个性化后侧入路治疗胫骨平台后髁冠状面骨折

目的:探讨个性化后侧入路治疗单纯性胫骨平台后髁冠状面骨折手术方法。方法:12例单纯性胫骨平台后髁冠状面骨折的患者,采用后内侧或后外侧以及后内后外联合入路切开复位内固定治疗。结果:12例均获随访,随访时间8-24个月,平均13个月。患者膝关节功能评定按Hohl评分标准:优10例,良2例。复查X线片:骨折复位良好,关节面未见明显塌陷。结论:个性化后侧入路治疗单纯性胫骨平台后髁骨折冠状面可直视下暴露胫骨平台后髁,提供了更广阔的操作空间,有利于骨折的解剖复位内固定。     

不同类型的下颌骨骨折的手术治疗

目的：评估不同类型的下颌骨骨折的手术入路及固定方法。方法：对于52例不同类型下颌骨骨折患者采用不同的口外或口内切口及相应的固定方法。结果：52例患者伤口全部一期愈合,51例咬合关系恢复到伤前咬合关系,1例出现咬合关系不良,X线检查骨折线队位良好。结论：对于不同部位的下颌骨骨折应采用相应的手术切口及固定方法,以获得最好的疗效。     

髁突-翼外肌解剖复位与游离复位治疗髁状突骨折的疗效比较

目的:比较髁突-翼外肌解剖复位与游离复位治疗髁状突骨折的疗效,促进髁突形态恢复。方法:收治的80例单侧髁状突骨折患者随机分为两组,每组40例,A组行髁突-翼外肌解剖复位术,B组行髁状突游离复位术,术后3个月、6个月观察髁突形态及下颌骨运动功能变化。结果:A组治愈率为90%,高于B组的70.00%(P0.05);术后3个月A组髁状突吸收、张口受限、开口偏斜、咬合关系紊乱、关节弹响发生率分别为12.50%、15.00%、15.00%、7.50%、12.50%,均低于B组的32.50%、35.00%、37.50%、25.00%、35.00%(P0.05);术后6个月A组张口受限、关节弹响发生率为5.00%、2.50%,均低于B组的20.00%、20.00%(P0.05);两组术后并发症发生率比较差异无统计学意义(P0.05)。结论:髁突-翼外肌解剖复位术保留髁状突骨折患者骨折断端血运,髁突形态及下颌骨运动能力恢复良好,疗效优于髁状突游离复位术。     

29例髁状突骨折游离再植钛板坚固内固定治疗的临床观察

目的:探讨钛板坚固内固定在髁状突骨折游离再植治疗中的作用及影响因素.方法:对29例31侧髁状突骨折游离再植坚固内固定的患者术后复诊及X线片检查临床观察,对骨折类型、固定方式、愈合和并发症状况进行分析.结果:髁状突骨折单线形19侧,多线形和碎性12侧.单板固定24侧,双板固定7侧.疗效评价总满意率83.9%;不满意率占16.1%,其中张口受限2例,髁状突移位并伴骨折缝感染吸收3例.结论:钛板坚固内固定是颌后切口入路游离再植治疗髁状突中高位及复杂性骨折满意疗效的保证,双板固定能保障髁状突多线形和碎性骨折稳定性愈合,坚持张口训练能减少术后并发症出现.     

Twin-block矫治器治疗下颌后缩患者牙颌面硬组织及颞下颌关节变化的临床研究

目的:研究Twin-block矫治器对青少年安氏Ⅱ类错牙合下颌后缩患者牙合面及颞下颌关节的改建能力,从而评估该矫治器的矫治效果。方法:选取20例替牙期及恒牙列早期安氏II类错牙合下颌后缩患者,采用Twin-block矫治器进行治疗,治疗前后均拍摄X线头颅侧位定位片及颞下颌关节核磁共振片,进行牙合面硬组织及髁状突的测量,包括下颌骨长(Co-Gn)、下颌升支长(Co-Go)、下颌体长(Go-Gn)、髁状突宽度、髁状突高度以及关节间隙的测量。结果:与治疗前相比,下颌骨长(Co-Gn)、下颌升支长(Co-Go)、下颌体长(Go-Gn)均显著增加(P0.05),差异均有统计学意义;髁状突高度显著增加(P0.05),髁状突宽度及关节前、上、后间隙无明显变化(P0.05)。结论:Twin-block矫治器对生长发育高峰期患者具有明显的骨矫形作用,髁状突的适应性改建是其主要机制。     

119例髁突骨折远期疗效的调查研究

目的：髁突骨折是临床常见病和多发病,其治疗方法目前尚存在着一定争议。本研究拟总结髁突骨折治疗方法选择的原则和适应征,旨在为髁突骨折的治疗提供更多的参考依据。方法：对四川大学华西口腔医院收治的119例治疗后6个月以上的髁突骨折患者进行远期疗效调查,以电话随访的方式作问卷调查,询问患者的张口度、语言、吞咽功能、咬合、面部容貌、并发症、对疗效的满意程度等,按照治疗方法对患者进行分类,根据患者的情况评价该组病例的治疗效果及满意度,并评价髁突骨折治疗方法的选择是否合理。结果：参与随访的119例患者中,107例对疗效满意,满意率为89．92％,50例出现明显并发症,并发症发生率为42．02％。按照治疗方法将患者分为保守治疗、内固定、髁突摘除等6类,每种治疗方法的满意率比较无统计学差异（P〉0．05）,而并发症的发生率比较有统计学差异（P〈0．05）。结论：在正确选择治疗方法的前提下,保守治疗和手术治疗髁突骨折均可取得较令人满意的疗效,但应尽量避免采用髁突摘除术。     

225例髁突骨折病例的回顾性研究

目的:总结髁突骨折治疗方法选择的原则和适应征,为髁突骨折的治疗提供参考依据.方法:对225例髁突骨折住院病例进行回顾性分析,对患者的受伤年龄、性别、受伤原因、部位、合并损伤、治疗方法、疗效等方面进行分析.结果:髁突骨折多见于20-49岁男性,交通伤害的成年患者的常见病因,跌落损伤是小孩和老人患者的常见病因.骨折常发生在髁突颈,多合并颌面部其他部位骨折.高位骨折和(或)没有明显移位的骨折常采用保守治疗,中低位骨折和(或)有明显移位的骨折常采用手术治疗.结论:髁突骨折的高发人群是青壮年,最常见的致病因素为交通伤;现阶段髁突骨折的治疗方法主要有保守治疗和手术治疗,治疗方法的选择跟患者年龄、骨折部位和移位程度相关.     

幼龄犬髁突囊外损伤对髁突及下颌骨生长发育的影响

目的:研究幼龄犬髁突不同形式的囊外损伤对髁突局部及下颌骨生长发育的影响。方法:20只6月龄中华田园犬随机分为五组,除空白对照组外,分别建立幼龄犬单侧髁突颈部骨折、髁突颈部骨折后内固定、髁突颈部骨膜损伤及髁突颈部骨皮质损伤四种动物模型,饲养12w及24w后通过头颅CT三维重建测量的方法观察其对下颌骨对称性及生长量的影响,并通过组织学染色观察髁突局部生长中心的微观改变。结果:1仅单侧髁突颈部骨折组在损伤早期对下颌骨及髁突发育产生了影响,使损伤侧髁突颈部形态变短变粗,下颌骨长度也较对侧减小,但髁突及颈部的局部适应性改建会逐渐抵消这些影响,24w时下颌骨已不存在骨性不对称,但功能性原因仍能导致颏点出现向患侧的偏斜。2其余三种损伤形式在实验设定的观察期内对髁突及下颌骨的生长发育影响不大,但单侧髁突颈部骨折后内固定组在24w时也出现了下颌骨的功能性偏斜。3各种损伤形式对髁突及下颌骨生长发育的远期影响有待进一步实验证实。结论:生长发育期犬髁突囊外损伤对髁突及下颌骨生长发育的影响不大。     

经咬肌颌后路治疗髁突中低位骨折的疗效分析

目的:研究观察经咬肌颌后路对髁突中低位骨折的临床疗效分析.方法:将我院从2008年1月至2012年1月收治的200例髁突中低位骨折患者按随机数表法均分为实验组100例(采用经咬肌颌后路进行治疗),对照组100例(采用耳颞部入路治疗).随访跟踪1年,观察统计骨折恢复情况和治疗疗效及并发症.结果:实验组手术时间、住院时间、术后并发症发生率均低于对照组,组间差异在住院时间和术后并发症上有统计学差异(P＜0.05);实验组总有效率达90.0％,对照组为74.0％,组间差异有统计学意义(P＜0.05);实验组复诊率为19.4％,低于对照组26.1％,满意度78.5％,高于对照组66.3％,后遗症发生少于对照组,组间差异有统计学意义(P＜0.05).结论:经咬肌颌后路能有效治疗髁突中低位骨折,疗效值得肯定.     

下颌骨骨折钛板内固定的临床体会

近年来,随着交通事业的发展,下颌骨骨折呈上升趋势,如何使骨折的复位固定更佳,减少患者痛苦,早期恢复口腔功能,在临床上尤为重要。我院自2003年采用钛板内固定治疗下颌骨骨折58例,获得满意疗效,现报告如下。1临床资料1·1一般资料我院自2003~2005年共收治下颌骨骨折病人58例,其     

The human mandible: Lever or link?

The mammalian mandible, and in particular the human mandible, is generally thought to function as a lever during biting. This notion, however, has not gone unchallenged. Various workers have suggested that the mandible does not function as a lever, and they base this proposition on essentially two assertions: (1) the resultant of the forces produced by the masticatory muscles always passes through the bite point; (2) the condylar neck and/or the temporomandibular joint is unsuited to withstand reaction forces during biting. A review of the electromyographic data and of the properties of the tissues of the temporomandibular joint do not support the non-lever hypothesis of mandibular function. In addition, an analysis of the strength of the condylar neck demonstrates that this structure is strong enough to withstand the expected reaction force during lever action. Ordinarily the human mandible and the forces that act upon it are analyzed solely in the lateral projection. Moments are then usually analyzed about the mandibular condyle; however, some workers have advocated taking moments about other points, e.g., the instantaneous center of rotation. Obviously it makes no difference as to what point is chosen since the moments about any point during equilibrium conditions are equal to zero. It is also useful to analyze the forces acting on the mandible in the frontal projection, particularly during unilateral biting. The electromyographic data suggest that during powerful unilateral molar biting the resultant adductor muscle force is passing between the bite point and the balancing (non-biting side) condyle. Therefore, in order for this system to be in equilibrium there must be a reaction force acting on the balancing condyle. This suggests that reaction forces are larger on the balancing side than on the working side, and possibly explains why individuals with a painful temporomandibular joint usually prefer to bite on the side of the diseased joint.     

Size and shape of the mandibular condyle in primates

The relationships between the size of the articular surface of the mandibular condyle and masticatory muscle size, tooth size, diet, and biomechanical variables associated with mastication were studied by taking 12 measurements on skulls of 253 adult female anthropoid primates, including three to ten specimens from each of 32 species. In regressions of condylar length, width, or area against body weight, logarithmic transformations substantially improve the fit of the equations compared with untransformed data. There is a strong relationship between condylar measurements and body weight, with all correlations being .94 or higher. The slopes of the allometric regressions of length, width, and area of the condylar head indicate slight positive allometry with body size. Folivorous primates have smaller condyles than frugivorous primates, and colobines have smaller condyles than cebids, cercopithecines, or hominoids. When colobines are eliminated, the differences between frugivores and folivores are not significant. However, the two species with the relatively largest condyles are Pongo pygmaeus and Cercocebus torquatus, suggesting that there may be a relationship between unusually large condylar dimensions and the ability to crack hard nuts between the teeth. Cranial features having strong positive correlations with condylar dimensions include facial prognathism, maxillary incisor size, maxillary postcanine area, mandibular ramus breadth, and temporal fossa area. These data are interpreted as indicating that relatively large condyles are associated with relatively large masticatory muscles, relatively inefficient mandibular biomechanics, and a large dentition. These relationships support the growing evidence that the temporomandibular joint is a stress-bearing joint in normal function.     

Collagen I and II mRNA distribution in the rat temporomandibular joint region during growth

The distribution of type I and II collagen synthesis in the temporomandibular joint (TMJ) area of 1- to 28-day-old rats was studied after hybridization with probes to pro alpha1(I) and pro alpha1(II) collagen mRNA, and stain intensity through the various cartilaginous zones of the mandibular condyle and other areas of TMJ was assessed. The pro alpha(I) collagen mRNA was detected in the perichondrium/periosteum, in the fibrous and undifferentiated cell layers of the mandibular condyle, in the articular disc, and in all bone structures and muscles. The pro alpha1(II) collagen mRNA was found in the condylar cartilage and the articular fossa. Intensity in the condyle was highest in the chondroblastic layer and decreased towards the lower hypertrophic layer. In the condylar cartilage of the 21- to 28-day-old rats the chondroblastic cell zone was relatively narrow compared with the younger animals, whereas the reverse seems to be the case in the cartilage of the articular fossa. Changes in the pro alpha1(II) collagen mRNA were observed in the osseochondral junction area of the primary spongiosa, in that at the age of 5 days intense staining was found, whereas no staining was observed by 14 days. In the mineralizing zone, however, the majority of osteoblastic cells gave a positive signal with the pro alpha1(I) collagen probe. In conclusion, type II collagen synthesis of the mandibular condyle is restricted to its upper area. This differs from the long bone epiphyseal plate, where this type of collagen is produced virtually throughout the cartilage. Type II collagen synthesis of the fossal cartilage seems to increase as a function of age.     

Parathyroid hormone promotes cartilage healing after free reduction of mandibular condylar fractures by upregulating Sox9

After high fractures of the mandibular condyle, the insufficient blood supply to the condyle often leads to poor bone and cartilage repair ability and poor clinical outcome. Parathyroid hormone (PTH) can promote the bone formation and mineralization of mandibular fracture, but its effects on cartilage healing after the free reduction and internal fixation of high fractures of the mandibular condyle are unknown. In this study, a rabbit model of free reduction and internal fixation of high fractures of the mandibular condyle was established, and the effects and mechanisms of PTH on condylar cartilage healing were explored. Forty-eight specific-pathogen-free (SPF) grade rabbits were randomly divided into two groups. In the experimental group, PTH was injected subcutaneously at 20 µg/kg (PTH (1–34)) every other day, and in the control group, PTH was replaced with 1 ml saline. The healing cartilages were assessed at postoperative days 7, 14, 21, and 28. Observation of gross specimens, hematoxylin eosin staining and Safranin O/fast green staining found that every-other-day subcutaneous injection of PTH at 20 µg/kg promoted healing of condylar cartilage and subchondral osteogenesis in the fracture site. Immunohistochemistry and polymerase chain reaction showed that PTH significantly upregulated the chondrogenic genes Sox9 and Col2a1 in the cartilage fracture site within 7–21 postoperative days in the experimental group than those in the control group, while it downregulated the cartilage inflammation gene matrix metalloproteinase-13 and chondrocyte terminal differentiation gene ColX. In summary, exogenous PTH can stimulate the formation of cartilage matrix by triggering Sox9 expression at the early stage of cartilage healing, and it provides a potential therapeutic protocol for high fractures of the mandibular condyle.     

Remodeling of the temporomandibular joint following mandibular distraction osteogenesis in the transverse dimension

Transverse mandibular distraction osteogenesis involves moving the osteotomized segments of the mandible in either a varus or valgus direction. This maneuver allows for widening of the bigonial distance or for a lateral shift of an asymmetric mandibular midline. During this process, a significant amount of torque is placed on the mandibular condyles, because they act as the pivot point for the mandibular translation. Although standard linear distraction osteogenesis induces transient, reversible changes in the temporomandibular joint, it is not known what effect the varus and valgus stresses of transverse distraction have on the temporomandibular joint. We therefore designed a study to document the temporomandibular joint changes following various degrees of transverse distraction.Bilateral transverse mandibular distraction was performed on 10 adult, female mongrel dogs using an external, multiplanar mandibular distraction device. The distraction protocol was as follows: (1) complete osteotomy at the angle of the mandible, (2) 5-day latency period, (3) distraction rate of 1 mm/day, (4) rhythm of one turn per day, (5) linear activation 16 to 30 mm bilaterally, and (6) 8-week consolidation period. A variety of varus and valgus distraction vectors were applied to the mandible only after 10 mm of initial linear distraction had been achieved. Posteroanterior and lateral cephalograms were performed throughout the entire process. Pre-distraction and post-consolidation computed tomographic scans were also performed. Changes in mandibular conformation, axis of rotation, temporomandibular joint structure, and glenoid fossa changes were directly assessed by evaluating the postmortem craniofacial skeleton. The findings were compared with those of normal, age-matched mongrel dog skulls.Significant remodeling changes were observed in the temporomandibular joints of all animals involved in the study. The mandibular condyles demonstrated varying degrees of flattening and erosion at all contact points with the craniofacial skeleton. In some cases, the condyle became part of the distraction regenerate process and was hypertrophied in all dimensions. The condyles were frequently displaced out of the glenoid fossa, particularly on the side in the direction of varus distraction. When the latter occurred, a new fossa was created on the undersurface of the zygomatic arch. Varying degrees of mandibular rotation in the sagittal plane were also observed, which led to abnormal torquing of the condyles in the coronal plane, depending on whether the axis of rotation occurred primarily around the condyle or around the distraction regenerate zone.In conclusion, transverse mandibular distraction is an effective means of producing a varus or valgus shift in the gonion relative to the midsagittal plane. However, unlike linear or angular mandibular distraction, transverse distraction has a multitude of nontransient effects on the temporomandibular joint. Therefore it must be emphasized that in clinical practice, transverse distraction should be used cautiously. One must also be aware that such a maneuver in distraction can have negative effects on the temporomandibular joint.     

Some paleopathological cases of the ancient Anatolian mandibles

This paper deals with four cases of temporomandibular arthritis encountered in the mandibles of individuals who lived in Anatolia during protohistorical and historical times. Among these cases, are two mandibular condyles belonging to the Neolithic period and one mandibular condyle belonging to the Chalcolithic period showing an osteo-arthritic lesion. While in the temporomandibular joint of the individual belonging to Middle Bronze Age, arthritic double condyles is shown resulting in ankylosis.     

An in situ hybridization study of the insulin-like growth factor system in developing condylar cartilage of the fetal mouse mandible

The objective of this study was to investigate the involvement of the insulin-like growth factor (IGF) system in the developing mandibular condylar cartilage and temporomandibular joint (TMJ). Fetal mice at embryonic day (E) 13.0-18.5 were used for in situ hybridization studies using [35S]-labeled RNA probes for IGF-I, IGF-II, IGF-I receptor (-IR), and IGF binding proteins (-BPs). At E13.0, IGF-I and IGF-II mRNA were expressed in the mesenchyme around the mandibular bone, but IGF-IR mRNA was not expressed within the bone. At E14.0, IGF-I and IGF-II mRNA were expressed in the outer layer of the condylar anlage, and IGF-IR mRNA was first detected within the condylar anlage, suggesting that the presence of IGF-IR mRNA in an IGF-rich environment triggers the initial formation of the condylar cartilage. IGFBP-4 mRNA was expressed in the anlagen of the articular disc and lower joint cavity from E15.0 to 18.5. When the upper joint cavity was formed at E18.5, IGFBP-4 mRNA expression was reduced in the fibrous mesenchymal tissue facing the upper joint cavity. Enhanced IGFBP-2 mRNA expression was first recognized in the anlagen of both the articular disc and lower joint cavity at E16.0 and continued expression in these tissues as well as in the fibrous mesenchymal tissue facing the upper joint cavity was observed at E18.5. IGFBP-5 mRNA was continuously expressed in the outer layer of the perichondrium/fibrous cell layer in the developing mandibular condyle. These findings suggest that the IGF system is involved in the formation of the condylar cartilage as well as in the TMJ.     

Correlation between MRI evidence of degenerative condylar surface changes, induction of articular disc displacement and pathological joint sounds in the temporomandibular joint

Objectives: The relationship of bony changes in the condylar surfaces in articular disc displacement without reduction in temporomandibular joint (TMJ) was investigated using diagnostic imaging. The study also evaluated whether the bony changes in the condylar surfaces limit disc and condyle motion, and produce pathological joint sounds. Materials and methods: Thirty‐seven joints in 28 patients diagnosed with degenerative bony changes in the condylar surfaces radiographically and anterior disc displacement without reduction using magnetic resonance imaging (MRI) were studied. The bony changes were assessed by radiographic examination and classified into two types: pathological bone changes (PBCs) including erosion, osteophyte formation and deformity, and adaptive bone changes (ABCs) including flattening and concavity. MRI was performed on the TMJ to examine the configuration and position of the discs. Joint sounds in the TMJ were determined using electrovibratograghy with a joint vibration analysis. Results: The articular disc motion to the condyle in the PBC group was smaller than in the ABC group irrespective of the configuration of the disc, even though there were no significant differences between the two types of bony changes in the disc position during jaw closing. The joint vibration analysis of the TMJ showed that joint sounds with a higher frequency were observed in the PBC group than in the ABC group. High energy levels needed to produce the higher frequencies (over 300 Hz) were observed only in the PBC group.     

New aspects of the histology of the mandibular condyle in the rat

The function of the multipotential mesenchymal cells in the mandibular condyle was studied histochemically and histologically in 27 Long Evans/Turku rats. Sagittal sections from the temporomandibular joint were stained with haematoxylin and eosin, toluidine blue, or van Gieson's stain. A weakly orthochromatically stained fibrous layer was followed in the upper region by a weakly metachromatically stained mesenchymal cell layer. Deep within this was a strongly metachromatically stained layer of immature chondroblasts. The metachromasia of the matrix of these layers disappeared abruptly in an anterior direction and gradually in a posterior direction. The changes in the staining reactions are explained by the fact that mesenchymal cells can differentiate into chondrogenic or osteogenic cells depending on the environmental conditions. A new hypothesis is presented according to which regulation of the direction of condylar growth is achieved by choosing the cells for chondrogenesis more posteriorly or anteriorly from among the mesenchymal cells covering the whole condylar cartilage.