Evaluation of interdental space of the maxillary posterior area for orthodontic mini-implants with cone-beam computed tomography

Seong-Hun Kim, Hyeong-Gun Yoon, Yong-Suk Choi, Eui-Hwan Hwang, Yoon-Ah Kook, Gerald Nelson
American Journal of Orthodontics and Dentofacial Orthopedics 2009, 135 (5): 635-41

INTRODUCTION: Our objectives in this study were to measure in a group of patients the interradicular spaces between the maxillary second premolar and first molar, which is often used as placement sites for mini-implants, and to suggest simple guidelines for safe placement.

METHODS: Cone-beam computed tomography was used in 35 patients to measure interdental spaces and distances between the surface of the cortical bone and the closest interradicular area apically in 1-mm intervals in 9 axial images from the cementoenamel junction (CEJ). The cone-beam computed tomography data were analyzed by using anlaysis of variance (ANOVA) to evaluate the differences in interradicular distances, cortical bone surfaces, and narrowest interradicular spaces. A t test was also performed to evaluate sex and placement side differences.

RESULTS: Interradicular space became wider toward the apical area; several axial planes showed statistically nonsignificant differences from the CEJ to the root, and the average distance from the surface of the cortical bone to the area of the closest interradicular space was over 5 mm in the most sections.

CONCLUSIONS: Guidelines for safe placement are as follows: the initial point for mini-implant placement is near the mucogingival line (2-4 mm from the CEJ) and less than a 45 degrees apical angulation to the long axis of tooth, with a mini-implant diameter of 1.4 to 1.8 mm and length of about 6 mm (bone contact). A larger placement angle would increase the cortical bone contact; however, it is difficult to apply various traction materials and might increase the danger of maxillary sinus perforation.

Full Text Links

Find Full Text Links for this Article


You are not logged in. Sign Up or Log In to join the discussion.

Related Papers

Remove bar
Read by QxMD icon Read

Save your favorite articles in one place with a free QxMD account.


Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"