Alveolar bone density and its clinical implication in the placement of dental implants and orthodontic mini-implants

Evaluation of Alveolar Ridge Dimensions by Socket Preservation Therapy Using a Bone Graft and Platelet-Rich Fibrin: A Randomized Controlled Trial

BACKGROUND

Following the loss of a tooth, the new edentulous area of the ridge will undergo several adaptive modifications due to changes in function within and surrounding the socket. This bone resorption explains the need for socket preservation techniques in areas of esthetic concerns and functional demands. Demineralized freeze-dried bone allograft (DFDBA) possesses greater osteoinductive potential due to the exposure of bone morphogenetic protein (BMP-3​​​​​​)​and collagen fibrils and can be used efficiently in socket preservation techniques. DFDBA yields better results when combined with an autologous platelet concentrate, such as platelet-rich fibrin. Therefore, we formulated this randomized controlled clinical trial to assess the clinical and radiovisiographical outcomes of platelet-rich fibrin (PRF) and DFDBAs for extraction socket preservation in humans at different time intervals.

MATERIALS AND METHODS

This was a randomized controlled trial with 100 people as study subjects, and they were randomly divided into two groups: the test group (DFDBA and PRF placed in the extraction socket) and the control group (natural healing of the extraction socket). Clinical and radiographic evaluation using radiovisiography (RVG) was done at baseline, three-month, and six-month intervals. Cone-beam computed tomography (CBCT) was used at six months to determine the bone density in the test and control groups.

RESULTS

When compared from baseline to six months, the percentage change in clinical and RVG measurements for the test group was 15.96% (11.9064 mm) and 16.77% (12.1840 mm), respectively, whereas for the control group, it was 46.09% (14.0396 mm) and 47.61% (14.5716 mm), thus indicating lesser bone resorption in the test group as opposed to the control group. CBCT values also showed greater bone density for the test group (682.3120 HU) than the control group (503.8336 HU).

CONCLUSION

This study demonstrates the advantages of DFDBA bone graft with PRF compared to natural healing in achieving socket preservation by maintaining the marginal and buccolingual bone levels.

Correlation between Primary Stability of Dental Implants and Bone Density: A Retrospective Analysis

Dental implants have gained popularity in recent years. The most important variable in determining the effectiveness of the implant's primary stability is bone density. The success of the implant depends on proper procedure and implant stability. With this background, the aim of the present study was to study the correlation between primary stability and bone density. The present retrospective study was conducted among 2,440 patients who had undergone implant treatment in the Department of Implantology, Saveetha Dental College and Hospitals, Chennai, from June 2021 to February 2022. Data regarding patient's age, gender, implant location, bone density, and primary stability were taken into consideration. Association between primary stability and bone density was assessed using the Chi-square test. Of the subjects, 33.42% had D2 bone density in the lower posterior region; 13.98% had D3 density in the lower posterior region. Primary stability of 30-40 Ncm was seen in the majority of the subjects; 32.64% who had primary stability of 30-40 Ncm had D2 bone density. There was a statistically significant association between implant site and bone density (p = 0.04) and primary stability and bone density (p = 0.03). Within the limitations of the study, it can be concluded that there is a strong association between implant primary stability and bone density.

Prevalence and Association between Primary Stability and Bone Quality in Implants Placed in Edentulous Dental Arches: A Retrospective Analysis

Immediate function has become an accepted treatment modality for fixed restorations in completely edentulous jaws. The dental implants have gained immense popularity. A secure implant primary stability is positively associated with a successful implant integration and long term successful clinical outcome. The main aim of this study was to find the association between primary stability and bone density in implants placed in maxilla and mandible. A total of 1263 patients who had undergone implant placement from March 2020-March 2021 in Saveetha Dental College and Hospitals, Chennai, India were chosen for the study. The primary stability and bone density of these patients were collected from the hospital records. The collected data was compiled, reviewed, tabulated in Microsoft Excel sheet and entered in SPSS software for statistical analysis. In the present study, the patient aged between 28 and 37 years had undergone more implant placement (31%) with male predilection (53%). The most commonly associated primary stability was found to be 30-40 Ncm (51.37%) predominantly with D2 type of bone density (52.69%). A Chi-squared statistical test was done for primary stability and bone density and the P was found to be 0.00 (Chi-squared P < 0.05, statistically significant). The most predominant bone density was D2 associated with primary stability of 30-40 Ncm. The association between bone density and primary stability was found to be statistically significant. The present study shows a strong relationship between bone density and primary implant stability.

Advancements in oral and maxillofacial surgery medical images segmentation techniques: An overview

OBJECTIVES

This article reviews recent advances in computer-aided segmentation methods for oral and maxillofacial surgery and describes the advantages and limitations of these methods. The objective is to provide an invaluable resource for precise therapy and surgical planning in oral and maxillofacial surgery. Study selection, data and sources: This review includes full-text articles and conference proceedings reporting the application of segmentation methods in the field of oral and maxillofacial surgery. The research focuses on three aspects: tooth detection segmentation, mandibular canal segmentation and alveolar bone segmentation. The most commonly used imaging technique is CBCT, followed by conventional CT and Orthopantomography. A systematic electronic database search was performed up to July 2023 (Medline via PubMed, IEEE Xplore, ArXiv, Google Scholar were searched).

RESULTS

These segmentation methods can be mainly divided into two categories: traditional image processing and machine learning (including deep learning). Performance testing on a dataset of images labeled by medical professionals shows that it performs similarly to dentists' annotations, confirming its effectiveness. However, no studies have evaluated its practical application value.

CONCLUSION

Segmentation methods (particularly deep learning methods) have demonstrated unprecedented performance, while inherent challenges remain, including the scarcity and inconsistency of datasets, visible artifacts in images, unbalanced data distribution, and the "black box" nature.

CLINICAL SIGNIFICANCE

Accurate image segmentation is critical for precise treatment and surgical planning in oral and maxillofacial surgery. This review aims to facilitate more accurate and effective surgical treatment planning among dental researchers.

Validation of bone mineral density measurement using quantitative CBCT image based on deep learning

The bone mineral density (BMD) measurement is a direct method of estimating human bone mass for diagnosing osteoporosis, and performed to objectively evaluate bone quality before implant surgery in dental clinics. The objective of this study was to validate the accuracy and reliability of BMD measurements made using quantitative cone-beam CT (CBCT) image based on deep learning by applying the method to clinical data from actual patients. Datasets containing 7500 pairs of CT and CBCT axial slice images from 30 patients were used to train a previously developed deep-learning model (QCBCT-NET). We selected 36 volumes of interest in the CBCT images for each patient in the bone regions of potential implants sites on the maxilla and mandible. We compared the BMDs shown in the quantitative CBCT (QCBCT) images with those in the conventional CBCT (CAL_CBCT) images at the various bone sites of interest across the entire field of view (FOV) using the performance metrics of the MAE, RMSE, MAPE (mean absolute percentage error), R² (coefficient of determination), and SEE (standard error of estimation). Compared with the ground truth (QCT) images, the accuracy of the BMD measurements from the QCBCT images showed an RMSE of 83.41 mg/cm³, MAE of 67.94 mg/cm³, and MAPE of 8.32% across all the bone sites of interest, whereas for the CAL_CBCT images, those values were 491.15 mg/cm³, 460.52 mg/cm³, and 54.29%, respectively. The linear regression between the QCBCT and QCT images showed a slope of 1.00 and a R² of 0.85, whereas for the CAL_CBCT images, those values were 0.32 and 0.24, respectively. The overall SEE between the QCBCT images and QCT images was 81.06 mg/cm³, whereas the SEE for the CAL_CBCT images was 109.32 mg/cm³. The QCBCT images thus showed better accuracy, linearity, and uniformity than the CAL_CBCT images across the entire FOV. The BMD measurements from the quantitative CBCT images showed high accuracy, linearity, and uniformity regardless of the relative geometric positions of the bone in the potential implant site. When applied to actual patient CBCT images, the CBCT-based quantitative BMD measurement based on deep learning demonstrated high accuracy and reliability across the entire FOV.

Wnt/β-Catenin Signaling in Craniomaxillofacial Osteocytes

PURPOSE OF REVIEW

There is a growing appreciation within the scientific community that cells exhibit regional variation. Whether the variation is attributable to differences in embryonic origin or anatomical location and mechanical loading has not been elucidated; what is clear, however, is that adult cells carry positional information that ultimately affects their functions. The purpose of this review is to highlight the functions of osteocytes in the craniomaxillofacial (CMF) skeleton as opposed to elsewhere in the body, and in doing so gain mechanistic insights into genetic conditions and chemically-induced diseases that particularly affect this region of our anatomy.

RECENT FINDINGS

In the CMF skeleton, elevated Wnt/β-catenin signaling affects not only bone mass and volume, but also mineralization of the canalicular network and osteocyte lacunae. Aberrant elevation in the Wnt/β-catenin pathway can also produce micropetrosis and osteonecrosis of CMF bone, presumably due to a disruption in the signaling network that connects osteocytes to one another, and to osteoblasts on the bone surface.

CBCT Evaluation of Quality and Quantity of Bones for Immediate Implant Treatment Planning in Central Incisor Area in relation to Arch Form

Understanding the quality of the ridge and facial cortical bone in the aesthetic zone is important for treatment with an immediate dental implant. This study aimed to analyze bone density and widths of the facial cortical bone and alveolar ridge at the central incisors in relation to arch form. A total of 400 teeth from 100 cone-beam CT images were divided equally between the upper and lower central incisors. The central incisor area was assessed for the width of the facial cortical and alveolar bones at three different points (3 mm, 6 mm, and 9 mm from the cementoenamel junction). Arch forms and densities of cortical and cancellous bones in the interradicular regions were evaluated. The difference in facial cortical bone thickness at 3 points was smaller for the upper teeth than for the lower teeth on both sides. The alveolar bone width was higher in the maxilla than the mandible with highly significant differences (P < 0.001). The highest bone density was at the buccal aspect of the mandible (897.36 ± 136.72 HU), while the lowest density was at the cancellous bone of the maxilla (600.37 ± 126.63 HU). The dominant arch form was ovoid 71%, followed by square 20% and the tapering arch form 10%. The tapering arch form has the highest alveolar bone width in the upper jaw without statistical significance. The facial cortical bone thickness needs to be evaluated before implantation in the anterior region because it is less than two millimeters in both jaws. CBCT is important for the immediate implant. The ovoid shape was the dominant arch form.

Materials for Dentoalveolar Bioprinting: Current State of the Art

Although current treatments can successfully address a wide range of complications in the dentoalveolar region, they often still suffer from drawbacks and limitations, resulting in sub-optimal treatments for specific problems. In recent decades, significant progress has been made in the field of tissue engineering, aiming at restoring damaged tissues via a regenerative approach. Yet, the translation into a clinical product is still challenging. Novel technologies such as bioprinting have been developed to solve some of the shortcomings faced in traditional tissue engineering approaches. Using automated bioprinting techniques allows for precise placement of cells and biological molecules and for geometrical patient-specific design of produced biological scaffolds. Recently, bioprinting has also been introduced into the field of dentoalveolar tissue engineering. However, the choice of a suitable material to encapsulate cells in the development of so-called bioinks for bioprinting dentoalveolar tissues is still a challenge, considering the heterogeneity of these tissues and the range of properties they possess. This review, therefore, aims to provide an overview of the current state of the art by discussing the progress of the research on materials used for dentoalveolar bioprinting, highlighting the advantages and shortcomings of current approaches and considering opportunities for further research.

Factors affecting maxillary sinus pneumatization following posterior maxillary tooth extraction

Purpose

The aims of the present study were 1) to quantitatively evaluate the extent of sinus pneumatization and 2) to determine the factors affecting sinus pneumatization.

Methods

Based on implant treatment records, a list of patients who underwent implant placement on the posterior maxilla was obtained. Among them, patients with pre-extraction and post-extraction (before implant placement) panoramic radiographs were selected. After excluding radiographs with low resolution and image distortion, the radiographs before and after extraction were superimposed using computer software. Subsequently, the extent of sinus pneumatization (the vertical change of the sinus floor) was measured. Simple and multiple mixed models were used to determine the factors affecting sinus pneumatization.

Results

A total of 145 patients were eligible for the present investigation. The average extent of sinus pneumatization was 1.56±3.93 mm at 176 tooth sites. Male sex, single tooth extraction, extraction of an endodontically compromised tooth, a class I root-sinus relationship, and sinus membrane thickening >10 mm favored pneumatization, but without statistical significance. The maxillary second molar presented the greatest pneumatization (2.25±4.39 mm) compared with other tooth types. This finding was confirmed in the multiple mixed model, which demonstrated a statistically significant impact of the extraction of a second molar compared with the extraction of a first premolar.

Conclusions

Maxillary sinus pneumatization was 1.56±3.93 mm on average. The extraction of a second molar led to the greatest extent of pneumatization, which should be considered in the treatment plan for this tooth site.

Bone turnover markers to assess jawbone quality prior to dental implant treatment: a case-control study

Background

Bone quality is as important as bone mineral density in terms of bone strength. Bone turnover markers (BTMs) are clinical indicators of bone quality. In implant dentistry, bone quality is considered equivalent to bone density on radiographic assessments. The purpose of this study was to determine whether the BTM values are reflected in jawbone condition by evaluating the relationship at baseline and during follow-up in patients with prosthodontic implants.

Computed tomography (CT) scans were obtained and BTM (osteocalcin, bone-specific alkaline phosphatase, pyridinoline cross-linked carboxyterminal telopeptide of type I collagen, and crosslinked N-telopeptide of type I collagen) levels in blood samples were measured in partially edentulous eighteen patients before implant surgery. During the follow-up observation after implant surgery, marginal bone loss (MBL) was measured on dental radiography. We investigated the relationship between the presence of BTM abnormalities and radiographic bone density.

Results

More women than men had abnormal BTM values. Bone turnover was accelerated in the group of women with abnormal BTM values. The density of cancellous bone at the implant placement site was significantly lower in the patients with abnormally high BTM values than in their counterparts with BTM values in the normal range.

Conclusions

Female patients who undergo implant treatments may have reduced bone quality; evaluations of bone strength will require assessments of both BTMs and the density of cancellous bone.

A Novel Approach for Horizontal Augmentation of Posterior Maxilla Using Ridge Split Technique

Over the years, there have been a series of innovative approaches to the alveolar bone augmentation techniques. These have led to the modifications of the existing methods and the establishment of more efficient ways to obtain sufficient bone mass that is necessary for the implant procedure. The aim of this paper is to propose a novel augmentation technique, and to investigate its efficacy, particularly during the healing process of the maxillary alveolar bone prior to the implant treatment. During the application of the proposed methodology, first, the ridge-split technique was applied to the posterior maxilla. Then, a horizontal augmentation procedure was performed with an autogenous bone graft. Implants were placed at the second month of the surgery. Prosthetic rehabilitation was completed after the osseointegration of the implants. The technique was compared with the ridge-split method with simultaneous implant placement in 14 patients. The groups were divided into 2, the control group and the experimental group, each containing 7 patients. The aimed success criteria for the status of the endosteal implants were fulfilled and there were not any complications observed in the second year of follow-up.The basic practical innovation offered by the proposed surgical technique is to achieve the required horizontal dimension and to change the quality of the bone conveniently. The press-fit insertion leads to multipoint contact healing of the transported bone and the use of cortical block bone in posterior maxilla, led to a significantly advantageous higher stability level for both the placement and the survival of the implants.