Soft tissue defects

Purified solubilized bovine collagen is used as biomaterial for the treatment of soft tissue defects and has been used for the treatment of stress urinary incontinence since the late 1980s (1). Injected material precipitates at body temperature, forming a matrix allowing fibroblastic infiltration and formation of new tissue. It has been used for cosmetic purposes by injection in the dermis to correct scars and other contour deformities of the skin. 

Polymer meshes, such as polypropylene and polyester, are used for the repair of hernias and other soft tissue defects. Whereas fre use of me material has lead to a widely accepted improvement in this kind of surgery, their implantation can be associated with serious motion rates. In order to reduce the infection rates of such meshes, their surface properties have to be improved. 

Despite their advantages, PPF and other biodegradable polymers (e.g. oligo polyethylene glycol-fumarate), generally lack the mechanical properties required for regeneration of hard and dense cortical bone, and their utility is limited to soft tissue defects and non-load bearing bone defects. 

The largest voliune of polsrmeric materials used in dentistry is in prosthetic applications. Polymeric materials are also important in operative dentistry, being used to produce composite resins, dental cements, adhesives, cavity liners, and as a protective sealant for pits and fissures. Elastomers are employed as impression materials. Resilient prosthetic devices are oft en fabricated to restore external soft-tissue defects. Mouth protectors are fabricated to prevent injury to teeth, as well as prevent head and neck injinaes. Other polymer applications include fabricating patterns for metal castings and partial denture frameworks, impression trays, orthodontic and periodontal devices, space maintainers, bite plates, cleft palate obdurators, and oral implants. Polymeric materials may also be used to fabricate an artificial tongue, when disease results in its loss. 

Shandalov, Y., Egozi, D Koffler, J., Dado-Rosenfeld, D., Ben-Shimol, D., Freiman, A., Shor, E., Kabala, A., Levenberg, S., 2014. An engineered muscle flap for reconstruction of large soft tissue defects. Proc. Natl. Acad. Sci. U.S.A. Ill, 6010—6015. 

Intermittently prolapsing rectal mucosa appears as a low rectal mass, causing a smooth soft tissue defect. Sigmoidoscopy shows edematous mucosa due to rectal prolapse (Taylor 2003c) (Fig. 8.38). 

AlloDerai (LifeCell Corp.) Allogeneic acellular human dermis None Bum wounds repair of soft tissue defects [8-11]... 

Over the past two decades, HA has become the most extensively used material in plastic surgery, ophthalmology and orthopaedics. The use of HA in reconstructive surgery, as a dermal filler, dressing, or cream, centres on the restoration of soft tissue defects, and the treatment of wounds and burns. Typically, these defects are secondary to surgical or physical trauma, especially in subtractive surgeries, such as tumour removal. HA is used as a filler due to its ability not only to restore the lost volume, but to also improve the quality of the skin, namely its elasticity, plasticity and hydration. 

Sulamanidze MA, Salti G, Mascceti M, Sulamanidze GM (2000) Wire scalpel for surgical correction of soft tissue contour defects by subcutaneous dissection. Dermatol Surg 26 146-150... 

In calculating the percent of bone in the available space (bone/bone + soft tissue) the percent of new bone ingrowth ranges from 29 to 44%. Comparatively, in a study we recently completed in segmental defects in dog mandibles using coralline hydroxyapatite, the percent of new bon ingrowth in the available space averaged 14.28% at 2 months and 28.16% at 4 months. 

Inaeased risk of various cancers (e.g., lymphatics, blood, stomach, prostate, testes, brain, and soft tissues) was reported upon exposure to pesticides (Zahm and Blair 1993 Hayes et al. 1995 Zahm et al. 1997). Children s cancer, including brain tumors, leukemia, non-Hodgkin s lymphoma, sarcoma, and Wilms tumor due to direct or parental exposure to pesticides also has been determined (Fear et al. 1998 Kristensen et al. 1996 Pogoda and Preston-Martin 1997 Sharpe et al. 1995 Buckley et al. 1994). Often, the risk of cancer due to exposure to pesticides has been higher in children than in adults (Zahm and Ward 1998). Moreover, birth defects, including limb-reduction defects, have been linked to exposures to pesticides (Restrepo et al. 1990 Schwartz and LoGerfo 1998 Lin et al. 1994), as has a higher-than-normal risk of stillborn births (Pastore et al. 1997). 

Organic alkyl, aryl Gastrointestinal, skin, respiratory (minor) Soft tissues CNS effects, birth defects Inhibits enzymes alters microtubules, neuronal structure Deacylation. Fecal (alkyl, major) urine (Hg2+ after deacylation, minor)... 

Hypoparathyroidism can result from decreased production of PTH or failure of target organs to respond to PTH. In rare cases, it involves the production of genetically defective PTH. PTH provokes the kidney to conserve calcium and to excrete phosphate. Thus, hypoparathyroidism results in low plasma calcium and high plasma phosphate levels. The disease may result in the calcification of soft tissues because of the high plasma phosphate level. Elevated phosphate levels result in an increased rate of precipitation of calcium and phosphate as the calcium phosphate salt. The disease is treated with oral calcium supplements and phosphate-binding antacids to minimize the absorption of dietary phosphate. 

Polyesters have also been processed into tubular form for orthopedic and cardiovascular tissue engineering applications. Meinig and co-workers evaluated bone regeneration using tubular PLLA membranes in mid-diaphyseal defects in rabbit radii. The membrane prevented soft tissue formation in the defect area, and it allowed woven bone to fill the defect. Local inflammation or systemic intolerance was not observed, and the membranes remained intact for the entire 64-week study. 

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