Alveolar Bone Atrophy Research Articles

State of oral cavity tissues of rats in conditions of modeling metabolic syndrome

The prevalence of the metabolic syndrome has progressively increased in recent years and occurs on average in every fifth adult in the population of developed countries. Metabolic syndrome is a multi-structural complex of pathological changes, so the choice of an adequate experimental model is important in the study of this state. The study was carried out on the model of the metabolic syndrome adequate to the modern human diet and is easily reproducible. Purpose of the study. Assessment of the state of the tissues of the oral cavity of rats and blood serum under experimental metabolic syndrome.Material and methods. White male rats aged 1,5-2 months were used. An intact group (7 individuals) received a standard ration of the vivarium. In the experimental group (7 individuals), the metabolic syndrome was modeled by introducing into the diet of the internal pig fat at the rate of 20% of the weight of the feed and 10% fructose ad libitum instead of drinking water. The duration of the experiment was 70 days. The biochemical parameters of blood serum and tissues, the state of the dentoalveolar system, the parameters of the intercellular matrix of the mucous membrane and the bone tissue of the periodontal rats, as well as the mineral metabolism of bone tissue were evaluated.Results. Conclusions. A diet high in saturated fats and simple carbohydrates led to visceral obesity in experimantal animals, hyperglycemia, increased total cholesterol, hyperuricemia in the presence of cholesterol in high-density lipoproteins, an increase in the number and depth of carious lesions, alveolar bone atrophy, partial collagen degradation (oxyproline) glycosaminoglycans and the disruption of the intercellular matrix of the connective tissue of the periodontium, the mucous membrane of the oral cavity and bone tissue.

Residual Ridge Resorption– Revisited

AbstractThe Residual Ridge Resorption (RRR) is a major unsolved oral disease with unidentifiable characteristics and unwanted squealae causing physical, psychologic, and economic problems for millions of people all over the world. RRR is basically a term used to describe a condition that affects the alveolar ridge after tooth extractions even after healing of the wounds. RRR is a chronic, progressive, irreversible, and disabling disease, probably of multifactorial origin. The possible etiological factors could be divided into four categories: anatomic, metabolic, functional, and prosthetic. The primary structural change in the reduction of residual ridges is the loss of bone or reduction in the size of bony ridge under mucoperiosteum. The reduction in the ridge mainly occurs labially, lingually and on the crest. The reduction of the residual ridge leads to a variety of stages of ridge form, including high well-rounded, knife-edge, low well-rounded, and depressed forms. Alveolar bone atrophy is cumulative and irreversible, since alveolar bone cannot regenerate. It differs from one individual to the other. It also varies at different times and different sites. Some authors feel RRR as a normal physiologic process and not a disease but the cost in economic and human terms makes RRR as a major oral disease that can be described in terms of its pathology, pathophysiology, pathogenesis, epidemiology, etiology, treatment and prevention.

Virtual quad zygoma implant placement using cone beam computed tomography: sufficiency of malar bone volume, intraosseous implant length, and relationship to the sinus according to the degree of alveolar bone atrophy

The objective of this study was to investigate the malar bone volume and length that a zygomatic implant can engage, and the relationship to the sinus according to the degree of alveolar bone atrophy. A three-dimensional evaluation was performed using cone beam computed tomography scans from 23 patients with a totally edentulous maxilla; quad zygoma implants were virtually placed. The predictor variable was the amount of malar bone volume and length that a zygomatic implant can engage. The primary outcome variable was the relationship to the sinus according to the degree of alveolar bone atrophy. Other variables were the residual alveolar bone height to the floor of the sinus and the nasal cavity. The mean volume of malar bone engaged in this sample of 92 zygomatic implants was 0.19±0.06cm3. The implant had an extrasinus path in 60.9% of cases, a parasinus path in 25%, and an intrasinus path in 14.1%. The results suggest that the average volume of malar bone engaged by a zygomatic implant is constant regardless of implant position and the degree of alveolar bone atrophy. As alveolar atrophy increases, the trajectory of the implant becomes more parasinus and intrasinus. The examiners were able to find enough bone to adequately distribute the implants in all cases.

Comparative periodontoprotective effectiveness of diosmin or qvercetin in rats which received hormonal contraceptive

Aim: Determine periodontoprotective effectiveness of bioflavonoides diosmin and quercetin after introducing hormonal contraceptive. Methods: The rats received contraceptive (estradiol+drospirenon) during 30 days. Preparation of diosmin (“Normoven”) introduced per os in dose 84 mg/kg. Preparation of quercetin (“Quertulin”) introduced per os in dose 8 mg/kg. The activities of elastase and lysozyme were determined in gum and serum, the activities of alkaline (AlPh) and acid (AcPh) phosphatases, the contents of calcium and protein were determined in periodontal bone. The degree of bone atrophy of alveolar outgrowth was determined. Results: Was established that the introduction of the contraceptive decreased the mineralizing activity of the bone and increased the degree of atrophy of alveolar outgrowth. Simultaneous introduction of the bioflavonoides stimulated mineralizing activity and reduced the degree of atrophy of alveolar bone. Quercetin was more effective. Conclusion: Bioflavonoides have periodontoprotective activity after using hormonal contraceptive.

Full mouth rehabilitation with iliac bone graft for a patient with traumatic neuroma in mandible

Damaged sensory nerves in the facial area might show spontaneous recovery. However, imperfect regeneration, such as paresthesia, numbness, and painful pathologic regeneration can occur in some cases. Therefore, iatrogenic nerve damage should be avoided during implant placement in patients with alveolar bone atrophy. For placement of implants in the posterior area of the mandible, the corresponding anatomical structures including the inferior alveolar nerve are of concern. Herein, we presented a case of a patient who developed traumatic neuroma after undergoing full mouth rehabilitation with implants in another hospital. Treatment at our facility included the removal of all implants posterior to the mental foramen, followed by an autogenous iliac bone graft performed on the atrophied alveolar ridge of the mandible. Subsequently, implants were placed in the grafted sites. Finally, the patient showed functional and esthetic results.

Alternative Distraction Osteogenesis Technique After Implant Placement for Alveolar Ridge Augmentation of the Maxilla

An alternative technique to reconstruct atrophic alveolar vertical bone after implant placement is presented. The technique consists of distraction osteogenesis or direct surgical repositioning of an implant-and-bone block segment after segmental osteotomies that can be used in esthetic or unesthetic cases. Initially, casts indicating the implant position are obtained and the future ideal prosthetic position is determined to guide the model surgery. After the model surgery, a new provisional prosthesis is fabricated, and an occlusal splint, which is used as a surgical guide and a device for distraction osteogenesis, is custom fabricated. Then, the surgery is performed. For mobilization of the implant-and-bone block segment, 2 vertical osteotomies are performed and then joined by a horizontal osteotomy. The implant-and-bone block segment is moved to the planned position. If a small movement is planned, then the implant-and-bone segment is stabilized; for larger movements, the implant-and-bone segment can be gradually moved to the final position by distraction osteogenesis. This technique has good predictability of the final position of the implant-and-bone segment and relatively fast esthetic rehabilitation. It can be considered for dental implants in regions of vertical bone atrophy.

Skeletal anchorage in the past, today and tomorrow

Skeletal anchorage was not introduced as an alternative to conventional anchorage modalities. The first skeletal anchorage was a ligature through a hole in the infrazygomatic crest. This was replaced by surgical screws and finally the TADs, which were optimized with respect to the material and morphology, were developed. A bracket-like head allows for the use of the mini-implant as indirect anchorage, but should not be a tool for lost control resulting from badly planned biomechanics or failing compliance. Skeletal anchorage should serve as an adjunct to correct biomechanics, to enable treatments that could not be performed prior to the introduction of skeletal anchorage. The aim of this study was to test the hypothesis that temporary anchorage mini-screws help maintain bone density, height and width of alveolar processes in the extraction sites, and thus prevent the thinning of the alveolar ridge usually observed. In adult patients with degenerated dentitions the application of skeletal anchorage can allow for the displacement of teeth where no anchorage units are present, but also for the redevelopment and maintenance of atrophic alveolar bone. The basis for the optimal use of skeletal anchorage is that the correct line of action for the desired tooth displacement is defined and the necessary force system constructed either with the skeletal anchorage as direct or as indirect anchorage. After a period, during which osseointegrated implants were used as anchorage for tooth movement and bone maintenance, it was accepted that the mini-implants could serve also as anchorage for skeletal displacements avoiding loading of teeth.

Modern approaches to dental implants placement in deficient alveolar bone

The paper presents statistical data on implant placement procedures in Central Research Institute of Dentistry and Maxillofacial Surgery (Moscow, Russia) in 2010-2015. In 64% of cases inadequate bone volume was attributed to alveolar bone atrophy. Bone deficiency was equally often in upper and lower jaws (in 49.3 and 50.7%, correspondently) but varied in forms with complex configurations to be more specific for maxilla. The study also includes a series of clinical cases illustrating implant placement procedures in anatomically unfavorable settings.

Timed-release system for periosteal expansion osteogenesis using NiTi mesh and absorbable material in the rabbit calvaria.

This study aimed to improve bone regeneration using a timed-release system for periosteal expansion osteogenesis (TIME-PEO) using a shape memory alloy (SMA) mesh device and absorbable thread in a rabbit model. Twelve rabbits were used in this study. The device was inserted under the periosteum at the forehead, then pushed, bent, and attached to the bone surface and fixed with an absorbable thread. Rabbits were divided into groups C1 (5 weeks postoperatively without dynamic elevation), C2 (8 weeks postoperatively without dynamic elevation), T1 (5 weeks postoperatively from TIME-PEO), and T2 (8 weeks postoperatively from TIME-PEO). Newly formed bone was evaluated histologically and radiographically. The newly formed bone volume to elevated bone volume ratio was 6.1% in C1, 21.9% in T1 15.5% in C2 and 36.0% in T2. These quantitative data indicate that TIME-PEO group had a significantly higher volume than that of the control group (P<0.05). Histologically, multiple dome-shaped bones, outlined by thin and scattered trabeculae, over the original bone surface were evident in the T group. This technique appears to be a promising clinical alternative for alveolar bone augmentation and introduces the new concept of "dynamic guided bone regeneration" for atrophic alveolar bone.

Evaluation of dental panoramic radiographic findings in edentulous jaws: A retrospective study of 743 patients "Radiographic features in edentulous jaws".

PURPOSEThe aim of this study was to determine the frequency of significant panoramic radiographic findings and eventual treatment requirements before conventional or implant supported prosthetic treatment in asymptomatic edentulous patients.MATERIALS AND METHODSA total of 743 asymptomatic edentulous patients were retrospectively evaluated using a digital panoramic system. We analyzed the radiographic findings, including impacted teeth, retained root fragments, foreign bodies, severe atrophy of the posterior maxillary alveolar bone, mucous retention cysts, soft tissue calcifications and radiopaque-radiolucent conditions.RESULTSFour-hundred-eighty-seven (65.6%) patients had no radiographic finding. A total of 331 radiographic findings were detected in 256 (34%) patients. In 52.9% (n=175) of these conditions, surgical treatment was required before application of implant-supported fixed prosthesis. However, before application of conventional removable prosthesis surgical treatment was required for 6% (n=20) of these conditions.CONCLUSIONThe edentulous patients who will have implant placement for implant-supported fixed prosthesis can frequently require additional surgical procedures to eliminate pathological conditions.

Volumetric stability of autogenous bone graft with mandibular body bone: cone-beam computed tomography and three-dimensional reconstruction analysis.

ObjectivesThe purpose of this study was to estimate the volumetric change of augmented autobone harvested from mandibular body cortical bone, using cone-beam computed tomography (CBCT) and three-dimensional reconstruction. In addition, the clinical success of dental implants placed 4 to 6 months after bone grafting was also evaluated.Materials and MethodsNinety-five patients (48 men and 47 women) aged 19 to 72 years were included in this study. A total of 128 graft sites were evaluated. The graft sites were divided into three parts: anterior and both posterior regions of one jaw. All patients included in the study were scheduled for an onlay graft and implantation using a two-stage procedure. The dental implants were inserted 4 to 6 months after the bone graft. Volumetric stability was evaluated by serial CBCT images.ResultsNo major complications were observed for the donor sites. A total of 128 block bones were used to augment severely resorbed alveolar bone. Only 1 of the 128 bone grafts was resorbed by more than half, and that was due to infection. In total, the average amount of residual grafted bone after resorption at the recipient sites was 74.6%±8.4%.ConclusionVolumetric stability of mandibular body autogenous block grafts is predictable. The procedure is satisfactory for patients who want dental implants regardless of atrophic alveolar bone.

Histological and clinical analysis of fresh-frozen allogeneic vs autogenic bone grafts for 3D alveolar bone reconstruction

Reconstruction of atrophic alveolar bone can be made with many grafting materi- als. Autogenous bone, from intra- or extraoral donor sites, represents the best doc- umented material in terms of number of patients and follow-up; allogeneic freshfrozen bone (FFB), from dead bodies has been suggested as an alternative to overcome problems related to autogenous bone collection (1, 2). The aim of this work is to histologically and histomorphometrically compare bone biopsies obtained during dental implant placement in reconstructed jaws with either FFB or autologous iliac crest bone blocks using the same surgical grafting procedure. All samples were processed for ground sections and then underwent a histomorphometrical evaluation using a stereologic method. Twenty edentulous patients were treated with either FFB (14 patients, group A) or with autografts (6 patients, group B) iliac crest grafts. Five to 9 months later, dental implants were placed in the reconstructed jaws and bone biopsies were harvested. Reconstructive procedure was uneventful in 9 patients of group A and in all patients of group B. In 5 patients of group A, bone sequestra were obtained and processed for ground sections. These specimens showed the typical findings of a bone necrosis. All other samples from both groups presented the same values in terms of proportion of lamellar, newly formed bone and bone marrow. In group A, the decreasing proportion of blood vessels from apical to coronal, the larger amount of osteocytic lacunae in the apical portion and the fewer vessels in the coro- nal portion compared to group B, evoke an effort of the host bone to “integrate” the graft from the apical portion. FFB cannot be considered as successful and safe in alve olar bone reconstruction as autogenous bone grafting.

Clinical and Histological analysis of sinus floor elevation and alveolar bone augmentation using an interconnected superporous hydroxyapatite with beta-tricalcium phosphates: Preliminary results

The placement of dental implants in highly atrophic alveolar bone continues to be a major challenge in implant dentistry. Sinus floor elevation and guided bone regeneration (GBR) involves augmenting the bone with grafting materials to provide adequate support for implants. From the various materials available for the bone augmentation, autogenous bone is considered the gold standard because of its high osteoconductive, osteoinductive, and osteogenic potential. However, the collection of autogenous bone requires an extra surgical site for bone harvesting, which increases the risks of morbidity and discomfort.

Use of Trabecular Metal Implants for the Rehabilitation of a Maxillary Edentulous Arch: A Case Report

Background: This case report illustrates the use of trabecular metal (TM) implants to rehabilitate a severely atrophic maxillary arch that was successfully augmented by allografts.Case Presentation: A 68‐year‐old female was referred to a private practice for severely maxillary alveolar bone atrophy (e.g., subsinus bone height of &lt;1 mm on the left side and &lt;4 mm on the right side). Allograft bone block augmentation was used to regenerate ridge deficiency simultaneously with bilateral sinus augmentation. Six implants (four TM and two tapered) were placed, and bone specimens were obtained 6 months after grafting. Radiography and histologic analysis demonstrated that implants were positioned in non‐native bone. Removal torque test, performed at the second‐stage procedure, confirmed the successful osseointegration of implants. The definitive implant‐supported full‐arch prosthesis was then constructed and placed in function.Conclusion: The positive outcomes of this case report suggest that the rehabilitation of severely atrophic maxillary arch might be achieved by merging TM with new regenerative techniques without harvesting extensive quantities of autogenous graft.

Reconstruction of maxillary ridge atrophy caused by dentoalveolar trauma, using autogenous block bone graft harvested from chin: a case report

Background Dentoalveolar trauma, especially when involving front teeth, negatively affect the patient’s life; in particular, tooth avulsion is a complex injury that affects multiple tissues, and no treatment option offers stable long-term outcomes. The aim of this study was to report a case of reconstruction of atrophic anterior alveolar ridge after tooth loss, performed with autograft harvested from the chin, and subsequent prosthetic rehabilitation with the use of an osseointegrated implant. Case report A 23-years-old Caucasian girl, presented an atrophic alveolar bone in the area of tooth 11, as a result of tooth resorption 10 years after a tooth reimplantation procedure. Reconstruction was performed with autogenous bone harvested from the chin. After 6-months healing period to allow autograft incorporation, a dental implant was inserted. After further 6- months, a screw-retained implant supported metal-ceramic prosthesis was fabricated. Results The prosthetic rehabilitation was successful, and after a follow-up period of 5 years, the achieved result was stable. Conclusion It can be concluded that the autogenous bone graft harvested from the chin, is a safe and effective option for alveolar ridge defects reconstruction, allowing a subsequent placement of a dental implant supporting a prosthetic restoration.

歯槽骨萎縮症例に対しサンドイッチグラフト法により下顎臼歯部の骨造成を行った1例

We describe a patient who underwent bone augmentation for dental implant placement in the atrophic posterior mandible by sandwich osteotomy, focusing mainly on surgical technique. A 46-year-old woman was referred to our hospital because of alveolar bone atrophy in the posterior mandible. She had bone necrosis after the placement of three dental implants at a dental clinic. The patient hoped for dental rehabilitation supported by dental implants. Therefore, we performed bone augmentation by means of sandwich osteotomy with cancellous bone harvested from the iliac crest. The superior segment was elevated up to 7 to 8 mm after vertical and horizontal osteotomy. The graft bone was placed between the segment and the basal bone, and was then fixed with microplates. Although the patient had postoperative infection transiently, alveolar bone augmentation was accomplished successfully. Thirteen months after bone augmentation, two dental implantswere placed. At the 1 year 7 month follow-up after dental implant placement, the postoperative course was uneventful, with no bone resorption. This procedure was considered to be a very reliable and effective method for vertical bone augmentation in the atrophic posterior mandible.

Pre- and Postoperative Long-Term Assessment of Sinus Floor Augmentation Site Using Cone Beam Computed Tomography

Abstract Introduction. Sinus lift operations are planned in atrophic maxillary residual alveolar bone. There is little evidence how the quality and quantity of residual bone influence the dimension of sinus lifts. Aim of the Study. To evaluate relationship between amount of residual alveolar bone and sinus lift dimension. Materials and Methods. 73 sinuses of 54 patients were included in to the study. Preoperative and postoperative cone beam computed tomography scan of sinus lift operation site was performed. The measurement of atrophic alveolar bone height, width and radiodensity in planned sinus lift area was done. Postoperatively sinus lift height, width and length were measured. The sinus volume difference from both scans was calculated. Amount of bone substitute materials used was registered. Results. Residual alveolar bone mean height was 3.84 mm SD±2.28, width 7.15 mm SD±2.27, radiodensity 142.74 HU SD±155.38. Postoperatively mean sinus lift height was 15.81 mm SD±2.91, length 18.73 mm SD±5.21, width 12.70 mm SD±2.49. The mean sinus volume difference was 2422.70 mm3 SD± 3415.92. Mean amount of biomaterials used was 1.29 g SD±0.67. Conclusions. The less bone radiodensity was found in alveolar bone with more dimensions. The less quantity of atrophic alveolar bone leads to increase size of sinus lift.

Influence of crown–implant ratio on implant success rates and crestal bone levels: a 36‐month follow‐up prospective study

The aim of this prospective study was to determine how the crown-implant ratio (C/I ratio) influences crestal bone loss and implant success rates after a 3-year follow-up, using implants with a sintered porous surface (SPS). On the basis of preestablished inclusion and exclusion criteria, 151 of a cohort of 160 patients with single or partial edentulism were selected as eligible for the study. The 151 patients were treated consecutively from 2005 to 2007 using 280 SPS implants, which were restored with a single crown or a partial fixed denture. The data collection included both clinical and anatomical C/I ratios; other implant prosthetic factors were also recorded. Implants were divided into three groups according to the C/I ratio. Clinical and radiographic examinations were scheduled over a 36-month follow-up of functional loading according to a well-established protocol generally applied to determine implant success rates and crestal bone levels. Statistical analysis was used to determine any significant differences or correlations (P = 0.05). A total of 259 SPS implants in 136 patients were followed up for 36 months. According to the success criteria, the overall implant-based success rate was 98.1%, and the mean peri-implant bone loss (PBL) was 0.48 ± 0.29 mm. Statistical analysis revealed significant correlation between implant success rate and C/I ratio (P < 0.05) and between PBL and C/I ratio (P < 0.05). The critical threshold value of the anatomical and clinical C/I ratio for avoiding excessive bone loss or implant failure was 3.10 and 3.40. This prospective cohort study revealed that SPS implants offer a predictable solution for implant prosthetic rehabilitation in patients with edentulism characterized by different alveolar bone atrophy. From the biomechanical point of view, the C/I ratio would appear to be the main parameter capable of influencing implant success and crestal bone loss. Consequently, it is important not to exceed the threshold values in order to avoid excessive stress at the bone-implant interface capable of resulting in excessive crestal bone loss or implant failure.

A review of management options for rehabilitation of posterior atrophic maxilla with implants

Purpose: The placement of implants in the alveolar bone remains a challenge because of the resorption of the residual ridge resulting in insufficient bone volume in one or more dimensions. Need of the hour is to review the various options to rehabilitate posterior atrophic maxilla with/without bone modification procedures. Study Selection: MEDLINE/PubMed searches were conducted using the terms atrophic maxilla, implants, buttresses, grafts, maxillary sinus, osteotomy as well as combinations of these and related terms. The few articles judged to be relevant were reviewed. Results: Appropriate treatment planning is crucial and various factors need to be considered before placing implants in atrophic alveolar bone Bone grafting, osseodistraction and sinus lifts are invasive procedures. In addition, they add complexity and increase the number of surgical phases required for implant therapy. Different therapeutic alternatives, such as, short implants, or implants placed in specific anatomical areas like the pterygoid region, the tuber or the zygoma has allowed patient treatment to be expedited and minimally invasive. Conclusion: Important aspects that need to be considered for implant placement in posterior atrophic maxilla are discussed in this article and both surgical and non-surgical options are suggested. There is no consensus as to which treatment modality is superior to the other in literature. The decision to opt for either of the options, therefore, depends upon patient factors, and ultimately, the expertise and skill of the clinician.

Minimally invasive approach with tissue engineering for severe alveolar bone atrophy case

The gold standard of bone augmentation for dental implants in severe alveolar bone atrophy is autogenous bone graft, but it has disadvantages such as limited amounts of grafted bone, poor morphological and aesthetic outcomes, and donor-site morbidity and invasiveness, especially in cases with diseases. In this reported case, the authors applied a novel tissue engineering method as minimally invasive surgery for a 58-year-old patient who had severe bone atrophy. The method, tissue-engineered bone (TEB), composed of mesenchymal stem cells as stem cells, platelet-rich plasma as growth factor and guided bone regeneration membrane. After bone regeneration by TEB, three 13mm long dental implants were inserted. Adequate bone regeneration was shown by radiological analysis and histological observation. The augmented bone height was 4.2mm after the operation and the radiopaque areas were increased. The clinical progress over 2 years showed a good course without bone resorption. These results indicated that TEB, as bone regeneration treatment with minimal invasiveness, could be useful as one of the novel options in dental implant treatment with severe bone atrophy.