title: Detailed Anatomy of the Nasolabial Muscle in Human Fetuses as Determined by Micro-CT Combined With Iodine Staining.
abstract: OBJECTIVE
  This study aims to investigate the 3-dimensional (3D) anatomical structure of the orbicularis oris and nasalis, which are closely associated with the appearance of the upper lip and lower part of the nose. The relationship of the complicated 3D anatomical structure with the outline shape was also determined.
  
  
  METHODS
  Microcomputed tomography combined with iodine staining was used to scan the nasolabial tissues of 3 aborted fetuses. The strictly aligned, corrected, full-capacity, 2-dimensional (2D) grayscale images obtained were then used to reconstruct 3D structures using a 3D reconstruction software.
  
  
  RESULTS
  2D grayscale slices and a 3D anatomical model of the orbicularis oris and nasalis of the specimens were obtained. The 2D images and the 3D model confirmed the orbicularis oris anatomical structure reported in previous studies and also provided new insights (such as the close association of the formation of the philtral dimple, lip peak, philtral ridge, and nasal sill with the orbicularis oris). In addition, the results show that the nasolabial muscle consists of muscle fibers from different sources and is divided into four distinct parts: pars marginalis, pars peripheralis, muscle fibers of the levator labii superioris, and nasalis muscle fibers.
  
  
  CONCLUSIONS
  The 3D anatomical structures indicate that the orbicularis oris and nasalis are closely associated with the appearances of the upper lip and lower part of the nose. The results may aid plastic surgeons in performing cleft-lip correction surgery.
authors.affiliation: From the Department of Cleft Lip and Palate, Plastic Surgery Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Field of Plastic Surgery, Beijing, China.
authors.forename: Jiajun
authors.initials: J
authors.lastname: Wu
authors.forename: Ningbei
authors.initials: N
authors.lastname: Yin
mesh_terms: D000022:Abortion, Spontaneous; D005152:Facial Muscles / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D005260:Female; D005333:Fetus / Q000033:anatomy & histology*; D005865:Gestational Age; D006801:Humans; D007455:Iodine; D060052:Nasolabial Fold / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D011247:Pregnancy; D019651:Plastic Surgery Procedures / Q000379:methods; D012680:Sensitivity and Specificity; D013194:Staining and Labeling / Q000379:methods*; D055114:X-Ray Microtomography / Q000379:methods*
chemical_list: D007455:Iodine