Subjective values of different age groups in Japan regarding treatment for missing molars

Gerodontology 2010; doi: 10.1111/j.1741‐2358.2009.00357.x
Subjective values of different age groups in Japan regarding treatment for missing molars Objective: To determine how patients and dentists in Japan value the outcomes of different treatment options for missing molars. Materials and methods: Elderly removable‐denture wearers and dentate persons (senior group), preclinical dental students (young group), and prosthodontists were presented with five possible treatment options for missing lower bilateral first and second molars. The participants indicated on a visual analogue scale how they would value the treatment (utility value: UV), if they had received each of the treatments. Two‐way repeated measures anova was used for statistical analyses. Results: The UV for the shortened dental arch (SDA) without replacement was the lowest in every group. The young group rated the value of cantilever fixed partial dentures (FPD) and implants significantly higher than removable partial dentures (RPD), while the senior group rated the value of FPD and RPD significantly higher than implants. Those having experience with removable dentures were likely to place a higher value on the acrylic RPD. The prosthodontists rated the value of implants significantly higher than any other options. Conclusions: The participants in every group placed the lowest value on the outcome from the SDA in Japan. The denture wearers preferred the RPD, while prosthodontists preferred implants.     

Maxillary complete denture movement during chewing in mandibular removable partial denture wearers

Objectives: To evaluate the pattern of maxillary complete denture movement during chewing for free‐end removable partial dentures (RPD) wearers, compared to maxillary and mandibular complete denture wearers. Materials and methods: Eighteen edentulous participants (group I) and 10 volunteers with bilateral posterior edentulous mandibles (group II) comprised the sample. Measures of mean denture movement and its variability were obtained by a kinesiographic instrument K6‐I Diagnostic System, during the mastication of bread and a polysulphide block. Data were analysed using two‐way anova (α = 0.05). Results: Upper movement during chewing was significantly lower for group II, regardless of the test food. The test food did not influence the vertical or lateral position of the denture bases, but more anterior dislocation was found when polysulphide blocks were chewed. Group II presented lower intra‐individual variability for the vertical axis. Vertical displacement was also more precise with bread as a test food. Conclusion: It can be concluded that mandibular free‐end RPD wearers show smaller and more precise movements than mandibular complete denture wearers.     

应用电子散斑干涉术对单端固定桥的受载分析

本文目的是对单端固定桥的运动及其受力状态进行试验性研究。采用电子散斑干涉术这一新的光学技术分别对下颌单端固定桥修复前后进行４种垂直加载测试,观察实时显示的散斑干涉条纹图,并测量相应牙槽骨处的离面位移。     

Radiographic evaluation of alveolar ridge heights of dentate and edentulous patients

doi: 10.1111/j.1741‐2358.2010.00391.x Radiographic evaluation of alveolar ridge heights of dentate and edentulous patients Objective: To evaluate the reduction of residual alveolar ridge height on panoramic radiographs and the differences between denture wearers and non‐denture wearers. Materials and methods: The study consisted of 147 individuals (74 men and 73 women) [50 were denture wearers and 50 non‐denture wearers (examination groups) and 47 of them were dentate (control group)]. Individuals having diseases impacting on bone were excluded. Vertical measurements were made at 15 sites (central incisors, first premolars and molars at the left and right of both jaws and the distance between the zygoma/orbit). MANOVA (multi‐variate analysis of variation) was used for the statistical analysis of the results. Results: There were significant differences between the alveolar ridge heights of dentate and edentulous groups (p < 0.001). Between the denture wearer and the non‐denture wearer groups, there was significant difference in the lower jaw (p < 0.001), but no significant difference in the upper jaw (p = 0.635). There were also differences between men and women (p < 0.005) and upper and lower jaws at every measurement sites (p < 0.01). Conclusion: Reduction in residual alveolar ridge height was in close relation with gender, denture usage and edentulousness.     

Effect of oral hygiene education and motivation on removable partial denture wearers: longitudinal study

Objectives: The purpose of this study was to determine the effect of two different preventive oral hygiene education and motivation programmes on the plaque and gingival index, as well as denture hygiene of patients provided with removable partial denture (RPD) during a 12‐month follow‐up. Material and methods: A total of 53 partially edentulous patients were recruited for this study. The presence or absence of plaque and gingival bleeding by gentle probing was scored on all tooth surfaces at the preliminary visit. The plaque and gingival indexes were measured using the Löe index. Following treatment, the patients were randomly divided into three groups. In Control Group I, subjects were instructed to continue their personal oral hygiene routine. In Group II, participants were given verbal instructions and a self‐educational manual on oral hygiene without illustrations. In Group III, oral hygiene guidance was delivered using a combination of verbal instructions and a self‐teaching manual. To evaluate the effect of the different modes of instruction, the presence or absence of plaque and gingival bleeding was scored on all tooth surfaces (day zero examination) and re‐examined 7, 15 and 30 days, 3, 6 and 12 months following RPD placement. The state of denture hygiene was evaluated 7, 15 and 30 days and 3, 6 and 12 months following rehabilitation. Parametric statistics was applied to dental plaque and gingival indexes. For accumulation of plaque and calculus on the RPD, non‐parametric statistic was applied. Results: The frequency of plaque found during the preliminary visit was higher than that found in the other periods. With regard to gingival index, significant difference was found between the preliminary visit examination and other periods. There was a significant difference in the plaque accumulation on the denture surface between groups I and III. Conclusion: The different methods of oral hygiene instruction used in this study indicate that the type of education was not of significant importance.     

Prevalence of removable partial dentures users treated at the Aracatuba Dental School-UNESP

doi: 10.1111/j.1741‐2358.2012.00653.x
Prevalence of removable partial dentures users treated at the Aracatuba Dental School – UNESP Objectives: The aim of this study was to evaluate the frequency of removable partial dentures (RPD) at the Aracatuba Dental School. Methods: The study was conducted by analysing 412 clinical history of patients attended at the RPD clinics in the period from 2000 to 2007. Results: 412 charts were analysed: 148 (35.9%) men and 264 (64.1%) women. The mean age was 53.8 years (men) and 52.4 years (women). A total of 556 dentures were made; of these, 233 (41.90%) were maxillary and 323 (58.09%) were mandibular dentures. The most frequent Kennedy classification found was Class III (maxilla) and Class I (mandible). In the maxilla, 55% (126) of the major connectors were of the anterior–posterior palatal bar, while in the mandible, 64% (202) were the lingual bar. As regards the claps, 401 were circumferential and 318 were bar claps. Conclusion: The mean age of the patients was 52.9 years with higher prevalence of female patients; the most frequent Kennedy’s classification was Class I in mandible and Class III in maxilla; the most common major connector was anterior–posterior palatal bar for maxilla and lingual bar for mandible; the circumferential clasps were the most common retainer used in both jaws.     

Complete denture wearing and fractures among edentulous patients treated in university clinics

doi: 10.1111/j.1741‐2358.2011.00551.x
Complete denture wearing and fractures among edentulous patients treated in university clinics Objective: The prevalence of wearing and fracture of complete dentures was evaluated among edentulous patients treated in two dental schools in Brazil. Background: Acceptance and wearing of complete dentures are related to adaptive behaviour of edentulous patients. However, one reason that could interfere with the wearing dentures is their potential to fracture, which is still a common complication in denture rehabilitation practice. Material and methods: Two hundred and twenty‐four edentulous patients rehabilitated with complete dentures from 2000 to 2005 in Araçatuba and Araraquara Dental School, University of State of São Paulo, were assessed in 2006 and 2007 to answer a questionnaire about wearing and fracture of their dentures. Statistical analysis were performed using Epi Info software and chi‐squared test to compare maxillary and mandibular data (α = 0.05). Results: Almost 26% of the patients did not wear their dentures, and among the remainder, the majority wore the maxillary denture. About 30% of the dentures were fractured, with higher prevalence in the maxillary arch (p = 0.003). Conclusions: Discontinuation of wearing dentures was quite high, especially considering the treatment which was carried out in university clinics. Prevalence of fractures was also high, greater for the maxillary denture, and was one of the main reasons for non‐wearing of complete dentures.     

Analysis of the compressive strain below the removable and fixed prosthesis in the posterior mandible using a digital image correlation method

It was the purpose of this study to determine and analyse strains in the bone of posterior mandible below the removable and fixed partial dentures using Digital Image Correlation Method. Dried mandible with shortened dental arch (Kennedy Class 1) was used in the experiment. The mandible model was prepared for accepting two types of restorations for bilaterally missing molars conventional therapy, and removable and fixed partial dentures were manufactured following standard prosthetic protocol. The models with prosthetic restorations placed in situ were subjected to loading of 50-300 N, and photographed using two digital cameras as part of the digital image correlation method equipment. Afterwards, the obtained data for strains within restored mandible during loading ciclus were analysed in the software Aramis and graphically presented. Percentage size of the mandible strains within the line section are from 0.14 to 0.19% for the removable partial denture experimental model and 0-0.14% for the fixed partial denture experimental model. The study has demonstrated that Digital Image Correlation method can be used to measure strain on the mandible surface and replacements during loading and that from biomechanical perspective both therapeutic modalities can be equally useful for the restoration of the mandible with bilaterally distal edentulous spaces.     

The oral health‐related quality of life in edentulous patients treated with Conventional complete dentures

Objective: To compare the oral health‐related quality of life (OHRQoL) between patients with both maxillary and mandibular complete denture and those with either the maxillary or the mandibular complete denture. Background: Satisfaction of denture wearers can be estimated using the OHRQoL questionnaires like the OHIP‐EDENT and the Geriatric Oral Health Assessment Index (GOHAI). Methods: Two questionnaires were used to compare the OHRQoL between edentulous patients who had conventional removable complete denture on both jaws and those who had on either one of the jaws. Result: The age of the participants ranged from 42 to 75 years, with the mean age of 58 ± 8.12 years. The mean OHIP‐EDENT scores were significantly high among those who wore conventional dentures in both jaws (54.12 ± 5.21), compared with the participants who only had denture either on upper or lower jaw (46.52 ± 7.35). It was noticed that the mean GOHAI score was significantly lower (p < 0.05) among participants who had conventional denture on both upper and lower jaw (28.25 ± 3.67), as compared to those who had conventional denture only on one arch (35.12 ± 2.11). Conclusion: Patients with complete dentures in both jaw (Group I) were less satisfied than patients with single complete denture (Group II). The result obtained in this study shows dissatisfaction with conventional dentures among edentulous patients.     

Partial edentulism and removable partial denture design in a dental school population: a survey in Greece

Gerodontology 2011; doi: 10.1111/j.1741‐2358.2010.00382.x Partial edentulism and removable partial denture design in a dental school population: a survey in Greece Objectives: To investigate the pattern of partial edentulism and the most frequent designs of cobalt‐chromium removable partial dentures (RPDs), constructed at the Dental School of Athens, Greece. Methods and materials: Five hundred and fifty‐three patients, between 42 and 81 years old, mostly males, treated by undergraduate dental students, were included. The survey was based on visual evaluation of master casts and work authorisation to dental technicians. Aspects examined were: Kennedy Classification, modification areas, major connectors, clasping, placement of rest seats and indirect retention. Results: Kennedy Class I was the most common encountered in the maxilla (50.5%) and in the mandible (70%). The most frequent major connectors were the lingual bar (92.6%) and the U‐shaped palatal strap (54%). The most common clasp was the Roach (69.2%) in Class I and Class II. In Class III and IV, the most common was the occlusally approaching clasp (55% and 70%). The most frequent location of the rest was mesial of abutment teeth. On the average, 39.5% of Class I RPDs and 58.6% of Class II RPDs had indirect retainers. Conclusion: A combination of the two major philosophies of RPD design (biomechanical and hygienic) was evident in the RPDs examined in our study.     

整体铸造支架式可摘局部义齿添加人工牙的临床修理效果

目的：探讨整体铸造支架式可摘局部义齿添加人工牙的修理体会。方法：对240例佩戴整体铸造支架式可摘局部义齿的患者进行义齿添加人工牙修理,比较修理前后视觉模拟（VAS）评分、咀嚼功能及1年后人工牙的磨耗程度。结果：修复后VAS评分明显低于修复前,两者比较差异有统计学意义（P〈0.05）,但牙槽骨吸收距离未见明显差异（P〉0.05）。经过修复后义齿的固位稳定及咀嚼情况较修复前明显好转,在随访1年后,人工牙大多有轻到中度的磨耗,磨耗后出现23例颌位垂直距离缩短及2例下颌前移及偏移。结论：设计合理的支架连接体,并且尽量作添加人工牙和卡环的修理,可以延长义齿的使用寿命。     

Use of resin‐bonded extracoronal attachments with removable partial denture: case report

doi:10.1111/j.1741‐2358.2009.00298.x
Use of resin‐bonded extracoronal attachments with removable partial denture: case report Introduction: Resin‐bonded extracoronal attachments may be indicated for the abutment teeth of removable partial dentures, especially for anterior teeth when a cingulum rest must be provided. This type of treatment has a series of advantages such as minimal tooth reduction, supragingival margins, favourable stress distribution, and improved aesthetic appearance. Objective: To report a clinical case of oral rehabilitation using a combination of resin‐bonded extracoronal attachments joined by a Dolder bar with a removable partial denture. Case report: A 60‐year‐old male patient with only the canines in the maxillary arch was restored with a combination of resin‐bonded extracoronal attachments joined by a Dolder bar and a removable partial denture. Conclusion: Dentures with resin‐bonded extracoronal attachments can have a number of advantages over traditional clasp‐retained removable partial dentures.     

Effect of ill-fitting dentures on the swallowing duration in patients using polygraphy

doi: 10.1111/j.1741‐2358.2011.00536.x Effect of ill‐fitting dentures on the swallowing duration in patients using polygraphy Background: Surface electromyography (SEMG) has been widely used in the recent years to study swallowing physiology, offering a valid and reliable tool for identifying normal swallowing. The goal of our study was to assess the contribution of denture fitness in the age‐related increase of swallowing duration. Methods: Twenty denture wearers and 20 dentate individuals were analysed using SEMG and a computerised kinesiography of mandibular movement. Three spontaneous saliva swallowings were recorded for each patient with both their old and new prostheses. Three spontaneous saliva swallowings were recorded for each dentate person in two different recording sessions. Results: Old prosthesis mean swallowing time was 1.84 (SD ± 0.85) seconds while the new well‐fitting prostheses needed a 1.28 (SD ± 0.55) (p = 0.0009) swallowing time. The difference in swallowing time was significant (p = 0.01) between dentate subjects and individuals wearing an old prosthesis. No significant difference was found between dentate subjects and the same prosthesis wearers when a new well‐fitting prosthesis was worn. Conclusion: Data presented in this work suggest that part of the increased duration of swallowing showed by elderly and healthy people is because of incorrect an dental prosthesis. Prolongation of swallowing duration in the elderly population could be reconsidered in the light of the quality of dental device worn by the aged population.     

Jaw muscles and the skull in mammals: the biomechanics of mastication.

Among non-mammalian vertebrates, rigid skulls with tight sutural junctions are associated with high levels of cranial loading. The rigid skulls of mammals presumably act to resist the stresses of mastication. The pig, Sus scrofa, is a generalized ungulate with a diet rich in resistant foods. This report synthesizes previous work using strain gages bonded to the bones and sutures of the braincase, zygomatic arch, jaw joint, and mandible with new studies on the maxilla. Strains were recorded during unrestrained mastication and/or in anesthetized pigs during muscle stimulation. Bone strains were 100-1000 micro epsilon, except in the braincase, but sutural strains were higher, regardless of region. Strain regimes were specific to different regions, indicating that theoretical treatment of the skull as a unitary structure is probably incorrect. Muscle contraction, especially the masseter, caused strain patterns by four mechanisms: (1) direct loading of muscle attachment areas; (2) a compressive reaction force at the jaw joint; (3) bite force loading on the snout and mandible; and (4) movement causing new points of contact between mandible and cranium. Some expected patterns of loading were not seen. Most notably, strains did not differ for right and left chewing, perhaps because pigs have bilateral occlusion and masseter activity.     

The influence of mandibular implant-retained overdentures in masticatory efficiency

doi: 10.1111/j.1741‐2358.2011.00539.x The influence of mandibular implant‐retained overdentures in masticatory efficiency Objective: To evaluate the masticatory efficiency of patients rehabilitated with conventional dentures (CDs) or implant‐retained mandibular overdentures. Background: Despite the evident benefits of implants on mastication as assessed by subjective patient‐based outcomes, the extent of implant overdenture treatment effect on food comminution is not well established. Materials and methods: A randomised clinical trial was carried out with 29 completely edentulous patients divided into two groups. The first group was rehabilitated with a mandibular overdenture retained by two splinted implants with bar‐clip system, while the second group was rehabilitated with a mandibular CD. Both groups also were rehabilitated with maxillary CDs. Masticatory efficiency and patient satisfaction were assessed 3 months after denture insertion. Masticatory efficiency was evaluated through the colorimetric method with the beads as the artificial test‐food. Comparisons for masticatory efficiency and patient satisfaction were performed using Student’s t‐test (α = 0.05). Results: No significant statistical difference was found for masticatory efficiency (p = 0.198). Patient overall satisfaction was significantly higher for the mandibular overdenture (p < 0.001). In addition, mandibular overdenture patients were significantly more satisfied with chewing experience (p < 0.05) and retention of the lower denture (p < 0.005). Conclusion: The results of this study suggest that mandibular overdenture significantly improves chewing experience, although limited effect on masticatory efficiency has been observed.     

Hyperbaric oxygen therapy treatment for the fixation of implant prosthesis in oncology patients irradiated

doi: 10.1111/j.1741‐2358.2012.00636.x Hyperbaric oxygen therapy treatment for the fixation of implant prosthesis in oncology patients irradiated Objectives: This study aimed to present a clinical report of an irradiated oncologic patient who underwent hyperbaric oxygen therapy to be rehabilitated with implant‐supported prosthesis. Materials and Methods: A 67‐year‐old man was admitted at Oral Oncology Center (FOA‐UNESP) presenting a lesion on the mouth floor. After clinical evaluation, incisional biopsy and histopathological exam, a grade II squamous cell carcinoma was diagnosed. The patient was subjected to surgery to remove the lesion and partial glossectomy. Afterwards, the radiotherapy, in the left/right cervicofacial area of the supraclavicular fossa, was conducted. After 3 years of the surgery, the patient was submitted to hyperbaric oxygen therapy. Then, four implants were installed in patient’s mandible. Five months later, an upper conventional complete denture and lower full‐arch implant‐supported prosthesis were fabricated. Conclusion: The treatment resulted in several benefits such as improving his chewing efficiency, swallowing and speech, less denture trauma on the mucosa and improving his self‐esteem.     

隐形义齿对基牙龈沟内菌群的影响

目的将隐形义齿与传统卡环固位式可摘局部义齿进行对比,探寻隐形义齿对基牙龈沟内菌群的影响,从而指导活动义齿的选择和设计。方法下颌第一磨牙缺失的患者随机分成3组。分别戴用弯制卡环式可摘局部义齿、铸造卡环式可摘局部义齿和隐形义齿。定时对基牙龈沟进行取样并行细菌培养,并统计细菌总量、专性厌氧菌检出率以及G-菌检出率。结果戴牙后同期相比,隐形义齿组与传统卡环固位式可摘局部义齿相比,基牙龈沟内细菌总量更大,专性厌氧菌检出率及G-菌检出率更高,差异具有统计学意义。结论上述研究结果说明:相较于传统卡环固位式可摘局部义齿,隐形义齿对基牙龈沟内菌群的影响更大。对于牙周状况不佳的患者应当谨慎使用隐形义齿作为修复方式。     

The influence of age and denture wear on the size of edentulous structures

Objectives : This study was designed to evaluate the influence of age and denture use on the size of arches and residual ridges in edentulous patients. Design : At two nursing homes, maxillary and mandibular stone casts of 302 fully edentulous patients were utilized to measure the size of the arches and residual ridges, according to age and use of complete dentures. Age cohorts were divided into three groups; 60–69, 70–79, and 80–89 years old. Two hundred and forty‐nine denture wearers used complete dentures for at least 2 years before examinations. Fifty‐three non‐denture users had never worn removable prostheses. Chi‐square analysis (p<0.05) was used to establish the possible relations between the linear values and the size indexes of the ridges and arches and the two examined parameters: age and denture wear. Results : Young old patients possessed edentulous structures that were not significantly larger than elderly old patients in both the maxilla and the mandible. Non‐denture users had significantly bigger arches and ridges in both edentulous jaws than denture users. Conclusions : Young old, non‐denture users tended to have bigger residual edentulous tissues compared to elderly old patients who used complete dentures.     

Knowledge of prosthodontic treatment among denture-wearers and non-denture-wearers attending a dental institute in India: a survey report

Objective: Knowledge of subjects regarding prosthodontic treatment may play a role in their acceptance of the prostheses. The purpose of this survey was to assess the knowledge of prosthodontic treatment among the denture‐wearers and non‐denture‐wearers reporting to the Institute of Dental Sciences, Belgaum. Methods: A self‐designed closed‐ended questionnaire containing 14 questions was designed. Four‐hundred and nineteen subjects aged between 25 and 65 years were surveyed over a period of 2 months. Collected data were statistically analysed using chi‐squared test at a significance level of p < 0.05. Results: From the 419 subjects surveyed, 140 subjects (33.4%) were dentate and 279 subjects (66.6%) were edentulous either in the maxillary, mandibular or both arches. Among the 279 edentulous subjects, 143 (51.3%) did not use any kind of prosthesis. There was a statistically significant difference in knowledge regarding the replacement of teeth by artificial means, the number of visits required for the provision of a complete denture, problems with dentures among subjects using and not using them (p < 0.001) whereas no significant difference was found among the subjects regarding aesthetics with dentures and socializing with friends. Conclusion: Attempts should be made to raise the level of knowledge of both denture‐wearers and non‐denture‐wearers reporting to the Institute for any dental treatment.