jeune adulte , Vis orthopédiques , Tomodensitométrie à faisceau conique , Méthodes , Implantation endodontique endo-osseuse , Méthodes , Mandibule , Imagerie diagnostique , Chirurgie générale , Maxillaire , Imagerie diagnostique , Chirurgie générale , Radiographie dentaire , Méthodes , Reproductibilité des résultats , Sensibilité et spécificité , Chirurgie assistée par ordinateur , MéthodesRésumé
<p><b>OBJECTIVE</b>To investigate the palatal bone thickness in adult with normal occlusion.</p><p><b>METHODS</b>The cone beam computerized tomography records of 32 adults with normal occlusion (16 males and 16 females), mean age (30.1 ± 6.5) years, were used to measure the bone thickness at midpalatal area and the right and left palatal sides. Coronal slices at 3 mm intervals were generated. Slice 1 was the coronal slice through the posterior border to the incisive foramen, while Slice 7 was the coronal slice 18 mm away from the incisive foramen. At each coronal slice, the midpalatal sites were Site M and the sites on the exterior margin of the hard palatal were Site D. Four equally divided parts on the line linking Site M to Site D were named Site A, B, C from the interior to the exterior respectively. Palatal bone thickness were measured at these sites.</p><p><b>RESULTS</b>Significant differences were noted from Slice 1 to Slice 7, the bone thickness of palate tended to decrease from the front to the back. The thickest site at hard palatal was 12.6 mm, locating at Site D of Slice 1, while the thinnest site was 2.7 mm, locating at Site B of Slice 7. The palatal bone thickness ranged from 10.5 mm (maximum) to 5.8 mm (minimum) at Slice 2 and Slice 3. No statistical significance was found between the left and right sides (P > 0.05).</p><p><b>CONCLUSIONS</b>The favorable sites for miniscrew placement were the anterior region of the hard palate in adult. The length of miniscrew ranged from 5 mm to 10 mm can be placed from 6 mm posterior to the incisive foramen.</p>