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Evidence-Based Care of the Child With Deformational Plagiocephaly, Part I: Assessment and Diagnosis

      Abstract

      Non-synostotic deformational plagiocephaly (DP) is head asymmetry that results from external forces that mold the skull in the first year of life. Primary care providers are most likely to encounter DP when infants present for well-child care, and for this reason it is important that providers be competent in assessing, diagnosing, and participating in the prevention and management of DP. The purpose of this two-part series on DP is to present an overview of assessment, diagnosis, and evidence-based management of DP for health care providers. In Part I we provide a brief background of DP and associated problems with torticollis and infant development, and we present strategies for visual and anthropometric assessment of the infant with suspected DP. We also provide tools for differentiating DP from craniosynostosis and for classifying the type and severity of lateral and posterior DP. Part II (to be published in a future issue of the Journal of Pediatric Health Care) provides a synthesis of current evidence and a clinical decision tool for evidence-based management of DP.

      Key Words

      Objectives

      • 1.
        Explain the significance of the correlation between normal infant development and the development of positional/deformational plagiocephaly.
      • 2.
        Describe the implications of torticollis as it relates to the development and management of deformational plagiocephaly.
      • 3.
        Identify key features that distinguish synostotic from non-synostotic plagiocephaly.
      • 4.
        Demonstrate/describe the procedure for obtaining standardized measurements of the infant skull.
      • 5.
        Classify head asymmetry in an infant based on assessment findings according to type (lateral versus posterior) and severity (mild, moderate, and severe).
      “Plagiocephaly” refers to an asymmetrical, flattened deformity of the skull (
      • Robinson S.
      • Proctor M.
      Diagnosis and management of deformational plagiocephaly.
      ) and can be used to describe both synostotic and non-synostotic head asymmetry. Synostotic plagiocephaly, which is rare, is due to premature fusion of one or more of the sutures of the skull (
      • Smartt Jr., J.M.
      • Elliott R.M.
      • Reid R.R.
      • Bartlett S.P.
      Analysis of differences in the cranial base and facial skeleton of patients with lambdoid synostosis and deformational plagiocephaly.
      ). Non-synostotic plagiocephaly is often referred to as positional or deformational plagiocephaly (DP) because it results from external forces that mold the skull. In this article, DP refers to non-synostotic plagiocephaly, which presents most commonly as one of two forms: lateral DP (flatness on one side of the occiput) and posterior DP (central flattening of the back of the head). The purpose of this article is to provide an overview and strategies for assessment and classification of DP.

      Background

      In the first months of life, DP is closely associated with the infant’s motor development. Within the first weeks of an infant’s life, DP generally becomes more severe because the infant has little active positioning of the head; then the head shape begins to improve with progression of normal development (
      • Miller R.I.
      • Clarren S.K.
      Long-term developmental outcomes in patients with deformational plagiocephaly.
      ). The peak prevalence of DP is 4 months of age (
      • Boere-Boonekamp M.M.
      • van der Linden-Kuiper L.T.
      Positional preference: Prevalence in infants and follow-up after two years.
      ). Until 4 months of age, an infant is not able to hold his or her head up when sitting without support; at 6 months, the infant should have strong and steady head control. In his or her first 6 months, an infant’s head grows rapidly. In the first 3 months, the head circumference increases by about 2 cm per month, and it increases by about 1 cm per month between 4 and 6 months of age (
      • Guo S.
      • Roche A.F.
      • Moore W.M.
      Reference data for head circumference and 1-month increments from 1 to 12 months of age.
      ). After 6 months, the velocity of growth in head circumference decreases to about 0.5 cm per month (
      • Guo S.
      • Roche A.F.
      • Moore W.M.
      Reference data for head circumference and 1-month increments from 1 to 12 months of age.
      ).

      Generational and Cultural Factors and Head Shape

      The definition of a “normal” head shape depends in part on one’s cultural norms and practices, including sleep position. The use of external, mechanical forces to purposely mold the shape of an infant’s head (called artificial cranial deformation) was practiced by various cultures for thousands of years, and in ancient times skull shape was a measure of social distinction (
      • Ayer A.
      • Campbell A.
      • Appelboom G.
      • Hwang B.Y.
      • McDowell M.
      • Piazza M.
      • Anderson R.C.
      • et al.
      The sociopolitical history and physiological underpinnings of skull deformation.
      ). Swaddling also can result in a brachycephalic head shape, in which the ratio of the head width to head length (cephalic index [CI]) is higher (
      • Graham Jr., J.M.
      • Kreutzman J.
      • Earl D.
      • Halberg A.
      • Samayoa C.
      • Guo X.
      Deformational brachycephaly in supine-sleeping infants.
      ,
      • Jantz R.L.
      • Logan M.H.
      Why does head form change in children of immigrants? A reappraisal.
      ). In Asia, where infants traditionally are placed on their backs to sleep, brachycephaly is the norm; schoolchildren in Japan and Korea are reported to have a CI in the range of 85% to 91% (
      • Graham Jr., J.M.
      • Kreutzman J.
      • Earl D.
      • Halberg A.
      • Samayoa C.
      • Guo X.
      Deformational brachycephaly in supine-sleeping infants.
      ). Infants in Nigeria, where infants typically sleep prone, have a CI in the range of 75% to 78%. In the United States in 1977, when infants routinely were placed prone to sleep, the mean CI was 78% for a group of 1058 White children between the ages of 7 days to 20 years, with very little fluctuation across the age groups (
      • Dekaban A.S.
      Tables of cranial and orbital measurements, cranial volume, and derived indexes in males and females from 7 days to 20 years of age.
      ). In 2005 in the United States, when infants routinely were placed supine to sleep, the normative CI for healthy infants was 86% to 88% (
      • Graham Jr., J.M.
      • Kreutzman J.
      • Earl D.
      • Halberg A.
      • Samayoa C.
      • Guo X.
      Deformational brachycephaly in supine-sleeping infants.
      ). Some evidence indicates that children born in the more recent generation have heads that are wider and shorter than current published norms for age and gender, which were established in the 1970s (
      • Pomatto J.K.
      • Calcaterra J.
      • Kelly K.M.
      • Beals S.P.
      • Manwaring K.H.
      • Littlefield T.R.
      A study of family head shape: Environment alters cranial shape.
      ).

      Risk Factors for Deformational Plagiocephaly

      Sleep position is one of a number of proposed risk factors for DP. Several prospective cohort studies of infants (
      • Hutchison B.L.
      • Hutchison L.A.
      • Thompson J.M.
      • Mitchell E.A.
      Plagiocephaly and brachycephaly in the first two years of life: A prospective cohort study.
      ,
      • van Vlimmeren L.A.
      • van der Graaf Y.
      • Boere-Boonekamp M.
      • L’Hoir M.
      • Helders P.
      • Engelbert R.
      Risk factors for deformational plagiocephaly at birth and at 7 weeks of age: A prospective cohort study.
      ) and case series studies of infants with DP (
      • Golden K.A.
      • Beals S.P.
      • Littlefield T.R.
      • Pomatto J.K.
      Sternocleidomastoid imbalance versus congenital muscular torticollis: Their relationship to positional plagiocephaly.
      ,
      • Losee J.E.
      • Mason A.C.
      • Dudas J.
      • Hua L.B.
      • Mooney M.P.
      Nonsynostotic occipital plagiocephaly: Factors impacting onset, treatment, and outcomes.
      ) have suggested that possible risk factors for DP include assisted delivery, first-born child, male sex, cumulative exposure to the supine position, and infant neck problems. DP is also associated with intrauterine constraint (
      • Stellwagen L.
      • Hubbard E.
      • Chambers C.
      • Jones K.L.
      Torticollis, facial asymmetry and plagiocephaly in normal newborns.
      ). Although many of these risk factors are not preventable, supine sleep position seems to be the best predictor of DP independent of these factors (
      • Joganic J.L.
      • Lynch J.M.
      • Littlefield T.R.
      • Verrelli B.C.
      Risk factors associated with deformational plagiocephaly.
      ). Infant care trends over time and cultural norms seem to support this finding, as evidenced by a recent shift in recommendations for infant positioning in the United States.

      Correlation With the Back to Sleep Campaign

      In 1992 the American Academy of Pediatrics (AAP) published a report recommending that healthy infants be placed to sleep on their side or backs (
      American Academy of Pediatrics
      American Academy of Pediatrics Task Force on Infant Positioning and SIDS: Positioning and SIDS.
      ). Since the AAP’s Back to Sleep campaign, the incidence of sudden infant death syndrome has decreased more than 40% (
      • Persing J.
      • James H.
      • Swanson J.
      • Kattwinkel J.
      American Academy of Pediatrics Committee on Practice and Ambulatory Medicine, Section on Plastic Surgery and Section on Neurological Surgery
      Prevention and management of positional skull deformities in infants.
      ). Prior to 1992, the incidence of DP was estimated at 1 in 300 infants (
      • O’Broin E.S.
      • Allcutt D.
      • Earley M.J.
      Posterior plagiocephaly: Proactive conservative management.
      ). After the recommendation a dramatic increase of up to 600% in referrals for plagiocephaly was reported by primary care providers and craniofacial centers (
      • Argenta L.
      • David L.R.
      • Wilson J.A.
      • Bell W.O.
      An increase in infant cranial deformity with supine sleeping position.
      ). Because many positional head shape deformities improve with time (
      • Hutchison B.L.
      • Stewart A.W.
      • Mitchell E.A.
      Characteristics, head shape measurements and developmental delay in 287 consecutive infants attending a plagiocephaly clinic.
      ), the existence of DP is higher in younger infants, and estimates of prevalence are highly age-dependent.
      • Bialocerkowski A.E.
      • Vladusic S.L.
      • Wei Ng C.
      Prevalence, risk factors, and natural history of positional plagiocephaly: A systematic review.
      noted that the point prevalence of DP at 1 year of age (6.8%) has not significantly changed in the past 40 years, and they suggested that an increase in referral rates may be the result of increased awareness of early referral for evaluation of infants with skull deformities, rather than an increase in prevalence.

      Developmental Factors Related to Deformational Plagiocephaly

      Emerging evidence suggests that infants with DP are less active (
      • Hutchison B.L.
      • Hutchison L.A.
      • Thompson J.M.
      • Mitchell E.A.
      Plagiocephaly and brachycephaly in the first two years of life: A prospective cohort study.
      ), have variable tone (
      • Fowler E.A.
      • Becker D.B.
      • Pilgram T.K.
      • Noetzel M.
      • Epstein J.
      • Kane A.A.
      Neurologic findings in infants with deformational plagiocephaly.
      ), and are delayed in some areas of development compared with their age-matched peers (
      • Collett B.
      • Breiger D.
      • King D.
      • Cunningham M.
      • Speltz M.
      Neurodevelopmental implications of “deformational” plagiocephaly.
      ,
      • Hutchison B.L.
      • Stewart A.W.
      • Mitchell E.A.
      Characteristics, head shape measurements and developmental delay in 287 consecutive infants attending a plagiocephaly clinic.
      ,
      • Speltz M.L.
      • Collett B.R.
      • Stott-Miller M.
      • Starr J.R.
      • Heike C.
      • Wolfram-Aduan A.M.
      • Cunningham M.L.
      • et al.
      Case-control study of neurodevelopment in deformational plagiocephaly.
      ). The association between neurological development and synostotic skull asymmetry has been a focus of research for several years (
      • Kapp-Simon K.A.
      • Figueroa A.
      • Jocher C.A.
      • Schafer M.
      Longitudinal assessment of mental development in infants with nonsyndromic craniosynostosis with and without cranial release and reconstruction.
      ,
      • Kapp-Simon K.A.
      • Speltz M.L.
      • Cunningham M.L.
      • Patel P.K.
      • Tomita T.
      Neurodevelopment of children with single suture craniosynostosis: A review.
      ,
      • Panchal J.
      • Amirsheybani H.
      • Gurwitch R.
      • Cook V.
      • Francel P.
      • Neas B.
      • Levine N.
      Neurodevelopment in children with single-suture craniosynostosis and plagiocephaly without synostosis.
      ,
      • Sidoti Jr., E.J.
      • Marsh J.L.
      • Marty-Grames L.
      • Noetzel M.J.
      Long-term studies of metopic synostosis: Frequency of cognitive impairment and behavioral disturbances.
      ), but until recently, it was presumed that plagiocephaly without synostosis was not associated with developmental delay (
      • Panchal J.
      • Amirsheybani H.
      • Gurwitch R.
      • Cook V.
      • Francel P.
      • Neas B.
      • Levine N.
      Neurodevelopment in children with single-suture craniosynostosis and plagiocephaly without synostosis.
      ). Within the past few years, however, evidence has increased for a significant association, if not a causal pathway, between developmental delay and deformational (non-synostotic) plagiocephaly (
      • Collett B.
      • Breiger D.
      • King D.
      • Cunningham M.
      • Speltz M.
      Neurodevelopmental implications of “deformational” plagiocephaly.
      ,
      • Fowler E.A.
      • Becker D.B.
      • Pilgram T.K.
      • Noetzel M.
      • Epstein J.
      • Kane A.A.
      Neurologic findings in infants with deformational plagiocephaly.
      ,
      • Hutchison B.L.
      • Stewart A.W.
      • Mitchell E.A.
      Characteristics, head shape measurements and developmental delay in 287 consecutive infants attending a plagiocephaly clinic.
      ,
      • Hutchison B.L.
      • Stewart A.W.
      • De Chalain T.B.
      • Mitchell E.A.
      A randomized controlled trial of positioning treatments in infants with positional head shape deformities.
      ,
      • Speltz M.L.
      • Collett B.R.
      • Stott-Miller M.
      • Starr J.R.
      • Heike C.
      • Wolfram-Aduan A.M.
      • Cunningham M.L.
      • et al.
      Case-control study of neurodevelopment in deformational plagiocephaly.
      ).
      • Speltz M.L.
      • Collett B.R.
      • Stott-Miller M.
      • Starr J.R.
      • Heike C.
      • Wolfram-Aduan A.M.
      • Cunningham M.L.
      • et al.
      Case-control study of neurodevelopment in deformational plagiocephaly.
      conducted a case-control study of infants with DP with age-matched and sociodemographic-matched control subjects. They found clinically significant differences in gross motor development; infants with DP scored lower on items such as sitting up, rolling back to side, and crawling. In a similar case-control study,
      • Fowler E.A.
      • Becker D.B.
      • Pilgram T.K.
      • Noetzel M.
      • Epstein J.
      • Kane A.A.
      Neurologic findings in infants with deformational plagiocephaly.
      found significant variability in tone among children with DP at the time of diagnosis.
      • Robinson S.
      • Proctor M.
      Diagnosis and management of deformational plagiocephaly.
      noted that the current body of evidence does not suggest that DP by itself is a risk factor for delayed development in infants. Rather, the association between some developmental delays and DP indicates that providers should be aware of an increased possibility of delay among infants with DP, and developmental assessment is essential as part of the management of children with this condition.

      Torticollis and Deformational Plagiocephaly

      Torticollis is the most common associated finding in infants with deformational plagiocephaly (
      • Rogers G.F.
      • Oh A.K.
      • Mulliken J.B.
      The role of congenital muscular torticollis in the development of deformational plagiocephaly.
      ). Although limited evidence exists to establish whether torticollis leads to or results from DP,
      • Rogers G.F.
      • Oh A.K.
      • Mulliken J.B.
      The role of congenital muscular torticollis in the development of deformational plagiocephaly.
      propose that torticollis precedes head shape changes based on their prospective study of 371 infants with cranial asymmetry. They propose that head positional preference is due to cervical imbalance rather than environmental factors (because of the location of the crib or the preferred side for breastfeeding, for example), and that head position preference manifests as torticollis, which later leads to flattening of one side of the head. Based on a prospective study of 102 healthy newborns,
      • Stellwagen L.
      • Hubbard E.
      • Chambers C.
      • Jones K.L.
      Torticollis, facial asymmetry and plagiocephaly in normal newborns.
      reported that most newborns have mild or moderate craniofacial asymmetries, and as many as one in six newborns have torticollis.
      • Stellwagen L.
      • Hubbard E.
      • Chambers C.
      • Jones K.L.
      Torticollis, facial asymmetry and plagiocephaly in normal newborns.
      suggest that many newborns with limited neck range of motion are not diagnosed or reported because of an incomplete examination or because only the most severe cases are reported. The high prevalence of torticollis at birth supports the hypothesis that deformation follows head rotational preference.
      Regardless of the direction of influence, torticollis is important to identify and manage as part of the management plan for DP, because torticollis can limit efforts at repositioning therapy and normal development (
      • van Vlimmeren L.A.
      • Helders P.J.
      • van Adrichem L.N.
      • Engelbert R.H.
      Torticollis and plagiocephaly in infancy: Therapeutic strategies.
      ). An early referral to physical therapy is important and torticollis needs to be treated as a separate condition, which involves a multidisciplinary approach (
      • Do T.T.
      Congenital muscular torticollis: Current concepts and review of treatment.
      ). For an infant with torticollis, early referral should be initiated, although the specific protocol depends on each practitioner.

      Assessment and Diagnosis of Deformational Plagiocephaly

      Knowing when to monitor and when to refer requires an ability to recognize early DP, distinguish DP from craniosynostosis, and recognize improvement or worsening of head asymmetry in an infant.
      Pediatric primary care providers are competent to diagnose DP (
      • Robinson S.
      • Proctor M.
      Diagnosis and management of deformational plagiocephaly.
      ). Keen assessment and diagnostic skills may maximize outcomes and minimize cost for families and payers through judicious use of referrals. Knowing when to monitor and when to refer requires an ability to recognize early DP, distinguish DP from craniosynostosis, and recognize improvement or worsening of head asymmetry in an infant. Referring an infant with DP too early may lead to unnecessary specialty visits, whereas referring an infant too late may limit the treatment options for an infant with progressive DP (
      • White N.
      • Warner R.M.
      • Noons P.
      • McAlister E.M.
      • Solanki G.
      • Nishikawa H.
      • Dover M.S.
      Changing referral patterns to a designated craniofacial centre over a four-year period.
      ).
      In addition to clinical examination, many tools are available for the clinical diagnosis of DP, including anthropometric calipers, molding devices, digital devices with software analysis, photography, radiologic imaging, and three-dimensional scanning devices (
      • McGarry A.
      • Dixon M.T.
      • Greig R.J.
      • Hamilton D.R.
      • Sexton S.
      • Smart H.
      Head shape measurement standards and cranial orthoses in the treatment of infants with deformational plagiocephaly: A systematic review.
      ). Varying degrees of clinical expertise in diagnosing DP also exist. Craniofacial dysmorphologists are specialists who encounter this condition on a regular basis. Primary care providers are competent in assessment and diagnosis and participate in the prevention and management of DP. Radiologic imaging is costly, subjects infants to radiation, and is not necessary for the majority of children with plagiocephaly; imaging that is required generally should be ordered by specialists rather than by primary or acute care providers (
      • Hutchison B.L.
      • Stewart A.W.
      • Mitchell E.A.
      Characteristics, head shape measurements and developmental delay in 287 consecutive infants attending a plagiocephaly clinic.
      ,
      • Persing J.
      • James H.
      • Swanson J.
      • Kattwinkel J.
      American Academy of Pediatrics Committee on Practice and Ambulatory Medicine, Section on Plastic Surgery and Section on Neurological Surgery
      Prevention and management of positional skull deformities in infants.
      ,
      • Robinson S.
      • Proctor M.
      Diagnosis and management of deformational plagiocephaly.
      ). Referral to craniofacial specialists is recommended for a new diagnosis of moderate to severe DP or in cases where etiology is unclear (
      • Robinson S.
      • Proctor M.
      Diagnosis and management of deformational plagiocephaly.
      ).

      Visual Assessment

      Examination of the infant with possible plagiocephaly should include observation from the anterior, posterior, and vertex positions (
      • Losee J.E.
      • Mason A.C.
      Deformational plagiocephaly: Diagnosis, prevention, and treatment.
      ). When viewing the infant from the front (facial view), look for symmetry of cheeks, eyes, and ears. In up to 80% of infants with lateral DP, the forehead on the side of the flattening is shifted forward (
      • Losee J.E.
      • Mason A.C.
      Deformational plagiocephaly: Diagnosis, prevention, and treatment.
      ). In some cases of plagiocephaly, the top of the head may not be level (
      • Nield L.S.
      • Brunner M.D.
      • Kamat D.
      The infant with a misshapen head.
      ). In infants with posterior DP (brachycephaly), the head appears wide, and the skull may be prominent above the ears (
      • Regelsberger J.
      • Delling G.
      • Tsokos M.
      • Helmke K.
      • Kammler G.
      • Kranzlein H.
      • Westphal M.
      High-frequency ultrasound confirmation of positional plagiocephaly.
      ). From a posterior perspective, look for symmetry of the base of the skull, because occipitomastoid bulging may indicate craniosynostosis of the lambdoid suture on that side of the skull (
      • Losee J.E.
      • Mason A.C.
      Deformational plagiocephaly: Diagnosis, prevention, and treatment.
      ). From a vertex (bird’s eye) view, look for symmetry between the right and left sides and note any flatness on one portion of the head. The normal head shape is slightly longer than it is wide (
      • Dekaban A.S.
      Tables of cranial and orbital measurements, cranial volume, and derived indexes in males and females from 7 days to 20 years of age.
      ). Figure 1 shows key findings in lateral and posterior DP from a vertex perspective. Placing one index finger in each of the infant’s external auditory canals and viewing from above can aid in detecting anterior or posterior displacement of one ear, which can occur in plagiocephaly (
      • Smartt Jr., J.M.
      • Elliott R.M.
      • Reid R.R.
      • Bartlett S.P.
      Analysis of differences in the cranial base and facial skeleton of patients with lambdoid synostosis and deformational plagiocephaly.
      ). From a side view, look for flatness on the back of the head or a high, sloping forehead. Also note symmetry of the left and right sides. A view of the infant’s head from below (“worm’s eye view”) can be achieved when the infant is supine. From this vantage point, look for symmetry of the ear position, a smooth arch of the forehead, and the degree to which cheeks are of equal height (Nield et al., 2007). As you interact with the infant, note any preference for right or left lateral rotation of the neck. Finally, look and feel for any ridging of suture lines, which can indicate craniosynostosis.
      Figure thumbnail gr1
      Figure 1Vertex views of mild, moderate, and severe lateral and posterior deformational plagiocephaly.

      Distinguishing Deformational From Synostotic Plagiocephaly

      Persistent progressive head shape deformities may be due to factors other than external forces that lead to molding. In some cases, plagiocephaly is a result of premature fusion of one or more sutures (craniosynostosis). Although craniosynostosis is rare (about 1 in 2000 live births;
      • Kabbani H.
      • Raghuveer T.S.
      Craniosynostosis.
      ), it is important to rule out synostosis as a primary cause of abnormal head shape in an infant. The most common type of non-syndromal craniosynostosis is sagittal synostosis, which presents as a long, narrow head with bitemporal narrowing and a palpable bony ridge along the top of the head (
      • Nield L.S.
      • Brunner M.D.
      • Kamat D.
      The infant with a misshapen head.
      ). The type of craniosynostosis that presents most like deformational (or positional) plagiocephaly is lambdoid craniosynostosis, which is very rare (approximately 1 in 300,000 births;
      • Persing J.
      • James H.
      • Swanson J.
      • Kattwinkel J.
      American Academy of Pediatrics Committee on Practice and Ambulatory Medicine, Section on Plastic Surgery and Section on Neurological Surgery
      Prevention and management of positional skull deformities in infants.
      ).
      Lambdoid craniosynostosis can be distinguished from DP by history and clinical presentation (Table 1). Two important distinguishing features are ear displacement (the ipsilateral ear is posteriorly displaced in lambdoid craniosynostosis and anteriorly displaced in DP) and the presence of palpable bony ridges along the lambdoid suture in lambdoid craniosynostosis (
      • Kabbani H.
      • Raghuveer T.S.
      Craniosynostosis.
      ). Bilateral coronal synostosis can lead to brachycephaly, which presents similarly to posterior DP (
      • Blaser S.I.
      Abnormal skull shape.
      ). If there is doubt about the presence of synostosis in an infant with an abnormal head shape, or if signs or symptoms of increased intracranial pressure or poor brain growth are noted, the provider should refer the infant directly to a pediatric craniofacial clinic and/or a neurosurgeon (
      • Nield L.S.
      • Brunner M.D.
      • Kamat D.
      The infant with a misshapen head.
      ).
      Table 1Key differences between synostotic and non-synostotic plagiocephaly
      CharacteristicNon-synostotic (deformational) plagiocephalySynostotic plagiocephaly
      Cause/definitionAbnormally shaped head due to external forces applied to the skull, not due to craniosynostosisPremature fusion of one or more cranial sutures; exact cause unknown; genetic and environmental factors may play a role
      Common typesLateral deformational (positional) plagiocephaly; posterior deformational plagiocephaly (positional brachycephaly)Bilateral coronal craniosynostosis (synostotic brachycephaly); sagittal craniosynostosis (dolichocephaly/>scaphocephaly); metopic craniosynostosis (trogonocephaly)
      Distinguishing featuresRound, symmetrical head shape at birth; parallelogram or brachycephalic head shape; ear may be anteriorly displaced; no palpable bony ridgesMay have abnormal head shape at birth; trapezoid head shape; ear may be posteriorly displaced; palpable bony ridges
      ManagementRepositioning and physical therapy; helmet in some casesUsually surgery; helmet in some cases
      Note: Adapted from Table 1, Table 2 in
      • Nield L.S.
      • Brunner M.D.
      • Kamat D.
      The infant with a misshapen head.
      .

      Anthropometric Assessment

      Accurate and consistent physical measurements aid in the diagnosis and clinical management of the infant with an abnormal skull.
      Accurate and consistent physical measurements aid in the diagnosis and clinical management of the infant with an abnormal skull. The value of each measurement lies in comparison with age-related norms or the individual patient at another point in time (
      • Hall J.G.
      • Allanson J.E.
      • Gripp K.W.
      • Slavotinek A.M.
      Handbook of physical measurements.
      ). In addition to routine measurements of head circumference (occipital-frontal circumference), measurements of the infant’s cranial width, length, and transcranial diameters allow the practitioner to diagnose, classify, and monitor the presence and severity of plagiocephaly (see Table 2, Table 3). These measurements can be taken with anthropometric spreading calipers or sliding calipers (Figure 2). Head length is measured at the glabella (i.e., the most prominent midpoint between the eyebrows) and the opisthocranion (i.e., the most prominent point on the occiput). These same landmarks are used to measure head circumference. Head width is measured at the maximal biparietal diameter, which may be most easily viewed from above. The infant should be upright for these measurements. The effects of thick hair can be minimized by holding the caliper points firmly against the skull (
      • Hall J.G.
      • Allanson J.E.
      • Gripp K.W.
      • Slavotinek A.M.
      Handbook of physical measurements.
      ).
      Table 2Cranial measurements used in documenting deformational plagiocephaly
      ParameterMeasurementExample (vertex view)
      Cranial width (breadth)The greatest transverse diameter of the head, on a horizontal plane
      Cranial lengthThe distance from the forehead to most posterior point of the head, in the same plane as measured in head circumference
      Cephalic index (cranial index)The ratio of the cranial width to the cranial length
      Occipital-frontal transcranial diameterDetermine the sites on the left and right sides of the head where the deformation is the most prominent; measure the diagonal distances between these sites
      Transdiagonal difference (transcranial diagonal difference)The difference between two transcranial diameters
      Note: Measurements are taken with sliding or spreading calipers.
      Table 3Diagnostic guide for determining type and severity of lateral and posterior deformational plagiocephaly
      Lateral deformational plagiocephalyPosterior deformational plagiocephaly (brachycephaly)
      Clinical findings
       Occiput (vertex view)Ipsilateral occipital flattening

      Contralateral occipital bossing
      Uniform occipital flattening
       Ear position (vertex view)Ipsilateral ear may be anteriorly displacedNormal
       Face, forehead (anterior, lateral, and vertex views)May be normal; more severe cases may present with the following: mandibular asymmetry, ipsilateral frontal bossing, contralateral forehead flattening, ipsilateral cheek anteriorly displacedTemporal bossing, increase in vertical height in severe cases
       OtherTorticollis, head position preferenceLarge size, history of limited activity or limited mobility
      Severity
      There is no firm professional consensus on the best way to subjectively or objectively classify severity of plagiocephaly; these severity categories are based on our review of published reports. The clinician's rating of severity should be used as part of a holistic assessment and to guide the practitioner in decision-making with the algorithm provided with this article.
       MildTDD
      Based on Hutchison et al. (2005).
      3-10 mm
      Flattening restricted to the back of the skull (type I)
      Based on Argenta et al. (2004).
      CI
      Based on Hutchison et al. (2010).
      : 82%-90%
      Central posterior deformity (“ping-pong ball depression”)
      Based on Argenta et al. (2004).
       ModerateTDD
      Based on Hutchison et al. (2005).
      10-12 mm
      Malposition of ear (type II), forehead deformity (type III)
      Based on Argenta et al. (2004).
      CI
      Based on Hutchison et al. (2010).
      : 90%-100%
      Central posterior deformity and widening of posterior skull
      Based on Argenta et al. (2004).
       SevereTDD
      Based on Hutchison et al. (2005).
      > 12 mm
      Malar deformity (type IV), vertical or temporal skull growth (type V)
      Based on Argenta et al. (2004).
      CI
      Based on Hutchison et al. (2010).
      : > 100%
      Vertical head, head growth, or temporal bossing
      Based on Argenta et al. (2004).
      Note: CI, Cephalic index (or cranial index); TDD, transcranial diameter difference.
      a There is no firm professional consensus on the best way to subjectively or objectively classify severity of plagiocephaly; these severity categories are based on our review of published reports. The clinician's rating of severity should be used as part of a holistic assessment and to guide the practitioner in decision-making with the algorithm provided with this article.
      b Based on
      • Hutchison B.L.
      • Hutchison L.A.
      • Thompson J.M.
      • Mitchell E.A.
      Quantification of plagiocephaly and brachycephaly in infants using a digital photographic technique.
      .
      c Based on
      • Argenta L.
      • David L.
      • Thompson J.
      Clinical classification of positional plagiocephaly.
      .
      d Based on
      • Hutchison B.L.
      • Stewart A.W.
      • De Chalain T.B.
      • Mitchell E.A.
      A randomized controlled trial of positioning treatments in infants with positional head shape deformities.
      .
      The CI is used to quantify the ratio of head width to head length (
      • Kolar J.C.
      • Salter E.M.
      Preoperative anthropometric dysmorphology in metopic synostosis.
      ), which increases with posterior DP. The CI is calculated as the ratio of the head width to the head length, multiplied by 100. In lateral DP, the most notable change in head shape may be observed in the difference between the diagonal measurements of the infant skull (occipital-frontal transcranial diameter, Table 2). The difference between the right and left diagonal measurements is the transdiagonal difference, and this value is considered the gold standard for quantifying the degree of asymmetry in lateral DP (
      • Glasgow T.S.
      • Siddiqi F.
      • Hoff C.
      • Young P.C.
      Deformational plagiocephaly: Development of an objective measure and determination of its prevalence in primary care.
      ). Cranial vault asymmetry also has been used to quantify the ratio of oblique measurements, but authors are inconsistent regarding the measurement points for cranial vault asymmetry (
      • Lee R.P.
      • Teichgraeber J.F.
      • Baumgartner J.E.
      • Waller A.L.
      • English J.D.
      • Lasky R.E.
      • Xia J.J.
      • et al.
      Long-term treatment effectiveness of molding helmet therapy in the correction of posterior deformational plagiocephaly: A five-year follow-up.
      ,
      • Lipira A.B.
      • Gordon S.
      • Darvann T.A.
      • Hermann N.V.
      • Van Pelt A.E.
      • Naidoo S.D.
      • Kane A.A.
      • et al.
      Helmet versus active repositioning for plagiocephaly: A three-dimensional analysis.
      ,
      • Loveday B.P.
      • de Chalain T.B.
      Active counterpositioning or orthotic device to treat positional plagiocephaly?.
      ), and therefore comparisons are less informative across cohorts.

      Determining Severity

      One of the most significant challenges in diagnosing and quantifying DP is distinguishing mild, moderate, and severe deformities (
      • Robinson S.
      • Proctor M.
      Diagnosis and management of deformational plagiocephaly.
      ). Using a consistent method to quantify severity is important so the clinician can document, monitor, and make treatment decisions for DP. Quantifying the severity of plagiocephaly is difficult because many providers use an expert opinion approach that is not well documented and varies by practitioner (
      • Glasgow T.S.
      • Siddiqi F.
      • Hoff C.
      • Young P.C.
      Deformational plagiocephaly: Development of an objective measure and determination of its prevalence in primary care.
      ). Some authors have proposed rating scales based on visual assessment criteria.
      • Argenta L.
      • David L.
      • Thompson J.
      Clinical classification of positional plagiocephaly.
      proposed a five-stage clinical classification of lateral DP based on the presence or absence of five clinical findings: posterior asymmetry, ear malposition, frontal asymmetry, facial asymmetry, and temporal bossing or posterior vertical cranial growth. Severity of posterior DP is based on the presence or absence of a central posterior deformity, widening of the posterior skull, and vertical head growth or temporal bossing (
      • Argenta L.
      • David L.
      • Thompson J.
      Clinical classification of positional plagiocephaly.
      ).
      Classification of DP severity is also guided by quantitative assessments of skull asymmetry, expressed as transdiagonal difference for lateral DP and CI for posterior DP. Published reports of severity classification systems using these measurements vary widely, and standards remain to be established across disciplines. The most rigorous studies of skull measurements and their correlation with response to intervention were conducted by Hutchison and colleagues, who conducted a randomized clinical trial of positioning treatments for 126 infants with DP (
      • Hutchison B.L.
      • Stewart A.W.
      • De Chalain T.B.
      • Mitchell E.A.
      A randomized controlled trial of positioning treatments in infants with positional head shape deformities.
      ) and a case-control study of 31 infants with DP (
      • Hutchison B.L.
      • Hutchison L.A.
      • Thompson J.M.
      • Mitchell E.A.
      Quantification of plagiocephaly and brachycephaly in infants using a digital photographic technique.
      ). The authors tracked head symmetry of infants with DP using digital photographic techniques, which allowed them to define meaningful measurement cutoff points for lateral and posterior DP severity. We have incorporated these values into a combined schematic for determining severity of lateral and posterior DP based on a holistic assessment that includes both visual and anthropometric assessments. These assessments are presented in Table 3 with a diagnostic guide for determining the type and severity of lateral and posterior DP.

      Conclusions

      Torticollis, variable tone, and developmental delay may be present in children with DP, and the assessment of the infant should include particular attention to development and tone.
      DP is a common condition, particularly in cultures where infants sleep in the supine position. This sleeping position is associated with a significant reduction in the risk of sudden infant death syndrome, but it also may be associated with molding of the infant’s head, especially before the infant develops motor skills. Research suggests that cumulative exposure to the supine position is a primary factor in the development of DP (
      • Bialocerkowski A.E.
      • Vladusic S.L.
      • Wei Ng C.
      Prevalence, risk factors, and natural history of positional plagiocephaly: A systematic review.
      ). Torticollis, variable tone, and developmental delay may be present in children with DP, and the assessment of the infant should include particular attention to development and tone.
      Future research should be aimed at identifying potential causal pathways between DP, torticollis, and developmental delays, understanding whether there is a shared etiology, and understanding to what extent risk factors are modifiable or non-modifiable. Because DP itself is often self-limiting with conservative strategies, and because associated morbidity is low, research on the assessment, diagnosis, and management of this condition may be limited by low prioritization among funders for the type of studies that provide the highest quality evidence. For this reason, it is particularly important for primary care providers to focus on early prevention and management of this condition. Treatment of severe DP is undoubtedly more costly than early management of mild or moderate DP.
      Understanding the risk factors and natural course of development and skull growth will enable the pediatric health care provider to actively participate in the prevention and early management of DP. Practitioners who include a comprehensive visual assessment of the infant’s head in every well-child examination are likely to recognize early signs of asymmetry when the condition is most amenable to conservative management (
      • Bialocerkowski A.E.
      • Vladusic S.L.
      • Wei Ng C.
      Prevalence, risk factors, and natural history of positional plagiocephaly: A systematic review.
      ,
      • Robinson S.
      • Proctor M.
      Diagnosis and management of deformational plagiocephaly.
      ,
      • van Vlimmeren L.A.
      • van der Graaf Y.
      • Boere-Boonekamp M.M.
      • L'Hoir M.P.
      • Helders P.J.
      • Engelbert R.H.
      Effect of pediatric physical therapy on deformational plagiocephaly in children with positional preference: A randomized controlled trial.
      ,
      • Xia J.J.
      • Kennedy K.A.
      • Teichgraeber J.F.
      • Wu K.Q.
      • Baumgartner J.B.
      • Gateno J.
      Nonsurgical treatment of deformational plagiocephaly: A systematic review.
      ). The practitioner can diagnose, monitor, and make appropriate referrals by accurately measuring and documenting dimensions of the asymmetric skull using consistent techniques as previously described. In Part II of this two-part series on DP (to be published in a future issue of the Journal of Pediatric Health Care), we will provide a review of the most current evidence on management of DP and an algorithm for clinical decision making.

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      Biography

      Wendy S. Looman, Associate Professor and Pediatric Nurse Practitioner, School of Nursing, University of Minnesota, Minneapolis, MN.
      Amanda B. Kack Flannery, Pediatric Nurse Practitioner, School of Nursing, University of Minnesota, Minneapolis, MN.