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PubMed1991

Surface resorption following two forms of rapid maxillary expansion.

Rapid maxillary expansion (RME) is a useful orthodontic technique for correction of posterior cross-bite of skeletal origin. The aim of the present study was to compare the frequency and nature of root resorption in premolars subjected to RME by means of either a tissue-borne, fixed split acrylic (Haas) palatal expansion applicance, or an all-wire framework appliance. Another factor examined was the relationship between the pattern of resorption and the duration of the retention period. RME was performed on five patients using the fixed split acrylic appliance and on four patients with the all-wire framework appliance. Following the transverse expansion, two upper and two lower premolars were extracted and processed for histological examination. Root resorption was found mainly on the buccal surfaces of all maxillary premolars. The resorption lacunae covered more of the root surface in premolars treated with an all-wire framework appliance compared to premolars treated with the acrylic expansion plate. The largest resorption areas were found on teeth extracted shortly after the expansion period and the smallest on premolars retained for a relatively longer period. Mandibular premolars showed neither buccal nor lingual resorptions. It was concluded that maximum anchorage of the expansion device, using the tissue-borne acrylic appliance, seems preferable in order to minimize the incidence of buccal surface root resorption. A longer post-treatment observation time is needed in order to draw more specific conclusions regarding the healing process of the damaged root surface.

Acrylic Resins↗
PubMed2004

The beginning of a new era in tissue expansion: self-filling osmotic tissue expander--four-year clinical experience.

The osmotic tissue expander is a new device made of a hydrogel expanding skin that does not require external fillings. Once implanted, it absorbs body fluids, which leads to a gradual swelling of the device. The swelling phase is completed in 6 to 8 weeks and results in skin gain. Different shapes and sizes are available, and the devices can be used in almost every area of the body. Over a 4-year period, the osmotic tissue expander was used in 58 patients in different areas of the body. A round osmotic tissue expander was mainly used in breast reconstruction, and a rectangular expander was used for defect coverage after excision (i.e., of scars and tumors). The mean age of the patients was 49.34 years (range, 4 to 76 years). During the expansion phase, the patients noted only a little discomfort and pain for the first few days. Without a silicone membrane in the first-generation expander, the rate of successful explantation and good final result was 81.5 percent. In a few cases, rapid swelling of the device led to the introduction of a silicone membrane that encloses the expander and leads to a slower, more gradual, and consistent swelling. After introduction of the silicone envelope, the success rate improved to 91 percent. The expander is now used with a silicone membrane in every case. The osmotic tissue expander has many advantages compared with the conventional expander: there is no need for painful external fillings and the risk of external infections is avoided. The expander is 10 percent of its final volume and only requires a short incision and a small pocket. An operation can easily be performed under local anesthesia, with minimal tissue mobilization in older children and compliant patients.

Adolescent↗
PubMed1995

[Recent advance and future of plastic and reconstructive surgery].

Plastic and reconstructive Surgery has progressed very rapidly in the past decade. It is because of free vascularized composite tissue transfer based on progress of microsurgery and anatomical study of blood circulation to skin, fascia, muscle, bone and joint. Adding to this, many new techniques and concepts including craniofacial surgery, laser surgery, tissue expansion method, microvascular coupling device and computer assisted surgery appeared to the field of reconstructive surgery. In this article these main fields of plastic and reconstructive surgery are commented about its present situation and future aspect.

Adult↗
PubMed1999

Treatment of congenital anophthalmos with self-inflating polymer expanders: a new method.

Congenital anophthalmos is a rare malformation in which the optic vesicle fails to develop. This leads to a small bony orbit, a constricted mucosal socket, short eyelids, reduced palpebral fissure and malar hypoplasia. The treatment includes both aesthetic and functional aspects. Therefore, a two-step procedure is described using a new self-inflating hydrogel expander. A lens-shaped expander with a diameter of 8 mm expands the lids and the mucosal socket to allow insertion of an eye prosthesis. As a second step, orbital expansion is performed with a spherical device. The expanders absorb lacrimal fluid from the mucosal socket or tissue fluid and start swelling when implanted in the orbital tissue. The insertion of an expander into the orbit as well as into the conjunctival pocket including its fixation by a single suture took only a few minutes and was an easy procedure. The expansion of the small conjunctival sockets was successfully completed in all cases within a period of 2-4 weeks. The weight (= volume in ml) of devices increased from 0.15-1.5 g (lens-shaped expander; weight in grams = volume in ml) respectively, 0.3-3.5 g (spherical device). The expanders inserted in orbital tissue increased from 0.4-4.4 g. This is equivalent to a 10 to 11 fold increase in their water-free volumes. Orbital expansion with spherical devices in combination with the inserted eye prosthesis enlarges the lid and palpebral fissures also. In contrast to conventional silicon balloon expanders, the procedure using self-inflating hydrogel expanders is simple and highly efficient.

Absorption↗
PubMed1999

Tissue expander infections in children: look beyond the expander pocket.

Infection of the expander pocket is the most common complication encountered with soft-tissue expansion. It is usually due to direct inoculation with skin flora either at the time of expander insertion or from extrusion of the device. The authors report two cases of infection of tissue expanders in which the children had concomitant infected sites distant from the prosthesis. Etiological bacteria of common pediatric infections like otitis media and pharyngitis were cultured from the infected expander pocket, raising suspicion that translocation of the organism to the expander had occurred. Aggressive antibiotic treatment, removal of the prosthesis, and flap advancement is advocated.

Child, Preschool↗
PubMed1997

The use of external tissue expansion in the management of wounds and ulcers.

A series of 43 wounds and ulcers in 37 patients were treated with the use of constant-tension approximation devices for periods ranging from 7 to 28 days. The etiologies of the lesions were diabetes; posttraumatic, including iatrogenic causes; neuropathic; pressure sores; and collagen disease. The approximation device is described and the technique of applying the device is detailed. The results are presented in tabulated form. The contraindications to the use of this methodology are discussed and the importance of patient selectivity is stressed. Evidence is presented to indicate that constant-tension approximation increases the healing rate as well as provides partial or complete full-thickness coverage, depending on the size of the wound. Such coverage reduces the recurrence rate and is usually only achieved by an operative approach, which is thus avoided. The socioeconomic advantages of this approach are mentioned.

Debridement↗
PubMed1990

Enhancement of expansion of guinea pig skin by local delivery of an anticontractile agent using a new bilumen expander.

We have shown previously that anticontractile agents used with tissue expanders provide significantly more rapid expansion in an animal model than in controls without these agents. We describe an improved method of delivery involving a perforated concentric envelope enclosing a tissue expander (type 2) in place of the single circumferential perforated catheter (type 1) used previously by us. Eleven guinea pigs received a type 1 expander and ten received a type 2 expander. The anticontractile agent theophylline was delivered in saline around each expander, and all the expanders from both groups were inflated to a similar pressure every three days for twelve days. Significantly greater expansion, in terms of total volume delivered to the expander, was noted using the type 2 expander. We conclude that the concentric device offers further improvement, probably as a result of more uniform distribution of the agent in the tissue around the expander.

Animals↗
PubMed1992

The biomechanical and histopathologic effects of surface texturing with silicone and polyurethane in tissue implantation and expansion.

There has been considerable interest in determining the effect of morphologic alterations of prosthetic surfaces on capsule response in breast surgery. The purpose of this study was to provide a precise, three-dimensional evaluation of soft-tissue response to surface modifications in both implantation and expansion. Expandable 100-cc prostheses were designed with one of three surfaces: textured silicone (Biocell), standard smooth silicone, or polyurethane (Natural-Y, Meme). A new submuscular implantation site in the rabbit was developed. Each animal randomly received a smooth-surface device on one side and either a textured silicone or polyurethane device on the other. In one group of animals, the prostheses were expanded monthly. Capsular response was evaluated monthly in vivo using standardized techniques as well as biomechanical methods for up to 6 months in the expander group (n = 7 to 16) and 8 months in the implant group (n = 7 to 15). Analysis of biomechanical and histologic data revealed that prosthetic surface morphology can specifically alter capsular response. Polyurethane was the only effective surface in preventing capsular contracture in implantation. In expansion, both textured silicone and polyurethane surfaces resulted in significantly less capsular contracture and less resistance to expansion than comparable smooth-surfaced controls. Statistical comparisons reveal that the biomechanical methods utilized in this study provide the most precise and objective method of defining overall soft-tissue contracture around implanted biomaterials.

Animals↗
PubMed1982

A self-inflating tissue expander.

Tissue expansion is a means of mechanically creating an excess of soft tissue, contiguous to a defect, for use in reconstruction. To accomplish this, a self-inflating implant has been designed, tested, and used clinically. It offers potential advantages over similar percutaneously inflated devices, but has also presented new problems. Histologically, tissue expansion in the guinea pig is relatively innocuous, utilizing this implant; clinical results were similarly encouraging. Further clinical studies and applications await the identification of a more permeable membrane.

Adolescent↗
PubMed2001

The management of pressure sores by constant-tension approximation.

The management of pressure sores in medically compromised patients is problematic as they are seldom candidates for major surgical procedures. We treated 52 pressure sores in 49 patients (including three bilateral lesions) by constant-tension approximation. The lesions were distributed as follows: 21 sacral, two ischial, 13 trochanteric and 16 posterior heel. The average age was 75 years and there were 22 males and 27 females. All patients had significant co-morbid conditions that, except for one wheelchair-bound person,confined them to bed. Nine patients were insensate; in two comatose cases this state was temporary. The management regime consisted of excision of the pressure sore and expansion of the skin and subcutaneous tissue using devices that, by means of continuous low-grade tension, approximated the wound edges, together with rigorous wound toilet and the judicious use of sutures. In total, 38 pressure sores healed primarily without recurrence, including three wounds that partially reopened and healed; 11 of these patients died, with healed wounds, at varying times between 2 and 48 months after treatment. Nine patients whose lesions were closed died within a month of treatment, and five patients, three of whose lesions were completely closed and two partially closed, were lost to follow-up; their lesions were not regarded as healed. This minimally invasive technique used to close pressure sores in elderly patients with co-morbid conditions has a satisfactory success rate.

Aged↗
PubMed1999

[Suture expansion osteogenesis for closing the posterior hard palate: an experimental study in dogs].

OBJECTIVE: This study investigated the possibility of a new approach, e.g. suture expansion osteogenesis for closing the posterior hard palate. By this technique we might hope to replace missing tissue in the clefts by tissue regeneration and achieve bony repair in the posterior hard palate and circumvent the problems of speech and facial growth seen in traditional cleft surgery. METHODS: Nine 8-month mongrel dogs were divided into three groups: the control(n = 1), sham control(n = 2) and the experimental group(n = 6). In six experimental dogs, an 8 mm wide cleft was made surgically. Suture expansion devices made of NiTi-shape memory alloy with force levels of 200 g, 360 g and 480 g were secured in the palatine bones to expand the lateral sutures of the palatine bones. Clinical and histological examinations were performed to observe the changes. RESULTS: The clefts in the experimental group were closed completely sooner or later within a period from 5 to 14 days. While the clefts in the sham group became a little larger than their original size. There was significant new bone formation at the edge of the expanded suture. CONCLUSION: The clefts in young dogs could be closed by the technique of suture expansion. The NiTi-SMA expander used in the study was consistently effective and all the force levels could induce a great amount of new bone formation with the trabeculae being thinner and longer by heavy forces.

Animals↗
PubMed1990

Pressure dermatitis from an implanted pacemaker.

In this eleventh report of dermatitis conforming to the outline of an underlying pacemaker, the authors suggest that most of these reactions are isomorphic responses to expansion of the subcutaneous tissues by the hard device. Allergic contact dermatitis has been documented in a few cases.

Biopsy↗
PubMed2000

A new technique for the treatment of syndactyly with osseous fusion of the distal phalanges.

In treating complex syndactyly of the hand, including bony union of varying degrees, how to cover the exposed bone surface is still disputable. The authors adopted a homemade device for the treatment of a case of syndactyly with terminal bony union. External tissue expander theory was applied to their device, and expansion of the cutaneous bridge was followed by division of the fused distal phalanges. Two months later the raw bone could be covered simply with the expanded local skin, and no skin graft was needed except for at the base of the affected fingers. This technique produces good cosmetic results of the fingertips and nail grooves without secondary deformities.

Humans↗
PubMed1993

Chronic tissue expansion.

BACKGROUND: Chronic tissue expansion is an extremely useful addition to the dermatologic surgeon's skills. OBJECTIVE: To review chronic tissue expansion. METHODS: The relevant literature is summarized. Two case histories are presented as examples of the utility of chronic tissue expansion. RESULTS: The history of tissue expansion is briefly reviewed. Indications pertinent to the practice of dermatologic surgery are discussed. The devices themselves are described, as well as new experimental advances. The general procedure for utilizing tissue expanders is outlined, as well as relevant histologic changes that occur in expanded skin. Both common and rare complications are covered, with attention to prevention. CONCLUSION: Chronic tissue expansion provides an excellent means for obtaining extra tissue for cosmetic and reconstructive surgery.

Aged↗
PubMed1988

A twin tissue expander used in the elimination of alopecia.

The tissue expansion system developed at Odstock Hospital in 1983 and subsequently used in clinical practice is described. The case report illustrates the use of the twin version of this device in the elimination of male pattern baldness. Data are given revealing the tissue compliance and growth response to hydraulic expansion.

Adult↗
PubMed1999

Nasal expansion in the fetal lamb: a first step toward management of cleft nasal deformity in utero.

The cleft nasal deformity, a combination of malpositioned cartilage and tissue and postrepair scarring, is a difficult problem to correct. To harness the potential of scarless fetal wound healing, in utero repair of cleft lip and palate deformities has been studied but the fetal cleft nose deformity has not been addressed. The purpose of this study was to manipulate the fetal nasal shape in utero as a first step toward restoration of normal nasal form in cleft nasal deformities. To do this, preformed hypertonic sponges were placed into the right nostril of eight fetal lambs during the second trimester (when scarless cutaneous wound repair is known to occur). Then, the size and shape of fetal nasal structures were analyzed after selected time periods (1, 2, and 6 weeks) with measurements, routine histologic examination, and three-dimensional computed tomographic scans of the experimentally expanded noses compared with the control nonexpanded noses of the birth twins or age-matched specimens. Results showed that experimentally expanded nasal structures had markedly increased in septal length measurement, in nostril area (doubled), and in intranasal volume (more than doubled). Histology showed normal cellular elements without scarring in the tissue sections from the expanded nasal areas. In conclusion, the shape of nasal tissue can be manipulated without scarring in second-trimester fetal lambs after placement of a nasal expansion device. This study is an experimental first step toward restoring normal nasal form by repositioning alar cartilages and soft tissue during fetal cleft repair.

Animals↗
PubMed1988

Magna-Site tissue expander: an innovation for injection site location.

The Magna-Site tissue expander simplifies the use of tissue expanders by facilitating the location of the injection port, thereby reducing the risks associated with faulty injection placement in the past. The injection port is smooth except for the innocuous palpation bumps, drastically reducing the problems of erosion at the injection port site encountered in the past. No drawbacks were encountered with the use of this expander relative to the use of other currently marketed expanders. The new product is available at a cost similar to expanders currently available. It is felt by the authors that this expander represents the next logical step in the evolution of this technology. Just as Dr. Cohen thought, "It will be exciting to see what new devices are created to further enhance the concept of tissue expansion."

Equipment Design↗