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.

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.

Evaluation of Bone Change by Digital Subtraction Radiography After Implantation of Tooth ash-plaster Mixture / 대한구강악안면방사선학회지

PURPOSE: To assess the methods for the clinical evaluation of the longitudinal bone changes after implantation of tooth ash-plaster mixture into the defect area of human jaws. MATERIALS AND METHODS: Tooth ash-plaster mixtures were implanted into the defects of 8 human jaws. 48 intraoral radiograms taken with copper step wedge as reference at soon, 1st, 2nd, 4th, and 6th week after implantation of mixture were used. X-ray taking was standardized by using Rinn XCP device customized directly to the individual dentition with resin bite block. The images inputted by Quick scanner were digitized and analyzed by NIH image program. Cu-equivalent values were measured at the implanted sites from the periodic digital images. Analysis was performed by the bidirectional subtraction with color enhancement and the surface plot of resliced contiguous image. The obtained results by the two methods were compared with Cu-equivalent value changes. RESULTS: The average determination coefficient of Cu-equivalent equations was 0.9988 and the coefficient of variation of measured Cu values ranged from 0.08 ~ 0.10. The coefficient of variation of Cu-equivalent values measured at the areas of the mixture and the bone by the conversion equation ranged from 0.06 ~0.09. The analyzed results by the bidirectional subtraction with color enhancement were coincident with the changes of Cu-equivalent values. The surface plot of the resliced contiguous image showed the three dimensional view of the longitudinal bone changes on one image and also coincident with Cu-equivalent value changes after implantation. CONCLUSION: The bidirectional subtraction with color enhancement and the surface plot of the resliced contiguous image was very effective and reasonable to analyze clinically and qualitatively the longitudinal bone change. These methods are expected to be applicable to the non-destructive test in other fields.

A Clinical Study of Congenital Syphilis (in the View of Bone Change) / 대한정형외과학회잡지

Syphilis was known to be generalized disease and it had been decreased until 1960's. But, it has been increased again recently. The author analysed the 22 cases of congenital syphilis which were treated at department of orthopaedic surgery at Ewha Womans University Hospital from Jan. 1979 to July 1983 and the following results were obtained. 1. There were no significant changes of the number of patient by years. 2. Common symptom and sign were hepatosplenomegaly(84%), fever(62%) and skin changes(50%), and pseudoparalysis was observed in one case. 3. Radiologic bone changes were observed in 11 cases (50%) and the following results were obtained: a. Below the two week old, there was relatively low incidence of bone change with 22%. b. There was high incidence of bone change in prematurity with 75%. c. Common features of bone changes were periosteal reaction, osteochondritis and metaphysitis (91%). Pathologic fracture was observed. in one case. 4. Although we have observed the bone changes only in 50% of cases, all the other reports has reported more than 80% and we thought that radiologic bone change would aid the diagnosis of congenital syphilis.