Landes Constantin A, Laudemann Katharina, Petruchin Oksana, Mack Martin G, Kopp Stefan, Ludwig Björn, Sader Robert A, Seitz Oliver
Department of Oral, Maxillofacial, and Plastic Facial Surgery, Goethe University Frankfurt, Frankfurt am Main, Germany.
J Oral Maxillofac Surg. 2009 Oct;67(10):2287-301. doi: 10.1016/j.joms.2009.04.069.
To evaluate tripartite paramedian versus bipartite median osteotomy in surgically assisted rapid maxillary expansion. Tripartite osteotomy was performed between the lateral incisors and canines at the former premaxillary junction to avoid midline diastema, septal and columellar dislocation, and asymmetric expansion, minimizing high-distraction forces through bilateral doubled osteotomy on periodontia and thus reducing vestibular attachment loss and producing stable callus formation to avoid relapse.
The preoperative and postexpansion computed tomography data from 50 patients were analyzed in multiplanar viewing for bodily segment movement, vestibular bone loss, and transverse skeletal and dental widening with predefined landmarks. Of the 50 patients, 22 had undergone tripartite and 28 had undergone bipartite osteotomy.
Using an independent t test, both osteotomies permitted adequate transverse skeletal expansion in the premolars, converging, however, in the molars. Bipartite osteotomy resulted in less symmetry in transverse skeletal widening, greater bodily segment movement in the first premolar/molar, and greater vestibular bone loss. Tripartite osteotomy resulted in greater overall expansion and less bone remodeling. On variance analysis, tripartite bone-borne distraction resulted in the greatest decrease of transverse expansion in patients older than 20 years. The tripartite osteotomy also provoked distractor- and age-independent outward segmental movement. Bipartite osteotomy resulted in distractor- and age-independent inward segmental movement. Bipartite osteotomy showed the greatest bone resorption in patients younger than 20 years old in the molars and tripartite osteotomy in patients older than 20 years in the premolars.
Tripartite paramedian osteotomy allowed greater overall symmetric expansion compared with bipartite median osteotomy, with, however, a decline in transverse widening to the posterior. Bipartite osteotomy should be preferred whenever good periodontal status permits greater vestibular bone loss and a midline diastema and asymmetric expansion and a midline shift will be tolerated by the patient. Tripartite osteotomy should be chosen whenever a midline diastema and shift, septal and columellar dislocation, asymmetric expansion, and larger distraction forces on the paradontia, resulting in vestibular attachment loss, are to be avoided.
评估在外科辅助快速上颌扩弓中三部分正中截骨术与两部分正中截骨术的效果。三部分截骨术在前磨牙交界处的侧切牙和尖牙之间进行，以避免中线间隙、鼻中隔和鼻小柱脱位以及不对称扩弓，通过对牙周组织进行双侧双重截骨将高牵张力降至最低，从而减少前庭附着丧失，并产生稳定的骨痂形成以避免复发。
对50例患者术前及扩弓后的计算机断层扫描数据进行多平面观察，分析身体节段移动、前庭骨丢失以及利用预定义标志点进行的横向骨骼和牙齿增宽情况。50例患者中，22例行三部分截骨术，28例行两部分截骨术。
采用独立t检验，两种截骨术均能使前磨牙获得足够的横向骨骼扩弓，但磨牙处二者结果趋同。两部分截骨术导致横向骨骼增宽的对称性较差，第一前磨牙/磨牙处身体节段移动更大，前庭骨丢失更多。三部分截骨术导致整体扩弓更大且骨重塑更少。方差分析显示，三部分骨支持式牵张在20岁以上患者中导致横向扩弓减少最多。三部分截骨术还引发了与牵张器和年龄无关的向外节段移动。两部分截骨术导致与牵张器和年龄无关的向内节段移动。两部分截骨术在20岁以下患者的磨牙中显示出最大的骨吸收，而三部分截骨术在20岁以上患者的前磨牙中显示出最大的骨吸收。
与两部分正中截骨术相比，三部分正中截骨术能实现更大的整体对称扩弓，不过向后方的横向增宽会减少。只要牙周状况良好，患者能耐受更大的前庭骨丢失、中线间隙、不对称扩弓和中线移位，就应首选两部分截骨术。只要要避免中线间隙和移位、鼻中隔和鼻小柱脱位、不对称扩弓以及牙周组织上较大的牵张力导致前庭附着丧失，就应选择三部分截骨术。
