特发性髁突吸收的研究进展

特发性髁突吸收（ICR）是一种髁突进行性的不明原因吸收,会导致髁突体积减小、下颌升支高度降低、下颌骨顺时针旋转、前牙进行性开始,形成骨性Ⅱ类高角开始的不协调面型。本文将对近年来ICR的病因、发病机制、诊断及治疗的相关文献进行综述。     

髁突特发性吸收的研究现状

颞下颌关节髁突特发性吸收(ICR)是一种髁突渐进性、不明原因的吸收导致前牙开、下颌后缩所致的严重的面部畸形的疾病。国内外的研究发现,ICR具有青春期女性发病倾向,患者雌激素水平降低或有口服避孕药史。但迄今学术界尚无法解释ICR患者不出现像骨质疏松症一样的全身性骨骼疾病,而只在髁突发生特异性吸收这一现象。本文对只发生在髁突吸收的这种特异性现象的研究现状进行了综述。     

髁突特发性吸收的临床观察

目的 通过对髁突特发性吸收（idiopathic condylar resorption,ICR）患者临床资料的回顾性分析,总结ICR的临床特点和影像学特点,探讨ICR可能的发病因素,提高诊断水平。方法 收集2007年6月—2012年7月中山大学附属口腔医院颞下颌关节病诊治中心收治的ICR患者46例,对其进行随访观察。记录患者面型、颞下颌关节症状及咬合状况;借助全景片、头颅定位正侧位片、许勒位片检查,以了解患者下颌支高度、髁突骨质破坏情况、颅面结构特征等影像学变化,借助颞下颌关节锥形束CT（CBCT）检查及造影检查,了解髁突吸收与关节盘-突结构改变之间的关系。结果 46例患者中,男4例,女42例（91.30%）,以青少年为主。患者均呈安氏Ⅱ类面型,侧貌突,侧貌不美观,下颌骨后缩,下颌支高度降低,前牙开、后牙早接触、安氏Ⅱ类错。多伴关节区弹响、杂音。X线平片显示,髁突形态变小甚至消失;下颌支垂直距离变短;头影测量呈安氏Ⅱ类高角型特征;TMJ CBCT造影示关节盘-突关系改变,尤其以关节盘穿孔较为常见,穿孔位置多在关节盘后区。结论 ICR具有独特的发病机制和临床特征。TMJ关节盘移位与ICR可能存在相关性。     

成人开牙合患者髁突形态的CBCT观察研究

目的探讨成人开牙合患者髁突形态的差异,研究咬合与髁突形态之间的相关性。方法随机选取正常覆牙合,开牙合患者各20人,均为18~36岁成人。拍摄患者双侧颞下颌关节CBCT,分别测量并计算髁突上部高度与升支高度比(UCH/RH)及髁突高度与宽度比(CW/TCH)。将髁突形态分为四种类型:A型-直立型;B型-后倾型;C型-前倾型;D型-尖型,观察开牙合患者髁突形态的差异。结果 1开牙合组患者UCH/RH及CW/TCH均小于正常牙合组(P<0.05);2A类与C类属于正常髁突形态,占正常覆牙合组的73%。B类和D类属于异常髁突形态,在开牙合组患者中占26.7%;3开牙合组患者两侧髁突高度也显示不对称(P<0.05)。结论开牙合组患者髁突高度相对正常覆牙合人群较短,且两侧髁突高度的对称性低,髁突形态异常比例较高。     

特发性髁突吸收患者下颌骨CBCT影像特点的研究

目的:研究特发性髁突吸收(ICR)患者下颌骨锥体束CT(CBCT)的影像学特点。方法:选取ICR患者和正常志愿者各41例,应用Invivo5软件测量所有受试者下颌骨CBCT数据资料,并进行统计学分析。结果:ICR组与正常组间SNB、NP-FH、S-Go、S-Go/N-Me、Co-Go、H、ACo-PCo、PCo-Co、前斜角、S-Ar-Go、Co-Go-Me的差异有统计学意义(P<0.05),而N-Me、Go-Me、S-Co、ACo-Co、后斜角无统计学意义(P>0.05)。结论:ICR仅发生在髁突的顶端和前斜面,以髁突高度降低为主。ICR患者的下颌后缩由下颌骨后下旋转引起,而非髁突后移所致。     

特发f生髁突吸收的颞下颌关节锥形束CT分析

目的利用特发性髁突吸收（ICR）患者的锥形束CT（CBCT）资料,探讨其颞下颌关节的变化。方法对39例ICR患者及28例正常人行颞下颌关节的CBCT扫描,测量颞下颌关节结构的各相关指标,并进行统计学分析。结果 ICR组与正常组间髁突内外径、前后径、水平角、关节结节斜度、关节上间隙等测量指标之间的差异均有统计学意义（P＝0.000）,表现为ICR组的髁突内外径、前后径、结节斜度、关节上间隙等减小,水平角则增大。结论 ICR的影像学主要表现是髁突的变小、前斜面的吸收、结节斜度的降低,同时髁突有往前内旋转和往上移动的趋势,这些指标可用来评估ICR的进展、疗效及预后。     

下颌髁突软骨细胞凋亡的研究

近年来,有关软骨发育和软骨疾病中软骨细胞凋亡及各种调节因素逐渐受到人们重视。本文对下颌髁突软骨及其病变中的细胞凋亡及调节因素作一综述。     

Osseous changes of the mandibular condyle affect backward-rotation of the mandibular ramus in Angle Class II orthodontic patients with idiopathic condylar resorption of the temporomandibular joint

Objective: To evaluate whether osseous changes of the temporomandibular joint (TMJ) condyle affect backward rotation of the mandibular ramus in Angle Class II orthodontic patients with idiopathic condylar resorption (ICR).

Methods: Twenty Japanese women with Class II malocclusion with ICR (ICR group) and 24 women with Class II malocclusion without ICR (non-ICR group) were examined. Pre-treatment panoramic radiographs were used to measure condylar ratios. Pre-treatment lateral cephalograms were used to evaluate maxillofacial morphology.

Results: The ICR group had a significantly smaller condylar ratio, greater backward rotation of the ramus, less labially inclined upper incisors, and a steeper occlusal plane. The increased backward rotation of the ramus in the ICR group was significantly associated with a smaller condylar ratio.

Conclusion: Angle Class II patients with ICR had shorter condylar height attributable to osseous changes of the TMJ condyle, and the shorter condylar height may affect subsequent backward rotation of the ramus.     

Evaluation of post-surgical stability in skeletal class II patients with idiopathic condylar resorption treated with functional splint therapy

PurposeTo assess postsurgical stability of mandibular advancement combined with orthodontic treatment, following functional splint therapy, in patients with idiopathic condylar resorption (ICR).Patients and methodsSixteen patients who were treated with functional splint therapy followed by orthognathic surgery combined with orthodontic treatment between 2010 and 2017 were included in this retrospective study. The primary outcome variable was skeletal stability, measured on the y-axis to point B (y-axis–B). Cephalometric analysis, including measurement of temporomandibular joint spaces, was carried out on serial magnetic resonance images (MRI) prior to orthognathic surgery (T0), immediately after surgery (T1), and after at least 1 year of follow-up (T2). The differences in the data between time points were compared using statistical analyses.ResultsAll patients obtained an esthetic facial profile after orthognathic surgery, with normal occlusion as well as normal protrusive and laterotrusive excursion after treatment. Mean advancement of the mandible immediately following surgery (y-axis–B, T1 − T0) was 7.28 ± 5.79 mm. This was the only skeletal measurement that showed a sagittal positional change of the mandible. Mean backward movement (T2 − T1) was −1.04 ± 2.35 mm (p₂ = 0.116). Thirteen out of 16 patients experienced no postsurgical relapse or less than 2 mm of mandibular backward movement (81.25%), while two out of 16 patients showed more than 2 mm of mandibular backward movement (12.5%).ConclusionsPatients who underwent mandibular advancement combined with orthodontic treatment, following functional splint therapy, exhibited a stable mandibular position at the 1-year follow-up. This study indicated that functional splint therapy prior to orthognathic surgery for mandibular advancement may be a good adjuvant treatment for ICR patients.     

Evaluation of mandibular condylar movement exercise for patients with internal derangement of the temporomandibular joint on initial presentation

The aim of the present study was to evaluate mandibular condylar movement in a group of Japanese women who presented with closed lock of the temporomandibular joint. A total of 148 women aged between 19 and 75 years were included in the study. We examined mouth-opening, protrusion, and lateral excursive movements, and divided the patients into two groups (74 experimental cases and 74 controls). The experimental group was treated with exercises of the mandibular condyle, and the median (range) maximum mouth-opening increased from 27 (range 11-34) mm to 38 (24-47) mm. In control cases, it increased from 29 (range 20-35) mm to 30 (20-39) mm without exercise. In the experimental group, the median (range) maximum lateral movement on the opposite (unaffected) side increased from 8 (3-12) mm to 9 (5-13) mm. In the control group it remained similar at 7 (3-12) mm and 7 (3-12) mm. In the experimental group, the median (range) lateral movement on the affected side increased from 6 (2-13) mm to 8 (3-13) mm. In controls it remained similar at 6 (2-12) mm and 6 (2-12) mm. In the experimental group, the median (range) maximum protrusion increased from 6 (3-12) mm to 7 (4-12) mm, and in the control group from 6 (2-10) mm to 7 (2-10) mm. There was a significant difference between the experimental (50/74, 68%) and control groups (3/74, 4%) in the degree of increased mouth-opening. Exercise of the first mandibular condylar seems to be useful in the treatment of closed lock on initial treatment.     

Pathological changes in the TMJ and the length of the ramus in patients with confirmed juvenile idiopathic arthritis

IntroductionJuvenile idiopathic arthritis (JIA) is characterized by a progressive destruction of the joints. The temporomandibular joints (TMJ) are especially likely to be affected. The often undetected arthritis in the TMJ in particular can cause significant destruction and craniofacial developmental abnormalities. The aim of this study was to analyze the destructive impact of JIA on TMJ and mandibular development.Material and methodsWe analyzed a total of 92 joints and mandibular rami using digital cone-beam tomography (CBT) and compared 23 consecutively treated JIA patients with 23 healthy controls, matched for age and gender. We evaluated ramus length, vertical depth of the articular fossa, anterior–posterior dimensions of the mandibular head and condylar process. The statistical analysis was performed using non-parametric Wilcoxon and Kruskal–Wallis Rank Sum tests.ResultsThe JIA patients exhibited significantly more pronounced asymmetries. However, we were unable to detect significant differences in the metric measuring distances. The different JIA subtypes exerted no statistically significant influence.ConclusionsThe possible destruction arising as a result of JIA concerns the TMJ and the length of the mandibular ramus. These craniofacial anomalies demonstrate the central importance of sufficiently early detection and timely treatment in the prevention of such growth disturbances.     

健康人髁突运动中心前伸和大张口轨迹特征的研究

目的 探讨髁突参考点选择不同对髁突运动轨迹形态的影响。方法 利用自行开发的髁突运动中心轨迹显示分析系统，分别以运动中心，终末绞链轴点作为参考点，研究30名健康人下颌前伸和大张口时髁突运动的矢状面轨迹。结果 运动中心位于终末绞链轴点的前上方，二者轨迹不同。健康人的髁突运动中心大张口迹轨，为一斜向前下方的平滑曲线，形态稳定，没有轨迹异常特征出现且左右侧对称，大张口运动轨迹起止点连线距离与前伸运动轨迹起止点连线距离的比值大于1．5。而终末绞链轴点大张口轨迹左右侧不对称，形态不稳定，会出现不规则形状，大张口运动轨起止点连线距离与前伸运动轨迹起止点连线距离的比值较小。结论 对于同一健康个体，运动中心轨迹较终末绞链轴点轨迹更恒定。