Association of residual ridge resorption with systemic factors in home-living elderly subjects

Application of masticatory control in dental treatment for elderly individuals

Taiwan transitioned to an aged society in 2018. Appropriate dental treatment is important for elderly individuals. Previously, reconstruction of the dentition was thought to help regain chewing function. However, concerns of the elderly population, such as decline in learning ability and saliva secretion, complicate dental reconstruction. Overlooking the special needs of elderly individuals may lead to impaired chewing function, resulting in nutritional imbalances and increased burden on the digestive tract, causing more health disorders. For the elderly population, treatment must be aimed at restoring as much chewing function as possible with minimal changes. Additionally, regular oral hygiene care, proper design of fixed partial dentures, and implant placement greatly reduce the difficulty in adapting to a new prosthesis. These measures allow us to provide better quality of life for elderly individuals.

A case control study to investigate the effects of denture wear on residual alveolar ridge resorption in edentulous patients

OBJECTIVES

To investigate the effect of complete denture wearing on residual ridge resorption in edentulous patient compared with edentulous patient who never wore dentures.

METHODS

Patients who had been edentulous for at least five year who had never worn dentures successfully were matched to edentulous denture wearing control patients. To control for factors possibly associated with alveolar ridge resorption patients who had been rendered edentulous in one arch before the other, smokers, those taking steroids, bisphosphonates, with histories of autoimmune diseases, diabetes mellitus or osteoporosis at any time during their period of edentulousness were excluded. Case and control groups were matched for age, sex and time since being rendered edentulous. Statistical analyses were undertaken using Person's Chi squared (X²) test and Fisher's exact test.

RESULTS

30 edentulous patients who had not worn dentures for at least five years were identified and matched with 30 controls. All control patients were the same age ± 2 years and had been edentulous for the same number of years ± 2 years of their respective controls. There was no significant difference between age and time since being rendered edentulous between case and control. Denture wearers had significantly more maxillary and mandibular residual alveolar ridge resorption than did non denture wearers. Severe ridge resorption was mostly confined to the denture wearing group.

CONCLUSION

Patients wearing complete dentures for more than 5 years had significantly more residual alveolar ridge resorption than was found in non-denture wearing edentulous patients.

Quantitative Assessment of the Edentulous Posterior Maxilla for Implant Therapy: A Retrospective Cone Beam Computed Tomographic Study

Aim

Dimensional changes of the alveolar bone are often noted in horizontal and vertical planes as a sequel to tooth extraction, particularly in the maxillary posterior region due to alveolar bone resorption combined with pneumatization of the sinus. The aim of this retrospective study was to quantitatively assess the maxillary residual alveolar ridge using cone beam computed tomography (CBCT) scans.

Materials and methods

A total of 349 edentulous sites from 250 CBCTs were evaluated. The apico-coronal bone height and bucco-palatal crest width were measured in sagittal and coronal slices, respectively. Additionally, the obliqueness of the sinus floor at the edentulous sites was also evaluated.

Results

One hundred and twelve (55.45%) of the molar and 74 (54.42%) of the premolar sites had a horizontal ridge dimension < 6 mm, whereas 137 (67.83%) of the molar and 61 (44.86%) of the premolar sites showed an apico-coronal height < 8 mm. Furthermore, 183 (54.14%) of the evaluated sites had an oblique sinus floor morphology.

Conclusion

Additional augmentative procedures are thus required in a high percentage of the population at the edentulous maxillary posterior site for rehabilitation using a standard dimension implant. This study stresses on the need for a three-dimensional CBCT prior to implant surgery for proper treatment planning.

Effect of denture soft liner on mandibular ridge resorption in complete denture wearers after 6 and 12 months of denture insertion: A prospective randomized clinical study

Purpose:

Soft liners act as a cushion between the denture base and the residual ridge. Hence, it is important to study their effect on resorption of mandibular denture bearing area. Therefore, the purpose of this study was to evaluate the influence of soft denture liner on mandibular ridge resorption after 1 year in completely denture wearers.

Materials and Methods:

Twenty-eight completely edentulous patients having age between 45 and 60 years with well-formed ridges in class I jaw relations were selected as per the inclusion and exclusion criterion. Randomization chart was used to enroll participants in experimental and control groups who were given mandibular dentures with and without soft denture liner, respectively. Vertical measurements were made on orthopantomograph and analyzed using Adobe Photoshop 7.0 software at five points, i.e., one at central incisor and two points at right and left first premolars and two in each first molar region.

Results:

On application of repeated measures analysis of variance, both groups showed a significant change in bone height after denture delivery (P < 0.05). Intergroup comparison (Wilcoxon rank sum test) of bone height in different regions at various time intervals showed statistically significant difference in bone levels (P < 0.05) from baseline to 6 months and baseline to 12months (P < 0.01), while the difference was statistically not significant during 6 and 12 months’ period.

Conclusion:

The use of soft denture liner significantly reduces the residual ridge resorption in complete denture wearers as compared to conventional denture wearers (without denture liner) over a period of 1 year.

Do Porous Titanium Granule Grafts Affect Bone Microarchitecture at Augmented Maxillary Sinus Sites? A Pilot Split-Mouth Human Study

BACKGROUND

The aim of this randomized controlled clinical study was to analyze the bone microarchitecture at augmented maxillary sinus sites by using different materials in patients to compare the effect of porous titanium granules as a sinus augmentation material with bone microstructural features.

MATERIALS AND METHODS

Eight subjects with bilateral atrophic posterior maxilla of residual bone height <4 mm included in this study and each patient was treated with bilateral sinus augmentation procedure using xenograft with equine origin (Apatos, Osteobiol; Tecnoss Dental) and xenograft (1 g) + porous titanium (1 g) granules (Natix; Tigran Technologies AB). Sixteen human bone biopsy samples were taken from patients receiving two-stage sinus augmentation therapy during implant installation and analyzed using microcomputerized tomography. Three-dimensional bone structural parameters were analyzed in details: tissue volume, bone volume, percentage of bone volume, bone surface and bone surface density, bone specific surface, trabecular thickness trabecular separation, trabecular number, trabecular pattern factor, structural model index, fractal dimension, and bone mineral density.

RESULTS

No statistically significant differences were found between groups according to bone structural parameters.

CONCLUSIONS

Porous titanium grafts may ensure a space for new bone formation in the granules, which may be a clinical advantage for long-term success.

Edentulism and associated factors among community-dwelling middle-aged and elderly adults in China

OBJECTIVE

To investigate the prevalence of self-reported edentulism and its associated risk factors among community-dwelling adults aged 45 years and older in China.

MATERIALS AND METHODS

Data from the national baseline survey (2011-2012) of the China Health and Retirement Longitudinal Study (CHARLS) were used for this study (N = 17 167). Bivariate and multivariate logistic regressions were conducted to assess the predictors of edentulism. Models 1 and 2 were based on the whole sample. Models 3 and 4 were based on the subsample (N = 9933) from whom anthropometric and blood biomarker data were available.

RESULTS

The prevalence of edentulism was 8.64% among Chinese adults aged 45 and above. As shown by Model 1, older age was a robust predictor for edentulism (odds ratio [OR] = 3.81 for people aged 55-64; OR = 11.22 for people aged 65-74; OR = 24.05 for people aged 75 and above). Other factors positively associated with edentulism included being female (OR = 1.25), rural residence (OR = 1.30), asthma (OR = 1.48), depression (OR = 1.20), reduced physical function (OR = 1.37) and current smoking status (OR = 1.36). People with higher educational levels (OR = 0.75 for people who can read and write; OR = 0.64 for people who obtained a junior high school education or above) and better-off economic status (OR = 0.80) were less likely to be edentate. The association between edentulism and age, educational level, economic status and physical function remained significant in Model 3, and in addition, being underweight appeared as another strong predictor (OR = 1.93).

CONCLUSIONS

The estimated prevalence of edentulism and the identified associated factors will provide epidemiologic evidence for future research and interventions in the target population in China.

Horizontal bone augmentation in full-arch maxillary implant-supported restorations: a preliminary clinical report

PURPOSE

The purpose of this study was to describe a technique for horizontal maxillary bone grafting in combination with implant placement for full arch.

MATERIALS AND METHODS

Patients requiring complete rehabilitation of the edentulous maxillae were included. Two axial mesial implants and 2 tilted distal ones were placed approximately 2 mm buccally about the centre of the bone crest. A graft made of a mixture of deproteinized bovine bone and platelet-rich plasma was placed buccally covering bony dehiscence. Horizontal bone gain and differences in bone volume were evaluated 6 months after surgical intervention, at the time of prosthetic loading, through comparison of standardized cone beam computed tomographic scans.

RESULTS

A total of 10 patients were consecutively treated after the proposed protocol. After 6 months, the mean horizontal bone gain was 1.87 ± 0.54 mm for the left side and 1.79 ± 0.78 mm for the right side without any significant difference between them. The bone volume increased by 610.5 ± 27.57 mm after 6 months.

CONCLUSIONS

It can be postulated that the proposed protocol may provide a significant horizontal bone gain for minimizing the anterior cantilever in full-arch prosthesis.

Beyond Ischemic Heart Disease: Are There other Health Benefits from Drinking Alcohol?

Evidence is growing that alcohol consumption confers health benefits beyond protection from ischemic heart disease. We review this evidence with regard to cerebrovascular disease, peripheral vascular disease, diabetes, cholelithiasis (gallstones), cognitive functioning, and stress reduction and subjective psychosocial benefits. Other possible benefits are briefly considered. The weight of evidence suggests that low-level alcohol consumption offers some protection against ischemic stroke. The evidence that moderate alcohol consumption protects against diabetes and gallstones is also fairly strong. The possibility of other health benefits cannot be dismissed. For all the conditions considered, more research is indicated. The application of more appropriate statistical techniques, studies of patterns of drinking, and experimental approaches to delineating underlying mechanisms should enable firmer conclusions to be drawn. A better understanding of both the benefits and the risks of alcohol use for individuals and populations will facilitate the development of appropriate program and policy interventions to promote health.

Association of Neutral Zone Position with Age, Gender, and Period of Edentulism

PURPOSE

The changing dynamics of an aging mouth influence the position of the neutral zone (NZ). While the advantage of the NZ concept in complete denture treatment is quite established, what is not clearly understood is its position in relation to the crest of the residual ridge due to conflicting reports from previous studies. The purpose of this study was to investigate the distance and direction of NZ position in relation to crest of the residual ridge in edentulous patients and its association with age, gender, and period of edentulism.

MATERIALS AND METHODS

A cross-sectional study was conducted in 133 patients (70 males, 63 females) with a mean age of 58.81 ± 11.78 years. NZ recording was done using admix material by following standard procedures. Two metallic wires were adapted, one on the ridge and another on the center of the occlusal rims, and standardized digital radiographs were made. The position of NZ in relation to the crest of the residual ridge was recorded by noting the direction and measuring the distance between the adapted wires digitally at five locations (right molar, right premolar, incisor, left molar, left premolar regions).

RESULTS

Age, gender, and period of edentulism had no significant association with the position of NZ. No specific trend was observed in the in NZ position with a non-significant correlation.

CONCLUSIONS

Distance and the direction of neutral zone position in relation to crest of the residual ridge in edentulous patients bear no significant relationship with factors such as age, gender, and period of edentulism.

Complete Edentulism and Comorbid Diseases: An Update

The relationship between complete edentulism, which is the terminal outcome of a multifactorial oral disease process and other comorbid diseases, was first reported in 2009. Although the relationship between edentulism and a multitude of systemic diseases was reported, none of the publications studied could determine causality of tooth loss on the incidence of any comorbid disease. Since that publication, there has been a renewed interest in this relationship, and a plethora of new articles have been published. This article will provide an update on articles published since 2008 on the relationship between edentulism and comorbid diseases, and will include the relationship between complete edentulism and such comorbid conditions as malnutrition, obesity, cardiovascular disease, rheumatoid arthritis, pulmonary diseases (including chronic obstructive pulmonary disease), cancer, and even mortality.

Signs of Combination Syndrome and removable partial denture wearing

Introduction: Combination Syndrome (CS) is a pathological condition observed in maxillary complete denture (CD) and mandibular removable partial denture (RPD) wearers. Purpose: The aim of this study was to observe and measure the prevalence of CS signs in treatment-seeking wearers of maxillary CD associated or not with RPD (mandibular Kennedy Class I). The association between RPD wearing and the number of CS clinical signs was also evaluated. Material and method: The sample included 62 patients seen at the Department of Dentistry, Federal University of Rio Grande do Norte (UFRN). A clinical oral examination was conducted to assess the presence of specific clinical signs of CS as described by Kelly (1972): bone resorption in the maxillary anterior region, tuberosity overgrowth, palatal papillary hyperplasia, extrusion of mandibular anterior teeth and bone resorption in the mandibular posterior region. The chi-square test at the 95% level of significance was used to test the association between dependent and independent variables. Result: Mandibular resorption was the most frequent complication (93.5%). There was a statistically significant difference between RPD wearers and non-wearers with regard to extrusion of mandibular anterior teeth (p = 0.045). Conclusion: Within the limitations of the present study, a high prevalence of CS clinical signs was observed, but no association between RPD wearing and syndrome characteristics was found.

Evaluation of the morphological changes in the mandible for dentate and totally edentate elderly population using cone-beam computed tomography

PURPOSE

The loss of teeth considerably modifies the mandibular shape. The aim of this study was to compare the morphological changes in the mandible for dentate and totally edentate elderly subjects using cone-beam computed tomography.

METHODS

In total, 50 cone-beam computed tomography patients (25 dentate, 25 edentate) without any maxilla-mandibular dysmorphosis were analyzed retrospectively. Panoramic representations of the mandible with superimposed axial slices and cross-sectional slices were developed with the cone-beam computed tomography scans. Values of the mandibular cortical index, bone quality index, gonial angle, antegonial angle, antegonial depth and condyle angle in the left and right side were measured.

RESULTS

There was a significant difference in the mandibular cortical index between the total edentate group and the dentate group in the left side of the mandible (p < 0.001). There was a significant difference in the bone quality index between the total edentate group and the dentate group in the right side and the left side (p < 0.001). There was a significant difference in the bone quality index between the right side and the left side (p < 0.005). When comparing gender, there was only a difference in the right side (p < 0.05).

CONCLUSIONS

Our study concluded that the mandibular basal bone morphology changes as a consequence of tooth loss. Cone-beam computed tomography is shown to be a good tool in investigating and achieving these results.

Dental implants placed on bone subjected to vertical alveolar distraction show the same performance as those placed on primitive bone

Introduction: Vertical osteogenic alveolar distraction (VOAD) allows for the augmentation of the alveolar ridge for the placement of dental implants in atrophic alveolar ridges. The goal of this paper is to assess long-term peri-implant bone resorption in implants placed on bones subjected to VOAD, comparing it with a group of patients who had implants placed directly on the alveolar bone without previous bone regeneration. Material and Methods: We conducted a follow-up study on 32 patients who were divided into two groups: The Distraction Group (14 patients), and the Distraction-Free Group (18 patients), who received a total of 100 implants. Peri-implant bone loss was measured by means of panoramic X-rays, at the time of loading and one year later, and in 35 implants of each group after 3 years of functional loading. Results: The peri-implant bone resorption (PBR) average observed in the Distraction Group at the time of prosthetic placement is higher (0.50±0.09 mm) than in the Distraction-Free Group (0.25±0.06 mm), showing statistically significant results (p=0.047). PBR levels 1 year after loading were the same for both groups (0.66 mm). At 3 years, they were higher in the Distraction Group (1.03 ± 0.22 mm vs. 0.68 ± 0.08 mm).

Key words:Bone resorption, alveolar distraction osteogenesis, dental implants.

Patient-specific finite element analysis of viscoelastic masticatory mucosa

The purpose of this study was to analyze the stress and strain inside of the oral mucosa in partially-edentulous patients. The patient-specific finite element models of the mucosa and the bone were constructed using the CT images and in-vivo surface measurement during a continuous load. The mean initial shear modulus of 8.3 × 10^–5 (GPa) and the mean relaxation time of 503 (s) were determined as the viscoelastic properties of the mucosa. The increase of the highest maximum compressive strain during the continuous loading was observed in all the patients, however; the intensity of strain was not in accordance with the thickness of the mucosa. It is suggested that the variations of the morphology and the initial modulus of the mucosa should be considered in the mathematical approaches to detect the mechanical responses of the oral mucosa.

Influence of the patients' sex, type of dental prosthesis and antagonist on residual bone resorption at the level of the premaxilla

Objectives: To analyze the height and width of the ridge at the level of the premaxilla in edentulous patients, evaluating whether the sex of the patient, type of prosthetic rehabilitation and antagonist have an influence. Material and Method: We randomly selected a total of 89 patients, having an average age of 66.21 years old. A total of 308 measurements were made, all of them at the level of the premaxilla, in the intercanine area. As dependent variables, we analyzed the patients’ sex, age and the antagonist: removable (dental) prostheses (RP), fixed (dental) prostheses (FD), natural dentition (ND). As independent variables, we measured the height and residual width in sagittal sections provided by tomographic studies using Dentascan®. Results: We observed a significantly smaller ridge in women versus in men, and in patients whose antagonist was a fixed prosthesis; whereas for the type of prosthesis, we did not observe significant differences between the two categories analyzed. Conclusions: Bone resorption at the level of the premaxilla is a variable process in which a smaller size is observed (height and width) in women and when the antagonist is a fixed prosthesis.

Key words: Bone resorption, premaxilla, dental prosthesis, edentulous.

Residual ridge atrophy in complete denture wearers and relationship with densitometric values of a cervical spine: a hierarchical regression analysis

BACKGROUND

The rate of residual ridge atrophy (RRR) and its association with mineral density of other bones have not yet been fully explained.

OBJECTIVE

To measure RRR over a 5-year period in complete denture wearers and relate it to the density of a cervical spine (CSBD).

MATERIALS AND METHODS

Sixty-two patients (different gender, age, body mass index, duration of edentulousness (DE) and different denture-wearing habits) participated. A copper stepwedge was attached to the cassette, and 50 lateral radiograms met the criteria to be included.

RESULTS

A significant decrease in vertical height was observed in all measured sites. The amount of RRR was highest in frontal areas of both jaws and decreased gradually towards lateral regions. Hierarchical regression analysis revealed that the amount of RRR in the maxillary frontal area could be explained up to 48.4% by the variable DE and only up to 6.1% by the CSBD, while gender had almost no influence (1%). Similar results were obtained for the lateral maxillary RRR (33.9%; 7%; 2%), frontal mandibular RRR (40; 8.4; 0.4%) and lateral mandibular RRR (31.5%; 3.4%; 7.7%).

CONCLUSION

Skeletal bone density, reflecting systemic and hereditary factors, is weakly related to RRR (3.4-8.4%).

Correlation between residual ridge resorption and radiomorphometric indices

OBJECTIVES

The study evaluated the relationship between residual ridge resorption (RRR) and radiomorphometric indices, including mandibular cortical index (MCI), mandibular cortical width (MCW) and panoramic mandibular index (PMI), along with demographic factors.

MATERIAL AND METHODS

Panoramic radiographs of 1863 patients over 20 years of age were assessed. Gender, age and dental status of each patient were recorded. Relationships between RRR and demographic factors and radiomorphometric indices were evaluated using chi-square and Fisher's exact tests with level of significance of p = 0.05.

RESULTS

Residual ridge resorption was not affected by gender (p > 0.05), but was more frequently seen in patients over the age of 50 compared with those below 49 years of age (p < 0.001). RRR was significantly associated with edentulism (p < 0.001) and with severe erosions of endosteal margin of mandible (p < 0.05). RRR was more frequently seen in patients with PMI below 0.30 (p < 0.001) and with MCW below 3 mm in 50- to 69-year-old age group (p < 0.001).

CONCLUSIONS

Patients younger than 50 years of age who demonstrate severe erosions of endosteal margin of mandible and have MCW < 3 mm and PMI < 0.30 appear to be suitable candidates for early implant placement or for maintaining roots or natural teeth to preserve bone, regardless of gender.

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.

Anatomic evaluation of maxillary sinus septa: surgery and radiology

The anatomical structure of the maxillary sinus is fundamental to maxillofacial surgery. The presence of septa, located at the inner surface of the maxillary sinus, increases the risk of sinus membrane perforation during sinus elevation for dental implant surgery. The aim of this study was to evaluate the anatomy of maxillary sinus septa.Data in this study was obtained from a total of 205 cases. One hundred and seventy-seven patients were partially edentulous (PE) whereas 28 patients had no teeth. Dental computerized tomography (dental CT) was used in the assessment of 410 sinus segments (205 left and 205 right segments). The prevalence of sinus segments with septa was found to be 145/410. Septa were detected in 91 of the 177 PE cases. There were a total of 26 septa in 18 of the 28 completely edentulous (CE) cases. A total of 165 septa were detected in these segments. The prevalence of septa was 46.4% (26/56) in the CE, and 39.2% (139/354) in the PE segments. Thirty septa were found in the anterior, 110 in the middle and 25 in the posterior region. All detected septa were located mediolateral direction. Their relative position: lateral, middle or medial were also noted. The height measurements of the septa varied amongst the different positions. In view of the fact that septa of various heights and courses can develop in all parts of the maxillary sinus, timely and adequate assessment of the inner aspect of the maxillary sinus is essential to avoid complications during sinus augmentation procedures.

Radiomorphometric indices and their relation to alveolar bone loss in completely edentulous Turkish patients: a retrospective study

STATEMENT OF PROBLEM

In edentulous patients, alveolar bone loss is a critical factor that affects denture retention, stability, and masticatory function. In addition to their use for the assessment of bone quality, panoramic radiomorphometric indices have been used to observe signs of bone resorption. Currently, there is no published data on the possible relationships between bone loss, radiomorphometric indices, and edentulism.

PURPOSE

The purpose of this study was to investigate the influence of age and gender on the mandibular cortical index, panoramic mandibular index, and mandibular cortical width, as well as alveolar bone loss and bone height, using panoramic radiographs of patients having been edentulous for more than 2 years.

MATERIAL AND METHODS

Panoramic radiographs of 94 edentulous patients (41.5% men and 58.5% women) were assessed. In addition to gender and age, the mandibular cortical index (normal cortex, mild or severe erosions on endosteal margin of the mandible), panoramic mandibular index, mandibular cortical width at the mental foramen region, alveolar bone loss, and bone heights of the premolar and molar regions of the mandible were recorded. Statistical comparisons were performed using chi-square, Mann-Whitney U, Kruskal-Wallis, and 2-way ANOVA tests (alpha=.05).

RESULTS

Mild erosions on the endosteal margin of the mandible were more frequently seen in age groups of <or=60, and severe erosions on the endosteal margin of the mandible were more frequently observed in age groups of >60 in women (P<.001). While the mean values of the mandibular cortical width were stable as age increased in men, the mean mandibular cortical width values decreased significantly with age in women (P<.01). The panoramic mandibular index, alveolar bone loss, and bone heights were not affected by age or gender.

CONCLUSIONS

Severe erosions on the endosteal margin of the mandible are seen more frequently in women over 60 years in age. While mean mandibular cortical width values are stable in men over 60 years, mean mandibular cortical width values decrease significantly in women of the same age group.

Edentulism and comorbid factors

INTRODUCTION

Complete edentulism is the terminal outcome of a multifactorial process involving biological factors and patient-related factors. It continues to represent a tremendous global health care burden, and will for the foreseeable future. The purpose of this review is to determine what comorbid factors exist for the completely edentulous patient.

METHODS

This literature review evaluated articles obtained via the National Library of Medicine's PubMed Website, using keywords of edentulism with various combinations of the terms comorbidity, incidence, health, nutrition, cancer, cardiovascular health, diabetes, osteoporosis, smoking, asthma, dementia, and rheumatoid arthritis. Abstracts were selected and screened, and selected full-text articles were reviewed. Articles were limited to those with adequate patient cohorts and a minimum of 2-year follow-up data.

RESULTS

Edentulism was found to be a global issue, with estimates for an increasing demand for complete denture prostheses in the future. Completely edentulous patients were found to be at higher risk for poor nutrition, coronary artery plaque formation (odds ratio 2.32), to be smokers (odds ratio 2.42), to be asthmatic and edentulous in the maxillary arch (odds ratio 10.52), to being diabetic (odds ratio 1.82), to having rheumatoid arthritis (odds ratio 2.27), and to having certain cancers (odds ratios varying from 1.54 to 2.85, depending on the type of cancer). Chronic residual ridge resorption continues to be the primary intraoral complication of edentulation, and there appear to be few opportunities to reduce bone loss in the edentulous patient.

CONCLUSIONS

While the completely edentulous patient seems to be at risk for multiple systemic disorders, whether development of these disorders is causal or casual has not been determined. To minimize the loss of residual alveolar ridges, exemplary complete denture therapy, along with the establishment of routine recall systems, should be the ultimate goal of treatment of this patient cohort.

Denture-related hyperplasia: a clinical study of a turkish population group

Inflammatory fibrous hyperplasia (epulis fissuratum) (IFH) and inflammatory papillary hyperplasia (IPH) are oral mucosal diseases caused by ill-fitting denture wearing. A study was carried out on a group of Turkish people consisted of 131 female and 39 male complete denture wearers (n= 170) distributed in two age groups (30-60 and 60-80 years old). The analysis of data collected from patients showed that while the incidence of IFH was higher in women than in men, the incidence of IPH was similar. Most lesions were found in the 30-60 year-old group. The incidence of lesions increased as the denture wearing period increased. Soft tissue growth was the main complaint of the patients with IFH and IPH. In the maxilla, the incidence of IFH was higher than IPH. There was also a significant difference between the distribution of the lesion types in the jaws. There were a larger number of lesions in the maxilla compared to the mandible and most IFH lesions were located in the anterior region of the jaws.

Sex differences in denture satisfaction

OBJECTIVES

Males and females differ in their responses to many health conditions and treatments. The aim of this randomized clinical trial was to determine whether there are differences in the way that male and female edentulous elders rate their satisfaction with new mandibular implant overdentures (IODs) and conventional dentures (CDs), at 6 and 12 months following delivery.

METHODS

Edentulous elders (n=256) were randomly assigned to receive maxillary conventional dentures and either mandibular overdentures supported by two implants with ball attachments or conventional dentures. Participants rated their general satisfaction, as well as other features of their dentures (comfort, stability, ability to chew, aesthetics, etc.) prior to treatment and 6 and 12 months after delivery.

RESULTS

Ratings of satisfaction with IODs were significantly higher than with CDs. Six months after delivery, females in the CD group rated their general satisfaction and satisfaction with ability to chew and aesthetics significantly lower than did the males. The sex differences in the CD group remained at 12 months after delivery. However, males and females in the IOD group rated their general satisfaction and all six subcategories equally.

CONCLUSIONS

Elderly females are less satisfied with conventional dentures than elderly males with regards to aesthetics and ability to chew, but equally satisfied with implant overdentures. At 6 and 12 months after delivery, elderly edentulous males and females wearing mandibular implant overdentures were significantly more satisfied than those wearing conventional dentures.

Retromolar Ridge in Edentulous Patients: Clinical Considerations

PURPOSE

A removable denture base should cover the mandibular retromolar regions to provide proper basal seal and denture function in edentulous patients. The bony residual ridge form, attached muscles, and covering mucosa provide support, stability, and retention of the planned prosthesis. There is insufficient information regarding bone anatomy, mucosal tissues, and muscles in the retromolar region after tooth loss. The purpose of this study was to examine the tissue morphology in the mandibular retromolar area of edentulous subjects and report on the clinical inferences in prosthetic and implant dentistry.

MATERIALS AND METHODS

Specimens included 75 edentulous and eight dentate dry mandibles examined by macroscopic observations and linear measurements for size determinants in the left and right retromolar regions. Buccolingual histological sections of the mandibular retromolar region from seven edentulous subjects were also examined. The specimens were from the Department of Anatomy and Anthropology, Sackler School of Medicine, Tel Aviv University.

RESULTS

The specimens evaluated in this study revealed that a bony retromolar ridge can be large, with adjacent muscles attached several millimeters below its edentulous bone crest, or small, with muscles attached to the buccal and lingual bone crests. In all examined jaws, bony mylohyoid ridges (MR) and buccal shelves with affixed muscle fibers were present regardless of the remaining mandibular bone form and size.

CONCLUSIONS

The mylohyoid muscles attached to MRs and the buccinator muscles affixed to buccal bony shelves are some of the barriers to the chronic but limited bone resorption, following tooth loss, time of edentulism, systemic factors, and denture wear.

Morphologic Characteristics of Bony Edentulous Jaws

PURPOSE

The objective of this study was to examine bone tissue characteristics of edentulous arches and residual ridges in different regions of the human jaws.

MATERIALS AND METHODS

For the study, 24 maxillary and 99 mandibular completely edentulous dry specimens were examined macroscopically and by linear and caliper measurements. Width and length of the edentulous arches were registered from the molar regions to the crest of the incisor zone. Residual ridges were quantified at the incisor, premolar, and molar regions.

RESULTS

Arches and ridges varied in size and shape. A trabecular bone track was present at the edentulous surface. In the maxillary arch, trabecular tissue was external to the cortical palatal vault, and in the mandible, the trabecular bony stretch was inside the cortical plates along the entire edentulous surface of the jaw. Of the ridges, 38% were thin knife-edged. In the maxilla, bone resorption was centripetal, and the crest of the edentulous arch was external to the osseous base of the cranium. In the mandible, resorption was centrifugal, forming an edentulous crest lingual to the mental protuberance anteriorly and to the mandibular base posteriorly. This discrepancy produced a reverse horizontal overlap of the residual crests, where the edentulous maxilla was at the same level or internal to the facing edentulous mandible.

CONCLUSIONS

This study, performed on 123 human edentulous dry bone specimens, indicates that the edentulous arch and the residual ridge take many forms. At the occlusal surface of the edentulous jaw a trabecular track is the remaining scar after tooth extraction. To accommodate an entire metal osseointegrated implant within the residual bone volume, crest reduction and bone grafts may be required as preprosthetic surgical measures. After tooth loss, maxillary resorption was centripetal and apical, whereas mandibular resorption was centrifugal and also apical, resulting in a reversed horizontal relationship in fully edentulous subjects.

Assessment of mandibular bone mineral density in patients with type 2 diabetes mellitus

OBJECTIVES

To assess mandibular bone mineral density in patients with type 2 diabetes mellitus using panoramic radiographs.

METHODS

Nineteen patients with type 2 diabetes mellitus and 17 control subjects participated in the study. Bone mineral density measurements were performed on the panoramic radiographs with the help of a five-step copper stepwedge phantom, attached to each film cassette, which was calibrated before hand by dual energy X-ray absorptiometry (DXA). The analysis was performed on digitized images by dedicated software (Scion Image). The accuracy of the measurement technique was also evaluated by cross-calibration with a DXA phantom.

RESULTS

Mean mandibular bone mineral density (g cm(-2)) was 1.53+/-0.27 in women and 1.52+/-0.29 in men with type 2 diabetes. In age and gender matched control subjects the values were 1.56+/-0.28 and 1.46+/-0.23 in women and in men, respectively. No statistically significant difference was observed between groups in mandibular bone mineral density.

CONCLUSIONS

The present study showed that bone mineral density of the mandible does not seem to be affected in patients with type 2 diabetes mellitus. We also observed that a panoramic radiograph could serve for accurate mandibular bone density determination, when calibrated well with the DXA method.

Responses of jawbone to pressure*

OBJECTIVE

To provide a literature review of bone resorption of edentulous jaws focusing on responses to pressure.

BACKGROUND

After the extraction of all teeth in a jaw there is a continuous reduction of the residual ridge. The individual variation of bone resorption is great, and the aetiology is complex and not yet well understood.

MATERIALS AND METHODS

A search of the literature published up to May 2003 on bone resorption and pressure was performed using PubMed/Medline.

RESULTS

Animal studies have demonstrated that excessive and constant pressure induces bone resorption. Recent experimental research has indicated that bone resorption is a pressure-regulated phenomenon with a lower threshold for continuous than for intermittent pressure. Clinical studies have suggested that residual ridge resorption is due more to the effects of denture wearing than to disuse atrophy. However, the results of leaving out dentures at night are not conclusive. Nor does the literature offer any strong evidence for the so-called combination syndrome, which has been described as a result of unfavourable loading. Clinical studies using multivariate analyses indicate that female gender and systemic factors may be of greater importance than oral and denture factors. Implant-supported prostheses have a bone preserving effect rather than the continuing resorption under complete dentures.

CONCLUSIONS

The best way to reduce bone resorption is to avoid total extraction, preserve a few teeth and fabricate overdentures. In edentulous jaws, placement of implant-supported prostheses will lead to less bone loss and may even promote bone growth. To increase our knowledge of residual ridge resorption extended experimental, clinical and statistical methods will be needed, preferably including collaboration between dental and medical researchers.

Analysis of the prevalence of different topographical characteristics of the residual ridge in mandibular free-end arches

This study observed the prevalence of different types of residual ridge inclination in free-ends of mandibles and reported possible correlative factors that may affect resorption. For this purpose, periapical radiographs and individual data collected from a sample of 64 hemiarches were used. Two radiographs were taken of each free-end, and tracing was employed to determine the angles formed by the resorption configuration in the area of the 1st mandibular molar. The following conclusions were drawn: 1) the great majority of alveolar ridges were distally descending; 2) the average angle was wider for users of mandibular removable partial dentures; 3) the results obtained suggest that the type of opposing maxillary arch affects the inclination of mandibular ridges; 4) greater inclination was observed when the 2nd bicuspids of the mandible were the abutment teeth; 5) no significant correlation was established between age, sex and residual ridge resorption.

The combination syndrome: a literature review

Although combination syndrome is recognized by many clinicians, documented observations seem to be rare. The aim of this article was to critically review the literature regarding combination syndrome to evaluate the evidence for this concept. A search of the dental literature with Medline/PubMed through July 2002, focusing on the combination syndrome and related features, was undertaken and combined with a hand search of older references and textbooks on removable prosthodontics.

[Non-invasive evaluation of an injectable bone substitute]

Despite the increasing number of techniques for the preservation of bone ridges after dental avulsion, no precise evaluation of alveolar filling has been performed to date. The criteria of available measurement techniques (probes, retroalveolar or panoramic radiography, and lateral teleradiography) are not sufficiently reliable and precise. This study investigated the reliability of evaluation based on CT images in comparison with retroalveolar radiography (the most precise radiographic technique, providing standardised images), direct measurements, and images obtained in scanning electron microscopy. After a preliminary investigation ex vivo, a study was performed in vivo on three beagles. Mandibular premolars were extracted, and the corresponding alveoli were filled with an injectable bone substitute composed of a calcium phosphate mineral load associated with hydroxypropyl methylcellulose. Measurements performed on CT images relative to visual and automatic detection of density changes and studies of density curves provided better precision than those obtained by retroalveolar radiography.

External apical root resorption of posterior teeth in asthmatics after orthodontic treatment

External apical root resorption is an undesirable sequela of orthodontic treatment, resulting in loss of tooth structure from the root apex. It has been proposed that systemic factors, such as the inflammatory mediators produced in asthma, may enter the periodontal ligament and act synergistically to enhance root resorption. The aim of this study was to determine if asthmatic patients exhibited a higher incidence or severity of external apical root resorption compared with healthy (no medical conditions) patients after fixed orthodontic treatment. Records were obtained from patients treated with fixed appliances; 99 were healthy and 44 had asthma. Using OPGs (panoral films), posterior external apical root resorption was measured on all first and second premolars, mesiobuccal and distobuccal roots of the upper first molars, and mesial and distal roots of the lower first molars, giving 4 measurements per quadrant. A 4-grade ordinal scale was used to determine the degree of external apical root resorption. Combined tooth analysis (adjusted for treatment time, appliance, and extractions) showed that asthmatics had significantly more external apical root resorption of posterior teeth after treatment compared with the healthy group (P =.0194). Tooth-by-tooth analysis (adjusted for treatment time, appliance, extractions, headgear, overbite, overjet, sex, and age at start of treatment) found the upper first molars were most susceptible to external apical root resorption. Although the incidence of external apical root resorption was elevated in the asthma group, both asthmatics and healthy patients exhibited similar amounts of grade 2 (moderate) and grade 3 (severe) resorption.

Association of edentulousness with systemic factors in elderly people living at home

OBJECTIVE

To examine the association of edentulousness with systemic factors: age, gender, tobacco-smoking, alcohol intake, body mass index, functioning in daily living, cortical thickness at the mandibular angle, and systemic diseases: bone-fracture (an indicator for osteoporosis), diabetes, thyroid disease, hyperparathyroidism, asthma, heart failure, hypertension.

METHODS

The study population comprised 293 elderly subjects, 124 (42%) edentulous and 169 (58%) dentate. The data from clinical and radiographic examinations and structured interviews were analyzed by multiple logistic regression.

RESULTS

When edentulousness in both the mandible and the maxilla was considered, history of bone fracture and tobacco-smoking were significantly related to complete edentulousness with odds ratios (OR) of 2.51 (95% CI: 1.47-4.28) and 2.42 (95% CI: 1.32-4.43) respectively, associations independent of age and gender. A similar association was found for the edentulous mandible. In the elderly subjects with an edentulous maxilla, besides the significant factors of history of bone fracture and tobacco-smoking, asthma was also associated with edentulousness at an odds ratio of 10.81 (95% CI: 1.38-84.66), oldest subjects most often being edentulous (OR: 2.23, 95% CI: 1.13-4.39). Diabetes was not related to edentulousness either in the mandible or in the maxilla.

CONCLUSIONS

The finding of associations of history of bone fracture, tobacco-smoking, and asthma with edentulousness emphasizes the association of systemic conditions with edentulousness. Advanced age was related to an edentulous maxilla. The relationship between asthma and total tooth loss in the maxilla might suggest a local oral effect of medications used by asthmatic patients.

Clinical morbidity and sequelae of treatment with complete dentures

Wearing complete dentures may have adverse effects on the health of both the oral and the denture-supporting tissues. This article is a review of selected literature on the sequelae of treatment with complete dentures in the specific areas of residual ridge resorption, mucosal reactions, burning mouth syndrome, temporomandibular disorders, and patient satisfaction. Recent literature found with a Medline search from 1952 to 1996 is included in this review. Residual ridge resorption is an inevitable consequence of tooth loss and denture wearing, with no dominant causative factor having been found. Mucosal reactions have a multifactorial cause, most of which can be easily treated. Most patients are satisfied with their complete dentures. Correlations between anatomic conditions and denture quality and patient satisfaction are weak. Psychologic factors seem to be extremely important in the acceptance of and adaptation to removable dentures. There are still no reliable methods to predict the outcome of complete denture treatment and there are many problems related to treatment with complete dentures. Although the prevalence of an edentulous condition is decreasing, the great number of edentulous people warrants the continuing efforts of basic and clinical research on removable partial dentures. Complete denture prosthodontics will remain an important part of dental education and practice. In addition to clinical and technical skills, insight into patient behavior and psychology and communication techniques are also necessary.

Oral status and prosthetic factors related to residual ridge resorption in elderly subjects

Our earlier studies on edentulous elderly subjects have shown associations of severe resorption in the mandibular residual ridge with female gender and systemic diseases. The aim of this study was to examine whether other factors also were related to residual ridge resorption (RRR). Among 177 edentulous elderly subjects effects on RRR were investigated with regard to history of edentulousness and denture-wearing, the condition of the dentures and soft tissues, dental status of the opposing jaw, and oral hygiene habits. No significant association was found between degree of resorption and duration of edentulousness in either the mandible or the maxilla. RRR was related to denture quality (P < 0.05); however, severe resorption was not. In the maxilla previous use of removable partial dentures was a factor contributing to the resorption (odds ratio (OR), 2.4); flabby ridge was related to the severity of the resorption (OR, 2.4). This study showed local factors related to RRR more often in the maxilla than in the mandible, thus suggesting that severe resorption in the mandible is influenced more by systemic factors than by those investigated in this study.