Plate fixation after mandibular osteotomy

Skeletal asymmetry in patients who undergo orthognathic surgery is frequently associated with postoperative temporomandibular joint (TMJ) disorders caused by condylar rotation. This study was designed to elucidate the relation between changes in the condylar long axis and TMJ function after bisagittal split osteotomy (BSSO). A total of 42 patients with mandibular prognathism underwent BSSO. Split osseous fragments were secured by standard titanium plates in 22 patients; bent titanium plates were used to secure fragments in 20 patients. The angle of the bent plates was adjusted to avoid displacement of the condyle after osteotomy, as compared with condylar position on preoperative submental-vertical (S-V) cephalograms. The postoperative position of the condyle was assessed on X-ray film, and changes in TMJ function were evaluated. The condylar long axis differed significantly on X-ray film between patients using a standard titanium plate and those using a bent plate (P<0.05), and no sign of TMJ functional impairment was noted in the bent-plate group. Although the use of bent plates requires further study, maintenance of a suitable position of the condyle relative to the condylar axis is one of the conditions for a successful outcome of BSSO.     

双板坚固内固定在髁突骨折手术中的应用及效果评价

目的 探讨双板坚固内固定在下颌骨髁突骨折手术中的应用及效果评价。方法 对28例下颌骨髁突骨折患者行2块钛板坚固内固定术,术后随访拍摄全景片或三维CT,对患者的咬合关系、张口度、张口型、钛板及骨折情况等进行评价。结果 28例患者术后骨折固位良好;咬合关系、张口度、张口型恢复正常;无1例出现钛板变形或断裂、骨折移位;2例出现面神经轻度瘫痪,予以神经营养药物治疗后,3月内恢复正常;2例术后1月出现颞颌关节弹响,取出钛板后好转。结论 双板坚固内固定治疗下颌骨髁突骨折是一种较为理想的方法。     

Maxillary stability following Le Fort I osteotomy in combination with sagittal split ramus osteotomy and intraoral vertical ramus osteotomy: a comparative study between titanium miniplate and poly-L-lactic acid plate.

PURPOSE: The purpose of this study was to compare changes in maxillary stability after Le Fort I osteotomy with titanium miniplate and poly-L-lactic acid (PLLA) plate (Fixsorb-MX; Takiron Co, Osaka, Japan). PATIENTS AND METHODS: The subjects were composed of 47 Japanese patients with diagnosed jaw deformity: 24 underwent Le Fort I osteotomy and sagittal split ramus osteotomy (SSRO); and 23 underwent Le Fort I osteotomy intraoral vertical ramus osteotomy without internal fixation. Each group was divided into titanium plate and PLLA plate groups. Time course changes between plate groups were compared using lateral and posteroanterior cephalography. RESULTS: Significant differences were identified between titanium plate and PLLA plate groups in A point after Le Fort I osteotomy and SSRO (P < .05). Significant differences existed between titanium plate and PLLA plate groups in vertical component of posterior nasal spine after Le Fort I osteotomy in both combinations with SSRO and intraoral vertical ramus osteotomy (P < .05). However, no significant differences were identified in measurements on posteroanterior cephalography. CONCLUSION: These results suggest a slight tendency for vertical impaction after Le Fort I osteotomy both in combination with SSRO and intraoral vertical ramus osteotomy with PLLA plates, although differences in time course changes were not clinically apparent, and normal occlusion was established in all patients.     

翼外肌-髁突解剖复位内固定治疗髁突骨折的探讨

目的:探讨髁突骨折进行解剖复位和小型钛板坚强内固定的手术适应证、方法和治疗效果。方法:以髁头脱位骨折、髁颈和髁颈下骨折移位角度大于30°～45°、下颌支垂直高度降低超过4～5mm为适应证,对收治的23例28侧髁突骨折患者采用改良耳颞部"拐杖"型切口或颌后进路,行翼外肌-髁突解剖复位及张力带小型钛板坚强内固定。术后3～6个月复诊,检查面型、开口度、开口型、咬合关系、咀嚼力,并以此进行疗效评价。结果:所有患者面型对称,开口度较术前明显增大,开口型显著改变。2例术后错牙合患者经1周颌间牵引,恢复正常。影象学检查示髁突无移位,骨折无错位。钛板无移位,髁突表面无明显吸收现象。患者咀嚼有力。2例面瘫患者经治疗后3个月恢复。结论:选择合适病例,进行翼外肌-髁突开放性解剖复位固定,是一种既能恢复解剖形态又能恢复咀嚼功能的有效方法。     

坚固内固定治疗髁突中低位骨折15例报告

目的:探讨手术切开复位坚固内固定治疗髁突中低位骨折的治疗效果.方法:对15例髁突中低位骨折病例施行开放复位行小型钛板坚固内固定治疗,记录手术前后张口度、面神经损伤及咬合关系恢复情况及术后颞颌关节功能状况,手术前后全颌曲面断层片及CT对比骨折复位与愈合状况.结果:所有患者张口度均＞3 cm,咬合关系良好.关节区疼痛和弹响2例,面神经暂时性损伤4例.影像学检查显示髁突外形良好.结论:髁突中低位骨折明显移位者应用微型钛板内固定可获得满意效果.     

翼外肌-髁突解剖复位内固定治疗髁突颈骨折60例的临床分析

目的 探讨髁突颈部骨折时进行髁突-翼外肌解剖复位坚强内固定的适应证、手术方法 及术后效果。方法 对髁突颈部骨折出现髁头脱位突破关节囊、髁突和髁突颈下骨折移位成角大于30°~45°、下颌支垂直高度降低超过4~5 mm的骨折患者,采用耳屏前绕耳轮脚向上后耳颅沟切口,行翼外肌-髁突肌解剖复位坚强内固定方法 治疗。术后1、3、6个月复诊,检查面型、开口度、开口型、牙合关系、咀嚼力、面神经功能,三维CT重建上下颌骨,根据临床和影像学进行评价。结果 术后1月,所有患者面型对称、牙合关系好、开口度均较术前增大;无骨折移位、患侧咀嚼力减弱、8例额纹变浅。3月后,所有病例面型对称、开口度≥3.5 cm、开口型无偏斜、骨折一期愈合、髁突表面未见骨质吸收、面神经瘫痪症状恢复、双侧咬合力对称。6月后观察所有项目同术后3月。结论 髁突骨折经耳屏前后上绕耳轮脚切口,能较好的保护颞下颌关节区相关血管神经;对髁突颈部骨折行翼外肌-髁突解剖结构开放性复位内固定,是一种恢复解剖形态和关节功能的有效方法 ,在术后3月内可判定其效果。     

Functional and radiographic long-term results after bad split in orthognathic surgery

Bilateral sagittal split osteotomy (BSSO) is a standard procedure in orthognathic surgery. The aim of the present study was to perform a matched pair analysis (bad sagittal split versus regular sagittal split) regarding the functional and radiographic long-term results after BSSO. Of 110 cases of mandibular hypoplasy treated with BSSO, 7 cases of bad sagittal splits (Group A) were selected, clinically examined and matched to 7 cases where no bad split occurred (Group B). The Research Diagnostic Criteria for Temporo Mandibular Disorders (RDC/TMD), condylar morphology scale (CMS) and ramus height measurements using orthopantomograms were carried out in the follow-up period to observe the clinical and functional status and condylar resorbtion or remodelling. The mean follow-up time was 28.6 months. The RDC/TMD examination did not show a higher incidence of temporomandibular dysfunction, including pain or clicking in the bad split group. Patients without a bad split showed statistically significant (p<0.05) better mouth opening. The CMS measurements were comparable in both groups. When compared with regular splits, bad splits, if treated in an appropriate manner, have a good chance of functional success, although, some mandibular movements can be compromised.     

髁突多发性骨折微型钛板内固定的近期观察

目的:观察髁突多发性骨折后,微型钛板内固定的疗效。方法:8例11侧髁突多发性骨折病例,术中将多发性骨折的髁突1.0cm以上的骨折片复位,微型钛板固定,基本恢复解剖形态。结果:本组病例术后张口度基本正常,前伸运动、侧向运动无障碍,咬合关系基本正常。结论:微型钛板内固定可有效的治疗髁突多发性骨折。     

Skeletal stability after mandibular setback surgery: Comparison between the hybrid technique for fixation and the conventional plate fixation using an absorbable plate and screws

PurposeThe purpose of this study was to compare the temporal changes in condylar long axis and skeletal stability after sagittal split ramus osteotomy (SSRO) with the hybrid fixation technique and the conventional plate fixation.Patients and methodsOf 44 Japanese patients diagnosed with mandibular prognathism, 22 underwent SSRO with the conventional plate fixation (1 u-HA/PLLA plate and 4 monocortical screws in each side) and 22 underwent SSRO with a hybrid fixation technique (1 u-HA/PLLA plate and 4 monocortical screws and bicortical screw in each side). The temporal changes in condylar long axis and skeletal stability were assessed by axial, frontal, and lateral cephalograms. After surgery, breakage of the plate and screws was checked by 3-dimensional computed tomography (3DCT).ResultsAlthough there was a significant difference between the groups regarding Me–Ag in T1 (P = 0.0138), there were no significant differences between the groups for the other measurements in lateral, frontal and axial cephalometric analysis in each time interval. In two cases, 4 sides in the conventional plate fixation group, failure of the absorbable plate was found by 3DCT. However, there was no breakage in the hybrid fixation group.ConclusionThis study suggested that there were no significant differences in the postoperative temporal changes between the two groups in mandibular setback surgery.     

Functional and radiological results of open and closed treatment of intracapsular (diacapitular) condylar fractures of the mandible

The study was performed to evaluate and compare the results of open and closed treatments of diacapitular fractures of the mandible. Following open reduction and internal fixation (ORIF) 14 patients with 15 displaced condylar fractures, which had caused a shortening of the mandibular ramus, were examined clinically (Helkimo index), radiologically (Orthopantomogram, Clementschitsch [reversed Towne's] view, Submentovertex view) and axiographically (CARDIAX). These findings were compared to a group of 29 patients with 34 similar condylar fractures which had been treated using closed techniques. Following ORIF patients showed better radiological results with regard to the mandibular ramus height, resorption and pathological changes to the condyle, compared to the patient group after closed functional treatment. In both groups some signs of dysfunction persisted, although there were slightly better results in the ORIF group. In 30% of the closed treatment group, lateral deviation during mouth opening, crepitus and occlusal disturbances were noted. No cases of occlusal disturbance were observed in the ORIF group. The axiographic examinations revealed a significant limitation of movement of the fractured condyle in both groups. However, after open treatment, the temporomandibular joint displayed significantly less irregularities in the condylar paths. In cases of complex reconstruction of the mandibular condyle, ORIF appears to improve the function of fractured condyles, when combined with a postoperative therapeutic exercise regime.     

Condyle-preserved arthroplasty versus costochondral grafting in paediatric temporomandibular joint ankylosis: a retrospective investigation

We aimed to evaluate results of condyle-preserved arthroplasty and costochondral grafting in growing children with temporomandibular joint ankylosis through medium-term follow-up and three-dimensional metric analysis. We assessed 11 patients (14 sides) with type II ankylosis (group A) and 11 patients (13 sides) with type III/IV (group B) from January 2012 to December 2015. Group A patients received condyle-preserved arthroplasty and group B patients received costochondral grafting. Postoperative computed tomography was used to measure condylar height, condylar width, mandibular ramus height and mandibular body length. Changes in maximum mouth opening were evaluated >1 year postoperatively.Postoperative follow-up showed similar average maximum mouth opening and one case of recurrence in each group. Computed tomography measurements showed that condylar width and mandibular ramus height increased in both groups A and B (P < 0.05). Moreover, in group A, condylar angulation of medially displaced malformation decreased by 13.2° (P < 0.05), and mandibular body length increased by 5.7 mm (P < 0.05). Thus, both condyle-preserved arthroplasty and costochondral grafting were effective surgical methods for treatment of temporomandibular joint ankylosis. Moreover, compared with group B, group A patients manifested more remarkable mandibular growth, at least in the anteroposterior direction of the mandibular body.     

替牙期骨性Ⅲ类不同垂直骨面型患者的髁突形态特点

目的 比较替牙期骨性Ⅲ类不同垂直骨面型患者的髁突形态特点及差异,为替牙期颅面部生长发育的研究和临床诊疗提供一定的参考依据。方法 选择替牙期骨性Ⅲ类错患者共60例为研究对象,按照不同的垂直骨面型分为高角组、均角组和低角组,每组20例。采用计算机辅助X线头影测量技术,对3组患者的全颌曲面断层片进行测量,比较各组间髁突形态特点。结果 替牙期3组患者的髁突上部高度h值有统计学差异（P＜0.01）,高角组最小,低角组最大（P＜0.05）;升支高度RH值组间无统计学差异（P＞0.05）;h/RH值组间有统计学差异（P＜0.01）,高角组低于均角组和低角组（P＜0.05）;髁突高度与髁突颈部宽度的比值在组间亦无统计学差异（P＞0.05）。结论 替牙期骨性Ⅲ类不同垂直骨面型患者的髁突形态存在差异,这可能与不同垂直骨面型的生长趋势有关。     

Comparison of stability of mandibular segments following the sagittal split ramus osteotomy with poly-l-lactic acid (PLLA) screws and titanium screws fixation

The purpose of this study was to retrospectively compare the stability of the mandible following the surgical orthodontic treatment by sagittal split ramus osteotomy (SSRO) and orthodontic multi-bracket treatment using fixation methods with poly-l-lactic acid (PLLA) or titanium screws. The sample examined was 23 subjects with PLLA screws (PLLA group) and 22 subjects with titanium screws (Titan group). Lateral cephalometric radiographs were reviewed before surgery (T0), 2–3 days after surgery (T1), 1 month after surgery (T2), and after postoperative orthodontic treatment (T3) and changes in the position of bony segments were examined by cephalometric linear and angular measurements. A similar movement of the mandible following setback surgery was indicated, and statistical analysis showed no significant differences in skeletal changes between the two groups during whole postoperative periods. However, a relapse following surgical counterclockwise rotation of the distal segment in PLLA group tended to be slightly greater during T1–T2 compared with Titan group. These results suggest that a use of the PLLA screw fixation may not influence on the stability of bony segments after mandibular setback surgery by SSRO during the postoperative period, although a slight tendency for clockwise rotation of the distal segment was indicated in patients with PLLA screws. It is suggested that fixation of bony segments with PLLA screws after SSRO may be effective in properly selected cases.     

髁突骨折手术治疗的临床研究

目的：探讨手术治疗髁突骨折的适应证、技术要点和并发症的发生因素。方法：回顾分析5年来采用手术治疗的116例髁突骨折病例的临床资料,分别采取切开复位内固定术和髁突摘除术,随访3个月至3年,复查内容包括患者咬合关系、开口度、开口型、神经损伤、颞下颌关节症状、面型和X线检查。结果：外形和功能均显著恢复,113例咬合关系恢复正常,占97.4%;115例张口度恢复正常,占99.1%;X线复查髁突骨折解剖复位率94.8%;15例儿童患者恢复良好,无下颌骨发育障碍等严重并发症发生。结论：坚强内固定技术是治疗髁突骨折的较好方法,严重移位或脱位的儿童髁颈和髁颈下骨折应采用可吸收接骨板进行内固定。     

Maxillary stability after Le Fort I osteotomy using three different plate systems

The purpose of this study was to compare postoperative changes in maxillary stability after Le Fort I osteotomy in three groups: with an unsintered hydroxyapatite (u-HA)/poly-L-lactic acid (PLLA) plate; a PLLA plate; and a titanium plate. Subjects comprised 60 Japanese patients diagnosed with mandibular prognathism. All patients underwent Le Fort I osteotomy and bilateral sagittal split ramus osteotomy. All patients were randomized in groups of 20 to a u-HA/PLLA group, a PLLA plate group and a titanium plate group. Changes in postoperative time intervals between the plate groups were compared using lateral and posteroanterior cephalography. The uHA/PLLA group had significantly larger values than the PLLA group regarding change of mx1-S perpendicular to SN between 3 and 12 months (T3) (P=0.0269). The uHA/PLLA group had a significantly larger value than the PLLA group regarding change of S-A perpendicular to SN between baseline and 1 month (T1) (P=0.0257). There was no significant difference in the other measurements. This study suggests that maxillary stability with satisfactory results could be obtained in the u-HA/PLLA, PLLA plate and titanium plate groups, although there was a slight difference between the u-HA/PLLA and PLLA plate systems in Le Fort I osteotomy.     

下颌骨髁突不同类型骨折钛板内固定手术治疗相关影响因素分析

目的：分析下颌骨髁突不同类型骨折进行钛板内固定手术及其影响术后并发症的相关因素,为以后下颌骨髁突骨折治疗总结经验以便更好的为患者服务。方法：收集温州医科大学附属口腔医院2003年4月~2012年4月手术完成的下颌骨髁突骨折行钛板内固定患者,手术前后复查对比下颌骨全景片、下颌骨平扫CT、下颌骨矢状CT及颅颌三维CT重建。依据下颌骨骨折部位分为髁突囊内骨折,髁突颈部骨折,髁突基部骨折3组,对3组骨折术后患者的咬合状况、开口度、面神经功能等恢复情况进行回顾性分析。结果：210例随访病例中,术后咬合关系恢复不良30例;螺钉松动57枚,钛板断裂0例,面神经颧支损伤15例,面神经颞支损伤30例,张口受限伴下颌运动曲线患侧偏斜35例。结论：解剖手术能力或者面神经的个体变异;创口感染;不适当的应力集中、钛板和螺钉的位置、数量及固定部位,颌间牵引,关节周围相关软组织复位状况等为影响下颌骨髁突骨折坚强内固定手术并发症相关因素。     

A long-term comparative study of two rigid internal fixation techniques in terms of masticatory function and neurosensory disturbance after mandibular correction by bilateral sagittal split ramus osteotomy

Bilateral sagittal split ramus osteotomy (BSSO) is widely used to treat mandibular prognathism. Several methods have been described for fixation of the bony segments. This study compared two methods of rigid fixation (bicortical screws and monocortical miniplates) to identify differences in postoperative masticatory function and neurosensory disturbance after 5 years of mandibular set-back correction. 77 women who had undergone BSSO for Class III malocclusion were reviewed, and masticatory functions and neurosensory recovery were examined with the appropriate indicators pre- and postoperatively (at approximately 1 month, and 1, 2, 3, 4, and 5 years). Masticatory function exhibited similar recovery patterns in both groups. Orthognathic surgery improved occlusal force and occlusal contact area, but longer than 4 years after surgery may be required for postoperative occlusal functions in prognathic patients to reach the level of healthy subjects. The groups showed no significant differences in the recovery of parameters of masticatory functions and neurosensory disturbance even 5 years after surgery. In the evaluation of temporomandibular joint function using the Helkimo index, the score was significantly higher for the screw group than for the miniplate group. This suggests that BSSO fixed with miniplates may offer a relatively safe and reliable procedure yielding adequate results and high patient satisfaction.     

The Anatomical Basis for Plate Fixation in BSSO to Minimize Condylar Torquing: A Comparative CT Study of Mandibular Advancement and Setback

IntroductionCondylar displacement after bilateral sagittal-split osteotomy (BSSO) occur in the sagittal plane as clockwise/counter-clockwise rotation of the ramus, in the coronal plane as medial/lateral inclination, or in the axial plane as medial/lateral condylar torquing. The purpose of this prospective CT study was to evaluate the role of plate fixation in minimizing condylar torquing or rotational changes in the axial plane.Materials and MethodsThis prospective study was carried out on 26 patients, 13 of whom underwent advancement BSSO and 13 setback BSSO, without maxillary LeFort I osteotomies. All mandibular movements were symmetrical. Fixation of the osteotomized segments was achieved with a single 4-hole plate and monocortical screws. In case of mandibular setbacks, a straight plate was used, whereas an inset-bent plate was used for advancements. Computed tomography scans were obtained preoperatively and postoperatively to measure condylar rotation or torqueing in the axial plane. An increase in condylar angle on axial slices was considered as lateral condylar torquing, whereas a decrease was considered as medial condylar torquingResultsA mean medial condylar torquing of 0.2° was noted postoperatively in case of setbacks (p > 0.05 not significant). This suggested minimal condylar torquing, indicating that the proximal and distal segments maintained contact at the anterior vertical osteotomy fixed with a straight plate. In case of advancements, a mean lateral condylar torquing of 2.2° was noted postoperatively (p < 0.005, highly significant). This suggested that the proximal segment flare at the anterior vertical osteotomy site was maintained by inset-bent plate fixation.ConclusionThe gaps between the proximal and distal segments created by mandibular advancement and setback should be maintained. An attempt to close these gaps, especially in mandibular advancement, will result in an unfavourable axial condylar torque. Consequently, the areas of bony contact between the proximal and distal osteotomy sites created by mandibular advancement and setback should be maintained as well.     

颌下切口下颌升支垂直截骨在髁突高位骨折手术中的应用

目的:探讨应用颌下切口下颌升支垂直截骨术治疗髁突高位骨折的效果。方法:对16例(19侧)下颌骨髁突高位骨折患者采用颌下切口下颌骨升支后缘垂直截骨取出升支后缘骨块将骨折的髁突游离后取出,体外直视下将骨折片与升支后缘骨块复位固定后再回植,行颞下颌关节重建。结果:于术后6、12、24个月复查全部患者的开口度为30～48 mm,平均34.92 mm。所有患者咬合关系良好,无关节疼痛症状。部分病人有轻度开口偏斜,均<3 mm,有1例患者有关节弹响。结论:颌下切口下颌升支垂直截骨是治疗髁突高位骨折的一种可选择方法,具有操作简便、复位准确、近期疗效满意等优点。     

长螺钉在下颌骨髁突斜形骨折内固定中的应用研究

目的:探讨长螺钉在下颌骨髁突骨折内固定中的应用,对其疗效进行初步评价。方法:对29例髁突高位斜形骨折患者经耳前途径行髁突解剖复位长螺钉内固定。测量术前、术后高度正常侧与降低侧下颌升支长度差值的变化(双侧髁突骨折时至少一侧为矢状骨折,该侧升支高度正常者才纳入研究),骨折段前后向及内外侧向的夹角,对结果进行统计分析及随访观察。结果:患者术后愈合良好,X线测量显示:术前患侧升支缩短高度平均6.6mm,术后为2.3mm,升支高度有显著性恢复;术前前后向平均夹角为47.7°,术后为9.8°,术前内外向平均夹角为60°,术后为16.9°,两组均有显著性改善。13例随访患者主观满意(随访时间为3～23个月,平均9个月),平均开口度为39mm,开口型正常,前伸、侧向运动幅度均大于5mm,无功能障碍。除2例双侧髁突骨折患者的髁突中度吸收外,其余均恢复良好。结论:长螺钉可用于髁突斜形骨折开放复位的内固定,特别是累及囊内的高位骨折,但其长期效果有待进一步随访观察。