title: Relaxin affects the dentofacial sutural tissues.
abstract: This is a report of an exploratory study of how the hormone relaxin might modulate the remodeling of connective tissue within the craniofacial sutures and periodontal tissues. Relaxin is a hormone that was discovered to be produced by the pregnant female. It is responsible for the relaxing of the pubic symphysis; the birth canal is widened for parturition. It has also been shown to have effects on other areas of the body, including ligaments and regions containing collagen and fibroblastic activity. Twenty-one Swiss retired-breeder mice were used to: 1) immunohistochemically demonstrate the presence of relaxin within the sutures; 2) demonstrate its effects on the integrity of the suture-like tissues; and 3) assay its effects on protease activity. Relaxin in concentrations of 250 and 500 ng/ml was used in the treated samples and allowed to incubate in complete tissue culture for 24 h. The results indicate the presence of relaxin within the cranial suture. Histological observations revealed definite changes in the collagen fibril arrangement in the PDL - from being dense and highly organized with a perpendicular direction between tooth and bone to randomly organized and loose, lacking any direction between tooth and bone. An elevation in the protease activity was evident in the relaxin-treated samples. This naturally occurring hormone might be used as an adjunct to orthodontic therapy as it appears to have the capacity to alter the physical properties of the connective tissue within sutures, gingival tissue, and the PDL. Potential indications for use include instances of sutural and soft tissue adaptation of orthopedic expansion in non-growing patients by a reduction in the tension of the stretched soft tissue envelope following orthognathic surgery (particularly the expanded palatal mucosa), periodontal ligament remodeling during or after tooth movement promoting stability, rapid gingival tissue remodeling during space closure in extraction sites, and by a decrease in the amount of scar tissue formation following frenectomies.
authors.affiliation: Princeton Professional Park, Suite B-12, 601 Ewing St., Princeton, NJ 08540; University of Pennsylvania, Department of Biochemistry, School of Dental Medicine and Department of Orthodontics, Temple University, Philadelphia, PA; Department of Orthodontics, Temple University, Philadelphia, PA.
authors.forename: Jonathan L.
authors.initials: JL
authors.lastname: Nicozisis
authors.forename: Hyun-Duck
authors.initials: HD
authors.lastname: Nah-Cederquist
authors.forename: Orhan C.
authors.initials: OC
authors.lastname: Tuncay