Radiographic evaluation of alveolar ridge heights of dentate and edentulous patients

Occlusal force orchestrates alveolar bone homeostasis via Piezo1 in female mice

Healthy alveolar bone is the cornerstone of oral function and oral treatment. Alveolar bone is highly dynamic during the entire lifespan and is affected by both systemic and local factors. Importantly, alveolar bone is subjected to unique occlusal force in daily life, and mechanical force is a powerful trigger of bone remodeling, but the effect of occlusal force in maintaining alveolar bone mass remains ambiguous. In this study, the Piezo1 channel is identified as an occlusal force sensor. Activation of Piezo1 rescues alveolar bone loss caused by a loss of occlusal force. Moreover, we identify Piezo1 as the mediator of occlusal force in osteoblasts, maintaining alveolar bone homeostasis by directly promoting osteogenesis and by sequentially regulating catabolic metabolism through Fas ligand (FasL)-induced osteoclastic apoptosis. Interestingly, Piezo1 activation also exhibits remarkable efficacy in the treatment of alveolar bone osteoporosis caused by estrogen deficiency, which is highly prevalent among middle-aged and elderly women. Promisingly, Piezo1 may serve not only as a treatment target for occlusal force loss-induced alveolar bone loss but also as a potential target for metabolic bone loss, especially in older patients.

Insight into age-related changes of the human facial skeleton based on medieval European osteological collection

Aging changes in the facial skeleton are concentrated mostly in orbits, maxilla and mandible. The aim of this study was to analyze metric traits of the adult viscerocranium in a medieval sample from Cedynia (Poland, Central Europe) and confront the results with literature data for modern populations. It was assumed that diet-related greater biomechanical forces generated during mastication in medieval versus modern times led to slower rate of bone resorption with age. 3D models of the facial skeleton are created for 230 individuals, categorized into young, middle and old adults, and a subgroup of edentulous middle adults is distinguished. Orbits, piriform aperture, maxilla and mandible are measured using Geomagic Studio 12 and analyzed among age categories as well as dentate and edentulous subgroups. The values of the orbital and piriform aperture measurements tend to increase with age and reached statistical significance in males (right orbit height, left orbit width, piriform aperture surface area). In females, maxillary height significantly decrease at right first premolar and first molar, together with height of the right mandibular ramus. In edentulous individuals of both sexes the orbits are wider, and maxillary and mandibular heights are lower than in dentate individuals. This study reveals similar character and direction of the aging process of the facial skeleton in medieval and modern adults, however slower rate of resorptive changes is found in the former sample, which suggests, that diet-related biomechanical forces can influence intensification of the aging processes in the facial skeleton.

Interdisciplinary management of a partially dentate adult patient with a complex malocclusion

Adult patients may present with complex malocclusions requiring extensive oral rehabilitation. This case report demonstrates how carefully planned interdisciplinary management can provide pleasing outcomes despite the considerable initial clinical challenges.

The Role of Parathyroid Hormone in Alveolar Bone Resorption on Postmenopausal Women

Background:

Postmenopausal women exhibit reduced bone mineralization, which causes bone resorption, including that of alveolar bone. Parathyroid hormone has been shown to play a role in alveolar bone resorption.

Objective:

This study aims to analyze relationships between parathyroid hormone and other factors that may contribute to alveolar bone resorption in postmenopausal women.

Methods:

This cross-sectional study included 82 postmenopausal women aged 50–74 years, who resided in Central and East Jakarta, Indonesia. Subjects' data were obtained through questionnaires, dental examinations, and blood collection for the examination of parathyroid hormone levels by enzyme-linked immunosorbent assay and using panoramic radiography to measure bone resorption.

Results:

Spearman correlation analysis showed a significant correlation between parathyroid hormone level (p = 0.005) and extent of alveolar bone resorption, but age (p = 0.292), menopausal duration (p = 0.244), and number of missing teeth (p = 0.517) were not significantly correlated with the extent of alveolar bone resorption.

Conclusion:

Various factors play a role in the mechanism of bone resorption, so knowing the role of each factor is expected to reduce the effects of alveolar bone resorption that occurs in postmenopause. Among the factors investigated in this study, the parathyroid hormone was the sole factor correlated with postmenopausal alveolar bone resorption.

Mechanoadaptive Responses in the Periodontium Are Coordinated by Wnt

Despite an extensive literature documenting the adaptive changes of bones and ligaments to mechanical forces, our understanding of how tissues actually mount a coordinated response to physical loading is astonishingly inadequate. Here, using finite element (FE) modeling and an in vivo murine model, we demonstrate the stress distributions within the periodontal ligament (PDL) caused by occlusal hyperloading. In direct response, a spatially restricted pattern of apoptosis is triggered in the stressed PDL, the temporal peak of which is coordinated with a spatially restricted burst in PDL cell proliferation. This culminates in increased collagen deposition and a thicker, stiffer PDL that is adapted to its new hyperloading status. Meanwhile, in the adjacent alveolar bone, hyperloading activates bone resorption, the peak of which is followed by a bone formation phase, leading ultimately to an accelerated rate of mineral apposition and an increase in alveolar bone density. All of these adaptive responses are orchestrated by a population of Wnt-responsive stem/progenitor cells residing in the PDL and bone, whose death and revival are ultimately responsible for directly giving rise to new PDL fibers and new bone.

Alveolar ridge atrophy related to facial morphology in edentulous patients

OBJECTIVES

The morphology of the alveolar process determines the retention and stability of prosthetic restorations, thereby determining the result of the therapy. Considering that the edentulous jaws may be affected by the atrophy process, it was hypothesized that the morphology of the alveolar process of the maxilla may be dependent on the anterior facial height and anatomy of the mandible.

SUBJECTS AND METHODS

Twenty-five healthy edentulous Caucasian individuals were randomly chosen. Each subject underwent a lateral cephalogram before and after prosthetic rehabilitation. During exposition, newly made prostheses were placed in the patient's mouth. Teeth remained in maximal intercuspidation. Morphological parameters were evaluated according to the Ricketts, McNamara, and Tallgren's method.

RESULTS

An inversely proportional association was observed between patient age and the distal part of the maxilla. A statistically significant connection was noted between the vertical dimension of alveolar ridge and anterior total and lower facial height conditioned by prosthetic rehabilitation.

CONCLUSION

The height of the lateral part of the alveolar ridge of the maxilla remains in connection with the anterior total and lower facial height obtained in the course of prosthetic rehabilitation. The vertical dimension of the alveolar ridge of the maxilla seems to be in close relationship with the morphology of the lower jaw.

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.

A new bite block for panoramic radiographs of anterior edentulous patients: A technical report

Purpose

Panoramic radiographs taken using conventional chin-support devices have often presented problems with positioning accuracy and reproducibility. The aim of this report was to propose a new bite block for panoramic radiographs of anterior edentulous patients that better addresses these two issues.

Materials and Methods

A new panoramic radiography bite block similar to the bite block for dentulous patients was developed to enable proper positioning stability for edentulous patients. The new bite block was designed and implemented in light of previous studies. The height of the new bite block was 18 mm and to compensate for the horizontal edentulous space, its horizontal width was 7 mm. The panoramic radiographs using the new bite block were compared with those using the conventional chin-support device.

Results

Panoramic radiographs taken with the new bite block showed better stability and bilateral symmetry than those taken with the conventional chin-support device. Patients also showed less movement and more stable positioning during panoramic radiography with the new bite block.

Conclusion

Conventional errors in panoramic radiographs of edentulous patients could be caused by unreliability of the chin-support device. The newly proposed bite block for panoramic radiographs of edentulous patients showed better reliability. Further study is required to evaluate the image quality and reproducibility of images with the new bite block.

The relationship between facial morphology and the structure of the alveolar part of the mandible in edentulous complete denture wearers. A preliminary study

OBJECTIVE

Although the effect of involutional processes that occurs in the maxilla and mandible of edentulous subjects is obvious, the problem of factors definitely determining the direction of changes still remains unsolved. This study was aimed at determining the relationship between facial morphology and the structure of the alveolar part and the body of the mandible in edentulous complete denture wearers.

MATERIALS AND METHODS

Twenty-five healthy edentulous Caucasian patients in the 70.5 ± 9 years of age group were examined. All patients underwent tele-X-ray examination with the presence of currently used dentures in the oral cavity. To assess morphological parameters of the facial skeleton, cephalograms were analyzed according to Ricketts and Mc Namara method. To assess the mandible morphology, the films were measured using the method of Tallgren.

RESULTS

The period of edentulism was found to be negatively correlated with the anterior segment of the body of the mandible within its symphysis. The parameter corresponding to the location of the first lower molar showed a directly proportional correlation with G'-Sn', G'-Me', Sn'-Me', N-Ans, N-Me, Ans-Me, Co-Gn and Co-Go. Positive correlations were found between the parameters describing contour of the alveolar part of the body of the mandible and mandibular symphysis and G'-Me', Sn'-Me', N-Me, Ans-Me describing the height of the occlusal vertical dimension.

CONCLUSION

The study showed a directly proportional correlation between the vertical occlusal dimension of the lower face conditioned by prosthetic rehabilitation and the height of the alveolar part in the lateral regions of the mandible.

Photoelastic and finite element analyses of occlusal loads in mandibular body

This study proposed to evaluate the mandibular biomechanics in the posterior dentition based on experimental and computational analyses. The analyses were performed on a model of human mandible, which was modeled by epoxy resin for photoelastic analysis and by computer-aided design for finite element analysis. To standardize the evaluation, specific areas were determined at the lateral surface of mandibular body. The photoelastic analysis was configured through a vertical load on the first upper molar and fixed support at the ramus of mandible. The same configuration was used in the computer simulation. Force magnitudes of 50, 100, 150, and 200 N were applied to evaluate the bone stress. The stress results presented similar distribution in both analyses, with the more intense stress being at retromolar area and oblique line and alveolar process at molar level. This study presented the similarity of results in the experimental and computational analyses and, thus, showed the high importance of morphology biomechanical characterization at posterior dentition.

Resorption of mandibular alveolar bone following loss of molar teeth and its relationship to age at death in a human skeletal population

Estimating adult age at death in skeletal remains is problematic, particularly in older adults. Molar wear is arguably the most reliable ageing technique for palaeopopulations, but many older adult skeletons have lost their molar teeth ante mortem, precluding its application. Resorption of the alveolar process occurs following tooth loss, and this appears to continue for a prolonged period. The current work investigates the relationship of this process to individual age in a nineteenth century AD European archaeological skeletal series of known age at death (N = 92 individuals), and discusses its potential as an age indicator. Mandibular corpus height was measured at the different molar positions. In females, reduction of corpus height with age was found at molar positions showing ante mortem loss. In both sexes, a relationship was found between age and a simple composite measure of corpus height in the molar region in those showing ante mortem loss of one or more mandibular molars. The correlation was stronger in females (r = -0.74) than in males (r = -0.49), appeared approximately linear, and continued into the ninth decade, the oldest age group in the study material. The results suggest that investigation of height of the posterior part of the mandibular corpus as a skeletal age indicator for individuals that have lost one or more molar teeth is merited in other palaeopopulations.