Must radiation dose for CT of the maxilla and mandible be higher than that for conventional panoramic radiography?

We evaluated the feasibility of performing preoperative spiral CT of the maxilla and mandible with a radiation dose similar to that used for conventional panoramic radiography. The skin entrance doses of radiation used for spiral CT (collimation, 1 mm; pitch, 2; tube voltage, 80 kV; tube current, 40 mA) and for panoramic radiography (75 kV, 8 mA, 15 seconds) were measured in one patient by using thermoluminescent dosimeter chips. Results were 0.56 +/- 0.06 mGy for CT and 0.59 +/- 0.04 mGy for radiography. Image quality was adequate for preoperative implant planning. Spiral CT of the mandible and maxilla may therefore be feasible with a radiation dose of similar magnitude as that used for conventional panoramic radiography.     

Osteosarcoma of the mandible

We describe a case of osteosarcoma of the mandible presenting as a soft tissue mass associated with an enlargement of the mandibular canal at imaging work-up. Radiographic, isotopic, CT and MR features are reported.     

Large radiolucent lesion of the maxilla

In this cross-sectional study we investigated the effect of compressive and tensile forces applied on the proximal femur during weight-bearing activities. Ninety-seven men (29.9 +/- 1.7 years) were divided into two groups: 69 exercisers who had practiced regular high-impact weight-bearing activities for at least 5 years and 28 controls who had been sedentary for at least 5 years. The maximum isometric hip abduction strength was measured. The bone mineral density (BMD) of the femoral neck and the greater trochanter was assessed using dual-energy X-ray absorptiometry (DXA). Controls were considered as the reference population to calculate the Z score. Mean BMD values of the femoral neck were 0.97 g/cm2 on both sides in the exercisers and 0.83 g/cm2 on the right side and 0.84 g/cm2 on the left side in the controls. Mean BMD values of the greater trochanter were 0.86 g/cm2 on the right side and 0.87 g/cm2 on the left side in the exercisers, 0.73 g/cm2 on the right side and 0.72 g/cm2 on the left side in the controls. The BMD was significantly higher in exercisers at both trochanteric and cervical sites (P = 0. 0001). Both left and right hip abduction strength was significantly greater in the exercisers than in the controls (P < 0.05) and was positively correlated to cervical and trochanteric BMD (P < 0.01). In the exerciser group, the trochanteric Z score was higher than the cervical Z score at both right (P = 0.06) and left (P = 0.002) sides. Therefore, the proximal femoral BMD was significantly greater in exercised subjects as compared with sedentary controls. The difference was observed at the level of both the femoral neck (where it is known anatomically that only compressive gravitational forces are exerted) and the greater trochanter (where it is known that tensile forces are exerted). This result suggests the participation of both compressive and tensile forces in the mechanisms by which exercise influences bone trophicity.     

Brown tumor of the mandible

OBJECTIVE: To investigate the inhibitory effect of IL-10 on inflammatory reaction in rat mesangial cells (rMC). METHODS: Cell proliferation was tested by 3H-thymidine uptake and absolute cell counts. The production of IL-1 and TNF alpha by rMC was assessed by bioactivity assay and their gene expression by Northern blot hybridization. The expression of intercellular adhesion molecule-1 (ICAM-1) on rMC was determined by ELISA. RESULTS: IL-10 (25 ng/ml) inhibited 5% FCS and IL-1 induced cell proliferation by 39% and 52% respectively. It also suppressed the production of IL-1 and TNF alpha bioactivity by rMC by 48% and 68%, which was consistent with the decline of IL-1 and TNF alpha gene expression. The IL-1-induced expression of ICAM-1 on surface of rMC was attenuated by IL-10 treatment. CONCLUSION: Our data suggest that IL-10 may be an inhibitory cytokine in regulation of inflammatory reaction in glomerular mesangial cells.     

Ameloblastic carcinoma of the mandible

BACKGROUND: Ameloblastic carcinoma is a rare, aggressive odontogenic neoplasm of the jaws in which the epithelial cells exhibit cytologic features of recognizable ameloblastoma and malignancy. Cases with metastasis have been infrequently reported. METHODS: A case of a 64-year-old white woman with mandibular ameloblastic carcinoma with documented distant metastasis is presented. The patient's presenting symptoms included facial asymmetry of the right jaw over 2 months and the development of moderate trismus. Clinical manifestations, pathology, treatment, and biologic behavior are discussed. The nomenclature and classification of odontogenic carcinomas are reviewed, including entities that should be considered in the differential diagnosis. RESULTS: The patient underwent surgical resection consisting of mandibulectomy, parotidectomy, and modified radical neck dissection followed by radiation to both necks and tumor bed. Postsurgically, the patient developed pulmonary metastasis at 11 months and expired with widespread metastatic disease at 28 months. CONCLUSIONS: This case demonstrated an unusual behavior pattern in that local recurrence and regional metastasis did not occur. Distant metastasis occurred despite apparent adequate control of the primary mandibular tumor. The ameloblastic carcinoma is a highly malignant neoplasm which requires aggressive therapy. Prognosis is poor. Further reporting of ameloblastic carcinoma is encouraged.     

Giant cell reparative granuloma of the maxilla

Giant cell reparative granuloma (GCRG) is a rare nonneoplastic proliferative lesion of unknown etiology. It most commonly occurs in the mandible, but also occurs in other bones of the facial skeleton and cranial vault. Two cases of GCRG arising from the maxilla are presented. Histological and radiological features, and the pertinent literature on the subject are reviewed.     

Cross-sectional area of the mandible

PURPOSE: The anatomy of the mandible was examined by measuring the cross-sectional area (CSA) of multiple regions of 10 fully dentulous hemimandibles to provide a better understanding of regional structural differences that may have implications regarding biomechanical strength, surgical reconstruction, and fracture site frequency. MATERIALS AND METHODS: Fifteen cuts from the condyle to the symphysis were made of each hemimandible (n = 150 cuts). A Zeiss Videoplan digitizer was used to determine the CSA. RESULTS: The total CSA through the condyle was greater than the CSA through the condylar neck. The CSA through the ramus exceeded that of the condylar neck. The total CSA of the midramus was significantly greater than that of the upper ramus. The total CSA at the body, parasymphysis, and symphysis was significantly greater than at the mid-angle. The total CSA of the cortex increased anteriorly; these differences become significant between the condylar neck and the body, parasymphysis, and symphysis. The total CSA, and the CSA of the cortex and spongiosa, remained relatively constant from the inferior angle anteriorly. CONCLUSIONS: Significant differences exist in the CSA at different points, with an increase in the total, cortical, and spongiosal CSA anteriorly from the condylar neck to the angle. The total CSA and the CSA of the cortex and spongiosa remain relatively constant anterior to the inferior angle. These data suggest that bony CSA alone is not the sole factor in determining fracture site frequency.     

Therapy of the severely atrophied mandible

By means of a questionnaire with a complementary interview and physical examination, the site and nature of sports injuries were investigated over a 10-year period (1977-1987) in 97 elderly athletes (age range 70-81 years). The athletes were still active in training and competition with a mean competition background of 15 years. Of the subjects studied 30 were strength/power athletes and the remaining 67 endurance athletes. Altogether we found 273 sports-related injuries (169 acute and 104 overuse injuries). Of the injuries 75% had occurred in the lower extremities. The most commonly injured part of the body was the knee (20% of all cases). Sprains of the thigh and knee were the most frequent types of acute injury. In most cases the treatment prescribed was rest and physiotherapy. Surgery had been necessary in ten cases (3.7% of all injuries). Mean withdrawal from normal sporting activity had, in general, been 2-3 weeks. Of the injuries, one in five had, however, lasted over several years causing some disability during sporting activities.     

Fractures of the mandible in children

A review of 219 fractures of the mandible in children treated from 1960 through 1970 has been presented. The etiology, location, and treatment required were considered in relation to patient's age and dentition. The most common form of treatment was closed reduction and intermaxillary fixation.     

Carcinoma of the colon with mandible and liver metastases

The aortic rupture in the pulmonary parenchyma or the bronchi rarely results in an haemoptysis. It means in most of the cases the rupture of an aortica aneurysm. We relate the observation of a aorto-bronchial fistula from a tuberculosa origin in an old woman case. Although the tuberculosa aortitis is becoming very exceptional, it still remains the cause of aorta rupture, with the formation of a false aneurysm which is rapidly fatal and so, it is important to search for it before any capricious haemoptysis.     

Cranial fasciitis of the orbit and maxilla: extensive resection and reconstruction

A case of cranial fasciitis of childhood is described. This extensive cranio-orbital-facial lesion in a 3-month-old baby necessitated radical resection and immediate orbital and anterior cranial fossa reconstruction. The particular requirements of reconstruction in the infant are emphasised.     

Preimplant guided bone regeneration in the anterior maxilla

Guided bone regeneration is a clinical procedure aimed at promoting bone formation at sites where there is severe bone loss. The purpose of this article was to demonstrate reconstruction of deformations of the alveolar process resulting from traumatic injuries to maxillary incisor teeth by guided bone regeneration procedures followed by insertion of dental implants. In both cases, submembranous space-making was stabilized by human demineralized freeze-dried bone. Implant insertion at the sites of bone augmentation resulted in successful restorations. Histologic examination of biopsy samples from the submembranous hard tissue revealed particles of demineralized freeze-dried bone allografts partially surrounded by uninflamed connective tissue and by vital bone adjacent and adhered to the demineralized freeze-dried bone allograft particles.     

Biomechanics of torsion in the human mandible

Staff competence in the application of behavioral techniques is critical to improve quality of life for persons with a developmental disability. Development of efficient staff training programs is therefore of great importance. This paper describes some of the procedures most frequently used in staff training research. Research in this area is reviewed in relation to client outcomes as a function of staff training, maintenance of staff skills, and transfer of staff skills across settings, clients, and programs. Current concerns and further improvements in behavioural techniques, acquisitional strategies, and assessment are discussed.     

Transformation techniques for the fibula of the mandible

Parents of elementary school children in rural east-central Texas were surveyed about their attitudes toward and knowledge of Comprehensive School Health Education. Data indicated widespread support for health education compared to other subject areas. Parents felt alcohol and other drugs, nutrition, and first aid were the most important topics to be covered in elementary school, while sexuality, cancer, and stress were the least important. Parents were most comfortable discussing alcohol and other drugs, family life, and growth and development with their children and least comfortable discussing exercise, cancer, and sexuality. Implications for school health programs are discussed.     

Problems associated with the atrophic mandible

A range of treatment options has been presented regarding the use of dental implants to rehabilitate patients who otherwise have compromised function using conventional tissue-borne prostheses. This patient population offers significant challenges to both the surgeon and the prosthodontist. Generally speaking, IODs retained on two or more endosteal osseointegrated implants; transosteal, subperiosteal, ramus frame implant-supported and implant-retained prostheses, and a totally implant-supported design offer options to treat the severely atrophic mandible. When bone support or volume is so lacking that augmentation procedures are required, bone grafting can be considered as a treatment option. The state-of-the-art of implant treatment for the atrophic mandible offers to the dental professional and patient a variety of options. Thus far, it is too early to make specific recommendations as to which treatment offers the best option for each patient. It is fair to say that the ISP remains the gold standard against which other treatments can be compared.     

Surgical inferior repositioning of the maxilla: treatment considerations and comprehensive management

Authors studied two different groups of patients. One of them with febrile seizures and the other febrile seizures associated to epilepsy, in order to find risk factors for the presentation of this one. They conclude that epilepsy has a presentation rate of 9,6% in patients with previous febrile seizures, having the highest risk when they show previous familial seizures, neonatal pathology and altered EEG after the first febrile convulsion. They study the role of phenobarbital taken after febrile seizures, as prophylaxis. No effect was observed in the prevention of following epilepsy.