Assessment of aging characteristics of female condylar trabecular structure by cone-beam computed tomography

Objectives

This study was performed to analyze the aging-related changes of the female condylar bone mineral density (BMD) and trabecular structure by cone-beam computed tomography (CBCT), and determine whether the condylar structure shows obvious changes after menopause.

Methods

The CBCT images of 160 female patients who met the inclusion criteria for the study were collected and divided into four groups by age (20–29 years, 30–39 years, premenopausal, and postmenopausal groups). Computer processing software CT-Analyser (Version 1.15.2.2+; SkyScan, Antwerp, Belgium) was used to measure the condylar BMD and related indexes, namely the bone volume/tissue volume ratio (BV/TV), trabecular number (Tb.N), trabecular thickness (Tb.Th), trabecular separation (Tb.Sp), trabecular structure model index (SMI), and bone surface area/volume ratio (BS/BV). SPSS 12.0 (SPSS Inc., Chicago, IL, USA) was used to analyze the radiographic findings and statistical differences.

Results

No significant differences were found between the bilateral condyles in each group (P?>?0.05). BV/TV, Tb.N, and Tb.Th of the condyle decreased with age, and the postmenopausal group showed significantly different values for each index compared with the other groups (P?<?0.01). Tb.Sp, SMI, and BS/BV of the condyle increased with age, and the postmenopausal group showed significantly different values for each index compared with the other groups (P?<?0.01).

Conclusions

With increasing age, the female condylar bone volume decreases, the Tb.N and Tb.Th decrease, the gap between the trabecular bone increases, and plate-like trabecular bone gradually transforms into a rod-like form. These changes are much more obvious in postmenopausal women.

     

Bone microarchitecture and turnover in the irradiated human mandible

ObjectivesThe aim of this study was to assess the microarchitecture and turnover in irradiated cancellous mandibular bone and the relation with radiation dose, to elucidate the effects of radiotherapy on the mandible.Patients and methodsMandibular cancellous bone biopsies were taken from irradiated patients and controls. Micro-CT scanning was performed to analyze microstructural bone parameters. Bone turnover was assessed by histomorphometry. Local radiation dose at the biopsy site (Dmax) was estimated from radiotherapy plans.ResultsTwenty-seven irradiated patients and 35 controls were included. Osteoid volume (Osteoid Volume/Bone Volume, OV/BV) [0.066/0.168 (median/interquartile range (IQR), OV/BV; %), P < 0.001], osteoid surface (Osteoid Surface/Bone Surface, OS/BS) [0.772/2.17 (median/IQR, OS/BS; %), P < 0.001] and osteoclasts number (Osteoclasts per millimetre bone surface, Ocl/mmBS; mm²) [0.026/0.123 (median/IQR, Ocl/mmBS; mm²), P < 0.001] were decreased; trabecular number (Tb.N) was lower [1.63/0.63 (median/IQR, Tb.N; 1/mm⁻¹), P = 0.012] and trabecular separation (Tb.Sp) [0.626/0.24 (median/IQR, Tb.Sp; μm), P = 0.038] was higher in irradiated mandibular bone. With higher Dmax, trabecular number increases (Spearman's correlation R = 0.470, P = 0.018) and trabecular separation decreases (Spearman's correlation R = −0.526, P = 0.007). Bone mineral density (BMD, milligrams hydroxyappetite per cubic centimetre, mgHA/cm³) [1016/99 (median/IQR, BMD; mgHA/cm³), P = 0.03] and trabecular separation [0.739/0.21 (median/IQR, Tb.Sp; μm), P = 0.005] are higher whereas connectivity density (Conn Dens) [3.94/6.71 (median/IQR, Conn Dens), P = 0.047] and trabecular number [1.48/0.44 (median/IQR, Tb.N; 1/mm⁻¹), P = 0.002] are lower in Dmax ≤50 Gy compared to controls.ConclusionsRadiotherapy dramatically impairs bone turnover in the mandible. Deterioration in microarchitecture only affects bone irradiated with a Dmax of <50 Gy. The 50 Gy value seems to be a critical threshold to where the effects of the radiation is more detrimental.     

Effect of bisphosphonate treatment on the jawbone: an exploratory study using periapical and panoramic radiographic evaluation

Objective

This cross-sectional study aimed to explore potential jawbone changes secondary to bisphosphonate (BP) treatment of osteoporosis using digital panoramic and periapical radiography.

Methods

Thirty-nine women, previously examined with dual-energy X-ray absorptiometry, were radiographed by digital panoramic and/or periapical radiography. On periapical radiographs, trabecular bone structure and fractal dimension analyses of the mandibular first molar and edentulous regions were performed. On panoramic radiographs, the mandibular cortical width (MCW) was calculated, and trabecular bone structure and fractal dimension analyses of the trabecular bone in the alveolar and basal bones were performed. The results were compared between patients treated or not treated with BP using linear regression analysis to adjust for potential confounding factors.

Results

The analyses of periapical and panoramic radiological images showed no statistical differences in the jawbones between groups after bisphosphonate use for mean intervals of 4.3 and 5 years; respectively. Although the mandibular cortical width on panoramic radiography was correlated with BP use, it was not noted to be statistically significant.

Conclusions

The trabecular parts of the alveolar and basal bones and the MCW were not significantly altered by BP treatment in patients with osteoporosis over 4.3–5 years, as detected by digital periapical and panoramic radiography. The low dosages of bisphosphonates used in the treatment of osteoporosis may explain this lack of change in MCW. Dental radiographs should not be considered as a method to monitor BP-induced jaw bone alterations among osteoporotic patients.

     

Relationships between bone strength and bone quality: three-dimensional imaging analysis in ovariectomized mice

Objectives Low-energy trauma resulting in fractures of the distal femur is often observed in elderly patients with osteoporosis; such fractures are often associated with treatment difficulties and poor prognosis. The purpose of this study was to clarify the factors that affect the bone strength of the distal femur.Methods We used ovariectomized mice to demonstrate bone quality factors associated with deterioration of the strength of the distal femur. Ten-week old ICR-strain mice were ovariectomized or sham-ovariectomized. Total bone mineral density (BMD), total bone area, cortical BMD, cortical thickness, and trabecular BMD were measured by peripheral quantitative computed tomography in the distal metaphyseal region of the femora. As three-dimensional architectural parameters, the trabecular number, trabecular thickness (Tb.Th), trabecular separation, and connectivity density were measured in the same region by microcomputed tomography. The maximum load measured by compression testing of the distal metaphyseal region was regarded as the bone strength of each sample.Results No significant differences in total bone area or in cortical BMD were found between the groups. Bone strength showed the closest relationship with total BMD (r = 0.834). Multiple regression analysis demonstrated that total BMD greatly depended on cortical thickness. The addition of Tb.Th to trabecular BMD markedly reflected bone strength (R = 0.857), suggesting that Tb.Th affected bone strength more significantly than trabecular BMD.Conclusions These findings suggested that deterioration of bone strength of the distal femur (metaphysis) was not caused by a reduction in cortical BMD, but was related to reduced cortical thickness, which reduced total BMD, and to trabecular BMD and architecture, in particular to reduced Tb.Th.     

Effects of glucocorticoid-induced osteoporosis on bone tissue of rats with experimental periodontitis

ObjectiveTo evaluate the effects of osteoporosis induced by glucocorticoid (GIOP) on bone tissue of rats with experimental periodontitis (EP).Design48 male Wistar rats divided into groups: Naïve, EP, GIOP and GIOP + EP. Rats of GIOP and GIOP + EP groups received 7 mg/kg of dexamethasone intramuscularly once a week for 5 weeks. Following, EP and GIOP + EP groups were subjected to ligature-induced periodontitis. Naïve group experienced no manipulation. After 11 days, the animals were euthanized and left maxillae collected for macroscopic, radiographic, micro-tomographic and microscopic analysis of alveolar bone loss (ABL). Blood samples were collected for determination of bone-specific alkaline phosphatase (BALP) levels and the right femurs were removed for radiographic and biomechanical analysis.ResultsEP caused ABL and reduced BALP levels (p < 0,05), but it did not change the architecture or biomechanics of femur, compared to Naïve. GIOP did not cause ABL, but it significantly decreased alveolar bone mineral density (ABMD), bone percentage and trabecular thickness (Tb.Th) and increased alveolar bone porosity (p < 0.05) and significantly reduced BALP serum levels, as well as radiographic density and Young’s module of femur, compared to Naïve. There was a greater ABL in group GIOP + EP when compared to EP (p < 0.05). GIOP + EP caused a greater decrease on ABMD, Tb.Th, bone percentage and increased bone porosity (p < 0.05) and also presented a significant reduction in BALP levels (p < 0.05), in radiographic density and in Young’s module of femur compared to EP (p < 0.05).ConclusionsGIOP can potentiate the destructive effects of EP on alveolar bone and alter the systemic bone loss, by promoting bone resorption and reducing osteoblast activity.     

Micro‐computerized tomography analysis of alveolar bone loss in ligature‐ and nicotine‐induced experimental periodontitis in rats

Liu Y‐F, Wu L‐A, Wang J, Wen L‐Y, Wang X‐J. Micro‐computerized tomography analysis of alveolar bone loss in ligature‐ and nicotine‐induced experimental periodontitis in rats. J Periodont Res 2010; 45: 714–719. © 2010 John Wiley & Sons A/S Background and Objective: Nicotine reportedly is a risk factor for periodontitis, but accurate data regarding nicotine‐induced alveolar bone loss is lacking. The aim of this study was to quantitatively assess alveolar bone loss in ligature‐ and nicotine‐induced periodontitis in rats using micro‐computerized tomography (micro‐CT). Material and Methods: Thirty‐six adult male rats were treated by placing silk ligatures around the cervixes of the right second maxillary molar; the contralateral tooth was untreated. After ligation, the animals were randomly divided into three groups: group A received intraperitoneal injections of saline solution, group B received 0.83 mg of nicotine/kg/d, and group C received 1.67 mg of nicotine/kg/d. Six animals in each group were killed on days 14 and 28 after ligature placement, and then micro‐CT examinations were conducted. Results: In all groups, bone mineral density (BMD), bone volume fraction (BVF), trabecular number (Tb.N) and trabecular thickness (Tb.Th) values of the ligated sides were significantly lower than those of the unligated sides (p < 0.001), whereas alveolar bone height loss (ABHL) and trabecular separation (Tb.Sp) of the ligated sides were significantly higher than those of the unligated sides (p < 0.001). Compared with the control group, nicotine administration increased the ABHL value and decreased the BMD, BVF and Tb.Th values of both sides in a dose‐dependent manner (p < 0.05). Conclusion: Our results confirmed that ligature could cause significant loss in the trabecula of alveolar bone, and daily administration of nicotine resulted in further bone loss and microstructure deterioration.     

不同方式处理犬下颌磨牙区即刻种植间隙的效果评价

目的: 探讨在犬下颌磨牙区即刻种植中,不同方式处理拔牙窝与种植体之间的间隙后的新骨形成情况。方法: 选择 6 条 1.5~2.0 岁的拉布拉多犬作为实验对象,在每条犬下颌骨中拔除两侧的第四前磨牙和第一磨牙,分别植入 4 颗牙种植体（Astra Tech^®,4.0 mm × 10 mm）。种植体和拔牙窝骨壁之间的近远中间隙分别进行3种处理,分为空白组（NN组）、胶质银明胶海绵（Gelatamp） 组（EN组）和 Gelatamp + 可吸收胶原膜（CM）组（EG 组）。术后12周收集标本,进行显微CT 扫描和组织学分析。采用SPSS 25.0软件包进行统计学分析。结果: 牙种植术后 12 周存活率为 100%。显微CT 扫描结果显示,新骨高度、骨矿物质密度（BMD）、骨体积分数 （BV/TV）、骨表面积骨体积比（BS/TV）、骨小梁厚度（Tb.Th）、骨小梁数（Tb.N）和骨小梁间距（Tb.Sp）等指标,组间无显著差异。组织学分析结果显示,新骨形成面积和种植体与骨接触面积（BIC）在组间无统计学差异。结论: 使用不同方式处理种植体与拔牙窝之间的间隙后的12周内,与空白对照组相比,单独放置 Gelatamp 或与 CM 联合使用,对种植体周围新骨形成、BIC、BMD、BV/TV、BS/TV、Tb.Th、Tb.N 及 Tb.Sp 等均无显著影响。     

Dental imaging of trabecular bone structure for systemic disorder screening: A systematic review

The purpose of this systematic review was to evaluate the potential use of dental imaging assessment of trabecular bone structure in the maxillomandibular complex as an adjuvant screening tool to identify systemic disorders. Five electronic databases and grey literature were searched. Studies were included if they investigated subjects with altered trabecular bone determined by dental radiographs. The QUADAS‐2 assessed the risk of bias (RoB) among the studies, while the GRADE determined the strength of evidence. A total of 14 studies that included 1,466 individuals were considered eligible for the qualitative analysis. All studies presented an overall low RoB and low concern regarding applicability. Systemic disorders such as osteoporosis, osteogenesis imperfecta, diabetes, and primary hyperparathyroidism, with their respective control groups, were analyzed among the included studies. Osteoporosis was the condition presenting the most significant results, and 72% of the studies detected changes in the maxillomandibular trabecular bone structure. Studies exploring diabetic edentulous patients found less dense trabecular bone pattern (p < 0.05). In summary, periapical and panoramic radiographs, computed tomography, and cone beam computed tomography imaging could be considered useful for the assessment of the mandibular trabecular bone structure of patients affected by osteoporosis and patients with diabetes.     

Chronological changes in the microstructure of bone during peri-implant healing: a microcomputed tomographic evaluation

Our objectives were to examine the titanium-bone interfaces chronologically and to clarify the process of osseointegration using microcomputed tomography (microCT). The mandibular premolars of 3 dogs were extracted and 12 weeks later 2 Straumann dental implants were installed in each quadrant. The microstructural changes at the bone-implant interface at the first, fourth, and eighth weeks after installation were evaluated by microCT and a 3-dimensional image was constructed. The microstructural measurements at the bone-implant interface, including the trabecular number (Tb.N), bone volume fraction (BV/TV), structure model index (SMI), trabecular thickness (Tb.Th), trabecular separation (Tb.Sp) and connectivity density (Conn.D), were measured. Experimental outcomes were analysed for correlations between time and microstructural variables of trabecular bone. Tb.N increased significantly during the eighth week compared with that during the first and fourth week (p = 0.001, 0.002). BV/TV increased generally with time and there were significant differences (p = 0.003) between each time group. While Tb.Sp decreased with time and changed significantly during the eighth week compared with that during the first week (p = 0.021), differences in SMI, Tb.Th and Conn.D did not differ significantly according to time of implant. The significant increase in the Tb.N and BV/TV during the eighth week after insertion of implants indicates that the formation of new bone before the eighth week is the key to osseointegration.     

Mandibular trabecular bone as fracture indicator in 80‐year‐old men and women

The objective of the present study was to compare assessments of the mandibular bone as fracture risk indicators for 277 men and women. The mandibular trabecular bone was evaluated in periapical radiographs, using a visual index, as dense, mixed dense and sparse, or sparse. Bone texture was analysed using a computer‐based method in which the number of transitions from trabeculae to intertrabecular spaces was calculated. The sum of the sizes and intensities of the spaces between the trabeculae was calculated using Jaw‐X software. Women had a statistically significantly greater number of fractures and a higher frequency of sparse mandibular bone. The OR for having suffered a fracture with visually sparse trabecular bone was highest for the male group (OR = 5.55) and lowest for the female group (OR = 3.35). For bone texture as an indicator of previous fracture, the OR was significant for the female group (OR = 2.61) but not for the male group, whereas the Jaw‐X calculations did not differentiate between fractured and non‐fractured groups. In conclusion, all bone‐quality assessments showed that women had a higher incidence of sparse trabecular bone than did men. Only the methods of visual assessment and trabecular texture were significantly correlated with previous bone fractures.     

Assessing Bone Type of Implant Recipient Sites by Stereomicroscopic Observation of Bone Core Specimens: A Comparison With the Assessment Using Dental Radiography

Background: The aim of the study is to determine if bone quality evaluation of surgically obtained bone core specimens using a stereomicroscope is reliable for determining bone quality at implant recipient sites. Methods: Bone quality was presurgically assessed in 122 edentulous ridges obtained from 62 patients using periapical radiographs and categorized according to the Lekholm and Zarb classification. During surgery, bone specimens were trephined, and bone types were immediately classified using a stereomicroscope. Microarchitectural characteristics of bone cores were evaluated after being scanned using microcomputed tomography (micro‐CT). Results: Bone types of implant sites categorized from radiography and stereomicroscope had statistically similar distribution but poor interrater agreement. Using micro‐CT, maxillae and mandibles showed significant differences in microarchitectural characteristics of bone cores. Bone volume (BV), total volume (TV), and trabecular thickness (Tb.Th) increased, whereas bone surface density (BS/BV) and open porosity (Po.[Op]) decreased in mandibular bone cores compared with those in maxillary bone cores. Moreover, micro‐CT values of BV/TV and Po.(Op) statistically correlated with bone types assessed by stereomicroscopy, particularly in mandibles (adjusted means of BV/TV of Type 2 to 4 versus Type 1 decreasing from ?9.88%, ?15.09%, ?29.31%; those of Po.(Op) ranged from 9.77%, 15.06%, 29.52% in an upward trend). However, such correlations were not found in maxillae or when bone types were classified using periapical radiographs. Conclusions: Caution is needed when using presurgical periapical radiographs to predict bone quality at implant recipient sites. Surgically preserved bone core specimens, whenever obtainable, might offer additional information to accurately assess bone quality, particularly at mandibular implant sites.     

雌激素和应力环境改变对骨质疏松大鼠下颌骨骨小梁结构的影响

目的: 探讨骨质疏松状态下由于牙齿缺失后应力环境的改变,导致下颌骨骨小梁结构的变化及补充雌激素对其变化的影响。方法: 用去势法建立骨质疏松的大鼠动物模型,8周后拔除大鼠单侧所有上颌磨牙,模拟下颌骨高低应力环境的变化,用骨组织形态计量学的方法观察骨质疏松组、雌激素治疗组和假手术对照组双侧下颌骨骨小梁的变化。结果: 骨质疏松组低应力侧比高应力侧的Tb.Ar、Tb.Wi明显降低(P<0.01),Tb.Sp明显增大(P<0.05);正常组和雌激素组无明显差异;雌激素组高应力侧、低应力侧的Tb.Ar与骨质疏松组同期相比增大(P<0.05)。结论: 高应力可减缓骨质疏松所引起的下颌骨骨小梁的吸收,低应力则可加速骨吸收;雌激素的补充治疗阻止了去势后大鼠下颌骨骨质的吸收,并抑制低应力环境下颌骨的进一步丢失,促进了骨形成。     

Microcomputed tomography analysis of particular autogenous bone graft in sinus augmentation at 5 months: differences on bone mineral density and 3D trabecular structure

Objectives

This study investigated the effects of gender on the three-dimensional (3D) bone mineral density (BMD) and micromorphology of the trabeculae of matured autogenous bone grafts after sinus floor augmentation, and compared them to those of adjacent native bone.

Materials and methods

Ten bone biopsy samples were removed from the implant placement areas of patients who had received second-stage sinus floor augmentation, and analyzed by microcomputed tomography. BMD phantoms with two calcium hydroxyapatite densities (0.25 and 0.75 g/cm³) were used to determine the BMD of the grafted and native bone samples. The 3D structural parameters of the trabeculae, including percentage of bone volume (bone volume/tissue volume, BV/TV), trabecular thickness (Tb.Th), trabecular number, trabecular separation, trabecular pattern factor (Tb.Pf), and structure model index, were analyzed between males and females and between grafted bone and native bone.

Results

No significant gender-specific differences in BMD and 3D trabecular structure of either native or grafted bone were found (P?>?0.05). Compared to the adjacent native bone, the autogenous grafted bone exhibited lower BV/TV and Tb.Th as well as a higher Tb.Pf (P?<?0.05). Additionally, there was a weak positive correlation between the Tb.Th values of grafted and native bone (R ²?=?0.58).

Conclusions

In the maxillary sinus, autogenous grafted bone exhibited lower BV/TV, Tb.Th, and trabecular connectivity than the adjacent native bone. No significant gender-specific differences were found for either the BMD or 3D trabecular structure of grafted bone.

Clinical relevance

After bone remodeling, autogenous grafted bone revealed different 3D trabecular structure as compared to native bone.     

Relationship between bone mineral density and trabecular bone pattern in postmenopausal osteoporotic Brazilian women

Objectives

The aim of this study is to evaluate the relative efficacy of the mandibular trabecular bone in detecting osteoporotic-associated bone changes in Brazilian women.

Materials and methods

Seventy-three digital panoramic radiographs of healthy and osteoporotic postmenopausal women were used. Regions of interest were selected in the mandibular angle and body of the panoramic images, which were analyzed for fractal dimension (FD) and pixel intensity (PI). Statistical analysis evaluated the distribution pattern, compared normal with osteoporotic patients and the right with the left mandible, and assessed the relationship between FD and PI. The significance level was set at 0.05.

Results

FD and PI values were significantly different (p?<?0.05) between normal and osteoporotic patients for the right and left mandibular angle and for the left mandibular body. There was no significant difference (p?>?0.05) between the right and left mandibular angle for FD and PI, but a significant difference (p?<?0.05) was observed on the mandibular body for PI values. FD and PI values presented positive correlation.

Conclusions

The mandibular trabecular bone was effective in detecting osteoporotic changes, with the exception of the right mandibular body.

Clinical relevance

Mandibular trabecular bone shows a promising attempt of accurate detection of osteoporotic changes in some regions of the jaws. Fractal analysis and pixel intensity had strong positive correlation.     

Panoramic radiographic evaluation of the mandibular morphological changes in elderly dentate and edentulous subjects

Abstract

Objective. The aim of the present study was to analyze the changes in the gonial angle, ramus height, condyle height and cortical bone thickness in relation to gender and dental status in elderly patients. Materials and methods. The study population comprised 240 patients (age ranged from 60–69 years) who had digital panoramic radiographs taken for various purposes. One group consisted of 120 patients, 60 men and 60 women, who had all natural teeth present except for third molars. The second group consisted of the remaining 120 patients (60 men and 60 women) who were in a completely edentulous state (maxilla and mandible). The gonial angle, ramus height, condylar height and cortical bone thickness of the mandible were measured by computer software on their panoramic radiographs. Results. Women showed larger gonial angles than men, while men had greater cortical bone thickness and ramus height (p < 0.05). However, no significant difference in condylar height was found between both genders (p > 0.05). Edentulous subjects had a larger gonial angle than dentate subjects, while dentate subjects had greater cortical bone thickness on both sides and left side of condylar height (p < 0.05). The gonial angle had statistically negative correlations with cortical bone thickness and ramus height, regardless of gender. Conclusions. The outcomes of the present study indicate that the edentulous women undergo morphological changes of the mandible influenced by the dental status more than men.     

Role of dental panoramic radiographs in assessment of future dental conditions in patients with osteoporosis and periodontitis

Osteoporosis affects large segments of elderly populations, especially postmenopausal women. Bone mineral density (BMD) assessment of the skeleton by means of several pieces of equipment, such as dual-energy X-ray absorptiometry, have been useful in identifying individuals with low BMD or at high risk of suffering osteoporotic fracture. Recent investigators have demonstrated a significant association between BMD of the mandible and the peripheral skeleton in postmenopausal women. Some studies also have linked low BMD of the mandible and the peripheral skeleton with alveolar bone loss of the mandible and tooth loss. Dental panoramic radiology is a useful imaging modality by which the dentist can evaluate the whole dentition as well as the jawbones. Clinicians have started to focus on some mandibular panoramic indices, such as mandibular cortical index and mandibular cortical thickness, for the identification of elderly individuals who should undergo BMD assessment. In comparison with peripheral BMD measurement equipment in the medical field, the dentist will be able to identify osteoporotic elderly individuals by means of dental panoramic radiographs taken for the diagnosis of the teeth and the jawbones without additional cost. It is likely that the clinician may estimate the future risk of tooth loss in elderly individuals with periodontitis and osteoporosis by dental panoramic radiographs.     

Accuracy of radiographic pixel linear analysis in detecting bone loss in periodontal disease: Study in diabetic rats

IntroductionPeriodontitis, a complex infectious disease that may lead to irreversible loss of periodontium, is considered a predisposing agent for developing insulin resistance due to the release of inflammatory mediators, showing a bilateral relationship with diabetes mellitus. The investigation of periodontal disease requires a clinical approach and complete intraoral radiographs, even with increasing concerns about radiation exposure. Thus, this study assesses pixel linear analysis accuracy using digital radiography via Digora® in detecting alveolar bone destruction in diabetic rats with periodontal disease.Methodology40 rats were divided into groups (n = 10): control (C), rats with periodontal disease (PD), experimental diabetic rats (ED), experimental diabetic rats with periodontal disease (ED-PD). Diabetes was induced by streptozotocin and periodontal disease by periodontal ligature. After 30 days, maxillae bone destruction was obtained by linear analysis of vertical bone loss using digital radiography and then assessed by micro-CT and histology. Data were analyzed by ANOVA and Tukey’s test (p < 0.05).ResultsRadiographic, micro-CT and histological analysis presented accurate and similar results. PD and ED-PD groups showed higher bone destruction than C and ED groups (p < 0.05). Moreover, the ED-PD group had higher bone loss than the PD group (p < 0.05).ConclusionThe pixel linear analysis via digital radiography was an accurate, low-cost alternative in detecting alveolar bone loss in this rat model. Micro-CT and histological analysis may also be used to obtain linear measures to assess and compare periodontal bone destruction in diabetic rats.     

Estimation of Alveolar Bone Loss in Periodontitis Using Machine Learning

AimThe objective of this research was to perform a pilot study to develop an automatic analysis of periapical radiographs from patients with and without periodontitis for the percentage alveolar bone loss (ABL) on the approximal surfaces of teeth using a supervised machine learning model, that is, convolutional neural networks (CNN).Material and methodsA total of 1546 approximal sites from 54 participants on mandibular periapical radiographs were manually annotated (MA) for a training set (n = 1308 sites), a validation set (n = 98 sites), and a test set (n = 140 sites). The training and validation sets were used for the development of a CNN algorithm. The algorithm recognised the cemento-enamel junction, the most apical extent of the alveolar crest, the apex, and the surrounding alveolar bone.ResultsFor the total of 140 images in the test set, the CNN scored a mean of 23.1 ± 11.8 %ABL, whilst the corresponding value for MA was 27.8 ± 13.8 %ABL. The intraclass correlation (ICC) was 0.601 (P < .001), indicating moderate reliability. Further subanalyses for various tooth types and various bone loss patterns showed that ICCs remained significant, although the algorithm performed with excellent reliability for %ABL on nonmolar teeth (incisors, canines, premolars; ICC = 0.763).ConclusionsA CNN trained algorithm on radiographic images showed a diagnostic performance with moderate to good reliability to detect and quantify %ABL in periapical radiographs.     

Preliminary Clinical Study to Evaluate the Relationship between Systemic Bone Turnover and the Microstructure of the Alveolar Bone

The objective of this study was to assess the possibility of developing a clinical minimally invasive and standardized method to evaluate the relationship between the microstructure of the jaw bone and systemic bone turnover. For this purpose, we performed standardized bone biopsy of the alveolar bone, and compared the 3D bone microstructure using micro-computed tomography (micro-CT) with bone mineral density (BMD) of the lumbar spine and biochemical markers of bone turnover. We evaluated a total of 9 samples taken from 6 patients by standardized biopsy using a trephine bur. BMD was evaluated using dual energy X-ray absorptiometry (DXA). Regarding the biochemical markers of bone turnover, serum bone-specific alkaline phosphatase (BAP) and serum osteocalcin (OC) were used as bone formation markers, and urinary cross-linked N-telopeptides of type I collagen (NTx) and urinary deoxypyridinoline (DPD) were selected as bone resorption markers. We scanned micro-CT images of these samples. Bone volume fraction (BV/TV), trabecular thickness (Tb.Th), trabecular number (Tb.N), trabecular spacing (Tb.Spac), fractal dimension, trabecular bone pattern factor (TBPf) and node-strut (Nd.Nd/TV, TSL/TV) were measured. Regarding the correlations between the parameters of bone microstructures, TB/TV, Tb.N, fractal dimension, and node-strut seemed to be positively correlated and Tb.Spac and TBPf seemed to be negatively correlated with each other, but Tb.Th seemed to have a low correlation with other parameters. OC and/or BAP showed a significantly high correlation with many structural parameters (p < 0.05%). In conclusion, some microstructural parameters may change according to the systemic bone turnover.     

Trabecular bone mineral density of mandible and alveolar height in postmenopausal women

Mineral density of the trabecular bone of the mandible was determined by single-energy QCT (quantitative computed tomography) for 74 totally or nearly edentulous menopausal women. These results were compared with the bone mineral densities (BMD) of their lumbar area (L2–L4) and femoral collum, measured by dual-energy x-ray transmission, Lunar DPX. The remaining height of the residual ridge at the symphysis of the mandible was measured on computed tomography (CT) lateral projection view, and an index of the residual ridge status was introduced. To determine whether general osteoporosis status affects the remaining height of the residual ridges, we compared these values with all results for bone mineral density. The BMD of the lumbar area and that of the femoral collum correlated well with each other, but the BMD of the trabecular bone of the mandible did not correlate with either of the other two BMD measurements. Measurements of residual ridge height did not correlate with any BMD values. The effect of possible bone loss earlier in life is no longer apparent in mandibular height or trabecular BMD over 20 yr after tooth extractions.