Computed tomographic analysis of tooth-bearing alveolar bone for orthodontic miniscrew placement.
BACKGROUND
When monocortical orthodontic miniscrews are placed in interdental alveolar bone, the safe position of the miniscrew tip should be ensured. This study was designed to quantify the periradicular space in the tooth-bearing area to provide practical guidelines for miniscrew placement.


METHODS
Computerized tomographs of 30 maxillae and mandibles were taken from nonorthodontic adults with normal occlusion. Both mesiodistal interradicular distance and bone thickness over the narrowest interradicular space (safety depth) were measured at 2, 4, 6, and 8 mm from the cementoenamel junction.


RESULTS
Mesiodistal space greater than 3 mm was available at the 8-mm level in the maxillary anterior region, between the premolars, and between the second premolar and the first molar at 4 mm. In the mandible, sufficient mesiodistal space was found between the premolars, between the molars, and between the second premolar and the first molar at the 4-mm level. Safety depth greater than 4 mm was found in the maxillary and mandibular intermolar regions, and between the second premolar and the first molar in both arches.


CONCLUSIONS
Subapical placement is advocated in the anterior segment. Premolar areas appear reliable in both arches. Angulated placement in the intermolar area is suggested to use the sufficient safety depth in this area.
Department of Orthodontics, Oral Science Research Center, Institute of Craniofacial Deformity, College of Dentistry, Yonsei University, Seoul, Korea.
Kee-Joon
KJ
Lee
Euk
E
Joo
Kee-Deog
KD
Kim
Jong-Suk
JS
Lee
Young-Chel
YC
Park
Hyung-Seog
HS
Yu
D000328:Adult; D000539:Alveolar Process / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D019412:Anatomy, Cross-Sectional; D001641:Bicuspid / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D001863:Bone Screws; D002508:Cephalometry; D003724:Dental Arch / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D003758:Dental Implantation, Endosseous / Q000592:standards*; D015921:Dental Implants; D005260:Female; D006801:Humans; D008297:Male; D008334:Mandible / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D008437:Maxilla / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D008875:Middle Aged; D008963:Molar / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D052280:Orthodontic Anchorage Procedures / Q000592:standards*; D012016:Reference Values; D014057:Tomography, X-Ray Computed; D019227:Tooth Apex / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D055815:Young Adult
D015921:Dental Implants