Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “SUTURES”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 847 records · Page 47Linked to original sources
PubMed1999

Rhinoplasty: a simplified, three-stitch, open tip suture technique. Part I: primary rhinoplasty.

Tip suture techniques offer a reliable and dramatic method of tip modification without needing to interrupt the alar rim strip or add tip grafts. The present simplified three-stitch technique consists of the following: (1) a strut suture to fix the columella strut between the crura, (2) bilateral domal creation sutures to create tip definition, and (3) a domal equalization suture to narrow and align the domes. If required, columella septal sutures can be added; either a dorsal rotational suture or a transfixion projection suture can be used. This simplified method represents a refinement based on more than 13 years of experience with tip suture techniques. It does not require a complex operative sequence or specialized sutures. Primary indications are moderate tip deformities of inadequate definition and excessive width and certain specific tip deformities, including the parenthesis tip and nostril/tip disproportion. The primary contraindications are for patients with minor tip deformities that are best done through a closed approach and those with severe tip deformities requiring an open structure graft. The technique is simple, efficacious, and easily learned.

Adult↗
PubMed2002

Vascular closure staples-a new technique for biliary reconstruction: prospective randomized comparison with manual suture in an animal model.

BACKGROUND: In orthotopic liver transplantation the incidence of biliary complications is up to 49%. In view of the relative frequency of such complications despite seemingly good preconditions, method-related disadvantages of conventional suture must also be considered as a possible cause. These include perforating needle injury of the choledochal wall with at least temporary exposure of suture material in the lumen, suboptimal approximation of the mucosa, and an additional decrease in blood flow in the choledochal stumps as a result of suture-related tissue strangulation. Hence the search for alternative anastomosis techniques. METHODS: To evaluate the surgical suitability of extramucosal titanium clips (Vascular Closure Staples; VCS) in comparison with conventional manual suture, a study was performed in 36 pigs, which were randomly assigned to 4 groups, each containing 9 animals. Choledochal excision was performed in 18 pigs and transection in the other 18 pigs; end-to-end anastomosis was then carried out, using a VCS stapler in half of the animals in each of these two groups and conventional manual suture in the other half. Pre- and postanastomotic blood flow was measured during the surgery with the aid of a laser Doppler flow meter. The long-term behavior of the closure techniques was ascertained by regular laboratory checks over the ensuing 6-month observation period, after which the pigs were killed so that the specimens could be harvested. RESULTS: Using medium-sized VCS clips, we were able to create a tension-free, everted biliary anastomosis with exact mucosal approximation and no narrowing of the lumen, and without any technical problems during the performance of the procedure. Measurements with the laser Doppler flow meter showed well-preserved anastomotic blood flow after clip reconstruction, with significantly higher perfusion values than after manual suture. The postoperative courses of the investigated laboratory parameters did not reveal any significant differences between the two methods. In contrast, histomorphometric evaluation showed wall thickness and thus fibrosis in the anastomosis region to be less in the clip group than in the suture group (median: 510 microm versus 660 microm, P<0.001). In the pigs in which clip anastomosis was used, there were no detectable anastomotic stenoses; in the pigs in which conventional suture was used, however, ultrasonography revealed five anastomoses with varying degrees of narrowing. CONCLUSIONS: Extramucosal VCS clip anastomosis not only offers potential advantages with respect to nonpenetrating and optimal mucosal contact, investigations in animals also show it to be superior to conventional manual suture as regards anastomotic blood flow and medium-term fibrosis formation. We believe that our data and the available literature warrant a clinical evaluation of this technique in appropriate studies.

Anastomosis, Surgical↗
PubMed2000

Sutured posterior chamber intraocular lenses: indications and procedure.

Intraocular lens (IOL) implantation is the standard of care for treating aphakia when spectacle or contact lens correction is not viable. There is considerable controversy about the relative efficacy and safety of the different IOL implantation approaches, as well as their indications. Since the development of the modern, open-loop anterior chamber IOL (ACIOL) and the re-emergence of the iris-fixated claw IOL, ACIOL implantation for aphakia has regained popularity. However, the posterior chamber IOL (PCIOL)--namely, the capsular-supported PCIOL and, in the absence of capsular support, the iris-sutured or transsclerally sutured PCIOL--offers numerous advantages for certain patients. By virtue of their anatomic location in the eye, capsular-supported or sutured PCIOLs are appropriate for patients with glaucoma, diabetes, cornea guttata or low endothelial cell count, peripheral anterior synechiae, or known or suspected cystoid macular edema. They may also be appropriate when the patient with aphakia is young and has a relatively long life expectancy. The sutured PCIOL procedure--specifically, the transsclerally sutured PCIOL procedure--is far from benign, however, and surgical expertise is an important consideration. Recent surgical and technological advances, including the technique of burying the suture knot in sclera, use of an ab externo suturing approach in the normotonic eye, and the use of intraoperative endoscopy, have improved the accuracy of the transsclerally sutured PCIOL technique. Additional advances, including diagnostic ultrasound biomicroscopy and small-incision surgery with foldable, transsclerally sutured IOLs, may further improve patient management and clinical outcomes.

Aphakia↗
PubMed2003

Markers of osteoblast differentiation in fusing and nonfusing cranial sutures.

Accumulating clinical genetic data support the hypothesis that alterations in osteoblast differentiation are closely associated with craniosynostoses. Gain-of-function mutations in FGFR1, FGFR2, FGFR3, and Msx2 and loss-of-function mutations in Twist are examples of such alterations. Several studies have examined how these mutations alter the expression patterns for transcription factors such as Runx2 and noncollagenous extracellular matrix molecules such as osteopontin and osteocalcin. One limitation of such studies is that they examine samples derived from craniosynostotic patients with sutures that have already fused, thus missing the dynamic osteogenic process of suture fusion. In this study, in situ hybridization was used to localize Runx2, osteopontin, and osteocalcin expression in the sagittal and posterior frontal sutures in mice (n = 20), before (day 13), during (days 23, 33, and 43), and after (day 53) the period of physiological posterior frontal suture fusion. The data demonstrated similar patterns of expression in fusing (posterior frontal) and nonfusing (sagittal) sutures. The expression of all three genes was primarily concentrated in the osteogenic fronts of both sutures and decreased with time. Notably, none of the three genes was expressed in the mesenchyme of either fusing or nonfusing sutures. The data suggest that the molecular signals leading to bone formation along the osteogenic fronts in fusing and nonfusing sutures are similar, raising the possibility that other factors, such as antagonists of osteogenesis, might have a role in maintaining suture patency.

Animals↗
PubMed2004

Mechanisms of murine cranial suture patency mediated by a dominant negative transforming growth factor-beta receptor adenovirus.

Using a physiologic model of mouse cranial suture fusion, the authors' laboratory has previously demonstrated that transforming growth factor (TGF)-betas appear to be more abundantly expressed in the suture complex of the fusing posterior frontal compared with the patent sagittal suture. Furthermore, the authors have shown that by blocking TGF-beta signaling with a replication-deficient adenovirus encoding a defective, dominant negative type II TGF-beta receptor (AdDN-TbetaRII), posterior frontal suture fusion was inhibited. In this study, the authors attempt to further elucidate the role of TGF-beta in cranial suture fusion by investigating possible mechanisms of AdDN-TbetaRII-mediated cranial suture patency using both an established organ culture model and a novel in vitro co-culture system that recapitulates the in vivo anatomic dura mater/cranial suture relationship. In this article, the authors demonstrate that blocking TGF-beta signaling with the AdDN-TbetaRII construct led to inhibition of cellular proliferation in the suture mesenchyme and subjacent dura mater during the early period of predicted posterior frontal suture fusion. Interestingly, co-culture experiments revealed that transfecting osteoblasts with AdDN-TbetaRII led to alterations in the gene expression levels of two important bone-related molecules (Msx2 and osteopontin). Inhibiting TGF-beta signaling prevented time-dependent suppression of Msx2 and prevented induction of osteopontin, thereby retarding osteoblast differentiation. Furthermore, the authors demonstrated that the AdDN-TbetaRII construct was capable of blocking TGF-beta -mediated up-regulation of collagen IalphaI, an extracellular matrix molecule important for bone formation. Collectively, these data strongly suggest that AdDN-TbetaRII maintains posterior frontal patency, in part by altering early events in de novo bone formation, including cellular proliferation and early extracellular matrix production.

Adenoviridae↗
PubMed2005

Changing the convexity and concavity of nasal cartilages and cartilage grafts with horizontal mattress sutures: part I. Experimental results.

Prior studies indicated that horizontal mattress sutures can control the curvature of a convex lateral crus. This study undertook to ascertain the ideal spacing for mattress sutures, determine what effect they have on the subsequent strength of the cartilage, and compare that to the resultant strength after scoring procedures used to control curvature. Curved fresh cadaver septa of various thicknesses (0.5, 1, and 1.5 mm) were used. The ideal spacing (gap between suture purchases) for the mattress suture was sought in 15 specimens. The consequent change in stiffness (modulus) of the cartilage was measured in nine other specimens before and after suture placement and after scoring. If the spacing was too large, instability resulted. If it was too small, curvature correction could not be obtained. An ideal mattress spacing (6 to 8 mm for 0.5-mm specimens and 8 to 10 mm for 1.5-mm specimens) removed most curvature and provided stability. The mattress suture increased the stiffness (modulus) above normal and far above that when the curvature was removed by scoring. The mean composite modulus before suturing was 4.6 MPa. After ideally spaced sutures, it was 6.2 MPa, a 35 percent increase in stiffness. After scoring to improve curvature, it was 2.4 MPa, a 48 percent reduction in stiffness (p = 0.02, Wilcoxon signed rank test). The horizontal mattress suture technique corrects cartilage curvature if the appropriate spacing is used. The corrected cartilage is stiffer/stronger than normal cartilage and much stiffer/stronger than if scored.

Cadaver↗
PubMed2002

The telescoping suture--Part 1: Does this technique improve the mechanical behavior of a biomaterial?: Calf pericardium.

The authors study the mechanical behavior of calf pericardium employed in the construction of cardiac valve leaflets when subjected to telescoping suture, followed by tensile stress until rupture. One hundred twenty pericardial tissue samples were employed, 60 cut from root-to-apex and another 60 cut in transverse direction. Each of these two groups consisted of 12 control samples that were left unsutured and four sets of 12 samples each that were rejoined by telescoping suture using silk, Prolene, nylon or Gore-Tex., and subjected to tensile stress. At the rupture of the sutured tissues, the tensile stress of the suture materials ranged between 57.54 MPa for the series sewn lengthwise with Gore-tex and 114.08 MPa for the series sewn crosswise with silk. At these levels of stress, the deformation of the suture thread was much less marked than that of the calf pericardium, and internal stresses were produced that were difficult for the biomaterial to absorb. There was a loss of real load in all the sutured series when the observed resistance to rupture, expressed in kilograms, was compared with the estimated value. This loss of resistance did not invalidate the telescoping suture technique since the resistance to rupture was still much greater than that associated with suturing the two edges of the cut pericardium together. This report confirms the deleterious role of the shear force generated in the pericardium by the suture.

Animals↗
PubMed2005

Running combined simple and vertical mattress suture: a rapid skin-everting stitch.

BACKGROUND: Vertical mattress sutures are used in skin surgery to produce eversion of the wound edges, which produces a better, cosmetically acceptable scar. The disadvantages of this closure include the risk of wound hypereversion if tied too tightly, longer time to perform the stitch, and difficulties with grasping the externalized loops during suture removal. OBJECTIVE: To examine and discuss the new modification of running vertical mattress sutures, which can overcome the disadvantages. METHODS: Running combined simple and vertical mattress suture techniques are presented in a series of schematic diagrams that follow. RESULTS: The running combined simple and vertical mattress is easier and quicker to close the wound than the classic interrupted or running vertical mattress suture. Whereas the mattress suture everts the wound edges, the simple suture coapts the sides, preventing undue inversion or hypereversion of the wound. Suture removal is less uncomfortable for the patient and is performed faster by the medical staff owing to a reduction in the number of externalized loops by half compared with the classic vertical mattress stitch. CONCLUSION: Alternation of the vertical mattress and simple running suture saves the surgeon's time without lessening the advantages of good wound eversion and hence the formation of a less apparent, cosmetically more appealing scar after wound contraction.

Dermatologic Surgical Procedures↗
PubMed1980

Absorbable sutures (Dexon and Vicryl) in the corneolimbal incision. Used in lens implantation surgery.

In 115 consecutive cataract extractions with implantation of artificial lens a clinical evaluation of absorbable sutures--polyglactin (910) (Vicryl 7-0) and polyglycolic acid (Dexon 8-0)--in corneolimbal incision has been performed. The corneolimbal wounds were closed by continuous suture technique with one double loop knot at the 12 o'clock and 5-6 loops on each side of the 12 o'clock knot. The suture had disappeared after 8 weeks in 95% of the eyes. Two months after operation the visual acuity, the power of corneal astigmatism and astigmatic orientation remained unchanged in both the Vicryl and the Dexon sutured group. This provided effectuation of early full prescription of glasses. Most complications in this material were suture independent and appeared during the early postoperative period. In only one eye inadequate wound closure was noticed. Shallow anterior chamber and hypotonia of short duration occurred in 5 eyes. Four of these patients developed corneal dystrophy. In the Vicryl sutured group suture reactions took place in 87% of the eyes. With dexon suture no such reaction appeared. The use of absorbable sutures in corneolimbal incision technique implies several surgical advantages and is seemingly safe.

Absorption↗
PubMed1994

Suture adjustment in penetrating keratoplasty.

Postoperative adjustment of a single running penetrating corneal graft suture was done in 19 patients (22 adjustments). The short-term effect of this procedure was a mean reduction of corneal astigmatism of 4.39D (p < 0.0001). Thereafter, the corneal contour was fairly stable, provided that the running suture remained intact and tight. Localized loosening of the graft suture significantly increased the corneal astigmatism. Following removal of the graft suture no statistically significant mean change of corneal astigmatism was found. However, patients with a previously intact running suture tended to show increased astigmatism, while those with a previous localized suture loosening usually showed a decreased astigmatism after suture removal. The main benefit of suture adjustment is apparently the rapid and fairly stable reduction of postkeratoplasty astigmatism usually obtained, but unfortunately this effect seems chiefly to exist only as long as the graft suture remains intact and tight.

Adolescent↗
PubMed2002

Limited macular translocation with scleral retraction suture.

BACKGROUND/AIMS: Macular translocation with scleral imbrication is a new technique for treating subfoveal choroidal neovascular membranes (CNV). This procedure shortens the sclera but may result in a minimal decrease in the internal circumference of the globe and limits the amount of foveal displacement. The authors propose a new scleral retraction suture aimed at decreasing the internal circumference of the globe in an effort to increase foveal displacement. METHODS: Using a cadaver model, they compared the amount of scleral shortening using a standard scleral imbrication technique and a modified three suture scleral retraction technique. Sections of the globes were digitised and specialised software was used to estimate the amount of scleral shortening. Three patients with subfoveal choroidal neovascularisation underwent limited macular translocation using pars plana vitrectomy and macular detachment with the modified scleral suture technique. The main outcome measures were visual acuity, foveal displacement, and complications. RESULTS: In the cadaver model, the scleral retraction suture resulted in a flatter internal scleral fold compared to the standard suture technique and created approximately 890 microm of effective scleral shortening. In the patients who underwent macular translocation and laser photocoagulation of the CNV, visual acuity improved in two patients and worsened in one patient. The range of foveal displacement was 1400-2400 microm. CONCLUSION: The foveal displacements achieved in this limited study compared to median displacement previously published using standard suture techniques demonstrates that the scleral retraction suture technique may be a useful adjunct to limited macular translocation. The advantage of this type of suture in conjunction with translocation may depend on the effective scleral shortening offered by this retraction suture.

Aged↗
PubMed2003

Prenatal organization and morphogenesis of the sphenofrontal suture in humans.

OBJECTIVE: The aim of this study was to describe the prenatal structure and morphogenesis of the sphenofrontal suture. METHODS: Eleven human specimens, two embryos and nine fetuses, were prepared for light microscopy study of the sphenofrontal suture. Ten-micrometer sections were made with the microtome in the sagittal plane from the midline to the sphenoidal fontanelle. RESULTS: At the end of the fetal period, the sphenofrontal suture had a five-layer structure like the cranial sutures, and was formed by two different morphogenetic unities. The orbitosphenofrontal suture was formed between the membranous ossification of the orbital part of the frontal bone and the endochondral ossification of the lesser wing of the sphenoid bone, i.e. the ala orbitalis. In the early stage, a transient sphenoethmoidal cartilage was inserted between these two ossifications. The second unit, the lateral sphenofrontal suture, was formed between the frontal bone and the greater wing of the sphenoid, and the ossification was membranous in this portion. It is formed like the cranial suture, directly from the mesenchyme. CONCLUSION: The sphenofrontal suture is a typical fibrous suture arising from two morphogenetic unities.

Body Patterning↗
PubMed1991

[Changes in postoperative corneal astigmatism after laser dissection of corneo-scleral sutures].

In a group of 68 consecutive cases of high surgically induced corneal astigmatism following extracapsular cataract extraction or phacoemulsification, single limbal sutures were released by argon laser. Visual acuity and refractive results 2-6 weeks after treatment were compared to those before laser application. The effect of suture dissection was analyzed according to the number of sutures released, the follow-up time from cataract surgery and previous corneal astigmatism. The effect of suture dissection was not dependent on the interval from surgery up to 20 weeks postoperatively. The reduction in astigmatism amounts 2.25 dptr up to 8 weeks, occasionally 2.5 dptr 8-10 and 11-16 weeks after surgery, and 1.75 dptr up to 20 weeks thereafter (mean values). The longer the interval the more sutures had to be released. If only one suture was dissected, the reduction in astigmatism amounted 1.75 dptr (mean), if two sutures were released the effect was 2.5 dptr, three or more dissected sutures lead to a 3.4-dptr reduction in corneal astigmatism. The axis of astigmatism did not change in 52 of 59 cases, but in some subjects oblique astigmatism appeared after suture dissection.

Astigmatism↗
PubMed2005

Cyclic testing of flexible all-inside meniscus suture anchors: biomechanical analysis.

BACKGROUND: Flexible meniscus repair devices are designed to combine the benefits of rigid all-inside meniscus anchors with the biomechanical properties of sutures. HYPOTHESIS: Stiffness and pull-out strength of flexible all-inside suture anchors and conventional sutures under cyclic loading conditions will be comparable. STUDY DESIGN: Controlled laboratory study. METHODS: In 50 fresh frozen bovine menisci, artificial meniscus lesions were repaired with different meniscus fixation techniques: horizontal and vertical FasT-Fix, RapidLoc, and horizontal and vertical 2-0 Ethibond sutures. The specimens were cycled 1000 times between 5 and 20 N and then loaded to failure. RESULTS: All devices survived the cyclic loading protocol. There was no significant difference in the displacement between all repair techniques tested (horizontal FasT-Fix, 6.23 mm; vertical FasT-Fix, 5.34 mm; RapidLoc, 6.84 mm; horizontal 2-0 Ethibond, 6.03 mm; vertical 2-0 Ethibond, 5.61 mm (P > .05). Vertical and horizontal FasT-Fix suture anchors had a significantly higher stiffness and pull-out strength (94.1 N and 80.8 N, respectively) than did horizontal sutures (50.2 N) and RapidLoc devices (30.3 N) (P > .05). CONCLUSIONS: In this study, flexible all-inside meniscus anchors (FasT-Fix) had higher pull-out strength than did conventional vertical suture techniques. Biomechanical characteristics of the flexible RapidLoc are comparable to those of horizontal sutures. CLINICAL RELEVANCE: Flexible all-inside meniscus repair devices are an alternative to conventional suture techniques.

Animals↗
PubMed2006

The use of suture anchors in repair of the ruptured patellar tendon: a biomechanical study.

BACKGROUND: Rupture of the patellar tendon is a disabling injury that usually requires surgical treatment. The standard method of repair involves placing suture loops through transpatellar tunnels. The use of suture anchors in patellar tendon repair has not been previously described. HYPOTHESIS: No difference exists in the amount of gap formation during cyclic loading or in ultimate load-to-failure strength between repairs performed with anchors and those performed with 2 types of transpatellar sutures. STUDY DESIGN: Controlled laboratory study. METHODS: Six matched pairs of cadaveric knees were tested in a custom biomechanical apparatus based on an established model. Repairs were performed using either suture anchors with No. 2 FiberWire or transpatellar suture tunnels using 2 different types of suture-No. 5 Ethibond and No. 2 FiberWire. Gap formation across the repair site during 250 cycles of extension as well as ramp-up load to failure were measured for each repair. RESULTS: The mean total gap formation across the repair site at 250 cycles was 4.1 +/- 1.9 mm for the suture anchor group, 6.7 +/- 1.8 mm for the FiberWire tunnel group, and 8.5 +/- 2.7 mm for the Ethibond tunnel group. Mean load to failure was 779 +/- 183 N, 730 +/- 83 N, and 763 +/- 231 N, respectively. CONCLUSION: Significantly less gap formation throughout 250 cycles (P = .009) and no difference in load to failure occurred with patellar tendon repairs performed with suture anchors as compared with repairs performed with transpatellar tunnels. CLINICAL RELEVANCE: The newly described method, using suture anchors for repair of patellar tendon ruptures, may be clinically equal or superior to the established method of using transpatellar tunnels.

Aged↗
PubMed2006

Biomechanical comparison of traditional and locked suture configurations for arthroscopic repairs of the rotator cuff.

BACKGROUND: The optimal suture configuration for arthroscopic rotator cuff repairs is controversial. "Locked" suture configurations, which use a combination of simple and transverse suture loops, have demonstrated better fixation strength than have traditional simple and horizontal mattress techniques. PURPOSE: To compare traditional arthroscopic suture configurations to locked arthroscopic configurations in ability to resist gap formation under cyclic loading. STUDY DESIGN: Controlled laboratory study. METHODS: Crescent-shaped defects were created at the infraspinatus tendon insertion in 32 bovine shoulders. Four arthroscopic suture configurations were tested (8 specimens in each group): simple (group 1), horizontal mattress (group 2), locked mattress (group 3), and locked inverted mattress (group 4). A metal corkscrew suture anchor doubly loaded with No. 2 Fiberwire suture was used for the repairs. A cyclic loading protocol with application of forces from 10 to 180 N for a maximum of 2,500 cycles was used. The number of cycles required to form gaps of 5 mm and 10 mm was recorded. RESULTS: The locked mattress configuration (group 3) outperformed all other groups in resisting 5-mm gap formation (P < .0001), requiring a mean of 628 cycles in comparison to 65, 193, and 197 cycles for groups 1, 2, and 4, respectively. Both locked configurations (groups 3 and 4) were superior to traditional simple and horizontal mattress configurations in resisting 10-mm gap formation. CONCLUSION: The locked mattress suturing technique (group 3) provided the most secure tendon fixation of all arthroscopic configurations tested. CLINICAL RELEVANCE: The use of locked suture configurations for arthroscopic rotator cuff repairs may enhance tendon fixation and limit gap formation in the early postoperative period.

Animals↗
PubMed2006

Histomorphometric analysis of poly-L/D-lactide 96/4 sutures in the gastrocnemius tendon of rabbits.

BACKGROUND: Common Achilles tendon ruptures are not usually fixed by bioabsorbable sutures due to limitations in their strength retention properties. Modern technology has made it possible to develop bioabsorbable sutures with prolonged strength retention. AIMS: To evaluate histologically tissue reactions of poly-L/D-lactide (PLDLA) sutures implanted in Achilles tendon of rabbits. MATERIAL AND METHODS: Fifteen rabbits were evaluated at 2, 6 and 12 weeks postoperatively, with five rabbits in each follow-up group. PLDLA monofilament sutures were implanted into the medial gastrocnemius tendon. Polyglyconate monofilament sutures with similar diameter (Maxon 4-0, Cyanamid of Great Britain Ltd., Gosport, UK) were implanted in the contralateral gastrocnemius tendon. The histology was studied in hard-resin embedded samples. The thickness of the formed fibrous tissue capsule was determined histomorphometrically. RESULTS: PLDLA led to formation of significantly thinner fibrous tissue capsule than Maxon sutures of the same diameter. Median thickness (PLDLA vs. Maxon) at two weeks was 5.26 vs.13.22 microm, at six weeks 11.66 vs. 80.97 microm, and at 12 weeks 10.63 vs. 17.59 microm (p<0.01). CONCLUSIONS: During the 12 week follow-up period, PLDLA sutures implanted intratendineously formed thinner fibrous capsule than Maxon sutures of the same diameter. The suture materials were not totally absorbed by 12 weeks.

Animals↗
PubMed2003

Osteopontin expression in osteoblasts and osteocytes during bone formation under mechanical stress in the calvarial suture in vivo.

UNLABELLED: To clarify the role of OPN in bone formation under mechanical stress, we examined the expression and the function of OPN in bone using an expansion force-induced osteogenesis model. Our results indicated that OPN expression was enhanced during the bone formation and that OPN would be one of the positive factors for the bone formation under mechanical stress. INTRODUCTION: Bone formation is known to be stimulated by mechanical stress; however, molecules involved in stress-dependent regulation of bone formation have not yet been fully characterized. Extracellular matrix proteins such as osteopontin (OPN) could play a role in mediation of the mechanical stress signal to osteoblasts. However, the function of OPN in bone formation under mechanical force is not known. Therefore, we examined the expression and the role of OPN in bone formation in vivo under tensile mechanical stress. MATERIALS AND METHODS: Sagittal sutures of mice were subjected to expansion mechanical stress by setting orthodontic spring wires, and OPN expression during bone formation within the suture gap was examined. RESULTS: Expansion of the sutures resulted in bone formation at the edges of the parietal bones within the sagittal suture. Immunohistochemical analysis revealed abundant accumulation of OPN protein in the matrix of newly formed bone on the inner edge of the parietal bone within the mechanically expanded sutures. Osteoblasts forming bone within the suture subjected to tensile stress also exhibited high levels of OPN protein expression. Reverse transcriptase-polymerase chain reaction (RT-PCR) analysis indicated that OPN mRNA expression was enhanced in wild-type calvariae subjected to expansion force compared with the control calvariae where dead spring wires were set without expansion stress. In addition, type I collagen mRNA was also expressed in the calvariae under the mechanical stimuli. To understand the function of OPN, sagittal sutures in OPN-deficient mice were subjected the expansion stress, and bone formation within the suture to fill the expanded gap was compared with that observed in wild-type mice. OPN deficiency reduced bone formation at the edge of the parietal bone in contact with the expanded suture gap. CONCLUSIONS: These observations revealed that OPN plays a pivotal role in bone formation under tensile mechanical stress.

Animals↗