Biphasic sutural response is key to palatal expansion

Mani Alikhani, Sarah Alansari, Mohammed M. Al Jearah, Niraj Gadhavi, Mohammad A. Hamidaddin, Fadwah A. Shembesh, Chinapa Sangsuwon, Jeanne M. Nervina, Cristina C. Teixeira

Research output: Contribution to journalArticlepeer-review


Introduction: It is assumed that transverse force physically open maxillary sutures and induce tensile stress that directly stimulates bone formation. However, orthopedic tensile stress is static, which cannot directly stimulate bone formation. We hypothesize that the anabolic response to transverse forces is indirect, the result of inflammation-induced osteoclast activation followed by a transition into osteogenesis. To test our hypothesis, we evaluated tissue, cellular, and molecular responses in the sutures during maxillary expansion. Materials and methods: Sprague-Dawley rats (n = 95) were divided into four groups (n = 5 rats/group/time point, except for the expansion group, which did not have a day 0 sample): untreated control (C), sham (S), expansion (Exp), and expansion with nonsteroidal anti-inflammatory medication (Exp + NSAID). Maxillae were collected 0, 1, 3, 7, 14, and 28 days postexpansion for micro–computed tomography, light microscopy, gene expression, protein, and immunohistochemistry analysis. Results: Compared with the sham group, the Exp group showed early expression of cytokines in the mid-palatal suture, osteoclast activation, and bone resorption resulting in widening of the suture. Anabolic bone formation was delayed, occurring after this initial catabolic phase. NSAIDs significantly decreased sutural widening, bone formation, and skeletal and dental expansion. During the transition from catabolic to anabolic phase, expression of osteoclast-osteoblast communicator molecules increased significantly. Conclusion: Transverse force stimulates two distinct phases in the mid-palatal suture. An early catabolic phase, characterized by inflammation, osteoclast recruitment, and activity, results in bone resorption and sutural widening. Then osteoclasts activate osteoblasts resulting in an anabolic phase, during which the integrity of the skeleton is reestablished.

Original languageEnglish (US)
Pages (from-to)9-17
Number of pages9
JournalJournal of the World Federation of Orthodontists
Issue number1
StatePublished - Mar 2019


  • Biphasic theory
  • Craniofacial sutures
  • Maxillary expansion
  • Orthodontics
  • Orthopedic correction
  • Palatal expansion
  • Sutural response

ASJC Scopus subject areas

  • Orthodontics


Dive into the research topics of 'Biphasic sutural response is key to palatal expansion'. Together they form a unique fingerprint.

Cite this