Meta-analysis on the mandibular dimensions effects of the MARA appliance in patients with Class II malocclusions

Objectives:To evaluate the short- and long-term effects of the mandibular anterior repositioning appliance (MARA) on mandibular dimensions in patients with Class II malocclusion and to assess the stability of the MARA results.Materials and Methods:Multiple electronic databases were searched for articles published in any language until March 2014. A manual search was also performed of reference lists of retrieved articles. The primary outcomes were the short-and long-term effects of the MARA appliance on mandible dimensions. The secondary outcome was postretention stability. Outcome measures were total mandibular unit length, corpus length, and ramus height. Two reviewers examined all articles independently and assessed their methodologic quality. Meta-analyses were conducted using random-effects models. The Cochrane test and the I² statistic were used to assess heterogeneity. Sensitivity analyses were performed and publication bias was evaluated.Results:Seven retrospective clinical controlled studies that compared MARA with controls were included. Three of the studies were medium quality; the rest were low quality. Meta-analysis of the short-term effects revealed a significant increase in total mandibular unit length (1.16 mm/y) and ramus height (1.58 mm/y) with MARA and a nonsignificant increase in corpus length (0.21 mm/y). Analyses of the long-term effects showed a statistically significant advantage of MARA over controls for all three variables, but the effect sizes were small. More high-quality studies are warranted.Conclusions:The MARA appliance produced statistically significant mandibular growth enhancement in the short- and long-term. These findings, however, may not be clinically significant.     

The effect of light-emitting diode and laser on mandibular growth in rats

Objective:To evaluate the effect of a light-emitting diode (LED) and/or low-level laser (LLL) with or without the use of anterior bite jumping appliances (also known as functional appliances [FAs]) on mandibular growth in rats.Materials and Methods:Thirty-six 8-week-old male Sprague-Dawley rats weighing 200 g were obtained from Charles River Canada (St. Constant, QC, Canada) and were divided into six groups of six animals each. Groups were as follows: group 1: LLL; group 2: LLL + FA; group 3: LED; group 4: LED + FA; group 5: FA; and group 6: control (no treatment). Mandibular growth was evaluated by histomorphometric and micro computed tomographic (microCT) analyses.Results:The LED and LED + FA groups showed an increase in all condylar tissue parameters compared with other groups.Conclusion:The LED-treated groups showed more mandibular growth stimulation compared with the laser groups.     

Patient's experience of treatment for sleep apnoea with a mandibular advancement splint

Background and aimsObstructive sleep apnoea (OSA) is a well recognised clinical disorder in which there is narrowing and repeated collapse of the upper airway during sleep resulting in the cessation of breathing. Patients with mild to moderate sleep apnoea are often provided with mandibular advancement splint (MAS) therapy as a form of first line or definitive treatment. The aims of this audit were to evaluate patient satisfaction and success of MAS therapy.Methods93 patients diagnosed with sleep apnoea and suitable for a splint were recruited prospectively at Queen Victoria Hospital, East Grinstead between January 2009 and October 2010. A patient satisfaction questionnaire was developed by health professionals involved in the care of patients with sleep apnoea and assessed for face and content validity and reliability. Participants completed the questionnaire six weeks after the splint was fitted.Results44% who previously experienced snoring now reported no snoring and 47% reported less snoring since wearing the MAS appliance. 69% reported complete resolution of sleep apnoea symptoms. 37% experienced aching teeth and 33% experienced having a dry throat when wearing the appliance. 86% of sleeping partners felt that their quality of sleep was improved following their partners treatment.ConclusionsThe standards set for each criteria in this audit were met. MAS treatment has a key role to play in the management of obstructive sleep apnoea with high rates of patient satisfaction and the majority of patients partners reporting a significant improvement in their own and their partners sleep quality.     

健康成人下颌切牙管的锥形束CT测量分析

目的 利用锥形束CT测量下颌切牙管(mandibular incisive canal,MIC),了解其形态和特点,为临床提供参考.方法 观察2011年1月至2013年1月50名成人健康志愿者的锥形束CT图像,测量分析MIC的检出率、管径、长度及其与颌骨的关系.结果 在50例(100侧)锥形束CT图像中:MIC的检出率为100％(100/100),清晰率为71％(71/100);MIC的管径面积(唇舌径×垂直径)从起点至终点逐渐变小(左侧起点2.17 mm× 2.22 mm,终点0.82 mm× 0.92 mm;右侧起点2.14 mm×2.08 mm,终点0.87 mm×0.86 mm);MIC左右侧平均长度分别为17.84和17.73 mm;MIC在下颌骨唇舌向偏唇侧;在垂直方向MIC距下颌骨下缘较近,MIC到根尖的距离在尖牙最小.结论 锥形束CT对MIC有良好的检出率和清晰率;MIC在下颌骨的走行中偏向唇侧和下颌骨下缘.     

Superolateral Dislocation of the Mandibular Condyle: A Series of Seven Cases

Introduction

Anterior and anteromedial dislocations of the mandibular condyle are seen frequently in mandibular fractures. Less frequent are dislocations of the condylar head in the lateral, medial and posterior direction whereas superior dislocation into the middle cranial fossa is rare. We report a series of seven cases encountered over the years, which, incidentally, is the largest case series reported till date with lateral and superolateral dislocation of the condyle after a traumatic injury.

Materials and method

In all cases but one, the condyle was reduced by manual manipulation with the patient in general anaesthesia. In all cases but one there was simultaneous fracture in the mandibular symphyseal region. The associated fractures were reduced and fixed with bone plates and screws.

Results

Patients were generally free from any long term complications of injury or surgery except for facial nerve paresis of a transient nature in one case.

Conclusion

To our knowledge, this clinical series presents the first reported case of superolateral dislocation which required open reduction. The etiology and mechanism of dislocation has been discussed along with a brief review of the literature.

Electronic supplementary material

The online version of this article (doi:10.1007/s12663-015-0770-9) contains supplementary material, which is available to authorized users.     

An Unusual Presentation of Stafne Bone Cyst

Stafne bone cyst is a rare mandibular defect. It is a developmental abnormality that commonly presents as a small, well demarcated, and asymptomatic radiolucency seen at the angle of the mandible below the mandibular canal. There are usually no clinical signs nor symptoms. Diagnosis is commonly by plain X-ray, but use of more accurate imaging such as MRI is required in atypical cases. This case study reports an unusual presentation of Stafne bone cyst in the ramus of the mandible in a young man and reviews the relevant literature.     

Study of Efficacy and the Comparison Between 2.0?mm Locking Plating System and 2.0?mm Standard Plating System in Mandibular Fractures

Purpose

The purpose of this study was to evaluate the efficacy and comparison between 2.0 mm locking plate system and 2.0 mm Champy’s titanium mini plating system in mandible fractures.

Materials and Methods

A total of 20 patients with mandibular fractures were selected and divided into two groups A and B on randomized basis. Group A was treated with open reduction internal fixation using 2.0 mm locking plates and group B with 2.0 mm Champy’s titanium miniplates. All patients were followed up for 12 weeks postoperatively.

Results

Results of the study show less screw loosening, less precision in plate adaptation and less alteration of the osseous or occlusal relationship upon screw tightening in group A. Chi square test was applied to compare the results between the two groups. Statistical analysis did not show significant difference of incidence of malocclusion between the two groups (p value = 0.606). Statistical analysis using un-paired t test showed significant difference of working time between the two groups (p value = 0.00296). When comparing the overall complication rates according to plates used, the χ² test showed no statistically significant difference between the locking and nonlocking plates (p > 0.05).

Conclusion

It is observed in our study that the locking plate/screw system offers significant advantages over the conventional plating system. The precise adaptation required for using conventional plates is not needed when this locking plate/screw system is used. Locking plate/screw system provides better stability than the conventional plate/screw system.     

Predictability of pharyngeal airway space dimension changes after orthognathic surgery in class II patients: A mathematical approach

IntroductionAngle Class II malocclusion due to mandibular retrognathia is a common dentofacial deformity. It is well known that mandibular advancement increases pharyngeal airway dimensions. The aim of this study was to evolve a mathematical method for predicting posterior pharyngeal airway space (PAS) changes based on 2D lateral cephalographic radiographs (LCRs) and expected extent of mandibular advancement prior to BSSO.Materials and methodsLinear regression analyses were performed in order to investigate the relation between the posterior airway space and mandibular advancement. LCRs where carried out to assess skeletal landmarks and pharyngeal airway space pre- (T0) and postoperatively (T1). To detect changes postoperatively, the posterior airway space was divided into three units: nasopharyngeal airway space (superior airway space — SPAS), oropharyngeal airway space (mid airway space — MAS) and hypopharyngeal airway space (inferior airway space — IAS). The differences between the distances of distinct measurement points (DIFF) were measured pre- and postoperatively. DOA referred to the distance of mandibular advancement and DP to the distance between the measurement points preoperatively. The parameters a, b₁ and b₂ were the regression coefficients that were determined separately for each unit (SPAS, MAS, and IAS).Results49 patients (16 male and 33 female) with a mean age of 27.2 years (SD: 10.09), ranging from 18 to 51 years, who underwent mandibular advancement surgery (BSSO) were enrolled in this study. The mean distance of mandibular advancement was 5.05 mm (SD: 1.63). Regarding SPAS and IAS, mandibular advancement did not affect dimensions significantly: SPAS DIFF, 0.33 mm ± 1.13 mm (b₁, p = 0.0881; b₂, p = 0.087); IAS DIFF, 0.66 mm ± 2.45 mm (b₁, p = 0.342; b₂, p = 0.765). DOA and DP did not influence DIFF significantly in both sections. Regarding MAS, the mean effect of mandibular advancement was an expansion of 2.47 mm ± 2.24. The linear regression model showed a statistically significant (b₁, p = 0.0064; b₂, p = 0.0240) influence of DOA and DP on DIFF in posterior airway dimensions pre- and postoperatively.DiscussionBased on preoperative LCR imaging data, a linear regression model was developed as a mathematical approach to allow prediction of PAS development in patients with Angle Class II malocclusions of different degrees. Increasing mandibular advancement was shown to be linked to increasing PAS, while a greater distance between the measuring points preoperatively led to smaller predicted PAS increases postoperatively.ConclusionPredicting pharyngeal airway space (PAS) development after mandibular advancement by analysing lateral cephalometric radiographs (LCR) may be useful in the screening and treatment of obstructive sleep apnea syndrome (OSAS) patients. Our mathematical approach is a simple and sustainable prediction tool based on LTR data for patients with Class II malocclusions.     

A retrospective comparative study of mandibular fracture treatment with internal fixation using reconstruction plate versus miniplates

PurposeThis study compared the clinical success rates of mandibular fracture treatment using reconstruction plates or miniplates and clarified the selection criteria for reconstruction plates.MethodsAll patients who had surgically-treated mandible fractures from 2008 to 2017 with sufficient follow-up were retrospectively analyzed for information about the fracture condition, treatment, and outcomes.ResultsA total of 126 surgically-treated mandible fractures without mandibular condylar fracture in 105 patients (76 male, 29 female) were included. Reconstruction plates were used in 32 fractures with very good postoperative occlusal function. Four cases with complications requiring reoperation were treated using only miniplates. Variables that were statistically associated with follow-up surgery included simple versus comminuted mandible fracture, and the absence of teeth that could be used for intermaxillary fixation (P < 0.05). In the miniplates treatment for comminuted fracture, there was a significant difference in the treatment outcome depending on the number of free bone-fragments and the presence of bone-fragments requiring removal within 1 cm (P < 0.05).ConclusionReconstruction plates provided better treatment outcomes for comminuted fractures and fractures without teeth. Selecting a reconstruction plate that is capable of sufficiently overloading is important in comminuted fractures with multiple free bone-fragments and bone-fragments requiring removal.     

牙周牙髓联合病变的综合治疗效果观察

目的研究牙周牙髓综合治疗对下前牙牙周牙髓联合病变的疗效,以期为临床治疗提供依据。 方法收集2017年1月至2018年2月至广州市海珠区口腔医院就诊的31例下颌重度牙周炎伴牙髓病变前牙,给予牙周治疗（龈上洁治、龈下刮治及根面平整术）,根管治疗和松牙固定的综合治疗。记录患者基线、治疗后3个月、6个月、12个月的牙石指数（CI）、龈沟出血指数（SBI）、探诊深度（PD）、附着水平（AL）值,采用单因素重复测量资料方差分析统计数据（检验水准α = 0.05）,比较患牙治疗前、后差异,评价临床疗效。 结果31例患牙中,牙周牙髓联合治疗有效率为96.8%。患牙在术后3、6、12个月较基线相比,其CI、SBI、PD、AL值均显著下降,差异均有统计学意义（P<0.001）。术后6个月与3个月相比,PD、AL值继续下降,差异有统计学意义（F_PD = 112.51,P_PD<0.001;F_AL = 117.64,P_AL<0.001）;术后12个月较6个月仍持续降低,但差异无统计学意义（F_PD = 0.04,P_PD = 0.815;F_AL = 0.09,P_AL = 0.786）。 结论对于下前牙牙周牙髓联合病变,综合治疗效果显著。