“Occlusal Plane Orientor”: An Innovative and Efficient Device for Occlusal Plane Orientation

Correct occlusal plane orientation is a prerequisite in Prosthodontic reconstructive treatment therapy as it helps in achieving esthetics and phonetics anteriorly and forms a milling surface posteriorly where tongue and buccinator muscle position the food bolus during mastication. Activity of Muscles during clenching will be least, when the occlusal plane is made parallel to plane of lost natural teeth. Conventionally the ala-tragus line (Camper’s plane) is used as a guide for assessment of the occlusal plane and fox plane is used to check the parallelism between the two. Occlusal plane orientor is a new device developed to mark occlusal plane parallel to ala-tragus line on maxillary occlusion rim, thereby saving clinician’s time and increasing efficiency. Additionally, it is a useful tool for occlusal plane orientation in patients with facial deformity, absence of an eye or an ear.     

39例中老年人正常合X线头影测量法合平面斜度研究

用Ｘ线头影测量方法对３９例中老年人正常　进行了　平面斜度的直线相关分析和多元逐步回归分析，结果在明，　平面斜度（ＯＰ－ＦＨ）与腭平面斜度（ＰＰ－ＦＨ）呈高度正相关，与下颌平面角（ＦＭＡ）有正相关关系，而与颅底及颌面的硬组织线距测量项目无关。     

Occlusal Plane Location in Edentulous Patients: A Review

Occlusal plane orientation is an important factor in the construction of a complete denture. Occlusal plane could be oriented using landmarks in the mandibular arch as well as in the maxillary arch. In the mandibular arch there are few landmarks which could be used to orient the occlusal plane like the retromolar pad, corner of the lips (lower lip length) whereas the maxillary arch has a number of landmarks, of which the ala-tragal line is the most commonly used and the same being the most controversial. In the following article different landmarks and its accuracy for orientating the occlusal plane in an edentulous subject as studied by various authors has been discussed.     

A Method for Occlusal Reshaping

A method for occlusal reshaping is described using a step-by-step analysis starting from the articulation of models to the completion of the clinical procedures. Several newly introduced definitions are provided to help the reader understand the procedures. This article is divided into three parts: (1) the preliminary procedures, (2) the occlusal reshaping of the study casts, and (3) the clinical occlusal reshaping. The advantages of this particular method include establishment of anterior guidance before initiating posterior reshaping procedures, maintenance of maximum cusp height and fossae depth, the placement of forces along the mid vertical axis of the teeth, and the establishment of simultaneous even contact of the posterior teeth, while providing the desirable anterior guidance.     

开张式双垫与塑料垫治疗磨牙症的对比研究

目的：比较开张式双垫在治疗磨牙症中与塑料垫的临床疗效。方法：分别用自制的开张式双垫与塑料垫对48位磨牙症患者进行治疗,随访9个月。分别统计治疗结束1个月和9个时的停止磨牙列数和平均减少的磨牙时间。结果：戴用1个月停止磨牙数比为6∶12,戴用9个月停止磨牙数比为10∶21。其差异具有显著性（P〈0.01）。结论：开张式双垫治疗磨牙症优于塑料垫。     

上颌平面偏斜对牙列中线与正中矢状面吻合度影响

目的:针对颌面部不对称畸形患者,在计算机上应用正颌手术模拟软件,重建三维头颅模型并模拟正颌手术,通过对术前上颌平面偏斜的角度和模拟正颌术后上颌牙列中线与正中矢状面夹角的分析,得出二者之间的关系,为正颌手术提供参考。方法:选择在中国医科大学附属口腔医院口腔颌面外科就诊的20位颌面部不对称畸形患者进行研究,首先用三维CT影像重建出头颅模型,测量上颌平面与水平参考面的夹角,再利用软件模拟上颌Le FortⅠ型截骨,测量上颌牙列中线与正中矢状面的夹角,最后应用统计学软件进行统计分析,得出两个角度间的关系。结果:颌面部不对称畸形患者,上颌平面和水平参考面的夹角与上颌牙列中线和正中矢状面夹角存在正相关的线性关系,经过统计学分析,得到上颌平面和水平参考面的夹角X与上颌牙列中线与正中矢状面夹角Y的直线回归方程,为Y=1.997+12.109X。结论:颌面部不对称畸形患者,上颌平面偏斜对牙列中线与正中矢状面的吻合度存在相关性,该相关性可为正颌手术的整复提供原则性的参考。     

Reliability of Anatomic Reference Planes in Establishing the Occlusal Plane in Different Jaw Relationships: A Cephalometric Study

The purpose of this study was to evaluate the reliability of different anatomic reference planes in determination of Occlusal plane in dentulous and edentulous subjects with Angle’s class I and class II Maxillomandibular relationship. Eighty subjects were included in the study which was divided into four Groups based on dentition and skeletal relationship. The Group I (n = 20) and Group II (n = 20) includes young and completely dentulous subjects in Angle’s class I and class II relationship, respectively. The Group III (n = 20) and Group IV (n = 20) subjects were completely edentulous in Angle’s class I and class II relationship, respectively. For all subjects, right lateral cephalograms were taken and cephalometric analysis was done and data obtained from cephalometric tracings were then statistically analyzed. The results showed no significant difference of angle between Occlusal plane and Frankfort Horizontal plane, Camper’s plane and Palatal plane when Group I and Group III, and Group II and Group IV subjects were compared. The Frankfort Horizontal plane, Camper’s plane and the Palatal plane may be used as a reliable guide to establish Occlusal plane in edentulous subjects in both Angle’s class I and class II Maxillomandibular relationships.     

Occlusal conditions just after the relief of temporomandibular joint and masticatory muscle pain

When the signs and symptoms of temporomandibular joint disorders (TMD) are present, it is possible that occlusal conditions and mandibular movements are changed. Accordingly, the presence of occlusal interferences may be misjudged. It is therefore reasonable to consider that occlusal conditions should be examined just after the relief of symptoms. The comparison of occlusal conditions in 52 temparomandibular joint (TMJ) pain patients and 27 muscle pain patients with that in 60 asymptomatic controls was made. Occlusal examination in the patients was administered just after the relief of pain by bite plane therapy alone. The only occlusal factor which was associated with pain symptoms was no canine contact on the working side on laterotrusion. It is suggested therefore that further studies as regards this type of interference should be performed.     

Prevalence of Second Mesiobuccal Canals in Maxillary First Molars Detected Using Cone-beam Computed Tomography,Direct Occlusal Access,and Coronal Plane Grinding

Introduction

The purpose of this study was to determine the prevalence of the second mesiobuccal canal (MB2) in 100 maxillary first molars using 3 independent methods and a combination method.

Occlusal interference during mastication can cause pathological tooth mobility

BACKGROUND AND OBJECTIVE: Despite little evidence regarding the relationship between tooth mobility and nonworking contact, the evaluation of occlusion is performed mainly by the detection of premature and/or nonworking contacts during tapping movements and lateral excursion. The hypothesis of this study is that occlusal contact during mastication is potentially traumatic to periodontal tissue. It clarifies the relationship between chewing patterns and the status of periodontal tissue. MATERIAL AND METHODS: Subjects included 73 adults, 20-29 years of age (39 men and 34 women), with complete sets of teeth and no history of orthodontic treatment or periodontal disease. The closing chewing patterns of each subject were classified into three groups by the Masticatory Deviation Index, which depicts the deviation from the normal chewing patterns within 5 mm from the intercuspal position. Periotest was used to diagnose teeth mobility and the values were compared among the three groups. RESULTS: The present study indicates that the chewing movements which deviated from the normal chewing movements increased the mobility of specific types of teeth. CONCLUSION: The results of this study imply a relationship between chewing movements and tooth mobility and indicate that functional evaluation of occlusion is necessary for the examination of periodontal tissue. Occlusal evaluation with border and tapping movements might be insufficient, and functional occlusal evaluation during chewing movements can be clinically useful for using to evaluate periodontal tissue.     

An Alternative Technique for Fabrication of an Occlusal Device

Several methods have been described for fabrication of occlusal devices, but many require complex and time-consuming laboratory procedures. In this article, an alternative fabrication method for a hard occlusal device while maintaining the articulation of the cast is described.     

咬合不适综合征的研究现状

咬合不适综合征(occlusal discomfort syndrome, ODS)是一种以与咬合运动相关的持续咬合不适为特征的综合征,有些患者口腔内可以发现存在明显咬合关系不协调,有些也可没有明显的咬合异常。该疾病患者常伴有焦虑等心理学特征。ODS病因不明,通常继发于口腔修复和正畸治疗,咀嚼系统对咬合关系不协调的被动性适应可能是导致ODS的原因。ODS尚无报道系统治疗方案,患者口腔内无明显咬合关系不协调时,不恰当的修复、调牙合和正畸等治疗均有可能加重患者的病情,而心理治疗与认知行为疗法被认为对该疾病治疗效果显著。目前口腔医生对该疾病认识有限,该文旨在对ODS的流行病学特征、病因、临床表现、诊断与防治作一综述。     

Reliable and Repeatable Centric Relation Adjustment of the Maxillary Occlusal Device

This technique article describes a quantifiable, repeatable, and reliable method for occlusal device adjustment in centric relation using a leaf gauge. In addition, specific suggestions for occlusal device design are provided to enhance patient comfort with the prosthesis in place.     

Occlusal interferences and functional disturbances of the masticatory system

Abstract A total of 282 patient histories and occlusal analyses made by students for instructional purposes were evaluated. An attempt was made to correlate the slide from centric relation to centric occlusion (maximum intercuspation), and occlusal interferences in eccentric movements, to pain and/or symptoms of functional disturbances of the masticatory system. A slide in combination with balancing interference(s) was found almost twice as frequently in patients with pain and/or symptoms compared to patients with no symptoms. Neither the amount nor the direction of the slide was correlated with the pain and/or symptoms. The balancing interferences tended to be located on the pain and/or symptom side.     

The Position of the Occlusal Plane in Natural and Artificial Dentitions as Related to Other Craniofacial Planes

Purpose: This study aimed at determining the most reliable ala‐tragus line as a guide for the orientation of the occlusal plane in complete denture patients by use of cephalometric landmarks on dentate volunteers. Materials and Methods: Analysis was made for prosthodontically related craniofacial reference lines and angles of lateral cephalometric radiographs taken for 47 dentate adults. Variables were determined and data were analyzed using SPSS (SPSS, Inc., Chicago, IL). Results: Occlusal plane angle formed between the occlusal plane and Camper's plane had the lowest mean value in the angle formed with Camper's I, which represents the measure taken from the superior border of the tragus of the ear with a score of 2.1°. The highest was measured in the angle formed with Camper's III with a score of 6.1°, while the angle formed with Camper's II was 3.2°. The differences between the three planes in relation to the occlusal plane was significant (p < 0.001). Conclusion: The superior border of the tragus with the inferior border of the ala of the nose was most accurate in orienting the occlusal plane.     

酸蚀症患者的咬合重建修复

目的：探讨咬合距离降低的酸蚀症患者的修复治疗方法。方法：对酸蚀症患者进行咬合重建序列治疗,包括暂时性[牙合]垫式可摘局部义齿、冠延长术、根管治疗术以及固定与可摘局部义齿联合修复。结果：患者的咬合距离抬高、咀嚼和美观功能得到很好的恢复,无牙周炎症和颢下颌关节的异常。结论：对于咬合距离降低的酸蚀症患者进行修复时要注重咬合重建序列治疗。     

Preservation of Hypermobile Teeth by Establishing Posterior Occlusal Support Using Implant Prostheses: A 5‐Year Follow‐Up

For patients with periodontally compromised, hypermobile teeth, implant‐supported fixed dental prostheses (FDPs) or removable dentures are often used after extracting mobile teeth. The loss of native teeth may carry social consequences, depending upon the patient's age, state of health, and degree of social functioning. This report represents successful stabilization and preservation of questionable, hypermobile teeth that have been damaged by traumatic occlusion due to the loss of posterior support with a cross‐arch splinted FDP, as well as the implementation of posterior support using implant‐supported prostheses.     

基于ABAQUS软件的成人正中咬合关系评测方法研究

目的:利用ABAQUS软件,应用有限元方法对牙齿咬合进行仿真,并建立咬合接触关系的评测方法,以辅助医生制定正颌外科手术方案。方法:运用Mimics软件重建上下颌骨的三维几何模型,并在该模型的基础上对关节盘模型进行了简化,建立了上下颌骨的有限元模型,通过ABAQUS软件对咬合进行仿真计算。结果:通过对牙尖交错位进行咬合分析,得到牙齿表面上的应力分布云图,应用图像处理方法将应力区域分布转化成咬合点的形式,建立了用于评价咬合接触关系的评测方法。结论:该方法根据咬合点的情况判断手术后的咬合接触效果,可对正颌外科手术的术后咬合接触关系进行术前评测,并通过仿真结果辅助手术方案的完善,从而提高手术效果。