A clinical investigation on disc displacement in sagittal fracture of the mandibular condyle and its association with TMJ ankylosis development

This retrospective study evaluated the potential influence of the sagittal fracture pattern and articular disc displacement on the development of temporomandibular joint (TMJ) ankylosis. 33 sagittal fractures of mandibular condyles (SFMCs) in 19 patients were treated conservatively and were divided into non-ankylosis and ankylosis groups based on their prognosis. Using computed tomography (CT) images, the SFMCs were classified into types I, II and III, and the displacement of the articular disc was investigated using magnetic resonance imaging (MRI). There were 19 (58%) SFMCs in the non-ankylosis group: 5 were type I SFMCs, which did not show any disc displacement; the other 14 were type II SFMCs, which included 5 cases without disc displacement and 9 cases with disc displacement. In the non-ankylosis group, the lateral poles were completely or incompletely covered by the discs. There were 14 (42%) SFMCs in the ankylosis group, all of which were type III SFMCs showing disc displacement, and the lateral poles in these cases were not covered by the discs. This investigation confirmed that the disc position was highly associated with the position of the fractured fragment and that some SFMC patterns, especially type III SFMCs, indicated a high risk of TMJ ankylosis.     

下颌骨前段骨折伴发髁突骨折的诊治现状

下颌骨前段骨折（包括正中联合及旁正中的骨折）是下颌骨骨折最常见的类型之一,且常常与髁突骨折同时发生。受解剖因素的影响,这类骨折一旦处理不当容易出现包括面下部增宽,咬合紊乱,甚至关节强直等多种并发症。本文就这类骨折的特点、常见并发症、诊断方法以及治疗过程中应注意的问题作一综述。     

Outcomes of anterior disc displacement and condylar remodelling for sagittal fracture of the mandibular condyle in children after closed treatment

The aim of this study was to evaluate the outcomes of temporomandibular joint (TMJ) anterior disc displacement and condylar remodelling for sagittal fracture of the mandibular condyle (SFMC) in children. Disc displacement was observed in 20 patients with 24 SFMCs (age 4–12 years) via magnetic resonance imaging. After 6 months of closed treatment (T1), the joints were categorized based on the displaced disc status as complete reduction (DCR) or incomplete reduction (DICR). Moreover, condylar remodelling was compared between the groups using cone beam computed tomography images of the TMJ obtained at T1 and at the 1-year follow-up (T2; 15 patients with 18 displaced SFMCs). At T1, 17 of 24 joints with SFMC were assigned to the DCR group and six to the DICR group; one unilateral SFMC case developed ankylosis. Condylar depth and height differed significantly between the groups at T1, but not at T2. Intra-group comparison exhibited significant changes in the condylar depth and height over time in the DICR group. Thus, most of the anteriorly displaced discs (17/24, 70.8%) achieved reduction following closed treatment. Although sustained anterior disc displacement was associated with an increased depth and reduced height of the condyle, no clinical impairment was noted unless ankylosis developed.     

Outcomes of treatment for intracapsular fractures of the mandibular condyle: recommendation for a new classification

We know of no universally accepted classification for intracapsular condylar fractures. We propose here a new classification based on the concept of a “disc-condyle” unit, and validate the classification based on outcomes of treatment. From 1 January 2010 - 31 December 2014, 55 patients with unilateral intracapsular condylar fractures were classified into three types: type A has no reduction in mandibular height or displacement of the disc (n = 7); type B has displacement of the disc with no reduction in mandibular height (n = 17); and type C has reduced mandibular height with or without displacement of the disc (n = 31). We treated types B and C by open reduction and fixation, while type A fractures were managed non-surgically. At six month follow-up, we found no significant differences in the vertical height of the ramus, mandibular deviation, protrusion, or lateral protrusion between the fractured and healthy sides. All patients had normal occlusion postoperatively and only one patient (type C) reported pain. Magnetic resonance imaging and computed tomography showed good osseous healing and disc-condylar relations in all cases. Our results show that this new classification of intracapsular condylar fractures is a safe and easy way to obtain satisfactory outcomes of treatment. However, it needs further independent validation.     

Postoperative outcomes of adult patients with sagittal fractures of mandibular condyle: Quantitative evaluation and retrospective factor analysis

PurposeWe attempted to adopt quantitative methods to precisely evaluate the surgical effect of sagittal fractures of mandibular condyle (SFMCs) and aimed to determine differences in postoperative results between different groups of patients.Materials and methodsPostoperative data of patients with SFMC were collected and quantitative evaluations of subjective, clinical and imaging results were performed. SPSS software was used to analyze the data, and certain factors (gender, age, unilateral or bilateral SFMCs, injury time) were analyzed by univariate analysis.ResultsForty-four postoperative patients were included with an average follow-up of 15.7 months. Averages of resting pain, moving pain, and chewing pain were all <10. Averages of maximum mouth opening, protrusion, and ipsilateral excursive movement were 42.20, 4.80, and 5.98 mm, respectively. Moreover, 85.71% of condylar healing and remodeling was good, and average condylar absorption was 1.52 mm. Early-operated patients (injury time ≤2 weeks) exhibited greater ipsilateral excursive movement, higher condylar index, and lesser condylar absorption than late-operated patients (injury time >2 weeks). Patients with unilateral SFMC showed greater protrusive movement and higher condylar index than those with bilateral SFMCs.ConclusionMost patients with SFMCs could obtain good subjective, clinical and imaging results by appropriate surgical treatment. Early surgery could improve postoperative outcomes.     

Three-dimensional soft tissue effects of mandibular midline distraction and surgically assisted rapid maxillary expansion: an automatic stereophotogrammetry landmarking analysis

Studies on mandibular midline distraction (MMD) are mostly performed using conventional research methods. Concerning surgically assisted rapid maxillary expansion (SARME), more research is conducted using three-dimensional (3D) techniques. Research on bimaxillary expansion, the combination of MMD and SARME, is reported sparsely. The main objective of this study was to provide a 3D evaluation of soft tissue effects following SARME and/or MMD. Patients who underwent SARME and/or MMD between 2008 and 2013 were included. Stereophotogrammetry was undertaken at the following time points: preoperative (T1), immediately post-distraction (T2), 1 year postoperative (T3). An automatic 3D facial landmarking algorithm using two-dimensional Gabor wavelets was applied for the analysis. Twenty patients who had undergone SARME were included, 12 of whom had undergone bimaxillary expansion. Age at the time of surgery ranged from 16 to 47 years. There was a significant downward displacement of soft tissue pogonion. Furthermore, there was a significant mean increase of 2.20 mm in inter-alar width and a non-significant mean increase of 1.77 mm in inter-alar curvature point width. In conclusion, automatic stereophotogrammetry landmarking analysis of soft tissue effects showed downward displacement of soft tissue pogonion following bimaxillary expansion and transverse widening of the inter-alar width and a tendency towards an increase in inter-alar curvature point width after SARME.     

Relations between anterior disc displacement and maxillomandibular morphology in skeletal anterior open bite with changes to the mandibular condyle

In this study we investigated the relation between anterior disc displacement (ADD) and maxillomandibular morphology in skeletal anterior open bite with changes to the mandibular condyle. Thirty female patients (60 joints) with both conditions were evaluated. Magnetic resonance imaging of the temporomandibular joint (TMJ) was used to diagnose both ADD and changes to the mandibular condyle (erosion, osteophyte, and deformity). The relations among ADD, changes to the mandibular condyle, and maxillomandibular morphology were examined statistically. Changes to the mandibular condyle had a higher score than sym anterior open bite, the deviated side in asymmetric anterior open bite, and the non-deviated side. The score for disc displacement on the non-deviated side was lower than both the sym side and the deviated side. Unilateral changes to the mandibular condyle and unilateral disc displacement were not apparent in sym anterior open bite, but a unilateral non-displaced disc was seen only on the asymmetric side. Mandibular condylar changes were significantly more common on the deviated, than on the non-deviated, side. The SNB angle was significantly smaller, and the ANB, GZN, and SN-mandibular plane angles were significantly larger in sym anterior open bite. Overjet, ANB angle, GZN angle, and SN-MP angle were significantly larger, and the SNB angle was significantly smaller, in the presence of ADD without reduction and mandibular condylar deformity. We conclude that the prevalence of ADD without reduction and changes to the mandibular condyle were related to mandibular asymmetry and mandibular morphology in anterior open bite. This retrospective study suggests that ADD without reduction and mandibular condylar bone changes may be related to the progression of skeletal class II open bite and mandibular asymmetry in cases of skeletal open bite.     

Inferior alveolar and mental nerve injuries associated with open reduction and internal fixation of mandibular fractures: A Seven Year retrospective study

PurposeTo document adverse neurosensory changes in the inferior alveolar nerve (IAN) and mental nerve (MN) after surgical mandibular fracture treatment and to identify risk factors associated with these changes.Materials and methodsA retrospective study of patients surgically treated for mandibular fractures. The primary study variable was the postoperative change in IAN/MN neurosensory examination after fracture fixation. Risk factors were categorized as demographic, anatomic, experience of the operator, fracture displacement and number of miniplates placed at each fracture site. Appropriate statistics were computed.Results209 patients with 293 fractures were analysed. One hundred twenty fractures (41%) were located between the lingula and mental foramen, and 173 fractures (59%) were located distal to the mental foramen. Two hundred seventeen (41%) were displaced by 5 mm or more. In 38 fractures (13%), the IAN/MN neurosensory status worsened after treatment. In a multivariate model, fracture displacement, operator inexperience and two plate fixation were associated with a statistically significant risk (P ≤ 0.05) for postoperative deterioration of IAN/MN sensation.ConclusionFixation with two miniplates, fracture displacement of 5 mm or more and operator inexperience were associated with an increased risk for deterioration of the IAN/MN neurosensory status after treatment of mandibular fractures.     

即刻种植和早期种植对前牙美学区种植体周围软组织的影响分析

目的:分析即刻种植和早期种植对前牙美学区种植体周边软组织的影响。方法:随机抽取我院于2015年8月至2019年8月期间收治的60例单颗前牙缺失患者,其中有30例患者于拔牙后行即刻种植(观察组),30例拔牙后行早期植入(对照组),均予以Astra Tech种植体及种植体植入半年后给予氧化锆全瓷修复,并在半年后复查,对比分析两组患者的红色美学评分(PES)等。结果:两组患者对比PES总分和各节点PES评分无明显差异(P>0.05)而在各节点PES评分中,牙龈生物型和牙槽骨缺损、远中龈乳头,缺失牙位和牙龈高度及缺牙原因和近、远中龈高度存在显著相关性。结论:即刻种植和早期种植对前牙美学区种植体周边软组织之间的影响差异不明显,对前牙美学区种植体修复时软组织美学产生的主要影响包括缺失牙位、牙龈生物型及缺牙原因。     

Clinical experience and results with a Rhombic Plate for transoral endoscopically-assisted osteosynthesis of fractures of the condylar neck

The intraoral approach is favoured by many patients and surgeons for the treatment of fractures of the condylar neck, but the limited space offered by this approach can make positioning and fixation of the osteosynthesis plate difficult. A rhombic-shaped plate was designed specifically for use with the intraoral approach, and introduced into our clinical practice in 2012. We present the clinical and functional results in 81 patients with 98 fractures of the condylar neck who we have treated with this technique. Of these six required surgical revision, and ultimately all but two had satisfactory occlusion and mandibular function. Our complication rate of 6/81 (7.4%) compares favourably with those reported elsewhere, and confirms that open reduction and internal fixation of condylar fractures using the Rhombic plate through an intra-oral approach provides good outcomes.     

Long‐term side effects on the temporomandibular joints and oro‐facial function in patients with obstructive sleep apnoea treated with a mandibular advancement device

Patients with obstructive sleep apnoea (OSA) in long‐term treatment with a mandibular advancement device (MAD) to increase the upper airway space may develop changes in the temporomandibular joint (TMJ) and the oro‐facial function due to the protruded jaw position during sleep. The aim was to investigate the influence of long‐term MAD treatment on the TMJs, oro‐facial function and occlusion. This prospective study included 30 men and 13 women (median age 54) with OSA [Apnoea–Hypopnoea Index (AHI): 7–57]. They were examined with the Nordic Orofacial Test Screening (NOT‐S), the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) and cone beam computed tomography (CBCT) of the TMJs. The examination was performed before MAD treatment (T0), and 3–6 months (T1, no CBCT), 1 year (T2) and 3 years (T3) after treatment start. The results were analysed as long term (T0–T3, n = 14) and short term (T0–T2, n = 24) by t‐test, Fisher's exact test and anova . Both long‐ and short‐term analyses revealed a reduction in AHI (P < 0·002). Significant long term were increased scores in the NOT‐S Interview (P < 0·045), reduced vertical overbite (P < 0·031) and increased jaw protrusive movement (P < 0·027). TMJ changes were found as joint sounds in terms of reciprocal clicking and crepitus, short term as a decrease and subsequent recurrence (P < 0·053; P < 0·037). No significant radiological changes were found. In conclusion, MAD treatment is beneficial to some OSA patients, but might induce changes in the TMJs, the oro‐facial function and the occlusion. However, these changes seemed to be less harmful than previously reported with careful adaptation, control and follow‐ups.