Department of Orthodontics and Dentofacial Orthopedics, Al-Ameen Dental College and Hospital, Vijaypura, Karnataka, India, Phone: +91 9422613939, e-mail:
Department of Orthodontics and Dentofacial Orthopedics, Al-Ameen Dental College and Hospital, Vijaypura, Karnataka, India.
J Contemp Dent Pract. 2021 Oct 1;22(10):1135-1143.
The purpose of the study was to evaluate the efficacy of infrazygomatic (IZ) implants along with mini-implants for full-arch distalization of maxilla and reduction of gummy smile in patients with class II division I malocclusion.
Ten orthodontic patients were taken from the department of orthodontics and dentofacial orthopedics. Each patient required distalization and intrusion of the complete maxillary arch as a part of the treatment plan. Patients were of class II malocclusion with gummy smile. Initial leveling and alignment were done by using 0.22″ slot Mclaughlin Bennett Trevisi (MBT) prescription. Fav Anchor infrazygomatic crest (IZC) implants of 2 mm of head diameter and 14 mm length were inserted between first and second molar and 2 mm above the mucogingival junction in the alveolar mucosa and in the anterior region, two titanium mini-implants of 1.4 mm head diameter and 6 mm length. The screws were loaded immediately with e-chain with a minimal force from mini-implants in the anterior region to crimpable hook placed between lateral and canine and continuing the same till the IZ implants. To measure the amount of distalization and reduction of gummy smile, pre- and postlateral cephalograms were taken and assessed. Pre- and postdistalization and intrusion readings of all patients were obtained and calculated statistically for quantifying the amount of distalization of maxillary arch and intrusion for reduction of gummy smile.
The distalization of the maxillary arch achieved was 4.6 mm which is clinically and statistically significant. The anterior teeth in the study were intruded with a minimum of 3.8 mm which is clinically and statistically significant; the gingival smile line was reduced with a mean of 3.4 mm which is clinically and statistically significant. Overbite correction of 4 mm was done with the mean difference of 4 mm which is also statistically significant.
The IZ bone screws can be effectively used as an absolute anchorage to correct class II skeletal discrepancy with gummy smile devoid of premolar extraction with noninvasive procedure.
The use of IZC implants along with anterior implants, a biomechanical approach is effective in achieving full-arch distalization of maxilla and intrusion as the force vectors allow that the line of action passes through the center of resistance (Cr) of the entire maxillary arch, facilitates the distalization and intrusion of the maxillary arch, establishes ideal occlusion, and improves the smile esthetics.
本研究旨在评估在下颌颧骨（IZ）植入物和微型植入物的辅助下，对 I 类 2 分类错牙合患者进行上颌全弓远移和减少露龈笑的疗效。
从正畸和口腔颌面正畸科选取 10 名正畸患者。每位患者都需要进行上颌全弓远移和内收，作为治疗计划的一部分。患者为 I 类 2 分类错牙合伴露龈笑。通过使用 0.22 英寸槽口 Mclaughlin Bennett Trevisi（MBT）处方进行初始排齐和平整。在下颌第一和第二磨牙之间以及牙槽黏膜和前牙区黏膜上距龈缘 2 毫米处插入直径为 2 毫米、长 14 毫米的 Fav Anchor 下颧骨嵴（IZC）植入物，在前牙区插入直径为 1.4 毫米、长 6 毫米的两颗钛微型植入物。在前牙区用微型植入物上的最小力将 E 链加载到螺丝上，使螺丝弯曲到放置在侧牙和尖牙之间的可卷曲挂钩上，并继续直到 IZ 植入物。为了测量远移量和减少露龈笑的程度，拍摄了治疗前后的侧位头颅定位片并进行了评估。测量了所有患者远移和内收前后的读数，并进行了统计学计算，以量化上颌弓的远移量和减少露龈笑的内收量。
上颌弓的远移量为 4.6 毫米，具有临床和统计学意义。前牙内收量最小为 3.8 毫米，具有临床和统计学意义；龈笑线减少了 3.4 毫米，具有临床和统计学意义。通过平均 4 毫米的差异，完成了 4 毫米的覆合矫正，这也具有统计学意义。
IZ 骨螺钉可作为一种绝对支抗，有效治疗伴有露龈笑的 II 类骨骼错牙合畸形，无需拔牙，采用非侵入性手术。
IZC 植入物与前牙植入物联合使用，生物力学方法可有效实现上颌全弓远移和内收，因为力向量允许作用线通过上颌全弓的中心阻力（Cr），有助于上颌弓的远移和内收，建立理想的咬合，并改善微笑美观。
