口腔矫治器联合改良UPPP术治疗伴下颌后缩的中-重度OSAHS

目的：分析口腔矫治器联合改良悬雍垂腭咽成形术(modified-uvulopalatopharyngoplasty, M-UPPP)治疗伴下颌后缩的中-重度阻塞性睡眠呼吸暂停低通气综合征(obstructive sleep apnea-hypopnea syndrome, OSAHS)的疗效。方法：经多导睡眠描记法(polysomnography, PSG)诊断为中-重度OSAHS患者36例,且存在腭咽平面狭窄伴下颌后缩,行M-UPPP术。术后1个月按个人意愿分为两组：A组20例,接受手术并佩戴口腔矫治器;B组16例,单纯接受M-UPPP术。所有患者分别于术前、术后1个月、术后6个月行PSG监测,记录呼吸暂停低通气指数(apnea hypopnea index, AHI)、最低血氧饱和度(lowest oxygen saturation, LSaO2)值,X线头影测量舌后气道间隙(posterior airway space, PAS)值,并采用Epworth嗜睡量表(Epworth sleepness scale, ESS)及鼾声视觉模拟评分(visual analogue scale, VAS)评价患者的主观症状。结果：所有患者术后1个月AHI、LSaO2、ESS评分及鼾声VAS评分与术前相比差异均有统计学意义(均P＜0.05);术后1个月两组AHI、LSaO2、ESS评分、VAS评分及X线头影测量PAS值差异无统计学意义(P＞0.05);术后6个月A组患者PAS值及LSaO2较B组升高,AHI、ESS评分及VAS评分均较B组降低(均P＜0.05)。结论：对于明确为腭咽平面狭窄并伴下颌后缩的中-重度OSAHS患者,在患者有较好依从性的情况下,采用M-UPPP术联合佩戴个性化口腔矫治器的综合治疗,可取得较好疗效。     

帕瑞昔布钠超前镇痛在下颌角截骨术中的应用

目的:观察帕瑞昔布钠在下颌角截骨术中对就医者疼痛以及凝血功能的影响。方法:40例就医者分两组:实验组(P组)和对照组(D组),麻醉开始前15mi n P组静注帕瑞昔布钠40mg,D组静注0.9%生理盐水5ml。测定术前(T1)、术中(T2)、术毕(T3)、术后6h(T4)、术后24h(T5)的凝血功能变化;记录苏醒期躁动程度评分以及术毕、术后6h、术后12h时的疼痛VAS评分。结果:两组凝血功能无统计学意义(P>0.05);苏醒期躁动评分P组明显低于D组;P组VAS评分显著低于D组(P<0.05)。结论:静脉注射帕瑞昔布钠在不影响凝血功能的同时能明显减轻就医者术后疼痛,减少苏醒期躁动。     

黑龙江省汉族人下颌第一磨牙远舌根发生率的锥形束CT研究

目的:研究黑龙江省汉族人下颌第一恒磨牙的远舌根发生率。方法:采用锥形束CT扫描成像技术拍摄下颌第一恒磨牙113颗,对扫描图像进行三维重建,并选择不同方向的断层观察研究远舌根发生率。结果:在113颗下颌第一恒磨牙中,远舌根的发生率为42.5%(48/113),其中男性发生率为43.8%(28/64),女性发生率为40.8%(20/49);左侧发生率为38.6%(17/44),右侧发生率为44.9%(31/69),性别与部位没有显著性差异。结论:黑龙江省汉族人下颌第一恒磨牙牙根形态变异较大,掌握其特点有助于提高根管治疗的成功率。     

MicroRNAs regulate distal region of mandibular development through Hh signaling

Mandibular anomalies are often seen in various congenital diseases, indicating that mandibular development is under strict molecular control. Therefore, it is crucial to understand the molecular mechanisms involved in mandibular development. MicroRNAs (miRNAs) are noncoding small single-stranded RNAs that play a critical role in regulating the level of gene expression. We found that the mesenchymal conditional deletion of miRNAs arising from a lack of Dicer (an essential molecule for miRNA processing, Dicer^fl/fl;Wnt1Cre), led to an abnormal groove formation at the distal end of developing mandibles. At E10.5, when the region forms, inhibitors of Hh signaling, Ptch1 and Hhip1 showed increased expression at the region in Dicer mutant mandibles, while Gli1 (a major mediator of Hh signaling) was significantly downregulated in mutant mandibles. These suggest that Hh signaling was downregulated at the distal end of Dicer mutant mandibles by increased inhibitors. To understand whether the abnormal groove formation inDicer mutant mandibles was caused by the downregulation of Hh signaling, mice with a mesenchymal deletion of Hh signaling activity arising from a lack of Smo (an essential molecule for Hh signaling activation, Smo^fl/fl;Wnt1Cre) were examined. Smo^fl/fl;Wnt1Cre mice showed a similar phenotype in the distal region of their mandibles to those in Dicer^fl/fl;Wnt1Cre mice. We also found that approximately 400 miRNAs were expressed in wild-type mandibular mesenchymes at E10.5, and six microRNAs were identified as miRNAs with binding potential against both Ptch1 and Hhip1. Their expressions at the distal end of the mandible were confirmed by in situ hybridization. This indicates that microRNAs regulate the distal part of mandibular formation at an early stage of development by involving Hh signaling activity through controlling its inhibitor expression level.     

Rocker jaw: Global context for a Polynesian characteristic

Our goal is to describe the global distribution of the “rocker jaw” variant in human populations. Rocker jaw refers to mandibles that lack the antegonial notch, making them unstable on a flat surface. Data were collected by C.G. Turner II on 9,207 individuals from Asia, Europe, the Pacific, and the Americas, and by J.D. Irish on 3,526 individuals from North and South Africa. With a focus on Polynesia, where the trait is most common, frequencies are presented for subdivisions of Oceania, Australasia, Eurasia, the Americas, and Africa. While the rocker jaw is a Polynesian characteristic, the trait is found throughout the world. Within major geographic regions, there are interesting contrasts, for example, (a) the similarity of Jomon and Ainu and their difference from modern Japanese; (b) Aleuts and Northwest Coast Indians are similar and both are distinct from the Inuit and other Native Americans; and (c) North and Sub-Saharan Africans show a regional difference that parallels genetic and dental distinctions. Skeletons in South America that exhibit the rocker jaw have been interpreted as Polynesian voyagers who ventured to the west coast of South America. The rarity of rocker jaw in South American natives supports this view. The rocker jaw can be attributed to the unique basicranium morphology and large upper facial height of Polynesians, which highlights the integrated growth of a functional module (i.e., mastication) of the craniofacial complex. The unusually high frequency of the trait in Polynesians is a product of both function and founder effect/genetic drift.     

Registration of magnetic resonance and computed tomography images in patients with oral squamous cell carcinoma for three-dimensional virtual planning of mandibular resection and reconstruction

The aim of this study was to evaluate and present an automated method for registration of magnetic resonance imaging (MRI) and computed tomography (CT) or cone beam CT (CBCT) images of the mandibular region for patients with oral squamous cell carcinoma (OSCC). Registered MRI and (CB)CT could facilitate the three-dimensional virtual planning of surgical guides employed for resection and reconstruction in patients with OSCC with mandibular invasion. MRI and (CB)CT images were collected retrospectively from 19 patients. MRI images were aligned with (CB)CT images employing a rigid registration approach (stage 1), a rigid registration approach using a mandibular mask (stage 2), and two non-rigid registration approaches (stage 3). Registration accuracy was quantified by the mean target registration error (mTRE), calculated over a set of landmarks annotated by two observers. Stage 2 achieved the best registration result, with an mTRE of 2.5 ± 0.7 mm, which was comparable to the inter- and intra-observer variabilities of landmark placement in MRI. Stage 2 was significantly better aligned compared to all approaches in stage 3. In conclusion, this study demonstrated that rigid registration with the use of a mask is an appropriate image registration method for aligning MRI and (CB)CT images of the mandibular region in patients with OSCC.     

Complications after different methods for fixation of mandibular angle fractures: network meta-analysis of randomized controlled trials

The aim of this review was to compare mandibular angle fracture fixation methods that were evaluated through randomized clinical trials considering postoperative complications. Additionally, different treatment methods were ranked based on their performance. A systematic review was performed based on the Cochrane and PRISMA guidelines. The quality of evidence and network meta-analysis were conducted using the GRADE tool and R software, respectively. Four databases were searched, and the papers were selected based on the PICOS strategy. A total of 3584 papers were found. After screening 15 papers were included. One plate placed on lateral border (tension zone) presented lower risk than one plate placed on superior border (tension zone) for infection [risk ratio (RR): 0.48, 95% confidence interval (CI): 0.33 to 0.71] and plate removal necessity (RR: 0.44, 95% CI: 0.28 to 0.69), with moderate quality of evidence. There were no significant differences among the mandibular angle fracture treatments for malocclusion and paraesthesia outcomes. In conclusion, one plate placed on the lateral border in the tension zone is the best choice regarding postoperative infection and plate removal necessity when fixing mandibular angle fractures. None of the tested fixation methods were associated with a significant risk of malocclusion and paraesthesia events.