RESUMEN
Proper and accurate diagnosis is the key to successful treatment in onhodontia. Although several angular and linear measurements were proposed to provide an accurate assessment of sagittal skeletal jaw relationships, most of them were deficient in either validity or reproducibility. Recently a new cephalometric measurement named Beta angle was said to overcome the drawback of other measurements in sagittal skeletal jaw relationships assessment. Accuracy of Beta angle was studied in the present research regarding its validity and reproducibility. Its accuracy was confirmed and consequently mean values were computed for a group of Egyptian school children having different sagittal skeletal jaw relationships, Egyptian children [9-10 years] with Beta angle 32° +/- 2.5 have a class J skeletal pattern and with Beta angle 27° +/- 1.9, have a class JI skeletal pattern while with Beta angle 43.1° +/- 3,4 have a class III skeletal pattern. There was no sex difference regarding the Beta angle. Beta angle did not specify the affected jaw in class II and Class III patterns so additional measurements will be needed
RESUMEN
This study was undertaken to assess residual ridge resorption in the edentulous maxilla in patients with mandibular overdenture supported by four implants with two different designs using an x-ray soft-ware on digitized panoramic and lateral cephalometric radiographs. It consisted of twelve healthy male patients with mean age 58-66 years. The definitive treatment plan for the patients included fabrication of complete maxillary dentures and mandibular complete overdentures supported by four implants each, they were divided into 2 groups, Group I [OD]: Patients received a mandibular overdenture supported by four implants after attaching their dome shaped abutments and Group II [BOD]: Patients received a mandibular overdenture supported by a bar connected to the four implants. Standardized panoramic radiographs taken subsequent to loading and at annual recall visits for up to 3 years were measured for alveolar bone loss in the maxilla. Bone areas and reference areas were measured with an x-ray soft-ware, The proportional value between both was expressed as a ratio [R]. Bone loss was expressed as a relative change in R between two time points. Differences in resorption in the anterior and posterior parts of the maxilla were investigated. Lateral cephalometric radiographs were also taken to assess bone resorption in the anterior area. Group I [OD] showed more alveolar bone loss in the anterior area compared to group II [BOD] throughout the study period with no statistical significance difference [P>0.05] [5.1%-6.25%; 4.21%-5.1% respectively]. Posterior alveolar bone loss was higher in group I compared to group II with no statistical significance difference [P>0.05] [3.9%-4.7%; 2.2%-2.9% respectively]. In both groups, anterior area showed more alveolar bone loss when compared to posterior area and was statistically significant different [P<0,05]. In conclusion, the insertion of four implants to support a mandibular overdenture opposing a maxillary complete denture was a successful treatment modality that resulted in minimal bone loss in the maxilla through out the study period. Furthermore, when splinting the four implant with a bar, better results are achieved in terms of denture support, stability and less bone loss in the opposing jaw. Comparison of the bone area with the reference area on serial panoramic radiographs appears suitable for the assessment of residual ridge resorption in the maxilla
RESUMEN
The use of SPECT in the assessment of post-traumatic changes in the temporomandibular joint has been infrequent, as compared with other radiographic techniques. SPECT have the potential to detect active bone remodeling whereas corresponding radiographs may be normal or document past structural change in the joint. Thorough examination of TMJ especially after trauma saves the patient from neglected treatment and further complications. This study was conducted on 24 joints of 12 adult patients [10 males, 2 females], who undergone 3dimensional computerized tomography [3D-CT] to confirm and define the location and direction of the fractured segments then they were send for treatment. After one year they were sent to do MRI and SPECT examination. The results of this study revealed high percentage [66.6%] of displaced discs at the traumatized joints, also a considerable percentage of displaced discs in the unaffected joints. Small percentage [8.3%] of the affected joints showed disc deformities. [91.6%] of affected joints examined by SPECT were positive and gave high ratios of uptake, although 3 joints showed normal position and morphology on MR images. A considerable percentage [58.3%] of unaffected joints gave positive results on SPECT. Similarly five joints of them were normal on MRI. Sensitivity and specificity of SPECT was 83% and 58% respectively. There was a statistical significance difference regarding count ratio of the affected and unaffected joints [P < 0.05]. It was concluded that 3D-CT technique produced images that allowed an improvement in the visualization of affected structures. The clinician should not rely on results of MRI alone specially if they do not correlate with clinical symptoms, but should consider another confirmatory technique which is more sensitive for detecting and staging osseous diseases of the TMJ related to disc dysfunction. SPECT can detect altered joint mechanics that are not evident at functionally anatomic MR imaging.
RESUMEN
The accurate staging of patients prior to embarking on treatment for squamous cell carcinoma of the head and neck is essential. The aim of this prospective study is to compare the diagnostic accuracy of computed tomography [CT] and magnetic resonance imaging [MRI] in tumor staging of squamous cell carcinoma of the oral cavity. The value of magnetic resonance imaging [MRI] and computerized tomography [CT] in preoperative tumor T-staging was assessed prospectively in 24 patients with squamous cell carcinoma of the oral cavity. In each case, the MRI and CT findings were compared with post-operative histopathologic staging. The results of this study reveled that there were no statistical significance difference regarding tumor detection [although MRI was better than CT], bone invasion, lymph node involvement, and breaking down of the lesion [P>0.05]. MRI was better than CT regarding soft tissue extension and tumor margin detection and there were a high statistical significance difference [P<0.05]. For tumor staging, MR scanning is overall more accurate than CT. 90% of the cases were correctly staged with pathological findings compared to 80% on CT examination. Conclusion: If degraded images and Tl tumors are excluded, the techniques are comparable. MRI should also be used instead of CT when dental fillings obscure the region of interest. If there are good MRI facilities and an experienced team available, MRI can be used before CT. The ability of MRI to give an axial, coronal, and sagittal image allows an exact pre-operative view of tumor spread and assessment of infiltration into adjacent structures. MRI was superior to CT in soft tissue extension and tumor margin detection
RESUMEN
Modern radiological equipment for measuring bone mineral density [BMD] and bone mass in the jaws is expensive and is beyond the means and expertise of general dental practioners. It would be worthwhile if the changes of jaw hone demonstrated with equipment that is more readily available, such as panoramic radiography. Therefore, this study attempted to assess the diagnostic validity of panoramic radiomorphometric indices of the mandible in pre-menopausal and postmenopausal egyptian female patients and their potential use in identifying skeletal osteopenia or osteoporosis. Four indices, cortical thickness below the mental foramen [MI], panoramic mandibular index [PMI], mandibular cortical index [MCI] and antigonial index [Al] were measured on 600 panoramic radiographs of egyptian female patients which were divided into 2 groups, i- Group I: consisted of 300 dental panoramic radiographs [DPRs] of females aged between 25-44 years [premenopausal group]. ii- Group II: consisted of 300 dental panoramic radiographs [DPRs] of females aged between 45-65 years [post-menopausal group]. All quantitative indices showed a statistical significance difference between grout] I and II [P< 0.001]. In conclusion, although there are some limitations of using these indices panoramic radiography could be reliable in screening for osteoporosis. Ethnic background should be considered when comparing results of different populations