| Objective:Based on surgery-first approach,patients with skeletal Angle Class III malformations requiring orthognathic surgical treatment were classified.A suitable surgical procedure was selected for each subtype and postoperative rapid orthodontics was performed.Before and after treatment,the sagittal angulation and linear distance of the maxillofacial hard tissue was measured and analyzed to evaluate the therapeutic effect of this malformation.Select the surgical plan for clinical diagnosis and treatment,evaluate the efficacy of the method and data basis.MethodsThe X-ray cephalometric of patients with skeletal Angle Class III malocclusion treated with combination of orthognathic surgery and orthodontics were collected in the Department of Maxillofacial Plastic Surgery,Plastic Surgery Hospital,Chinese Academy of Medical Sciences from August 2014 to March 2017 were included in this study.There were 18 males and 25 females.Age 16-37,average 21.55 plus or minus 3.53 years.The landmarks related to the hard tissue of the representative cranial position in the preoperative(TO),postoperative(T1)days,postoperative 6 months or more(T2)measurements were analyzed and compared.Objective evaluation of surgical efficacy and postoperative stabilityand recurrence.Clinical classification and appropriate surgical methods:Type I:Ia.Complete skeletal mandibular protrusion with complete AnglE Class III malocclusion;Ib.skeletal mandibular protrusion with complete Angle Class III malocclusion.Intraoral sagittal split ramus osteotomy(SSRO)was used to treat patients with sagittal split ramus osteotomy(SSRO).Type ?:Ila.Osteoanglionic Angle Class III malocclusion with maxillary retraction and mandibular protrusion(excluding maxillary retrusion in the cleft lip and palate).The Lefort type I osteotomy was performed before the bilateral mandibular osteotomy.I1b.Implantation of the Lefort type I osteotomy with a pseudo-mandibular protrusion(simple maxillary retraction)of the Angle Class ? malocclusion.Type III:Mandibular alveolar protrusion(excluding functional),skeletal bone osteogenesis,mild bony osseous Angle Class ? malocclusion with orthodontic treatment and anterior occlusal,anterior protrusion not obvious.Anterior mandibular subapical osteotomy(AMSO)was used to retract the osteotomy of the anterior submandibular osteotomy.Result:Typel:treatment before and after the change of hard tissue marker points.Immediately after surgery,SNB,?ANB,and ?SND decreased by 4.41°,4.78°,and 4.06° respectively(p<0.001).Li,B,D,Pog,and Me retreated by 7.77mm,7.76mm,and 10.55mm,8.28 mm 8.59 mm respectively in the sagittal direction.(p<0.001).After surgery,the type III facial shape can be instantly improved and approach the normal range of the Chinese people.overjet changes from-1.14mm to 5.80mm.Due to the reserve to compensate for the gap,it appears to be slightly larger.After statistical analysis of postoperative stability(T2-T1),The recurrences of zSNB-ANB and Z-SND were 17.9%,23.4%,and 21.6%respectively(p<0.001),The recurrences of Li,B,and D,Pog and Me in the sagittal direction were 26.13%.19.07%.16.21%?23.07%>24.10%respectively(p<0.001).The average recurrence was between 1.7 and 2.07 mm,within acceptable limits.Type II:Treatment before and after the change of hard tissue marker points.Immediately after treatment,the?SNB and-ANB of hard tissue in the sagittal direction were decreased by 5.020,10.2°,and ?SNA increased by 5.01°(p<0.001)and A advanced 4.78mm(p<0.001).Li,B,Pog,Me retreated in a sagittal direction by 6.19 mm,6.15 mm,6.81 mm,and 9.07 mm(p<0.001).Overjet changes from-5.96mm to 6.08mm.When the two jaws undergo surgery at the same time,the movement of the single jaw bone is appropriate,and a more ideal aesthetic effect can be obtained instantaneously and the relationship between the dentition tip and the stump can be stabilized.Due to the reserve to compensate for the gap,it appears to be slightly larger.After statistical analysis of postoperative stability(T2-T1),The recurrences of ?SNB and ?ANB were 20.3%and 18.3%,and ?SNA was decreased by 7.5%(p>0.05)at 6 months and beyond.The recurrences of B.Pog in the sagittal direction were 20.7%,14.95%,18.9%(p<0.05),Me recurrence in the sagittal 22.16%(p>0.05).The average recurrence ranged from 0.92 to 2.01 mm and was within an acceptable range.Overjet changes from 6.01mm to 2.88mm.The maxillary osteotomy has good stability after operation.The displacement of the jaws is small,the recurrence distance is relatively small,and the surgical effect is stable.Type III:treatment before and after the change of hard tissue marker points.Immediately after treatment,the ?SNB and ?ANB decreased by 4.02° and 3.7°respectively.Li,B retreated 7.49mm 7.69mm(p>0.05)in the sagittal direction respectively.In terms of recurrence,the ?SNB and ?ANB increased by 18.7%and 12.4%,respectively,LI and B were shifted to 0.93mm and 1.10mm respectively,and the recurrence was less than 2mm.Overjet changes from-1.07mm to 4.07mm and tends to be normal.The efficacy of this group of patients was positive,and the correction of anterior occlusal and facial blemishes was effectively corrected.Because the operation did not change the molar relationship,the relationship between molars was relatively stable,and the impact of mandibular rotation and recurrence was less affected.Therefore,postoperative stability was better than those of type I and II.In conclusionBased on Surgery-first approach,appropriate surgical procedures were used to correct different types of deformities.Effective treatment of skeletal Angle Class III malocclusion resulted in a normal position of the upper and lower jaws and a significant improvement in the positive profile.1.The results of the hard tissue measurement of dental malformation after treatment are close to normal,and the appearance is satisfactory.2.The orthodontic treatment time is shortened based on Surgery-first approach and the rapid orthodontics achieves a good sharp nest relationship;3.For the Skeletal Angle Class III malocclusion Patients were classified into subtypes,and the necessity of suitable surgical procedures was selected,and it was helpful to achieve a stable surgical outcome.4.SFA was stable and the recurrence rate was closer than the traditional mode.The effect of SFA treatment needs long-term follow-up and observation.According to the stability classification and statistical data of the three groups of postoperative stability,the stability:AMSO is stronger than LEfort I+BSSRO is stronger than BSSRO based on Surgery-first approach. |
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