Assessing bone volume for orthodontic miniplate fixation below the maxillary frontal process

• Published in: Journal of orofacial orthopedics 2014-09, Vol.75 (5), p.399-408
• Main Authors: Präger, T.M., Brochhagen, H.G., Mischkowski, R., Jost-Brinkmann, P.-G., Müller-Hartwich, R.
• Format: Article
• Language: English
• Subjects: Adult; Bone Plates; Bone Screws; Dental Implantation - methods; Dentistry; Female; Humans; Imaging, Three-Dimensional - methods; Male; Malocclusion, Angle Class III - diagnostic imaging; Malocclusion, Angle Class III - therapy; Maxilla - diagnostic imaging; Maxilla - surgery; Medicine; Middle Aged; Miniaturization; Oral and Maxillofacial Surgery; Organ Size; Original Article; Orthodontic Anchorage Procedures - instrumentation; Orthodontic Anchorage Procedures - methods; Radiography; Reproducibility of Results; Sensitivity and Specificity; Suture Anchors; Young Adult
• ISSN: 1434-5293; 1615-6714
• DOI: 10.1007/s00056-014-0234-8

Objectives The maxillary bone below the frontal process is used for orthodontic anchorage; indications have included skeletally anchored protraction of the maxilla for treating Class III malocclusions or the intrusion of teeth in patients with a deep bite. This study was conducted to assess the condition of bone before cortically implanting miniplates in that area of the maxilla. Patients and methods A total of 51 thin-sliced computed tomography scans of 51 fully-dentate adult patients (mean age 24.0 ± 8.1 years; 27 men and 24 women) obtained prior to third-molar osteotomy were evaluated. Study parameters included total bone thickness, thickness of the facial cortical plate, and width of the nasal maxillary buttress. All these parameters were measured at different vertical levels. Results The bone volume adjacent to the piriform aperture was most pronounced at the basal level and decreased progressively toward more cranial levels. The basal bone structure had a mean total thickness of 7.8 mm, facial cortical plate thickness of 1.9 mm, and nasal maxillary buttress width of 9.2 mm. At 16 mm cranial to the aperture base, these values fell to 5.6 mm, 1.3 mm, and 5.8 mm, respectively. Conclusion These bone measurements suggest that screws 7 mm in length can be inserted at the base level of the piriform aperture and screws 5 mm long at the cranial end of the bone.