Comparing bone resorption after anatomical shoulder arthroplasty between various surgical procedures using a single-stem model

BackgroundIn shoulder arthroplasty, bone resorption around the stem can lead to stem loosening and makes surgery difficult at the time of revision. Proximal bone resorption after reverse shoulder arthroplasty can cause instability because of a decrease of deltoid wrapping effect. As factors of the stem itself, such as stem coating, shape, length, and use of bone cement, may also affect bone resorption, a single-stem model should be used to compare bone resorptions between different pathologies and surgical procedures. However, to date, a few reports have compared these differences in detail using a single-stem model. Therefore, we investigated the prevalence and location of humeral bone resorption in a single-stem model.MethodsThe study included 100 shoulders that underwent anatomical total shoulder arthroplasty (TSA) or humeral head replacement (HHR) with a single uncemented humeral stem from 2008 to 2018. The patients were 31 men and 69 women. The mean age at surgery was 72.9 years (range, 41-86 years). The patients were divided into three groups: especially, 25, 61, and 14 shoulders received TSA for primary osteoarthritis without rotator cuff tears (TSA group), HHR using an anatomical head with rotator cuff repair for cuff tear arthropathy (CTA) (HHR group), and HHR using a CTA head without rotator cuff repair (CTA group), respectively. Patients were monitored for a mean of 56 months (range, 12-98 months). The location of bone resorption was divided into seven zones as follows: zone 1, greater tuberosity; zone 2, lateral diaphysis; zone 3, lateral diaphysis beyond the deltoid tuberosity; zone 4, tip of the stem; zone 5, medial diaphysis beyond the deltoid tuberosity; zone 6, medial diaphysis; and zone 7, calcar region. The degree of bone resorption was classified from grade 0 to 4.ResultsBone resorption of grade 3 or higher was significantly more frequent at the greater tuberosity in the HHR and CTA groups (P < .001 and P < .001, respectively) than that in the TSA group. Grade 4 bone resorption was significantly more frequent in the CTA than that in the TSA and HHR groups in zone 1 (P = .016 and P = .041, respectively).ConclusionThe state of attachment of the rotator cuff to the greater tuberosity might affect bone resorption at the greater tuberosity, such as the greater tuberosity after shoulder arthroplasty. In cases of shoulder arthroplasty for arthropathy with rotator cuff tear, performing rotator cuff repair might prevent bone resorption.Level of evidenceLevel IV; Prognosis Study     

黄芩素调控 NLRP3 / Caspase-1 通路对牙周炎大鼠牙槽骨吸收的影响

目的 探索黄芩素调控核苷酸结合寡聚化结构域样受体蛋白 3 ( nucleotide-binding oligomerization domain-like receptor protein 3, NLRP3) / 半胱氨酸天冬氨酸蛋白酶 1 ( cysteine aspartate protease 1, Caspase1) 通路对牙周炎大鼠牙槽骨吸收的影响。 方法 将 40 只牙周炎大鼠随机分为模型组、 黄芩素组、 激活剂 组、 黄芩素 + 激活剂组, 另取 10 只正常作为对照组。 检测大鼠釉牙骨质界到牙槽嵴顶 (CEJ-AC) 的距离、 血清中白细胞介素-6 (IL-6)、 转化生长因子-β (TGF-β) 含量以及牙周组织病理变化、 IL-6、 TGF-β 阳性 表达和 NLRP3、 Caspase-1 蛋白表达。 结果 模型组大鼠 CEJ-AC、 NLRP3、 Caspase-1、 IL-6、 TGF-β 水平及 阳性表达水平以及蛋白表达水平均升高 (P< 0. 05); 经黄芩素干预后, 各项指标均降低 (P< 0. 05); 引入 激活剂明显削弱了黄芩素对牙周炎大鼠的抗炎作用。 结论 黄芩素通过抑制 NLRP3 / Caspase-1 通路减轻炎性反应, 控制牙槽骨吸收。     

A conceptual framework for treating jaw deformities in patients with abnormal condyles: preservation versus replacement of the glenoid fossa–disc–condyle–ramus

This article outlines a conceptual approach to the reconstruction of jaw deformities associated with abnormalities in the mandibular condyle. The authors describe a hierarchy of reconstruction, emphasizing use of the least invasive and progressing to the most complex and invasive techniques, depending on the nature and severity of the underlying deformity, prior operations, patient age, and stage of growth. Consider joint preservation orthognathic surgical correction, followed by biological techniques for replacement of the condyle, and avoid replacing a functional temporomandibular joint based only on radiographic remodeling and concerns about potential future flare-ups of disease based on anecdotal data.     

左上侧切牙Ⅲ型牙内陷牙髓及牙周联合治疗1例

本文报告1例因牙齿根面畸形导致严重根尖病变及牙周破坏的牙周牙髓联合病变的左上侧切牙,瘘道长期不愈,腭侧窄而深牙周袋,严重根尖病变及牙槽骨垂直吸收。通过显微根管治疗、根尖手术、引导牙周组织再生术治疗,实现了控制根尖及牙周感染,达到了保留患牙的目的。     

Prognosis and complications of mature teeth after lateral luxation: A systematic review

BackgroundDental trauma injuries are frequent in children and adolescents and can result in a sequela of future complications. Lateral luxation injuries are diagnosed when a tooth becomes displaced in a position other than axial and is often associated with alveolar bone fracture. Although the tooth is not immediately lost, pulp canal obliteration or pulpal necrosis can occur. The objective of this systematic review was to gather existing data on lateral luxation injuries to mature teeth to evaluate their overall prognosis and reported complications.Types of Studies ReviewedThe authors conducted a systematic search of the literature using MEDLINE, PubMed, Embase, and Cochrane databases in February 2019. They hand searched reference lists to identify additional literature. The authors included prospective and retrospective observational studies in the search. They screened a total of 291 articles, downloaded 28 articles, and included 4 articles in the study.ResultsThe most frequent complication reported for mature teeth with lateral luxation was pulpal necrosis (44.2%). Less frequent findings included surface resorption (14.0%), inflammatory resorption (8.5%), pulp canal obliteration (8.1%), and replacement resorption (0.9%). The included studies were cohort studies, which resulted in great heterogeneity, and the authors could not attempt a meta-analysis.Conclusions and Practical ImplicationsA large number of permanent teeth that experience lateral luxation are at risk of developing pulpal necrosis and other complications. Careful follow-up is required for these patients to treat complications as early as possible. Furthermore, the authors of this systematic review emphasize the importance of consistent reporting of dental trauma outcomes.     

Changes in Geometry and Transportation of Root Canals with Severe Curvature Prepared by Different Heat-treated Nickel-titanium Instruments: A Micro–computed Tomographic Study

IntroductionThe aim of this study was to compare the shaping ability of 4 different nickel-titanium systems, considering their variation in alloy treatment, kinematics, and design, used to prepare canals with severe curvature using micro–computed tomographic analysis.MethodsThirty-two mesial roots of mandibular molars with severe curvature were matched based on similar morphologic dimensions and assigned to 4 experimental groups (n = 8) according to the canal preparation: ProTaper Next (PTN; Dentsply Maillefer, Ballaigues, Switzerland), Reciproc (RC; VDW GmbH, Munich, Germany), Reciproc Blue (RCB, VDW GmbH), and TRUShape (TRU; Dentsply Tulsa Dental Specialties, Tulsa, OK) systems. Changes in 2-dimensional (area and perimeter) and 3-dimensional (volume, surface area, and structure model index) morphologic parameters as well as canal transportation were compared among groups using the analysis of variance post hoc Tukey tests with the significance level set at 5%.ResultsPreparation significantly increased all analyzed parameters. No statistically significant differences (P > .05) were observed between RC and RCB or between PTN and TRS in any of the analyzed parameters. In the cervical third, RC and RCB presented higher mean increases than PTN and TRU. In the apical third, there were no statistically significant differences (P > .05) among the systems.ConclusionsThe instruments of greater taper may promote greater morphologic changes. However, regardless of the number of instruments (multiple or single), the type of movement (rotation or reciprocating), the type of heat treatment of alloys, and the particular characteristics of each instrument (taper and design), the evaluated systems did not result in different dimensional changes and canal transportation in the critical apical area.     

氢氧化钙糊剂与根管内感染控制

感染控制对根管治疗的成功至关重要。尽管随着器械及设备的进步，对根管的清理及成形取得了很大的进展；然而，由于根管系统解剖结构错综复杂，使得获取清洁根管面临各种问题。例如：机械预备的宽度有限，不能彻底清理感染牙本质；冲洗技术的运用虽然可以去除根管器械预备后形成的玷污层，但对细菌内毒素的清除还是难以达到理想的效果，而残留的微生物、毒素等若得不到清除可能会在根尖周组织形成持续感染。因此，除外机械预备和冲洗，根管封药也是感染根管治疗过程中的重要步骤。氢氧化钙糊剂以其高效的抗菌作用在临床得到广泛使用。文章将对根管封药的必要性、氢氧化钙的作用机制及临床应用做一介绍。