Plagiocephaly

Plagiocephaly is due to positioning or synostosis of a single lambdoid or coronal suture (1):

• causes an abnormal head shape by restricting the growth of the cranium
  • manifests at birth or months later with the deformity of the skull known as plagiocephaly - in its broadest meaning, plagiocephaly, as derived from the Greek, means crooked head and is the presentation of true, simple craniosynostosis
  • refinements of the terminology to describe specific types of synostosis are derived from Greek roots, such as scaphocephaly and trigonocephaly, which characterize the appearances of the skull in sagittal and metopic synostosis, respectively.
  • plagiocephaly proper is generally reserved for the deformation of the skull seen in either coronal (anterior plagiocephaly) or lambdoid (posterior plagiocephaly) synostosis, or else in deformational plagiocephaly
    • deformational (or positional) plagiocephaly refers to a condition in which an infant’s head becomes deformed as the result of external forces applied to the malleable cranium
      • deformity can occur prenatally or postnatally
        • prenatally, congenital deformities are associated with a restrictive intrauterine environment, including a small maternal pelvis, abnormal uterine structure, large or multiple foetuses, paucity or excess of amniotic fluid, or increased abdominal or uterine muscle tone (2)
        • postnatally, cranial deformation has been attributed to a supine sleeping position, and congenital muscular torticollis, neurologic or cervical deficits, and premature birth, and and prolonged periods in car seats and infant carriers (2)
      • positional plagiocephaly is a non-synostotic condition in which there is a deformation of the cranial vault in the presence of otherwise open, normally functioning sutures
      • condition is characterized by right or left occipital flattening, with anterior advancement of the ipsilateral ear and forehead.
      • in the USA, the “Back to Sleep” campaign dramatically decreased the incidence of sudden infant death syndrome; however, its sequelae of deformational plagiocephaly have today reached epidemic proportions
      • current prevalence of deformational plagiocephaly is 10% to 15% (2)
      • positional plagiocephaly is a cranial vault deformation in the presence of open cranial vault sutures with no negative neurologic consequences
        • a distinct morphologic pattern and patent cranial sutures noted on confirmatory radiographic studies distinguish positional plagiocephaly from abnormal head shapes secondary to craniosynostosis
        • management consists of conservative (nonsurgical) means, depending on the extent of the cranial asymmetry and any contributing aetiological factors
          • reduction of the incidence of plagiocephaly can be achieved through early intervention and in educating parents about conservative preventive measures (eg, repositioning, physical therapy, supervised tummy time)
          • should preventative measures fail and infants develop persistent sleep patterns that result in craniofacial deformities, deformational plagiocephaly can be treated successfully with behaviour modification or cranial moulding-helmet therapy

References:

1. Lekovic GP et al. Cognitive impact of craniosynostosis. Seminars in Pediatric Neurology 2004; 11 (4): 305-310.
2. Littlefield TR et al. On the current incidence of deformational plagiocephaly: An estimation based on prospective registration at a single center Seminars in Pediatric Neurology 2004; 11 (4): 301-304.
3. Losee JE, Mason AC. Deformational plagiocephaly: diagnosis, prevention, and treatment Clinics in Plastic Surgery 2005; 32 (1):53-64.
4. Caccamese J et al. Positional plagiocephaly: evaluation and management Oral and Maxillofacial Surgery Clinics of North America 2004; 16 (4): 439-446.