title: A detailed anatomical assessment of the lateral tongue extrinsic musculature, and proximity to the tongue mucosal surface. Does this confirm the current TNM T4a muscular subclassification?
abstract: OBJECTIVE
  The current T4a subclassification of the TNM staging system for oral malignancies has been criticised as based almost exclusively on anatomical data. The aim of this study was to provide anatomical confirmation of the muscular constraints of T4a classification of oral tongue tumours.
  
  
  METHODS
  A detailed anatomical study describing and measuring the adjacency of the named extrinsic tongue muscles to the lateral tongue surface was completed on the Visible Human Female (VHF). The distance of styloglossus and hyoglossus to the over lying mucosa were determined.
  
  
  RESULTS
  The appearance, position, orientation and anatomical relationships of the lateral tongue extrinsic muscles, with comparison to their classical descriptions are described. The right VHF styloglossus was 1.3 mm (0.33-1.48) and left 2.91 mm (0.66-7.68) from the mucosal surface in the axial plane. The right VHF hyoglossus was 2.93 mm (1.48-4.96) and left 4.33 (1.68-8.71) from the mucosal surface in the axial line.
  
  
  CONCLUSIONS
  In the lateral tongue, styloglossus and hyoglossus are very superficial. The inclusion criteria of hyoglossus and styloglossus in the T4a staging does not appear justified based upon their anatomical position.
authors: Oxford Radiology Research Group, Oxford MRI Centre, John Radcliffe Hospital, Headley Way, Oxford, OX3 9DU, UK. Paul.william.boland@gmail.com
authors: Paul W
authors: PW
authors: Boland
authors: Kostas
authors: K
authors: Pataridis
authors: Karen A
authors: KA
authors: Eley
authors: Stephen J
authors: SJ
authors: Golding
authors: Stephen R
authors: SR
authors: Watt-Smith
mesh_terms: D002102:Cadaver; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D009061:Mouth Mucosa / Q000033:anatomy & histology; D018482:Muscle, Skeletal / Q000473:pathology*; D009367:Neoplasm Staging / Q000592:standards*; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods; D014059:Tongue / Q000033:anatomy & histology*; D014062:Tongue Neoplasms / Q000145:classification / Q000473:pathology*
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