Evaluation of the Implantation Position of Mini-Screws for Orthodontic Treatment in the Maxillary Molar Area by a Micro Ct

Abstract

The interalveolar septum between the upper first molar and the second premolar of the separated human maxillary bone was three-dimensionally observed by micro CT to evaluate the appropriate mini-screw type implant placement position by considering the relationship between the tooth roots and the maxillary sinus. After taking micro CTs of 5 human maxillary bones, horizontally sectioned images of the interalveolar septum area 2, 4, 6, 8, 10, and 12 mm deep from the crest of the alveolar ridge were reconstructed by three-dimensional reconstruction software. The bucco-lingual and mesio-distal lengths and area in each sectioned interalveolar septum were measured using digital image measurement software. Using the results, the interalveolar septum area between the upper first molar and the second premolar approximately 6-8 mm deep from the alveolar crest in the tooth root apical direction was determined to be the safest position for mini-screw implantation. Furthermore, lateral implantation from the palatal side was deduced to be the safest approach.

“Safe Zones” for miniscrew implant placement in different dentoskeletal patterns

“…These results are in agreement with those of previous studies that assessed the interradicular spaces in subjects with minor or no malocclusion. [10][11][12][13][14][15] However, significant differences in the interradicular spaces between different dentoskeletal patterns were observed. Subjects with Class II skeletal patterns presented significantly greater interradicular distances and larger areas in the maxilla when compared with the subjects with skeletal Class III patterns.…”

“…Interradicular distance has been the conventional method for assessment of interradicular space using radiographic images. [10][11][12][13] Moreover, the use of the alveolar crest as a reference for measurements is relatively simple and reliable, and provides a clinical guideline for miniscrew placement. [10][11][12][13] However, the simple linear measurements at defined heights from the alveolar crest do not provide complete information about each interradicular space.…”

“…[6][7][8] Several studies have been performed to assess the safe locations in the interradicular spaces for miniscrew placement, the so-called ''safe zones.'' [9][10][11][12][13][14][15] A minimal clearance of 1 mm of alveolar bone around the screw has been recommended to preserve the periodontal health. 10 Therefore, when the diameter of the miniscrew and the minimum clearance of alveolar bone are considered, interradicular space larger than 3 mm is needed for safe miniscrew placement.…”

Microimplants in lingual orthodontics

“…Üst ön grup dişlerin retraksiyonu veya üst molar dişler-in intrüzyonu için amacıyla palatinal bölgede 2. premolar, 1. molar ve 2. molar dişler arasına yerleştirilebilmektedirl-er. 13,[15][16][17] 3. Üst molarların mezial veya distal hareketlerini veya üst arka dişlerin intruzyonunu sağlamak için üst kanin diş ile 1. premolar diş arasındaki bukkal bölgeye uygulanırlar.…”

“…Alt arka grup dişlerin protraksiyonun sağlamak amacı ile alt kanin ile premolar diş arasındaki bukkal bölgeye uygulanırlar. 13,15,[17][18][19] Ayrıca mikroimplantların dişsiz bölgelere, çekim boşluk-larına yerleştirilmesi ile bu bölgelere komşu olan dişlere ortodontik hareket vermek mümkün olmaktadır.…”