We investigated an unusually large and severe outbreak of hepatitis B, primarily involving parenteral drug abusers and their sexual contacts, in Worcester, Massachusetts, over a 21-month period from 1983 to 1985. Of 135 patients with drug-related acute hepatitis B, 81 percent were parenteral drug abusers and 19 percent had sexual contact with drug abusers; 13 fulminant cases resulted in 11 deaths. Among the patients with hepatitis B, evidence of delta virus infection was found in 54 percent of drug abusers, 33 percent of their sexual contacts, and 9 percent of other patients with acute hepatitis B (P less than 0.001). Most of the delta infections (86 percent) were coinfections with hepatitis B virus; the balance were superinfections. Delta infection was strongly associated with fulminant hepatitis: 91 percent of patients with a fulminant outcome had delta infection, as compared with 45 percent of less severely ill drug abusers and their contacts (P = 0.0037). Alcohol, other drugs, and other hepatitis viruses could not be implicated as hepatotoxic cofactors for fulminant disease. This outbreak appeared to result from the concurrent spread of hepatitis B and delta viruses among new drug users. Control measures included the distribution to physicians of guidelines on prophylaxis in contacts of patients with hepatitis B, health education for drug abusers, and a hepatitis B vaccination program. Despite these efforts, the outbreak continued unabated until the number of new cases began to decline slowly in late 1986.
Cutting, Court M.D.; Grayson, Barry D.D.S.; McCarthy, Joseph G. M.D.; Thorne, Charles M.D.; Khorramabadi, Deljou M.S.; Haddad, Betsy M.S.; Taylor, Russell Ph.D. Author Information
The influence of dura mater on adjacent cranial sutures is significant. By better understanding the mechanisms of normal suture fusion and the role of the dura mater, it may be possible to delineate the events responsible for the premature suture fusion seen in craniosynostosis. In the Sprague-Dawley rat, the posterior frontal suture normally fuses between 12 and 20 days of postnatal life and has proved to be an excellent model to describe normal suture fusion. The purpose of this study was to document the critical role that the dura mater-suture complex may play on cranial suture biology. Forty Sprague-Dawley rats at 8 days of age were divided into two groups of 20 animals each. The control group (group A) had surgical disruption of the dura matercalvarial interface. This was accomplished by elevating a strip of cranium inclusive of the posterior frontal and sagittal sutures and replacement of the cranial strip back to its anatomic position, all with the dura mater left intact. The experimental group (group B) had the same calvarial elevation (strip craniectomy), but the sutural anatomy/alignment was rotated 180 degrees. This rotation placed the posterior frontal suture into the sagittal suture's anatomic position and the sagittal suture into the posterior frontal suture's anatomic position. All of these procedures were accomplished by leaving the underlying dura mater intact. Animals were killed at 20, 30, 40, and 50 days (12, 22, 32, and 42 days postoperatively), and tissue sections were examined with hematoxylin and eosin staining. Group A (control) showed normal but delayed suture activity. The posterior frontal suture fused, and the sagittal suture remained patent. Fusion was delayed, not beginning before 20 days (12 days postoperative) and showing complete fusion between 30 and 40 days. Group B (180degree calvarial rotation) demonstrated that the suture in the posterior frontal anatomic position (actual sagittal suture) fused between 20 and 40 days, whereas the suture in the sagittal anatomic position (actual posterior-frontal suture) remained patent throughout the study. This study demonstrates that the location of the dura mater-suture complex is important in determining either suture patency or closure in this model. Normal closure of the suture overlying the posterior frontal dura mater demonstrates that the dura mater itself, or forces derived in specific cranial locations, determines the overlying suture biology. (Plast. Reconstr. Surg. 101: 1441, 1998.)
The process of bone lengthening by cortical fracture and gradual distraction of callus has become well established in the enchondral bones of the extremities. In this study the principles of bone lengthening were applied to the membranous bone of the craniofacial skeleton using the growing dog mandible as a model
A computer program is described which aids the clinician in planning craniofacial surgical procedures. It operates on a three-dimensional landmark data base derived by combining posteroanterior and lateral cephalograins from the patient and from the Bolton normative standards. A three-dimensional surgical simulation program based on computerized tomographic (CT) data is also described which can be linked to the cephalometrically based program. After the clinician has selected the number and type of osteotomies to be performed on the patient, an automated optimization program computes the postoperative positions of these fragments which best fit the appropriate normal cephalometric form. The clinician then interactively modifies the design to account for such variables as bone-graft resorption, relapse tendency, occlusal disparities, and the condition of the overlying soft-tissue matrix. Osteotomy movement specifications are easily transferred between the CT-based and the cephalometrically based surgical simulation programs. This allows the automated positioning step to be performed on the cephalometrically based model while the interactive step is performed using the superior image provided by the CT-based model.
Mandibular distraction osteogenesis lengthens not only the affected skeleton but also the associated muscles of mastication. The purpose of this study was to determine medial pterygoid volume before and after distraction by using computed tomography. Using computed tomographic scans, the volume of the medial pterygoid muscle was determined before and after mandibular distraction in six pediatric patients. In four unilateral distraction patients (average age, 65 months), the average increase of the medial pterygoid muscle on the distracted side of the mandible was 29 percent, and on the contralateral nondistracted side, 10 percent. The average increase in medial pterygoid muscle volume in two bilateral distraction patients (each aged 8 months) was 75 percent. Results of this study demonstrate that distraction osteogenesis of the human mandible not only lengthens deficient bone, but it also increases the volume of the attached musculature.
