Periodic evaluation of the occlusal vertical dimension of maxillary dentures from the wax trial denture through 48 hours after polymerization

PURPOSE: This study measured the effects of commercial resin type on maxillary complete dentures with monoplane teeth by periodically comparing the occlusal vertical dimension of the polymerized dentures with the baseline, wax trial denture fiducial measurements. MATERIALS AND METHODS: Commercially available compression-molded, injection-molded, and fluid poly(methyl methacrylate) resins, as well as one compression-molded methyl acrylate ester copolymer, were evaluated. Ten dentures were fabricated from each resin using monoplane teeth. The occlusal vertical dimension at the articulator pin was measured at the wax denture stage for each specimen, and changes in occlusal vertical dimension for each denture were evaluated at a simulated laboratory remount, and at 0, 3, 6, 24, and 48 hours after a simulated clinical remount. Repeated measures analysis of variance (alpha = 0.05) and post hoc one-way factorial analysis of variance and Scheffe's F-Tests for each resin group were performed using ranks of raw data. RESULTS: Changes in the maxillary denture mean occlusal vertical dimensions were recognized throughout the evaluation periods compared with the wax-denture baseline, and time was a significant influence on displacement (p = .0001). Only the compression-molded poly(methyl methacrylate) dentures exhibited a mean laboratory remount occlusal vertical dimension that was significantly greater than the mean wax denture measurement, and all resin systems exhibited occlusal error that was significantly less than the laboratory remount measurements at 48 hours. At 48 hours, all resin groups exhibited mean occlusal vertical dimension changes that were less than 1 mm compared with the wax denture. Only compression-molded poly(methyl methacrylate) dentures exhibited a mean 48-hour clinical remount measurement that was statistically similar to the mean wax denture occlusal vertical dimension. CONCLUSIONS: Individual maxillary dentures from all resin types and at all intervals exhibited dimensional change. At the last evaluation period, the compression-molded poly(methyl methacrylate) showed no change in mean occlusal vertical dimension from baseline, whereas remaining groups exhibited occlusal vertical dimensions significantly less than baseline.     

Diagnostically restoring a reduced occlusal vertical dimension without permanently altering the existing dentures

The technique described provides the dentist with a means of diagnostically restoring the vertical dimension of occlusion for an edentulous patient, without permanently altering the dentures. This procedure is accomplished with a removable mandibular splint, which snaps over the mandibular denture. The procedure involves little clinical treatment time. The maxillary denture may also be temporarily overlayed in a similar manner, but the procedure is generally not as esthetically acceptable. Since the mandibular alveolar bone resorbs much faster than that of the maxillae in most edentulous patients, the mandibular denture usually is responsible for most of the loss of occlusal vertical dimension. The mandibular denture is therefore most frequently indicated for alteration to restore lost occlusal vertical dimension. Medicolegal implications, as well as practical considerations, suggest that the patient's present dentures should not be permanently altered before new dentures are found to be satisfactory.     

Modification of denture teeth for improved occlusal stability of a maxillary removable complete denture opposed by a mandibular implant-supported fixed complete denture: A clinical report

Wear of artificial teeth is the most common complication associated with an implant-supported fixed complete denture (ISFCD). This wear alters the occlusal scheme, with loss of eccentric occlusal balance and vertical dimension of occlusion (VDO). This clinical report describes the fabrication of a new maxillary removable complete denture opposing an existing ISFCD with occlusal modifications. Both prostheses received splinted zirconia crowns cemented with composite resin cement.     

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观察(牙合)垫式义齿修复牙列缺损伴咬合垂直距离过低的修复效果.方法 2002-2010年在南京医科大学附属南京第一医院口腔科,对17例牙列缺损伴咬合垂直距离过低患者采用(牙合)垫式可摘局部义齿修复,观察修复效果.结果 随访12～24个月,15例患者咀嚼功能、颜面美观等得到明显改善.结论 (牙合)垫式可摘局部义齿可以用于牙列缺损伴咬合垂直距离过低患者的义齿修复.     

Preservation of occlusal vertical dimension in overdentures.

The preextraction record is used to reestablish the occlusal vertical dimension in immediate and in later overdentures. A colored dot on the denture can be used to verify the occlusal vertical dimension after the dentures have been inserted.     

Ceramic flask technique for duplicating a complete denture

The possibilities for use of the duplicate denture are many. The duplicate denture serves as an excellent custom tray for the final working impression. If it is acceptable on the existing denture, the vertical dimension of the duplicate denture can be directly transferred to the articulator. If not acceptable, the vertical dimension can be altered and checked intraorally by adding or removing acrylic resin on the occlusal surface of the teeth. Alterations in esthetics, phonetics, and occlusion can easily be achieved and tested by replacing the original teeth of the duplicate denture with stock acrylic resin teeth. Alterations to the duplicate denture with subsequent patient approval prior to construction of a new prosthesis eliminates many problems associated with new dentures.     

Reestablishing occlusal vertical dimension using a diagnostic treatment prosthesis in the edentulous patient: A clinical report

To maintain a harmonious craniofacial system, the dental practitioner must establish an appropriate occlusal vertical dimension (OVD). Several methods can be used to determine an appropriate OVD. The patient presenting with decreased OVD represents a particular challenge for the dental practitioner in fabricating conventional dentures. This clinical report describes the use of a diagnostic treatment prosthesis to evaluate the patient's ability to manage such an increase in vertical dimension and to reestablish an appropriate occlusal vertical dimension. The use of a diagnostic treatment prosthesis at a vertical dimension 5 mm greater than what the patient presented with was determined to not cause discomfort over a 2-month period. A conventional complete denture was fabricated based on the patient's ability to handle the increase during the trial period. This report reviews the literature on this topic and describes a clinical technique for reestablishing the OVD in edentulous patients.     

Customizing palatal contours of a denture to improve speech intelligibility

Accurate approximation of palatal contours of a maxillary complete denture to a patient's tongue can improve speech intelligibility, if other factors such as tooth position, occlusal plane, and occlusal vertical dimension are satisfactory. Customizing palatal contours of a maxillary complete denture can be accomplished by using tissue-conditioning material, which provides sufficient working time for a patient to pronounce a series of sibilant sounds while recording dynamic impression of the tongue. This article describes a technique for customizing palatal contours of a maxillary complete denture with autopolymerizing acrylic resin to improve speech intelligibility.     

Measuring pressures under maxillary complete dentures during swallowing at various occlusal vertical dimensions. Part II: Swallowing pressures

The swallowing pressures of seven edentulous patients were measured at seven different occlusal vertical dimensions. In addition, the projection surfaces of the maxillary dentures were measured and the forces on the maxillary denture-bearing surfaces were calculated. The swallowing pressures were measured from the maxillary denture base-mucosal surface interface by means of a "closed" hydraulic system described in Part I. The mean values of swallowing pressures increased from 7.95 +/- 2.25 to 10.18 +/- 3.42 kPa as the occlusal vertical dimension increased, and then decreased to 8.38 +/- 3.55 kPa at the highest occlusal vertical dimension. The results of a two-way analysis of variance showed significant differences of swallowing pressures between patients (p less than 0.001) and between different occlusal vertical dimensions (p less than 0.001). The projection surfaces of maxillary denture bases were measured and ranged from 21.65 to 27.78 cm2. The forces exerted on these surfaces during swallowing were also calculated and ranged from 12.5 to 47.7 N.     

Determination of occlusal vertical dimension by means of controlled pressure against tissues supporting a complete denture

In order to establish the vertical dimension (VD) of a complete denture prosthesis, a new method of determining a comfortable mandibular position was tested using a recently designed hydraulic jack (hydraulic vertical displacement meter) in five edentulous patients. The device was designed so as to vary occlusal height by means of an extraoral jig connected to intra-oral hydraulic jacks, and to distribute the bite pressure applied against the denture-supporting tissue in approximately the same pattern as that produced by a denture with a VD preferred by the patient. The most comfortable mandibular position determined by this method coincided remarkably with the preferred VD of each patient in our study, indicating that the new device may be used to establish VD for complete denture construction.     

Combining fixed and removable restorations with linear occlusion to treat combination syndrome: a clinical report

Proper treatment sequencing is critical when a patient requires multiple fixed restorations in conjunction with a removable partial and complete denture. The vertical dimension, centric relation, and horizontal occlusal plane must be determined first, followed by a diagnostic wax-up that incorporates linear occlusal concepts to prevent anterior hyperfunction. A more predictable treatment outcome is possible when individual components are defined clearly.     

A Technique to Correct Anterior‐Posterior Tooth Discrepancy for a Maxillary Immediate Complete Denture

This article describes a chairside technique to correct inappropriate occlusal vertical dimension as well as the inaccurate anterior‐posterior tooth set‐up of a maxillary immediate complete denture. When fabricating an immediate denture, the inability of a wax‐denture trial and the potential for unpredictable complications during surgery, compromised esthetics and function of an immediate complete denture may pose a clinical problem, which needs instant correction. The technique described can provide an alternative method to correct and deliver a definitive immediate complete denture on the day of surgery.     

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。     

Tardive Dyskinesia Affected by Occlusal Treatment—A Case Report

The following is a case report of occlusal treatment for involuntary mandibular movement occurring in a 79-year old woman. This was diagnosed as sulpiride-induced tardive dyskinesia. The patient had been treated with sulpiride to improve gastrointestinal symptoms for five years until the onset of involuntary mandibular movement. The involuntary movement worsened even after discontinuation of the drug for 10 weeks. The dyskinesia improved in the course of treatment with an occlusal splint placed over her upper denture. After wearing the new denture with increased occlusal vertical dimension, the dyskinesia disappeared almost completely. Sirognathographic observation showed that previous denture wear evoked remarkable involuntary movement of the mandible once again. It is uncertain whether such improvement may result from discontinuation of the drug or from the occlusal treatment. However, it appears that occlusal factors played an important role in orofacial manifestation of tardive dyskinesia (TD) in this case.     

Effect of polymerization techniques on vertical dimension and tooth position in complete dentures

Due to the changes in the composition and processing of acrylic resins, it seems appropriate to evaluate the influence of polymerization methods about the alteration of occlusal vertical dimension and the horizontal positioning of artificial teeth of total dentures. For this, 64 specimens were made, simulating a maxillary total denture waxed from a standard maxillary denture. The experimental samples were divided into two groups: Group 1 - The resins were submitted to polymerization in a hot water bath, Group 2 - The same resins were submitted to poly-merization by microwave energy. The samples were measured horizontally and vertically before and after the polymerization process. Based on the results, it can be concluded that there was no statistically significant difference between the conventional polymerization method and the polymerization method by microwave, related to the stability of occlusal vertical dimension and horizontal positioning of artificial teeth on the specimens evaluated.     

Determination of vertical dimension by hydraulic intraoral jack

This paper describes the application of a hydraulic intraoral jig to the establishment of the vertical dimension of occlusion for full denture construction. The device enables the patient to establish an occlusal height which is most comfortable without the intervention or guidance of the dentist. Six patients for whom new dentures were to be constructed in the University of Otago School of Dentistry were invited to participate in the study. A conventional technique of denture construction was employed, but an additional stage was introduced after the jaw records had been taken and the casts mounted. Each patient was instructed in the use of the hydraulic jig and was asked to find a comfortable bite height in his own time. The results were compared with occlusal heights determined by conventional subjective methods. The former results proved to be more repeatable than those utilizing rest position and an average free-way space. The results are discussed and the implications outlined. Suggestions for further research using the hydraulic jig are made and the authors conclude that the hydraulic jig may be used to determine vertical dimension for full denture construction.     

The dynamic behaviour of a lower complete denture during unilateral loads: analysis using the finite element method

The purpose of this study was to analyse the correlation between the location and/or direction of unilateral load and the dynamic behaviour of a mandibular complete denture using the three-dimensional finite element method (FEM). The FE model consisted of the body of mandible, alveolar mucosa, and a complete denture, and it could simulate the condition of contact between the surface of the mucosa and mucosal surface of a denture. Load vectors, which simulated premature contacts, were calculated on the supposition that a premature contact on an occlusal facet causes a vertical load on it. Load-A, a load vertical to the anterior occlusal facet, caused the least displacement of the denture and less concentrated stress distribution. Load-P, a load vertical to the posterior occlusal facet, was characterized by the stress distributed in the lingual area of the pre-molar lesion on the contra-lateral side of the load. Load-B, a load vertical to the balancing occlusal facet, caused the largest displacement of the denture. The relationship between loads and stress distribution was agreed approximately with the observations previously reported, and lead to some suggestions about occlusion for complete dentures.     

Evaluation of the utility of cephalometric parameters in constructing complete denture. Part I: placement of posterior teeth

Various types of parameters, including cephalometric ones, have been used in the construction of complete denture. This study aimed to evaluate the utility of cephalometric parameters for this purpose. The position of the posterior teeth in a group of 42 edentulous patients, successfully rehabilitated with complete denture according to clinical parameters, was evaluated by cephalometrics. The following were determined: vertical dimension of occlusion (VDO); orientation of the occlusal plane; and subdivision of the denture space. The cephalometric parameters do not correspond to the clinical positioning of the posterior teeth in successful rehabilitation with complete denture.     

A potential link between oral status and hearing impairment: preliminary observations

Some previous studies suggest an association between tooth loss and hearing loss. The aim of this study is to assess the relation between oral status and hearing acuity. Forty-eight patients (mean age: 64.7 years) were allocated to four groups: one was wearing complete dentures in both jaws, another had shortened dental arches, a third had full dental arches in both jaws and the last lacked any occlusal stops (i.e. no occlusal vertical dimension, because of the absence of teeth or occlusal pairs). Audiological testing was performed in a noise-free chamber. Air and bone conduction were checked at different frequencies and the air-bone gap was determined. After correction for age and gender, a difference in air and bone conduction because of the oral status was found for low and for high frequencies while no significant differences were (P < 0.05) found for the air-bone gap. The number of teeth, number of occluding tooth pairs and presence or lack of occlusal vertical dimension, was significantly related to the gradient of hearing loss (P < 0.05). The discrepancy in hearing loss between complete denture wearers and patients without any occlusal vertical dimension, strengthens the hypothesis that it is the lack of the latter that is associated with hearing loss. At what level hearing loss occurs, needs further investigation.     

垫式可摘局部义齿联合软牙合垫治疗颞下颌关节紊乱病的疗效观察

目的观察利用垫式可摘局部义齿联合软垫对垂直距离过低的颞下颌关节紊乱病患者进行治疗的临床疗效。方法选择16例垂直距离过低的颞下颌关节紊乱病患者对其采用垫式可摘局部义齿联合软垫的方法进行修复治疗,做3个月和半年的随访,用Fricton指数和临床症状评价效果。结果 16例患者在接受治疗后Fricton指数较治疗前有明显下降,半年较3个月下降更为明显,统计学分析显示治疗3个月和半年与治疗前比较各项数据差异均有显著性(P<0.05),治疗半年与3个月比较JP、MP、PI无统计学意义(P>0.05)。结论 垫式可摘局部义齿可以在修复牙列缺损、恢复垂直距离的同时联合软垫有效治疗颞下颌关节紊乱病。