title: [Hard palate lengthening by palatal suture expansion: an experimental study in dogs].
abstract: OBJECTIVE
  Scar contraction and lack of bony support for soft palate in traditional surgery of cleft palate are main causes of a shortening soft palate and its developmental deficiency. The wound and scar also lead to aberration of facial growth. In order to resolve these problems, lengthening of hard palate by transverse palatal suture expansion was studied.
  
  
  METHODS
  Six mongrel dogs of 8-week age were used in the study. Amalgam markers were implanted in the hard palate of the animal. A NiTi-shaped memory alloy (NiTi-SMA) arch wire with a force level of 600 g was used to expand the palato-maxillary suture with a retention period of 8 weeks. The dogs were killed at the age of 36 weeks. Serial X-ray and cephalometry were used to investigate the changes.
  
  
  RESULTS
  The suture expansion was generally completed in 4 weeks. The distance of separation of the palatine bone and maxilla was 1.0 to 1.5 cm. Premaxilla became protrusive significantly at the beginning of the suture expansion, then restored gradually to its original position. The length of hard palate increased 4.6 to 5.9 mm by dry skull measurement.
  
  
  CONCLUSIONS
  Hard palate could be permanently lengthened anterior-posteriorly by transverse palatal suture expansion.
authors.affiliation: General Military Hospital, 100853.
authors.forename: C
authors.initials: C
authors.lastname: Liu
authors.forename: R
authors.initials: R
authors.lastname: Song
authors.forename: Y
authors.initials: Y
authors.lastname: Song
mesh_terms: D000818:Animals; D001852:Bone Lengthening / Q000379:methods*; D002508:Cephalometry; D004285:Dogs; D008437:Maxilla / Q000000981:diagnostic imaging; D009532:Nickel; D021362:Palate, Hard / Q000601:surgery*; D011859:Radiography; D013536:Suture Techniques; D015626:Tissue Expansion / Q000379:methods*; D014025:Titanium
chemical_list: C040654:titanium nickelide; D009532:Nickel; D014025:Titanium