About half of all burst fractures at the thoracolumbar junction lead to neurological impairment and several clinical series have demonstrated a statistically significant correlation between canal encroachment and neurologic impairment, but not directly related. Spontaneous canal remodelling over time due to bone resorption has been observed in conservatively treated burst fractures. The aim of this study was to measure spinal canal remodelling after stabilization of burst fractures. So, we evaluated 22 cases of surgically stabilized burst fractures of thoracolumbar junction about pre and postoperative spinal canal stenotic ratio and canal remodelling by bone resorption over time. The results were as follows; l. Pedicle splaying increases the spinal canal area and necessitates correction. 2. Patients with neurological deficits had average 53% encroachment and the neurological normal patient had a canal compromise of 33.9%. 3. Postoperatively canal encroachment had decreased to a mean of 17.4% and further reduced by resorption of bony fragment to a mean of 8.3% within 14 months. In conclusions, remodelling of the spinal canal by resorption of encroaching bone fragments is a consistent feature in surgically stabilized thoracolumbar burst fractures and most patients regain their prefracture canal demensions within 14 months.
Bone Resorption ; Humans ; Spinal Canal*

No abstract available.
Arthroplasty* ; Bone Resorption* ; Hip* ; Thigh*

Occupational acro-osteolysis pertains to bone resorption of the distal phalanges of the hands and feet among workers with vinyl chloride exposure. We report the case of a Filipino man with osteolysis of the distal phalanges of the hands initially considered to have systemic sclerosis. The patient had gradual shortening of the fingers, thickening of the skin over the extremities, and hypopigmented patches over a span of more than 20 years. His lower extremities presented with non-pitting edema, skin thickening, and neuropathy, without shortening of the digits. Difficulty of ambulation was apparent due to the development of feet inversion. Radiographic findings of the hands and feet included resorption of distal phalanges, erosive and sclerotic changes, and narrowed joint spaces. Other conditions considered were Hansen’s disease, skeletal tuberculosis, and diabetic neuropathic arthropathy, which were eventually ruled out. The final diagnosis was occupational acro-osteolysis secondary to vinyl chloride exposure. The patient underwent serial total contact casting of the bilateral lower extremities to relieve bipedal edema and to reposition the feet. This case emphasizes the significance of investigating a patient’s occupational history and highlights a rare sequela of exposure to a commonly used chemical agent in the manufacture of polyvinyl chloride products.
bone resorption ; vinyl chloride ; Filipino

STATEMENT OF PROBLEM: Periotest. and OsstellTM were known as the most objective and quantitative mobility tests available for evaluating stability of implant in vivo. Although a correlation between PTV widely used and ISQ recently introduced exist, a PTV was corresponded to various ISQ. A correct evaluation of implant stability could be obtained only after one has a thorough understanding of the limitations of devices and factors that affect measurements. PURPOSE: The purpose of this study was to investigate the causes of variables in the values obtained with these two tests. MATERIAL AND METHOD: A total of 333 implants: 134 Bra.nemark, 5 Silhouette and 194 ITI implants were investigated. Result: 1. There was a correlation between PTV and ISQ (Spearman correlation =0.39, p<0.0001) 2. The factors that affected ISQ were diameter of implant fixture, location of implant and implant system (submerged type vs non-submerged type). 3. The factors that affected PTV were diameter of implant fixture, location of implant, and elapsed time after implant placement. 4. There was no significant difference between different surface treatments of RBM, smooth surface and ti-unite on PTV and ISQ. 5. In radiographic finding, no saucerization or bone resorption has been detected in implants with ISQ values that were above the average level of each PTV. These higher values had higher bone densities around the implant fixture. Saucerization was observed in the most impants with ISQ values that were below the average level of each PTV. CONCLUSION: There was a correlation between ISQ and PTV. However, each measuring methods had factors influencing the measured values. PTV were less sensitive to marginal bone resorption and influenced with the striking point on an implant to the level of bone. With ISQ, the height of implant from bone level to transducer should be considered.
Bone Density ; Bone Resorption ; Strikes, Employee ; Transducers

STATEMENT OF PROBLEM: Periotest. and OsstellTM were known as the most objective and quantitative mobility tests available for evaluating stability of implant in vivo. Although a correlation between PTV widely used and ISQ recently introduced exist, a PTV was corresponded to various ISQ. A correct evaluation of implant stability could be obtained only after one has a thorough understanding of the limitations of devices and factors that affect measurements. PURPOSE: The purpose of this study was to investigate the causes of variables in the values obtained with these two tests. MATERIAL AND METHOD: A total of 333 implants: 134 Bra.nemark, 5 Silhouette and 194 ITI implants were investigated. Result: 1. There was a correlation between PTV and ISQ (Spearman correlation =0.39, p<0.0001) 2. The factors that affected ISQ were diameter of implant fixture, location of implant and implant system (submerged type vs non-submerged type). 3. The factors that affected PTV were diameter of implant fixture, location of implant, and elapsed time after implant placement. 4. There was no significant difference between different surface treatments of RBM, smooth surface and ti-unite on PTV and ISQ. 5. In radiographic finding, no saucerization or bone resorption has been detected in implants with ISQ values that were above the average level of each PTV. These higher values had higher bone densities around the implant fixture. Saucerization was observed in the most impants with ISQ values that were below the average level of each PTV. CONCLUSION: There was a correlation between ISQ and PTV. However, each measuring methods had factors influencing the measured values. PTV were less sensitive to marginal bone resorption and influenced with the striking point on an implant to the level of bone. With ISQ, the height of implant from bone level to transducer should be considered.
Bone Density ; Bone Resorption ; Strikes, Employee ; Transducers

Cholesteatoma is a cystic non tumorous lesion of the temporal bone that has the ability to destroy nearby structures by its power to cause bone resorption and as a result, fatal complications prevail. We aimed to conduct a comprehensive review for pathogenesis of acquired cholesteatoma, bone resorption mechanisms, and offer a future vision of this serious disease. We have reviewed different theories for pathogenesis of acquired cholesteatoma including the most relevant and updated ones with special emphasis on the mechanisms of bone resorption through Medline/PubMed research using the keywords ‘aetiopathogenesis, bone resorption, acquired cholesteatoma, temporal bone, and cytokines.’ In order to strengthen our study, we searched the reference lists of identified reviews. Cholesteatoma is a subject of debate among otolaryngologists since it was prescribed firstly. Over many decades, several theories were postulated for aetiopathogenesis of cholesteatoma with a tendency to follow more than one theory to explain the proper nature of that disease. Until now, the mechanism of bone resorption has yet to be more clarified. In the last century, a leap has occurred in the field of biomolecular cholesteatoma research which improved our knowledge about its pathophysiology and bone destructive mechanism. However, surgery is still the only available treatment. We conclude that discovery of new therapeutic choices for cholesteatoma other than surgery by the use of anti-growth, anti-proliferative, apoptotic agents as well as medications that antagonize osteoclastogenesis should be the main concern in the future clinical and experimental research work. Also, searching for predictors of the aggressiveness of cholesteatoma can affect the timing of intervention and prevent occurrence of complications.
Bone Resorption* ; Cholesteatoma* ; Cytokines ; Temporal Bone

The purpose of this study was to investigate the root resorption pattern in incisors in dog under intrusive orthodontic loadings of various magnitude and duration. Intrusive forces were generated by closed coil springs. Force magnitudes were 15-30gm, 50-60gm and 80-110gm. Durations were continuous and intermittent. Intermittent duration was applied at intervals of 12 hours. The readjustment of the force was done every 4 days. The forces were maintained for 30 days. All specimens were decalfied, embedded in paraffin and stained with hematoxylin-eosin stain. Observations were made with light microscope. The following results were obtained; 1. The continuity of root surface was ceased in all, except intermittent forced teeth with 25gm. 2. The root resorptions, cementoclasts and cemental lacunae, were increased around periapical regions and the destructive scope of bone was deeply extended as the exerted orthodontic forces increased. 3. It was inspected that, under the same forces, root resorption and bone destruction were more deeply appeared in the continuously forced teeth than the intermittently forced ones. 4. All of the alveolar bone, showed direct and undermining bone resorptions.
Animals ; Bone Resorption ; Dogs* ; Incisor* ; Osteoclasts ; Paraffin ; Root Resorption* ; Tooth

The purpose of this study was to evaluate root resorption and alveolar bone resorption pattern by jiggling movement. adult cats were divided into 4 groups (6, 12, 18, 24 days). ln test side, mesio-distal jiggling force was applied in right maxillary 1st premolar in 3 days cycle. ln control side, mesial force was applied in left maxillary 1st premolar, Radiographic and histologic observation were formed in 6, 12, 18, 24 days after force application. The results were as follow: Alveolar bone resorption was more severe by jiggling force than by unidirectional force. Root resorption pattern was not different between jiggling force and unidirectional force. Combined pattern of bone resorption and new bone formation appeared in jiggling group. New bone formation began to appear at periapical area of jiggling group after 24 days, because alveolar bone resorption was severe and extrusion resulted.
Adult ; Animals ; Bicuspid* ; Bone Resorption* ; Cats* ; Humans ; Osteogenesis ; Root Resorption*

STATEMENT OF PROBLEM: Stress concentration on the neck bone affects the bone resorption, and finally the implant survival. PURPOSE: In order to examine the stress distribution on the neck bone and prosthesis abutment for implants, decreasing abutment sizes were used. MATERIAL AND METHODS: Axisymmetric models were used to obtain the data required. These models were composed of 4mm implants with 3.4mm and 4mm abutments, 5mm implants with 3.4mm and 5mm abutments and 6mm implants with 3.4mm and 6mm abutments. All abutments were designed to received a 10mm high by 10mm diameter gold crown. Functional element analysis was used to obtain these results using data that consisted of 50 N vertical and 45 degree inclination forces. RESULTS: 1. Changing the diameter of the abutment on the implant affects the effect of the inclination forces more than the effect of the vertical forces. 2. Changing the diameter of the abutment on the implant affects the effect of the inclination forces more than the effect of the vertical forces. 3. Experimentation showed that the larger diameter implants provided a decreased neck bone stress, whereas a larger diameter abutment provided a decrease marginal abutment stress. 4. Experimentation showed that the neck bone and abutment received more stress from inclination forces than vertical forces. CONCLUSIONS: By decreasing the size of the abutment on the implant we were able to diminish neck bone stress.
Bone Resorption ; Crowns ; Neck ; Prostheses and Implants

< 0.05). Also significant difference is on volume resorption on two groups (P < 0.05). CONCLUSION: We found that more bone resorption occurred with iliac(endochondral) bone and when we use intraoral bone, that bone can maintain their vitality for alveolar ridge augmentation.
Alveolar Process* ; Alveolar Ridge Augmentation* ; Bone Resorption*