Evaluation of the relationship between the degenerative changes and bone quality of mandibular condyle and articular eminence in temporomandibular disorders by cone beam computed tomography.

OBJECTIVE: To evaluate whether there was a relationship between the degenerative bone changes and bone quality of the mandibular condyle and articular eminence in patients with temporomandibular disorder (TMD). METHODS: The study group consisted of 100 patients with TMD. "Diagnostic Criteria/TMD" was used to identify the pathologies. Degenerative bone changes and bone qualities were detected by cone beam computed tomography; the bone qualities were classified using the Bone Quality Index (BQI) scale. RESULTS: No statistically significant difference was found between degenerative bone changes and bone quality of the temporomandibular joint (TMJ) according to gender (p > 0.05). However, degenerative bone changes were more frequent than articular eminence in the mandibular condyle. BQI Type III was the most common bone quality among all types of degenerative bone changes. DISCUSSION: Although no causality relationship was found between the bone quality and degenerative bone changes, low bone quality was found in TMD patients.

Evaluation of Scapula and Humerus Bone Change after Repair of Small- to Medium-Sized Rotator Cuff Tears: Comparison between Healing and Retear Groups Using Three-Dimensional Computed Tomography.

Background: Rotator cuff tendon retears after rotator cuff repair cause glenohumeral joint instability, which results in changes in the glenoid and humerus head. However, limited data are available on the bone change after repair of small- to medium-sized rotator cuff tears. The aim of this study was to evaluate the difference of glenoid and humerus bone changes between healing and retear groups after repair of small- to medium-sized rotator cuff tears. Methods: Among patients who had arthroscopic repair due to small- to medium-sized rotator cuff tears from January 2009 to January 2017, 49 patients who underwent both preoperative and postoperative (at least 3 years after surgery) shoulder computed tomography were enrolled. Using three-dimensional reconstruction program (3D Slicer) and shape analysis program (SlicerSALT), we compared the occurrence and degree of glenoid bone change, glenoid inclination change, retroversion change, and glenoid center, as well as the degree of humerus head change, between the healing and retear groups. Results: The occurrence of glenoid bone change was significantly more common in the retear group than in the healing group (p = 0.026). The degree of bone change in the 11-1 o'clock axial plane and 10-8 o'clock, 11-7 o'clock, and 12-6 o'clock coronal plane and the degree of glenoid inclination change were significantly larger in the retear group than the healing group (p = 0.026, p = 0.026, p = 0.026, p = 0.026, and p = 0.014, respectively), but the average value of glenoid bone change in the retear group was within the range of 0.14 to 1.01 mm for each plane. The mean humeral head change was 5.69 ± 3.67 mm increase in the retear group and 1.27 ± 2.02 mm increase in the healing group. Compared with the healing group, the retear group showed statistically significantly increased humeral head change (p < 0.001). Conclusions: There was difference in glenoid and humerus bone change between the healing and retear groups at midterm follow-up after repair of small- to medium-sized tears. However, considering the measurement bias, the difference between the two groups was within the measurement error range.

The effect of loading time on marginal bone change of implants immediately placed after extraction: a retrospective study.

BACKGROUND: The purpose of this study is to compare and analyze the treatment outcomes between two groups which are both immediately placed implant cases, one is immediate loading, and the other is conventional loading group. METHODS: Medical records of the patients who underwent implant treatment which were immediately placed after tooth extraction were analyzed. Demographic data were collected and by using periapical or panoramic radiographic image, marginal bone level and distant crestal bone level were measured. Marginal bone change over time was analyzed and compared between immediate loading group and conventional loading group. RESULTS: A total of 71 patients, 112 immediately placed implants after tooth extraction were initially involved. Measuring was done with implants which had not failed (81). 10 implants were had failed and removed. The others were excluded because of follow-up loss, absence of radiographic image, etc. Demographic data were collected, and measured values were averaged at each follow-up and showed in linear graphs. CONCLUSIONS: In case of immediate implantation of dental implant after extraction, loading time could affect marginal bone level or biological width of the implant. Immediate loading group showed 0.92 mm (mean value) more bone loss compared to conventional loading group at bone-implant contact points 24 months after implantation. At distant crestal points, there was no noticeable difference in bone change pattern between two groups.

Transient hypercalcemia followed by hypocalcemia in a preterm infant after maternal magnesium sulfate therapy.

Maternal use of magnesium sulfate has been associated with neonatal hypocalcemia and bone changes. We report the case of a preterm male infant who presented hypercalcemia before developing hypocalcemia after maternal magnesium sulfate therapy. Magnesium sulfate was used for premature rupture of membranes for 32 days, and the patient was delivered at 33 weeks gestation. The cord blood showed ionized calcium 1.54 mmol/L. His serum calcium and magnesium were 11.4 mg/dL and 3.5 mg/dL after birth and fell to 6.6 mg/dL and 2.7 mg/dL at 6 hours, respectively. The intact parathyroid hormone level was 18 pg/mL at 6 h. Radiography showed transverse radiolucent metaphyseal bands of the proximal humerus bone, suggesting disturbance in normal ossification. Transient hypercalcemia before the development of hypocalcemia after maternal magnesium sulfate therapy has not been previously reported. We speculate that maternal long-term magnesium sulfate therapy led to defective ossification and transient hypercalcemia in the offspring. Subsequent hypocalcemia was thought to be due to the inhibition of parathyroid hormone secretion by hypercalcemia and hypermagnesemia.

Does Etelcalcetide reverse myelofibrotic bone changes due to hyperparathyroidism? A case report.

Secondary hyperparathyroidism (SHPT) in dialysis is common. A young man on chronic hemodialysis with SHPT developed pancytopenia with resistant anemia requiring transfusions. A bone marrow biopsy showed grade 3 fibrosis, depleted cellularity, osteosclerosis, and decreased myelopoiesis. He initiated Etelcalcetide 7⋅5 mg 3 times weekly with improvement in SHPT concomitant with near normalization of blood counts. Marrow biopsy at 12 months showed clearance of marrow reticulin, improvement of osteosclerosis and normalization of bone trabeculae, cellularity and myelopoiesis. This is a unique case in which Etelcalcetide treatment is comparable to parathyroidectomy on SHPT and is associated with significant improvement in severe myelofibrosis.

Alveolar bone response to maxillary incisor retraction using stable skeletal structures as a reference.

OBJECTIVES: To evaluate alveolar bone change in relation to root position change after maxillary incisor retraction via cone-beam computed tomography (CBCT) using stable skeletal structures as a reference. MATERIALS AND METHODS: A total of 17 subjects (age 24.7 ± 4.4 years) who required retraction of the maxillary incisors were included. Labial and palatal alveolar bone changes and root change were assessed from preretraction and 3 months postretraction CBCT images. The reference planes were based on stable skeletal structures. The Kruskal-Wallis test and Wilcoxon signed-rank test were used to compare changes within and between groups, as appropriate. Spearman rank correlations were used to identify the parameters that correlated with alveolar bone change. The significance level was set at .05. RESULTS: The labial alveolar bone change after maxillary incisor retraction was statistically significant (P < .05), and the bone remodeling/tooth movement (B/T) ratio was 1:1. However, the palatal bone remained unchanged (P > .05). The change in inclination was significantly related to labial alveolar bone change. CONCLUSIONS: Using stable skeletal structures as a reference, the change in labial alveolar bone followed tooth movement in an almost 1:1 B/T ratio. Palatal alveolar bone did not remodel following maxillary incisor retraction. The change in inclination was associated with alveolar bone change.

Relations between anterior disc displacement and maxillomandibular morphology in skeletal anterior open bite with changes to the mandibular condyle.

In this study we investigated the relation between anterior disc displacement (ADD) and maxillomandibular morphology in skeletal anterior open bite with changes to the mandibular condyle. Thirty female patients (60 joints) with both conditions were evaluated. Magnetic resonance imaging of the temporomandibular joint (TMJ) was used to diagnose both ADD and changes to the mandibular condyle (erosion, osteophyte, and deformity). The relations among ADD, changes to the mandibular condyle, and maxillomandibular morphology were examined statistically. Changes to the mandibular condyle had a higher score than sym anterior open bite, the deviated side in asymmetric anterior open bite, and the non-deviated side. The score for disc displacement on the non-deviated side was lower than both the sym side and the deviated side. Unilateral changes to the mandibular condyle and unilateral disc displacement were not apparent in sym anterior open bite, but a unilateral non-displaced disc was seen only on the asymmetric side. Mandibular condylar changes were significantly more common on the deviated, than on the non-deviated, side. The SNB angle was significantly smaller, and the ANB, GZN, and SN-mandibular plane angles were significantly larger in sym anterior open bite. Overjet, ANB angle, GZN angle, and SN-MP angle were significantly larger, and the SNB angle was significantly smaller, in the presence of ADD without reduction and mandibular condylar deformity. We conclude that the prevalence of ADD without reduction and changes to the mandibular condyle were related to mandibular asymmetry and mandibular morphology in anterior open bite. This retrospective study suggests that ADD without reduction and mandibular condylar bone changes may be related to the progression of skeletal class II open bite and mandibular asymmetry in cases of skeletal open bite.

Forehead deformities after tissue expansion: Retrospective analysis and recommendations.

BACKGROUND: Tissue expanders can lead to bone deformity as well as bone resorption. Not all changes in the cranial bone can be completely normalised after tissue expander extraction. This study aimed to investigate the potential factors for persistent forehead deformities after tissue expansion. PATIENTS AND METHODS: Cases of forehead tissue expansion performed from 2011 to 2015 were retrospectively reviewed. Demographic and clinical data were collected. Two plastic surgeons (Y.Q. and C.Q.) evaluated changes in the forehead by comparing preoperative and most recent postoperative photographs. The Fisher exact, chi-square and Student t tests, and univariate and multivariate logistic regression analyses were performed in this study. RESULTS: Sixty-seven patients underwent forehead expanded flap reconstructions and continuous follow-ups were done in the outpatient service. The mean duration of the follow-ups after expander removal was 33.86 months. Overall, 28 (41.8%) patients had forehead changes. Age, sex, indications for tissue expansion and follow-up time were not associated with forehead changes. There were significant differences in the total injection volume and expansion period between patients with forehead changes (41.8%) and those without (58.2%). No significant negative correlation was found between the duration of pressure bandage usage post-operatively and the occurrence of forehead changes. CONCLUSIONS: Our recommendations for performing tissue expansion in the skull area are as follows: (1) always choose expanders with the largest base dimension; (2) perform tissue expansion as quickly as possible and (3) do not cause overexpansion. In addition, there was no proven benefit of using pressure bandages when skeletal changes occurred.

Bone change after surgical treatment of mucous cyst at the interphalangeal joint of the great toe in a patient with rheumatoid arthritis.

Digital mucous cysts are a type of benign cysts of the digits, typically located at the distal interphalangeal joints or in the proximal nail fold, which usually occur on the hands. The diagnosis of digital mucous cysts is relatively easy because of its light-transmitting property, but the treatment is often difficult because of complications including recurrence, infection, diminished range of motion, and nail deformity. We report a case of rheumatoid arthritis (RA) showing good course after surgical treatment of mucous cyst at the interphalangeal joint of the great toe. In a case of RA, combination of synovectomy with surgical treatment of mucous cyst might be effective.

Evaluation of changes in the maxillary alveolar bone after incisor intrusion.

OBJECTIVE: This study was performed to investigate the changes in alveolar bone after maxillary incisor intrusion and to determine the related factors in deep-bite patients. METHODS: Fifty maxillary central incisors of 25 patients were evaluated retrospectively. The maxillary incisors in Group I (12 patients; mean age, 16.51 ± 1.32 years) were intruded with a base-arch, while those in Group II (13 patients; mean age, 17.47 ± 2.71 years) were intruded with miniscrews. Changes in the alveolar envelope were assessed using pre-intrusion and post-intrusion cone-beam computed tomography images. Labial, palatal, and total bone thicknesses were evaluated at the crestal (3 mm), midroot (6 mm), and apical (9 mm) levels. Buccal and palatal alveolar crestal height, buccal bone height, and the prevalence of dehiscence were evaluated. Two-way repeated measure ANOVA was used to determine the significance of the changes. Pearson's correlation coefficient analysis was performed to assess the relationship between dental and alveolar bone measurement changes. RESULTS: Upper incisor inclination and intrusion changes were significantly greater in Group II than in Group I. With treatment, the alveolar bone thickness at the labial bone thickness (LBT, 3 and 6 mm) decreased significantly in Group II (p < 0.001) as compared to Group I. The LBT change at 3 mm was strongly and positively correlated with the amount of upper incisor intrusion (r = 0.539; p = 0.005). CONCLUSIONS: Change in the labial inclination and the amount of intrusion should be considered during upper incisor intrusion, as these factors increase the risk of alveolar bone loss.

The influence of bone graft procedures on primary stability and bone change of implants placed in fresh extraction sockets.

BACKGROUND: This study was to evaluate the effect of bone graft procedure on the primary stability of implants installed in fresh sockets and assess the vertical alteration of peri-implant bone radiographically. METHODS: Twenty-three implants were inserted in 18 patients immediately after tooth extraction. The horizontal gap between the implant and bony walls of the extraction socket was grafted with xenografts. The implant stability before and after graft procedure was measured by Osstell Mentor as implant stability quotient before bone graft (ISQ bbg) and implant stability quotient after bone graft (ISQ abg). Peri-apical radiographs were taken to measure peri-implant bone change immediately after implant surgery and 12 months after implant placement. Data were analyzed by independent t test; the relationships between stability parameters (insertion torque value (ITV), ISQ abg, and ISQ bbg) and peri-implant bone changes were analyzed according to Pearson correlation coefficients. RESULTS: The increase of ISQ in low primary stability group (LPSG) was 6.87 ± 3.62, which was significantly higher than the increase in high primary stability group (HPSG). A significant correlation between ITV and ISQ bbg (R = 0.606, P = 0.002) was found; however, age and peri-implant bone change were not found significantly related to implant stability parameters. It was presented that there were no significant peri-implant bone changes at 1 year after bone graft surgery. CONCLUSIONS: Bone graft procedure is beneficial for increasing the primary stability of immediately placed implants, especially when the ISQ of implants is below 65 and that bone grafts have some effects on peri-implant bone maintenance.

Evaluation of changes in the maxillary alveolar bone after incisor intrusion / 대한치과교정학회지

OBJECTIVE: This study was performed to investigate the changes in alveolar bone after maxillary incisor intrusion and to determine the related factors in deep-bite patients. METHODS: Fifty maxillary central incisors of 25 patients were evaluated retrospectively. The maxillary incisors in Group I (12 patients; mean age, 16.51 ± 1.32 years) were intruded with a base-arch, while those in Group II (13 patients; mean age, 17.47 ± 2.71 years) were intruded with miniscrews. Changes in the alveolar envelope were assessed using pre-intrusion and post-intrusion cone-beam computed tomography images. Labial, palatal, and total bone thicknesses were evaluated at the crestal (3 mm), midroot (6 mm), and apical (9 mm) levels. Buccal and palatal alveolar crestal height, buccal bone height, and the prevalence of dehiscence were evaluated. Two-way repeated measure ANOVA was used to determine the significance of the changes. Pearson's correlation coefficient analysis was performed to assess the relationship between dental and alveolar bone measurement changes. RESULTS: Upper incisor inclination and intrusion changes were significantly greater in Group II than in Group I. With treatment, the alveolar bone thickness at the labial bone thickness (LBT, 3 and 6 mm) decreased significantly in Group II (p < 0.001) as compared to Group I. The LBT change at 3 mm was strongly and positively correlated with the amount of upper incisor intrusion (r = 0.539; p = 0.005). CONCLUSIONS: Change in the labial inclination and the amount of intrusion should be considered during upper incisor intrusion, as these factors increase the risk of alveolar bone loss.

The influence of bone graft procedures on primary stability and bone change of implants placed in fresh extraction sockets / 대한악안면성형재건외과학회지

BACKGROUND: This study was to evaluate the effect of bone graft procedure on the primary stability of implants installed in fresh sockets and assess the vertical alteration of peri-implant bone radiographically. METHODS: Twenty-three implants were inserted in 18 patients immediately after tooth extraction. The horizontal gap between the implant and bony walls of the extraction socket was grafted with xenografts. The implant stability before and after graft procedure was measured by Osstell Mentor as implant stability quotient before bone graft (ISQ bbg) and implant stability quotient after bone graft (ISQ abg). Peri-apical radiographs were taken to measure peri-implant bone change immediately after implant surgery and 12 months after implant placement. Data were analyzed by independent t test; the relationships between stability parameters (insertion torque value (ITV), ISQ abg, and ISQ bbg) and peri-implant bone changes were analyzed according to Pearson correlation coefficients. RESULTS: The increase of ISQ in low primary stability group (LPSG) was 6.87 ± 3.62, which was significantly higher than the increase in high primary stability group (HPSG). A significant correlation between ITV and ISQ bbg (R = 0.606, P = 0.002) was found; however, age and peri-implant bone change were not found significantly related to implant stability parameters. It was presented that there were no significant peri-implant bone changes at 1 year after bone graft surgery. CONCLUSIONS: Bone graft procedure is beneficial for increasing the primary stability of immediately placed implants, especially when the ISQ of implants is below 65 and that bone grafts have some effects on peri-implant bone maintenance.

Cambios óseos asociados a discopatías / Bone changes associated to disc disease

La resonancia magnética ha proporcionado nuevas oportunidades de hallazgos patológicos disco-vertebrales. No se considera importante en pacientes asintomáticos, pero resulta una aparición significativa en la degeneración vertebral de causa discal que, según la intensidad de las señales, fue clasificada por Modic como secuencias T1 y T2. Aunque existe controversia en cuanto a la discopatía, la resonancia es la única prueba disponible para correlacionar los descubrimientos imagenológicos con los síntomas del afectado.

The magnetic resonance has provided new opportunities of disk-vertebral pathological findings. It is not considered important in asymptomatic patients, but it is a significant emergence in the vertebral degeneration of discal cause that, according to the intensity of the signs, it was classified by Modic as sequences T1 and T2. Although controversy exists as for the disc disease, the resonance is the only available test to correlate the imagenologic findings with the symptoms of the patient affected.

Evaluation of temporomandibular joint disc displacement as a risk factor for osteoarthrosis.

Temporomandibular joint (TMJ) disc displacement is a clinical sign often found in patients with temporomandibular disorders (TMDs) and associated with TMJ osteoarthrosis. Osteoarthrosis is a degenerative joint disease that may be associated with pain and functional disability. The aim of this study was to evaluate the odds ratio (OR) of joints with disc displacement presenting osteoarthrosis via magnetic resonance imaging (MRI) analysis. In total, 224 TMJ images from patients with signs and symptoms of a TMD were evaluated. The OR, a measure of association, was used to calculate the likelihood of TMJ disc displacement (with or without reduction) with osteoarthrosis. Joints with anterior disc displacement with reduction (ADDwR) and anterior disc displacement without reduction (ADDwoR) were 2.73- and 8.25-times, respectively, more likely to have osteoarthrosis. A nine-times greater likelihood of osteophyte occurrence was observed in cases of ADDwoR, whereas a lower OR for their occurrence (OR 2.96) was observed in cases of ADDwR. The significant OR of joints with disc displacement presenting osteoarthrosis, particularly in cases of ADDwoR, emphasizes the importance of accurate assessment of changes in disc position, which may be associated with other painful and functional disorders of the TMJ.

Marginal bone response of implants with platform switching and non-platform switching abutments in posterior healed sites: a 1-year prospective study.

OBJECTIVES: This 1-year prospective study evaluated the implant success rate and marginal bone response of non-submerged implants with platform and non-platform switching abutments in posterior healed sites. MATERIAL AND METHODS: Nineteen patients (9 male, 10 female) with posterior partially edentulous spaces, between the ages of 23 and 76 (mean = 55.4 years), were included in this study. A total of 30 implants (15 implants restored with platform switching [PS] abutments [control] and 15 implants restored with non-platform switching [NPS] abutments [test]) were assigned between two groups using a randomization procedure. The definitive abutments with conical connections were placed at the time of surgery, and the definitive restorations were placed at 3 months. All patients were evaluated clinically and radiographically using standardized radiographs at time of implant placement (0), 3, 6 and 12 months after implant placement. Data were analyzed using Friedman test with post hoc pairwise comparisons, Mann-Whitney U-test, and Pearson's chi-square test at the significance level of α = 0.05. RESULTS: At 12 months, all 30 implants remained osseointegrated corresponding to a 100% success rate. The overall mean marginal bone level change at 12 months was -0.04 ± 0.08 mm for PS group and -0.19 ± 0.16 mm for NPS group. Statistically significant difference in the marginal bone level change was observed between groups at 0 to 12 months and 3 to 12 months (P < 0.05). CONCLUSIONS: This 1-year randomized control study suggests that when a conical implant-abutment connection is present, similar peri-implant tissue responses can be achieved with platform switching and non-platform switching abutments.

Percutaneous sclerotherapy for venous malformations in the extremities: clinical outcomes and predictors of patient satisfaction.

The purpose of this study is to retrospectively evaluate the clinical outcomes and to identify the predictors ofpatient satisfaction after percutaneous sclerotherapy for venous malformations (VMs) in the extremities. A totalof 48 patients with VMs in the extremities over 10 years of age underwent sclerotherapy to relieve symptoms, such as pain, swelling, functional limitations, and cosmetic problems. Self-assessment questionnaires were sentto rate the degree of symptom improvement and level of satisfaction. Clinical and imaging data from medicalrecords were analyzed to obtain information about VMs and sclerotherapy. The predictors for patientsatisfaction were determined by univariate and multivariate analysis of clinical variables. Forty patients (meanage, 28.2 years; range, 11-69 years) responded to the survey. Sixteen patients had VMs in the upper extremities, and 24 patients had VMs in the lower extremities. In 12 patients (30%), adjacent bone change was seen. After amean of 2.6 (range 1-10) sclerotherapy sessions, good response to pain, swelling, dysfunction, and cosmeticproblems was obtained in 83%, 74%, 79%, and 50% of patients, respectively. Thirty-two patients (80%) weresatisfied with their outcomes. On univariate analysis, absence of adjacent bone change, maximum diameter (<6.7 cm), and number of sclerotherapy sessions (<3) were significantly associated with patient satisfaction.Multivariate analysis revealed absence of adjacent bone change (odds ratio, 7.56; 95% confidence interval, 1.02-55.8) as an independent predictor for satisfaction. Thus, adjacent bone change significantly portended adissatisfied patient. In conclusion, percutaneous sclerotherapy was effective to relieve symptoms of VMs in theextremities, and most patients were satisfied with the outcomes. However, adjacent bone change was asignificant predictor of patient dissatisfaction.

A retrospective study of implant-abutment connections on crestal bone level.

This study compared the effects of external hex, internal octagon, and internal Morse taper implant-abutment connections on the peri-implant bone level before and after the occlusal loading of dental implants. Periapical radiographs of 103 implants (63 patients) placed between 2002 and 2010 were collected, digitized, standardized, and classified into groups based on the type of implant-abutment connection. These radiographs were then analyzed with image-processing software to measure the peri-implant crestal bone change during the healing phase (4 months after implant placement) and at loading phases 1 and 2 (3 and 6 months after occlusal loading, respectively). A generalized estimating equation method was employed for statistical analysis. The amount of peri-implant crestal bone change differed significantly among all time-phase pairs for all 3 types of implant-abutment connection, being greater in the healing phase than in loading phase 1 or 2. However, the peri-implant crestal bone change did not differ significantly among the 3 types of implant-abutment connections during the healing phase, loading phase 1, or loading phase 2. This retrospective clinical study reveals that the design of the implant-abutment connection appears to have no significant impact on short-term peri-implant crestal bone change.

Bone change of mandibular condyle using cone beam computed tomography / 대한구강악안면방사선학회지

PURPOSE: To assess bone changes of mandibular condyle using cone beam computed tomography (CBCT) in temporomandibular disorder (TMD) patients. MATERIALS AND METHODS: 314 temporomandibular joints (TMJs) images of 163 TMD patients were examined at the Department of Oral and Maxillofacial Radiology, Chonbuk National University. The images were obtained by PSR9000N (Asahi Roentgen Co., Japan) and reconstructed by using Asahivision software (Asahi Roentgen Co., Japan). The CBCT images were examined three times with four weeks interval by three radiologists. Bone changes of mandibular condyle such as flattening, sclerosis, erosion and osteophyte formation were observed in sagittal, axial, coronal and 3 dimensional images of the mandibular condyle. The statistical analysis was performed using SPSS 12.0. Intra- and interobserver agreement were performed by 3 radiologists without the knowledge of clinical information. RESULTS: Osteophyte (2.9%) was found more frequently on anterior surface of the mandibular condyle. Erosion (31.8%) was found more frequently on anterior and medial surfaces of the mandibular condyle. The intraobserver agreement was good to excellent (k=0.78-0.84), but interobserver agreement was fair (k=0.45). CONCLUSION: CBCT can provide high qualified images of bone changes of the TMJ with axial, coronal and 3 dimensional images.

Alveolar bone changes around the natural teeth opposing the posterior implants in mandible / 대한치과보철학회지

STATEMENT OF PROBLEM: Alteration of tooth function is assumed to be changed by stress/strain on the adjacent alveolar bone, producing changes in morphology similar to those described for other load-bearing bones. When teeth are removed, opposing teeth will not be functioned. When edentulous area is restored by implant prostheses, opposing teeth will be received physiologic mechanical stimuli. PURPOSE: The aim of this study was to evaluate the bone changes around the teeth opposing implant restoration installed mandibular posterior area. MATERIAL AND METHOD: Eight patients who had mandibular posterior edentulous area were treated with implants. Radiographs of the opposing teeth were taken at implant prostheses delivery(baseline), 3 months, and 6 months later. Customized film holding device was fabricated to standardize the projection geometry for serial radiographs of opposing teeth. Direct digital image was obtained. Gray values of region of interest at each digital image were measured and compared according to time lapse. Repeated measured analysis of variance and post-hoc Scheffe's test were performed at the 95% significance level. RESULTS: Alveolar bone changes around the natural teeth opposing the posterior implant in mandible showed statistically significant difference compared to control group(P0.05). There were no statistically significant differences of alveolar bone changes among mesial-crestal group, mesial-middle group, distal-crestal group, distal-middle group, and control group(P>0.05). CONCLUSION: Alveolar bone around the natural teeth opposing the implant prosthesis showed gradual bony apposition.