Pediatric maxillary fractures.

Pediatric craniofacial structures differ from those of adults in many ways. Because of these differences, management of pediatric craniofacial fractures is not the same as those in adults. The most important differences that have clinical relevance are the mechanical properties, craniofacial anatomy, healing capacity, and dental morphology. This article will review these key differences and the management of pediatric maxillary fractures. From the mechanical properties' perspective, pediatric bones are much more resilient than adult bones; as such, they undergo plastic deformation and ductile failure. From the gross anatomic perspective, the relative proportion of the cranial to facial structures is much larger for the pediatric patients and the sinuses are not yet developed. The differences related to dentition and dental development are more conical crowns, larger interdental spaces, and presence of permanent tooth buds in the pediatric population. The fracture pattern, as a result of all the above, does not follow the classic Le Fort types. The maxillomandibular fixation may require circum-mandibular wires, drop wires, or Ivy loops. Interfragmentary ligatures using absorbable sutures play a much greater role in these patients. The use of plates and screws should take into consideration the future development with respect to growth centers and the location of the permanent tooth buds. Pediatric maxillary fractures are not common, require different treatments, and enjoy better long-term outcomes.

Current-phase relationship, thermal and quantum phase slips in superconducting nanowires made on a scaffold created using adhesive tape.

Quantum phase slippage (QPS) in a superconducting nanowire is a new candidate for developing a quantum bit [Mooij et al. New J. Phys. 2005, 7, 219; Mooij et al. Nat. Phys. 2006, 2, 169; Khlebnikov http://arxiv.org/abs/quant-ph/0210019 2007]. It has also been theoretically predicted that the occurrence of QPS significantly changes the current-phase relationship (CPR) of the wire due to the tunneling between topologically different metastable states [Khlebnikov Phys. Rev. B 2008, 78, 014512]. We present studies on the microwave response of the superconducting nanowires to reveal their CPRs. First, we demonstrate a simple nanowire fabrication technique, based on commercially available adhesive tapes, which allows making thin superconducting wire from different metals. We compare the resistance vs temperature curves of Mo(76)Ge(24) and Al nanowires to the classical and quantum models of phase slips. In order to describe the experimentally observed microwave responses of these nanowires, we use the McCumber-Stewart model [McCumber J. Appl. Phys. 1968, 39, 3113; Stewart Appl. Phys. Lett. 1968, 12, 277], which is generalized to include either classical or quantum CPR.

Abdominal wall hernia repair: a comparison of sepramesh and parietex composite mesh in a rabbit hernia model.

BACKGROUND: This study compared Parietex composite mesh (PCM) with Sepramesh (SM) in terms of strength of tissue incorporation, adhesion formation, and mesh shrinkage, using an animal model. STUDY DESIGN: A two-phase, prospective, randomized study using 44 New Zealand white rabbits. Each animal underwent creation of a standardized ventral hernia defect, followed by repair using either SM or PCM. Half of each group was sacrificed and examined at 1 month, and the remainder at 5 months. Outcomes measurements were strength of incorporation (SOI), type and area of adhesions (AA), and mesh shrinkage. RESULTS: SOI for PCM was much greater than for SM, both at 1 month (60.8 N versus 42.6 N) and 5 months (70.9 N versus 31.5 N). The incidence of bowel adhesions was lower with PCM than SM, both at 1 month (1 versus 6) and at 5 months (0 versus 4). At 5 months, PCM demonstrated lower AA, both as a percentage of the mesh (5.6% versus 12.8%) and in terms of absolute area involved (321 mm(2) versus 840 mm(2)). PCM underwent considerably more shrinkage than SM, at both 1 month (38.2% versus 18.1%) and 5 months (17.4% versus 6.1%). CONCLUSIONS: PCM demonstrated a substantially stronger SOI, which improved over time, and SOI of SM decreased. PCM was also superior in terms of adhesion prevention, but underwent considerably more shrinkage in this experimental model.

Abdominal wall hernia repair: a long-term comparison of Sepramesh and Dualmesh in a rabbit hernia model.

Surgeons are faced with a wide variety of mesh products, which they can use to perform tension-free abdominal wall hernia repair. The purpose of this study is to compare Sepramesh (SM) and Dualmesh (DM) in terms of strength of tissue incorporation, mesh shrinkage, and adhesiogenesis. We conducted a prospective, randomized trial using 24 New Zealand White rabbits. Each animal underwent creation of a standardized ventral hernia defect and was randomized to receive either SM or DM repair. There were 12 animals in each study arm. Five months postoperatively, the animals were sacrificed and the hernia repairs were analyzed. Specimens were evaluated for strength of incorporation (SOI), mesh shrinkage, as well as the type and amount of adhesions. SOI for DM was not statistically different from SM (37.2N vs 40.8N). DM underwent significantly more shrinkage than did SM (50.8% vs 32.6%, P < 0.0001). Adhesions were predominantly omental in nature. DM demonstrated a greater amount of adhesed area as a percentage of the mesh (30.7% vs 25.2%), but fewer adhesions in terms of absolute area involved (636 mm2 vs 717 mm2). This difference was not statistically significant. Previous studies, terminated at 30 days, demonstrated an increased SOI for SM as compared to DM. This study shows that SOI for DM continues to increase over time such that it is equivalent to DM at 5 months. Though there is increased mesh shrinkage for DM, adhesions to the two materials are equivalent.

Sepramesh vs. Dualmesh for abdominal wall hernia repairs in a rabbit model.

PURPOSE: To compare the relative strength of incorporation and adhesion formation for mesh hernia repairs performed with Sepramesh (Genzyme Corp., Cambridge, Massachusetts) and Dualmesh (WL Gore and Assoc., Flagstaff, Arizona). METHODS: A prospective randomized study was conducted using 30 New Zealand white rabbits, with 15 animals randomized to each limb. A standardized abdominal defect was created in each animal. The defect was then repaired using either Sepramesh or Dualmesh. Animals were sacrificed at 4 weeks. The area of adhesions was determined using digital analysis of inked specimens. Strength of incorporation was determined using an Instron Tensiometer. (Department of Clinical Research, D. D. Eisenhower Army Medical Center, Fort Gordon, GA 30905.) RESULTS: Sepramesh had a 30.6% stronger strength of incorporation compared with Dualmesh. (p = 0.011) The difference in area of adhesions was not statistically significant between the 2 products. CONCLUSIONS: The use of Sepramesh for abdominal hernia repairs provides a significantly stronger strength of incorporation without increasing the amount of adhesions as compared with Dualmesh.

Subcuticular closure versus Dermabond: a prospective randomized trial.

2-Octylcyanoacrylate tissue adhesive (Dermabond, Ethicon, Inc, Somerville, NJ) is being used successfully for closure of minor lacerations. To date, however, there have been no studies evaluating its use in the operating room for surgical incisions. We conducted a prospective randomized trial to compare the closure of inguinal herniorrhaphy incisions using 2-octylcyanoacrylate tissue adhesive (Dermabond) with closures using 4-0 Monocryl (Ethicon, Inc) in a running subcuticular closure. A total of 46 incisions were randomized at the time of closure. Of these incisions 24 were randomized to Dermabond closure (TA) and 22 were randomized to subcuticular closure (SC). Performance measures included: time for closure, wound complications, and cosmesis. Cosmesis was evaluated by blinded evaluation of photographs of the incisions taken 4 weeks after surgery. Closure times for the TA group were faster than in the SC group (mean of 155 vs 286 seconds; P < 0.001). Wound complications were higher in the TA group (P = 0.045). Cosmesis was also felt to be better in the SC group with a score of 4.2 versus 3.88, but this did not reach statistical significance. Although the use of Dermabond did result in faster wound cultures it also resulted in an increase in wound complications. The difference in mean cosmetic score for each group was not statistically significant but trended toward better scores in the SC group. Based on these findings we do not feel Dermabond is an acceptable alternative to subcuticular suture closure in inguinal herniorrhaphy incisions.

Comparison of two different methods of quantitative coronary angiography in patients with acute coronary syndromes.

The minimal cost algorithm (MCA) commonly used for quantitative coronary arteriography has limitations in definition of complex lesion morphology. A gradient field transform (GFT) algorithm has been designed for the better analysis of complex lesions. We compared MCA with GFT in angiograms of 125 patients in the Myocardial Infarction with Novastan and t-PA (MINT) trial. Lesion border definition was rated as one (poor), two (good), or three (very good). While MCA- and GFT-derived reference diameters (RDs) were similar, GFT yielded smaller minimal lumen diameter (MLD) than MCA by 0.22 +/- 0.31 mm (P < 0.01), and the difference between GFT- and MCA-derived MLDs increased with decreasing MLD. Mean percent diameter stenosis (% DS) was 9.1% +/- 11.1% greater by GFT (P < 0.001). Lesion border definition in simple lesions was similar (not significantly different). However, in complex lesions GFT performed better (2.49 +/- 0.61 vs. 2.11 +/- 0.74; P < 0.05). Thus, GFT appears to improve analysis of complex lesions compared to MCA. GFTs role in angiographic trials and clinical practice deserves further study.