Abstract:

Objective

To anlysis the bone thickness of the palate in adolescents by Cone-beam computed tomography， and to explore the difference of the various regions of palate and the same regions of palate in adolescence with different sagittal skeletal patterns.

Methods

Ninety adolescents，12 to 16 years old， with average mandibular angle were selected and scanned with Cone-beam computed tomography. They were divided into three groups of ClassⅠ， ClassⅡ， and Class Ⅲaccording to their sagittal skeletal patterns. Each group consisted of 15 boys and 15 girls. The line of the posterior rim of the incisive foramen and the posterior nasal spine was made as the horizontal plane， the palatal bone thickness was measured at 0.0 mm， 2.0 mm， 4.0 mm and 6.0 mm lateral to the midpalatal suture on the sagittal plane and at 4.0 mm， 8.0 mm， 16.0 mm， 20.0 mm， 24 mm posterior to the level of the posterior margin of the incisive foramen on the coronal plane.

Results

（1）The palatal bone thickness increased from anterior to posterior in midpalatal suture， and decreased from anterior to posterior in mesial and lateral to midpalatal suture（P＜0.05）.（2）The palatal bone thickness increased from midpalatal suture to lateral region in anterior ，and decreased from midpalatal suture to lateral area in middle and posterior region（P＜0.05）. （3）Significant differences were observed in different sagittal skeletal patterns at the same region of palate （P＜0.05）. At the areas of Anterior Midline， Middle Midline， Posterior Midline， Anterior Medial， Anterior Lateral， there was significantly lower bone thickness in Class Ⅲthan in Class Ⅰand Class Ⅱand at the areas of Middle Medial， Posterior Medial， Middle Lateral，Posterior Lateral， Class Ⅲlower than ClassⅡonly.

Conclusions

（1）The best site for palatal implant anchorage is the anterior region in lateral to midpalatal suture； （2）The thinnest bone thickness was in Class Ⅲat the same region of palate， where was more reluctant to the damage of the basis of nose. We suggested to choose the shorter palatal implant anchorage for Class Ⅲ.

Key words: Cone-beam computed tomography, Sagittal skeletal patterns, Palate, Bone thickness