Resorption Volume Research Articles

Impact of mass effect, tumor location, age, and surgery on the cognitive outcome of patients with high-grade gliomas: a longitudinal study

High-grade gliomas are the most frequently occurring brain tumors and carry unfavorable prognosis. Literature is controversial regarding the effects of surgery on cognitive functions. We analyzed a homogenous population of 30 patients with high-grade glioma who underwent complete resection. Patients underwent extensive neuropsychological analysis before surgery, 7 days after surgery, and approximately 40 days after surgery, before adjuvant treatments. Thirty-four neuropsychological tests were administered in the language, memory, attention, executive functions, and praxis domains. The preoperative percentage of patients with impairment in the considered tests ranged from 0% to 53.3% (mean 20.9%). Despite a general worsening at early follow-up, a significant recovery was observed at late follow-up. Preoperative performances in language and verbal memory tasks depended on the joint effect of tumor volume, volume of surrounding edema, and tumor localization, with major deficits in patients with left lateralized tumor, especially insular and temporal. Preoperative performances in attention and constructive abilities tasks depended on the joint effect of tumor volume, volume of surrounding edema, and patient age, with major deficits in patients ≥ 65 years old. Recovery at late follow-up depended on the volume of resected tumor, edema resorption, and patient age. Longitudinal neuropsychological performance of patients affected by high-grade glioma depends, among other factors, on the complex interplay of tumor volume, volume of surrounding edema, tumor localization, and patient age. Reported results support the definition of criteria for surgical indication based on the above factors. They may be used to propose more customized surgical, oncological, and rehabilitative strategies.

Effect of gingival fibroblasts and ultrasound on dogs' root resorption during orthodontic treatment.

Objectives:To investigate the effect of using osteogenic induced gingival fibroblasts (OIGFs) and low intensity pulsed ultrasound (LIPUS) on root resorption lacunae volume and cementum thickness in beagle dogs that received orthodontic tooth movement.Materials and Methods:Seven beagle dogs were used, from which gingival cells (GCs) were obtained and were induced osteogenically to produce OIGFs. Each third and fourth premolar was randomly assigned to one of the five groups, namely, LIPUS, OIGFs, bone morphogenetic protein-2 (BMP-2), OIGFs + LIPUS, and control. All groups received 4 weeks of bodily tooth movement, then LIPUS-treated groups received LIPUS for 20 min/day for 4 weeks, and OIGFs groups received an injection of OIGFs near the root apex. Microcomputed tomography analysis was used to calculate root resorption lacunae volume and histomorphometric analysis was performed to measure the cementum thickness of each root at 3 root levels on compression and tension sides.Results:There was no significant difference in resorption volume between the treatment groups. OIGFs + LIPUS increased cementum thickness (P > 0.05) in third premolars near the apex, and LIPUS increased cementum thickness (P > 0.05) in fourth premolars near the apex. Furthermore, BMP2 increased cementum thickness at the coronal third at the compression side.Conclusion:OIGFs, LIPUS, and BMP-2 can be potential treatments for orthodontically induced root resorption, however, improvements in experimental design and treatment parameters are required to further investigate these repair modalities.

Genetic and clinical risk factors of root resorption associated with orthodontic treatment.

External apical root resorption (EARR) is a common complication in orthodontic treatment. Despite many studies on EARR, great controversies remain with regard to its risk factors. The objective of this study was to explore the relationship among sex, root movement, IL-1RN single nucleotide polymorphism (SNP) rs419598, IL-6 SNP rs1800796, and EARR associated with orthodontic treatment. Altogether 174 patients (with 174 maxillary left central incisors) were selected for this study. Cone-beam computed tomography was performed before the start of the treatment and at the end of the treatment. Cone-beam computed tomography data were used to reconstruct a 3-dimensional image of each tooth; the volume and the root resorption volume of each tooth were calculated. Three-dimensional matching was used to measure the amount of movement of each root. Genomic DNA was extracted from buccal swabs, and genotypes of SNP rs419598 and SNP rs1800796 of each subject were determined using TaqMan polymerase chain reaction genotyping (Applied Biosystems, Foster City, Calif). The data were analyzed with multiple linear regression analysis. The statistical analysis indicated no relationship between sex, tooth movement amount, and IL-1RN SNP rs419598 with EARR. The IL-6 SNP rs1800796GC was associated with EARR, and root resorption differed significantly between SNP rs1800796GC and CC. IL-6 SNP rs1800796GC is a risk factor for EARR. The amount ofroot movement, IL-1RN SNP rs419598, and sex as risk factors for EARR need further study.

A Preliminary Assessment of the Predictability of Fat Grafting to Correct Silicone Breast Implant-Related Complications.

Fat grafting in breast augmentation surgery is becoming increasingly popular and is allowing surgeons to fill the gaps that implant augmentation alone cannot. However, one current issue surrounding fat grafting is resorption. In this prospective study, the authors present their experience of fat grafting and resorption in 26 patients who had fat transfer to correct deformities or asymmetries following primary breast enlargement surgery. The fat utilized was harvested and processed using the Puregraft system. Fat grafting was performed until the problem was visually corrected, followed by an additional 30% overcorrection. Photographs were taken preoperatively and 1 year postoperatively, and analyzed utilizing cloud-based 3-dimensional imaging software to measure the breast volumes and calculate 1-year resorption rates. Both patients and physicians were asked to rate their satisfaction. The total volume of fat transferred ranged from 160 cc to 360 cc, with an average of 280 cc per procedure. The absolute volume of tissue resorption showed considerable variation (median, 42.6 mL; range, 5.5-62 mL). However, there was a very close correlation between the volume resorbed and the volume implanted: the more volume injected, the more volume absorbed. When expressed as a percentage of implanted tissue, the resorption rate was 27.5 ± 0.8% (mean ± standard deviation) with a very narrow range (25.7%-28.9%). Patients and physicians reported a satisfaction rate of "excellent" in 83.3% and 75% of cases, respectively. At 1 year, 25.7% to 28.9% of the injected fat had been resorbed in a predictable, reproducible, and effective manner. 4 Therapeutic.

Increasing the amount of corticotomy does not affect orthodontic tooth movement or root resorption, but accelerates alveolar bone resorption in rats.

The purpose of this study was to evaluate the relationships among the volume of bone cut during corticotomy, amount of tooth movement, volume of root resorption, and volume of the resultant alveolar bone resorption after tooth movement. Ten-week-old female Wistar rats were distributed into the corticotomy groups and a control group that underwent sham corticotomy. Two experiments employing two different orthodontic forces (10 or 25g) and experimental periods (14 or 21 days) were performed. The volumes of the bone cut by corticotomy were 0.1, 1.0, and 1.7mm3 in the 25g groups, and 1.0 and 1.7mm3 in the 10g groups. Nickel-titanium closed-coil springs were set on the maxillary left first molars to induce mesial movement. After orthodontic tooth movement, the amount of tooth movement, volume of root resorption, and volume of alveolar bone resorption were measured. Despite differences in the volume of bone cut among the different corticotomy groups, there were not significant differences in the amount of tooth movement and volume of root resorption between the control group and any of the corticotomy groups. However, higher volume of bone cut during corticotomy was significantly related to the decreased alveolar bone volume-in particular, to the reduced height of the alveolar bone crest after tooth movement. The volume of the alveolar bone cut during corticotomy does not affect tooth movement or root resorption in 10-week-old female Wistar rats; however, it may increase alveolar bone loss after tooth movement.

The effect of canine disimpaction performed with temporary anchorage devices (TADs) before comprehensive orthodontic treatment to avoid root resorption of adjacent teeth.

ABSTRACTObjective: The aim of this study was to evaluate the movement of impacted canines away from the roots of neighboring teeth before full-mouth bracket placement, performed by means of TADs to decrease undesired side effects on adjacent teeth. Methods: The study sample consisted of 34 palatally impacted canines, being 19 in the experimental group and 15 in the control group. In the experimental group, before placement of brackets, the impacted canine was erupted by means of miniscrews. In the control group, after initiation of comprehensive orthodontics, canine disimpaction was performed by means of a cantilever spring soldered to a palatal bar. At the end of treatment, volume of lateral incisors and canine root resorption were measured and compared by means of a CBCT-derived tridimensional model. Visual Analogue Scale (VAS) score, bleeding on probing (BOP) and gingival index (GI) were recorded. Clinical success rate was also calculated. Results: The volume of root resorption of lateral teeth in the control group was significantly greater than in the experimental group (p < 0.001). At the end of treatment, VAS score, GI and BOP were not significantly different between the two groups. Conclusion: Based on our results, it seems that disimpaction of canines and moving them to the arch can be done successfully carried out with minimal side effects by means of skeletal anchorage.

Influence of enamel matrix derivative on healing of root surfaces after bonding treatment and intentional replantation of vertically fractured roots.

The objectives of this study were to histopathologically evaluate cementum regeneration on root surfaces when an enamel matrix derivative (EMD) was used to bond a vertically fractured root and to evaluate the effectiveness of EMD in inhibiting root resorption. A total of 40 roots from 24 maxillary premolars in beagles were used. The root was vertically fractured using a chisel and mallet. Super-Bond was then used to bond the fractured root. In the experimental group, the root surface was treated with ethylenediaminetetraacetic acid and an EMD. The control group received no treatment. The root was then replanted in its original location. Histopathological observation and measurement using image-analyzing software were carried out after 8 weeks. In the experimental group, shallow resorption cavities developed on the root planed surfaces with new acellular cementum appearing over them. In the control group, no new cementum was seen on the planed surfaces, and there was connective tissue joining the roots. In some of the samples, resorption and multinucleated giant cells were seen. The experimental group showed a significantly larger volume of cementum formation (P < 0.001), and the volume of root resorption was significantly smaller (P = 0.004). When bonding and replanting tooth roots after a vertical fracture, the application of EMD was effective in regenerating cementum on root surfaces from which periodontal ligament had been lost in the area around the fracture line and in reducing the incidence of root resorption.

Using Micro-Computed Tomography to Evaluate the Dynamics of Orthodontically Induced Root Resorption Repair in a Rat Model.

ObjectiveTo observe dynamic changes in root resorption repair, tooth movement relapse and alveolar bone microstructure following the application of orthodontic force.Materials and MethodsForces of 20 g, 50 g or 100 g were delivered to the left maxillary first molars of fifteen 10-week-old rats for 14 days. Each rat was subjected to micro-computed tomography scanning at 0, 3, 7, 10, 14, 28 and 42 days after force removal. The root resorption crater volume, tooth movement relapse and alveolar bone microarchitecture were measured at each time point.ResultsFrom day 3 to day 14, the root resorption volume decreased significantly in each group. In the 20-g force group, the root resorption volume gradually stabilized after 14 days, whereas in the 50-g and 100-g force groups, it stabilized after 28 days. In all groups, tooth movement relapsed significantly from day 0 to day 14 and then remained stable. From day 3 to day 10, the 20-g group exhibited faster relapse than the 50-g and 100-g groups. In all groups, the structure model index and trabecular separation decreased slowly from day 0 to day 10 and eventually stabilized. Trabecular number increased slowly from day 0 to day 7 and then stabilized.ConclusionsThe initial stage of root resorption repair did not change significantly and was followed by a dramatic repair period before stabilizing. The most serious tooth movement relapse occurred immediately after the appliance was removed, and then the tooth completely returned to the original position.

Assessment of image quality in maxillofacial cone-beam computed tomography imaging

The aim was to evaluate image quality produced by a cone-beam CT (CBCT) scanner under various imaging modes. A modulation transfer function (07-538, Nuclear Associates, Carle Place, NY) was placed in an anthropomorphic head phantom (RS-250, Radiology Support Devices, Long Beach, CA). Overall, 67 CBCT scans were obtained by modifying the entire range of kilovolt (kV) and milliampere (mA) settings, using the CS 9300 CBCT scanner (Carestream Health, Inc., Rochester, NY). A total of 24 individual raters rated the images to evaluate line pairs visible. Upon completion of the evaluation process, 4 kV and mA combinations (85 kV × 12 mA, 90 kV × 4.0 mA, 60 kV × 6.3 mA, and 65 kV × 2.5 mA) were selected for further investigation. In all 10 dry skulls were scanned to measure the defect size of simulated root resorption in 4 different modes. Intraclass correlation (ICC) analysis was used to compare the agreement between the defect sizes measured from the scans compared to the actual physical volume. Low kV settings (60 kV) used in combination with moderate-to-high mA settings (4.0–15 mA) produced the best-perceived image quality, resulting in up to 56% reduction in the total radiation amount (mGy cm2) generated. High kV settings (85–90 kV) used in combination with high mA settings (8.0–15 mA) produced the lowest image quality. All 4 selected imaging modalities presented a high level of accuracy in detection of root resorption volume compared to actual physical volume (ICCs between 0.93 and 0.98). Radiation exposure from CBCT scans can be reduced while maintaining adequate image quality and diagnostic accuracy by performing scans using low kV and moderate-to-high mA settings.

Short-term effects of nicotine on orthodontically induced root resorption in rats.

To investigate the effect of nicotine exposure on root resorption in an in vivo rat model of orthodontic tooth movement (OTM), and its association with odontoclastogenesis and receptor activator of nuclear factor-kappa B ligand (RANKL) expression. Forty-eight 10-week-old male Wistar rats were divided into three groups. The negative control group was untreated. The left maxillary first molars in the nicotine-treated group and the positive control group received OTM with an initial force of 0.6 N in the mesial direction. Also, the nicotine-treated group received intraperitoneal injection of nicotine at 7 mg/kg per day. After 21 days, the rats were humanely killed. Eight rats from each group were randomly chosen for crater volume analysis by micro-computed tomography. For the remaining eight rats in each group, specimen slices were generated for histologic examination to determine the odontoclast number and the mean optical density value of RANKL. The resorption volumes in the nicotine-treated group were significantly larger than those in the control groups. Also, the nicotine-treated group displayed significantly higher number of odontoclasts and elevated RANKL expression compared to the control groups. In an in vivo rat model, nicotine exposure promotes odontoclastogenesis and RANKL expression, evoking aggravated root resorption during OTM.

CBCT-based volume of simulated root resorption - influence of FOV and voxel size.

To examine the influence of the field of view (FOV) and voxel size on the measurement of the volume of simulated internal root resorption (IRR) lesions through cone-beam computed tomography (CBCT). Eleven single-rooted teeth with IRR simulated by acid demineralization were studied. CBCT images were acquired using large FOV (voxel sizes of 0.200, 0.250 and 0.300 mm) and limited FOV (voxel sizes of 0.076, 0.100 and 0.200 mm). The IRR volumes were calculated using the Dolphin(®) software. Volumetric measurements were validated using IRR silicone putty casts. The analysis of variance (anova) for randomized block design complemented with the Tukey's test was employed. IRR volumes obtained using voxel sizes of 0.200 and 0.250 mm were similar (P > 0.05). However, both these values were significantly different from that obtained using the 0.300-mm voxel (P < 0.05). There was no significant difference between IRR volumes measured through voxel sizes of 0.076 and 0.100 mm (P > 0.05), but both differed significantly from that obtained through the 0.200-mm voxel (P < 0.05). There was no significant difference between the volumetric measurements of the 0.200-mm voxel images of the restricted and large FOV protocols. The mean volumes of the silicone casts were smaller than those calculated using a 0.200-mm voxel, but were similar to those obtained using voxel sizes of 0.076 and 0.300 mm. Despite the FOV protocol, voxel size can influence measurement of simulated IRR volumes. The importance of standardization of CBCT image acquisition protocols is emphasized, especially during follow-up of an IRR lesion, to prevent misinterpretation of its extent, which can create a bias in clinical decisions.

In vivo osteoprotegerin gene therapy preventing bone loss induced by periodontitis

The objective of this study was to investigate the effects of osteoprotegerin (OPG) gene therapy on alveolar bone resorption caused by experimental periodontitis in rats, thus forming a foundation for potential clinical applications of OPG gene therapy in the treatment of periodontitis and peri-implantitis. To study the effects of OPG on alveolar bone protection, an experimental periodontitis model was used by placing a bacterial plaque retentive silk ligature in the gingival sulcus around the maxillary second molar tooth, injection of Porphyromonas gingivalis and high carbohydrate diet. A total of 30 Sprague-Dawley rats were randomly divided into three groups, with 10 rats in each group: group I (control) was treated with 10 μL normal saline injection; group II with 10 μL mock vector; and group III with 10 μL local OPG gene transfer by transfection with in vitro constructed pcDNA3.1-human OPG (pcDNA3.1-hOPG). A subperiosteal injection was done adjacent to the second molars on days 0, 7, 14 and 21. Four weeks later, all animals were killed and radiographic, histological and immunohistochemical examinations were performed. Statistical analysis included ANOVA and LSD-Bonferroni test. Group III (OPG gene therapy) had significantly enhanced (p < 0.05) integrated optical density of OPG, had significantly decreased alveolar bone resorption volume and active osteoclast number (p < 0.05) through descriptive histological examination when compared with the other two groups at week 4. Local recombinant OPG plasmid-mediated gene therapy suppresses osteoclastogenesis in vivo and inhibits alveolar bone height reduction caused by experimental periodontitis in rats. OPG gene therapy may be beneficial in preventing progressive periodontal bone loss.

A Comparative Study of Bone Resorption between Implant Placement Sites and Non-Implant Placement Sites after Autogenous Block Bone Grafts in the Anterior Maxilla

The aim of this study was to compare the bone resorption differences between implant placement sites (IPS) and non-implant placement sites (NIPS) after autogenous block bone grafts in the anterior maxilla. Fourteen patients (58 edentulous sites) with alveolar atrophy in the anterior maxilla were treated with autogenous block bone grafts. CBCT examinations were performed at 1 month before surgery (T0), immediately after surgery (T1), 3 to 4 months after surgery (T2), 6 to 7 months after surgery before implant placement (T3), 12 to 13 months after surgery (T4), and the longest follow-up point (T5). Alveolar crestal and basal bone width (ACBW, ABBW), and alveolar bone height (ABH) were measured and divided into IPS (30 sites) and NIPS (28 sites). All results were compared by the Wilcoxon Signed Rank test. The bone resorption changes for both groups were the same. For these three parameters, ACBW didn’t change significantly from T2 to T3 and T4 to T5, ABBW didn’t change at every period from T2 to T5, and ABH didn’t change from T4 to T5. The bone resorption volume of ACBW and ABH in NIPS were more than in IPS after implant placement surgery, while the volume of ABBW was similar in both groups. At T5, the bone resorption percentages of ACBW, ABBW, and ABH were 25.57%, 16.85% and 43.84% in IPS, and 33.55%, 15.92% and 46.44% in NIPS. A more rapid loss of alveolar crest in NIPS resulted from implant placement surgery, and this reminded us of the importance of immediate implant placement.

Emerging Ideas: Instability-induced Periprosthetic Osteolysis Is Not Dependent on the Fibrous Tissue Interface

Stable initial fixation of a total joint arthroplasty implant is critical to avoid the risk of aseptic loosening and premature clinical failure. With implant motion, a fibrous tissue layer forms at the bone-implant interface, leading to implant migration and periprosthetic osteolysis. At the time of implant revision surgery, proresorptive signaling cytokines are expressed in the periimplant fibrous membrane. However, the exact role of this fibrous tissue in causing periprosthetic osteolysis attributable to instability remains unknown. We propose an alternative mechanism of periprosthetic osteolysis independent of the fibrous tissue layer, where pressurized fluid flow along the bone-implant interface activates mechanosensitive osteocytes in the periprosthetic bone, causing the release of proresorptive cytokines and subsequent osteoclast differentiation and osteolysis. An animal model for instability-induced osteolysis that mimics the periprosthetic bone-implant interface will be used. In this model, a fibrous tissue membrane is allowed to form in the periprosthetic zone, and pressurized fluid flow transmitted through this membrane reliably creates osteolytic lesions in the periprosthetic bone. In this study, half of the rats will have the fibrous tissue present, while the other half will not. We will determine whether the fibrous tissue membrane is essential for the release of proosteoclastic cytokines, leading to osteoclast differentiation and periprosthetic bone loss, by measuring the volume of bone resorption and presence of proresorptive cytokines at the bone-implant interface. We will determine whether the fibrous tissue membrane is crucial for osteoclastogenic signaling in the setting of periimplant osteolysis. In the future, this will allow us to test therapeutic interventions, such as specific cytokine inhibitors or alterations in implant design, which may translate into new, clinically relevant strategies to prevent osteolysis.

Histometric Study of Resorption on Replanted Teeth with Enamel Matrix-derived Protein

Enamel matrix-derived proteins (Emdogain) stimulate the proliferation of periodontal ligament cells, contributing to their regeneration. This study was to perform histometric assessment of root surface resorption in replanted teeth with the use of Emdogain®. Male Wistar rats (Rattus norvegicus), weighing 180 to 200 gm, were anesthetized, subjected to extraction of the upper right incisor tooth, which was then replanted into the alveoli with the following treatment: (a) control group--tooth with root canal filled with calcium hydroxide paste and (b) treated group--tooth with root canal filled with enamel matrix-derived protein. The animals were sacrificed 25 days after tooth replantation. The maxilla was processed to obtain thin sections (6 µ) and stained with hematoxylin and eosin. The resorption volume percentage of each dental element was calculated from the cementoenamel junction to the apex. Quantification of resorption revealed that Emdogaintreated teeth showed a lower percentage of resorption (31.58%) compared to controls (80.48%) (statistically significant values--t-test p-value=0.0431). It was concluded that Emdogain used as root canal filling has properties capable of showing a lower percentage of resorption in replanted teeth.

Evaluation on the efficacy and safety of calcium metaphosphate coated fixture

PURPOSEThe purpose of this study was to assess the difference in efficacy between calcium metaphosphate (CMP)-coated implant fixtures and conventional resorbable blasted media (RBM) processed implant fixtures.MATERIALS AND METHODSThis study targeted 50 implants from 44 patients who visited Dankook University Dental Hospital. Implantations were done separately for RBM treated and CMP-coated implants, although their design was the same. Calcium metaphosphate has a quicker biodegradation process through hydrolysis compared to other phosphate calcium groups. For the first year of the implantation, the resorption volume of marginal bone analyzed via radiography and perio-test value were measured, under the check plan. Their analyses were composed of a non-inferiority trials test. A 95% level of reliability was used.RESULTSIn the comparative analysis of the resorption volume of marginal bone and the perio-test value, no statistically significant difference was found between the CMP-coated implants and RBM implants.CONCLUSIONOne year after the implant placement, CMP-coated implants were found not to be inferior to the conventional RBM implants.

In vivo microcomputed tomography evaluation of rat alveolar bone and root resorption during orthodontic tooth movement

To observe the real-time microarchitecture changes of the alveolar bone and root resorption during orthodontic treatment. A 10 g force was delivered to move the maxillary left first molars mesially in twenty 10-week-old rats for 14 days. The first molar and adjacent alveolar bone were scanned using in vivo microcomputed tomography at the following time points: days 0, 3, 7, and 14. Microarchitecture parameters, including bone volume fraction, structure model index, trabecular thickness, trabecular number, and trabecular separation of alveolar bone, were measured on the compression and tension side. The total root volume was measured, and the resorption crater volume at each time point was calculated. Univariate repeated measures analysis of variance with Bonferroni corrections were performed to compare the differences in each parameter between time points with significance level at P < .05. From day 3 to day 7, bone volume fraction, structure model index, trabecular thickness, and trabecular separation decreased significantly on the compression side, but the same parameters increased significantly on the tension side from day 7 to day 14. Root resorption volume of the mesial root increased significantly on day 7 of orthodontic loading. Real-time root and bone resorption during orthodontic movement can be observed in 3 dimensions using in vivo micro-CT. Alveolar bone resorption and root resorption were observed mostly in the apical third on day 7 on the compression side; bone formation was observed on day 14 on the tension side during orthodontic tooth movement.

Depth and volume of resorption induced by osteoclasts generated in the presence of RANKL, TNF-alpha/IL-1 or LIGHT

Rheumatoid arthritis (RA) is associated with pathological bone destruction mediated by osteoclasts. Although RANKL has been reported as a crucial factor for osteoclastogenesis, several other factors increased in RA support osteoclast formation and resorption in the absence of RANKL such as TNF-alpha and LIGHT. To date, in vitro bone resorption experiments are reported as the mean area of bone resorption per cortical or dentine slices and do not provide any information about depth and volume of resorption. The aims of this study were to assess these parameters by light microscopy and vertical scanning profilometry (VSP). Peripheral blood mononuclear cells were used as a source of osteoclast precursors and were cultured for up to 21 days in the presence of RANKL, TNF-alpha/IL-1 or LIGHT. Mean area, depth and volume of resorption were assessed by light microscopy and vertical scanning profilometry. As expected, RANKL induced large resorption pits (10,876 ± 2190 μm 2) whereas TNF-alpha/IL-1 and LIGHT generated smaller pits (respectively 1328 ± 210 and 1267 ± 173 μm 2) with no noticeable differences between these two cytokines. Depth and volume of resorption measured by VSP showed that RANKL promoted deep resorption pits resulting in large volume of resorption. Interestingly, although mean area of resorption was similar between TNF-alpha/IL-1 and LIGHT, the depth and volume of resorption of these lacunae were significantly increased by 2-fold with TNF-alpha/IL-1. These results provide evidence that although LIGHT appeared elevated in the synovial fluid of RA patients, its role in bone resorption is less than TNF-alpha/IL-1 or RANKL.

Progressive osteolysis of the radius after distal biceps tendon repair with the bioabsorbable screw

Several complications have been reported with the use of the PLLA (poly-L-Lactide) bioabsorbable screw in orthopedic surgery. The hypothesis was that the use of a bioabsorbable screw in distal biceps tenodesis results in significant osteolysis of the radial bone. The correlation between osteolysis and functional and clinical outcomes was also studied. All consecutive patients who underwent anatomic repair of the distal biceps tendon with a bioabsorbable screw were included. From the x-ray taken immediately after the surgery, the ratio between the volume of the bone tunnel and the volume of the radius bone section was measured. This relation was calculated at different follow-up periods to obtain the percentage of tunnel enlargement over time. Complications, as well as functional and clinical outcomes, were also assessed. Mayo Elbow Performance Score (MEPS), the quick-Disability Arm Shoulder Hand (DASH), and the Short-Form 12 (SF-12) were used. Nineteen consecutive patients were available for follow-up. The average initial relative volume occupied by the screw tunnel was 49% of the bone section and increased to 61% at the last follow-up at an average of 22 months (range, 3-62 months). Eight of the 19 patients presented postoperative complications. There was only 1 case of complete bone filling of the tunnel, which was observed at a 5-year and 2-months follow-up. There was no significant correlation between the volume of bone resorption and functional and clinical outcomes. No correlation was found between the volume of bone tunnel and the functional outcome. However, the results indicate that the use of a bioabsorbable screw in distal biceps tendon repair results in significant bone osteolysis.

Three-dimensional morphology of root and alveolar trabecular bone during tooth movement using micro-computed tomography

To investigate the effects of force magnitude on three-dimensional alveolar trabecular bone structure and root resorption. Twenty-two 11-week-old Sprague Dawley rats were randomly assigned to two groups that received a mesially directed orthodontic force to the upper right first molars at different magnitudes of force, 30 g or 100 g, for 2 weeks. The contralateral molars served as controls. The teeth and alveolar bone around the teeth were dissected from the sacrificed animals and were scanned with micro-computed tomography (CT). Structural properties of the trabecular bone and resorption crater volume on the mesial roots of the maxillary first molars were analyzed. The bone volume fraction of the 30 g group and the 100 g group increased significantly in both groups, and trabecular separation of the 100 g group decreased significantly compared with controls (P < .05). The total root resorption volume in all experimental groups and the resorption volume of the lower distal surface in the 100 g group increased significantly compared with controls (P < .01). The volume of the upper mesial root surface in the 30 g group increased significantly compared with the 100 g group and controls (P < .05). The alveolar trabecular bone was denser after orthodontic force was applied for 14 days. The effects of 30 g and 100 g orthodontic forces on root resorption were different at the upper mesial and lower distal surfaces of the mesial roots of maxillary first molars.