ABSTRACT
Evaluate the use of cone beam computed tomography among orthodontists in two areas of the Pacific Coast region via an electronic survey sent to the chairs of the orthodontic programs at the University of California, San Francisco, and A.T. Still University in Mesa, Ariz. The survey link was subsequently forwarded to each program's alumni. Overall, 85.7 percent of the orthodontists reported using CBCT scans. The scans were primarily used for impacted/supernumerary teeth and temporomandibular joint disorders analysis.
Subject(s)
Cone-Beam Computed Tomography/statistics & numerical data , Orthodontics/statistics & numerical data , Arizona , Cone-Beam Computed Tomography/economics , Cone-Beam Computed Tomography/instrumentation , Humans , Imaging, Three-Dimensional/statistics & numerical data , Patient Care Planning , Pilot Projects , Practice Patterns, Dentists'/statistics & numerical data , Private Practice , Radiation Dosage , San Francisco , Temporomandibular Joint Disorders/diagnostic imaging , Tooth, Impacted/diagnostic imaging , Tooth, Supernumerary/diagnostic imagingABSTRACT
Epimorphic regeneration is a unique and complex instance of postembryonic growth observed in certain metazoans that is usually triggered by severe injury [Akimenko et al., 2003; Alvarado and Tsonis, 2006; Brockes, 1997; Endo et al., 2004]. Cell division and migration are two fundamental biological processes required for supplying replacement cells during regeneration [Endo et al., 2004; Slack, 2007]. However, the connection between the early stimuli generated after injury and the signals regulating proliferation and migration during regeneration remain largely unknown. Here we show that the oncogenes ErbB2 and ErbB3, two members of the EGFR family, are essential for mounting a successful regeneration response in vertebrates. Importantly, amputation-induced progenitor proliferation and migration are significantly reduced upon genetic and/or chemical modulation of ErbB function. Moreover, we also found that NRG1 and PI3K functionally interact with ErbB2 and ErbB3 during regeneration and interfering with their function also abrogates the capacity of progenitor cells to regenerate lost structures upon amputation. Our findings suggest that ErbB, PI3K and NRG1 are components of a permissive switch for migration and proliferation continuously acting across the amputated fin from early stages of vertebrate regeneration onwards that regulate the expression of the transcription factors lef1 and msxB.
