My first experience with deformational plagiocephaly was as a pediatric plastic surgery fellow at the famous Harvard teaching affiliate, Boston Children’s Hospital. To be frank, I was star-struck by the history and grandeur of the institution, and it was humbling to be even a small part of this iconic place. My mentor, the great John B. Mulliken, was known for his encyclopedic knowledge of all things plastic surgery, his razor-sharp intellect, and a hard-driving personality that was legendary among the Harvard community. Dr. Mulliken was hired by the late Joseph Murray, who won the 1990 Nobel Prize in Physiology/Medicine for the first successful kidney transplant, and had succeeded him as the de facto chief of pediatric plastic surgery at Boston Children’s (for proper accounting, Elof Eriksson was the actual chief, but he was an adult cosmetic surgeon who visited Children’s primarily to use the parking garage and to hang up his coat on his way over to his office at the Brigham and Women’s Hospital). Dr. Mulliken was the pinnacle of surgical academics, pumping out 30+ peer-reviewed publications per year, performing surgery 4 days/week, and spending his weekends seeing patients or working on manuscripts. He would come to the hospital every Saturday to see patients and work on various studies, and every Monday morning he would query why I was not at the hospital on Saturday as well. Of course, he knew the answer and his questioning was rhetorical and promulgated only to punctuate the fact that he was more committed than I was. My defense- that I had to moonlight on the weekends to support my young family (my salary was only $31,000/year, barely enough to covered my rent in Boston)- was met with a shrug of displeasure. Nevertheless, it was his sharp mind, red editing pen, and addictive sense of wonder and inquisitiveness that molded me into the academic surgeon I am today.
The end of each week during my fellowship was topped off with one of the greatest academic gatherings at the hospital- the craniofacial clinic. Each Friday, over 100 staff physicians, fellows, residents, and Harvard medical students would meet on the third floor and see patients from all over New England. Each patient was seen by the multiple teams of physicians in smaller patient rooms and then, after each group had formulated their opinions, each patient was brought to the main conference room to interact with and receive the groups plan for future care. The main conference room, where the collective group would discuss these treatment decisions, was always packed with trainees who sat attentively listening while the attending physicians argued among themselves the finer points of care. Many of these patients had incredibly complex medical conditions and it was profoundly instructive to watch the team discuss each issue and decide how to proceed. The conference often went well into the evening, but no one seemed to mind as the discussions were interesting and inspiring. Sound exciting? It was! Nevertheless, the amount of time I spent in the main conference room on most days was cut short. There was a longstanding tradition that the pediatric plastic surgery fellow would see and manage patients with less complex conditions, like plagiocephaly. Dr. Mulliken had written many papers on the subject and long ago had intellectually outgrown the topic. He had investigated this conditon long before the 1993 American Academy of Pediatric’s “Back To Sleep Campaign” recommendations for back sleeping and once back sleeping became widely practiced, the rapid number of cases of plagiocephaly effectively overwhelmed clinics of craniofacial surgeons like Dr. Mulliken. To be frank, most surgeons are not excited about managing conditions that NEVER require operative intervention. (ASIDE: There are some surgeons, such as Barry Eppley, who perform “skull reshaping” procedures for this condition for purely aesthetic reasons. Most of us in the field consider this practice idiotic since posterior cranial asymmetry is rarely visible on adults when viewed from the back and, even if it were, it can be readily concealed with modest hair growth. The skull reshaping procedure, which inserts some firm biocompatible material under the scalp, leaves a long scar that is arguably MORE VISIBLE than the asymmetry itself since hair never grows in the scar, costs a considerable amount of out-of-pocket expense as it is rarely covered by insurance, and risks implant exposure, infection, and other complications. It is difficult to understand why any rational person would pay their hard-earned money AND risk potential surgical complications to undergo one of these procedures when inevitably they must still wear their hair longer to camouflage the long posterior surgical scar. What some surgeons will do to make a buck…..)
So it was during my pediatric plastic surgery fellowship that I started seeing plagiocephaly patients, one after another, with the same basic story- a head rotation preference early in life, followed by progressive development of head flattening over the first few months, and then cessation of further flattening but a persistent asymmetry. While the location of the flattening could be on either side (plagiocephaly), directly in the back (brachycephaly), or a combination of the two (asymmetrical brachcephaly), the story and, ultimately, the underlying mechanism was always the same. Some parents thought the head preference (as the pediatricians like to call it) was just how the baby “liked” to sleep and never considered that there was an underlying reason why they ALWAYS turned their head to the same side. Other parents recognized this as abnormal and, perhaps at the prompting of their pediatrician, unsuccessfully tried every conceivable maneuver, including physical therapy, to get their infant to turn to the other side. Parents often showed up exasperated with handfuls of pillows and repositioning products that they had used with little or no effect. As a board certified orthopedic surgeon, it did not take long before I realized that every infant with this condition had one common characteristic, a “favored” and consistent head position during the first few months of life that could only mean one thing- that almost every patient with deformational plagiocephaly was born with congenital muscular torticollis (CMT) and that this underlying condition was the most ubiquitous cause of most forms of acquired head flattening.
While the association between torticollis and plagiocephaly had been previously described, it was considered only one of many risk factors and not the primary risk factor for positional head flattening. The problem with most of the studies then (and many of them even now) is how the investigators chose to measure and define CMT. Classically, CMT is an imbalance in tone of the sternocleidomastoid (SCM) muscles, the long muscle that runs obliquely from the mastoid prominence (the bump on the cranium just behind each ear) to the sternum and clavicle in the upper front of the chest wall. When one SCM muscle is tight, the other one is invariably loose or weak. The imbalance develops in utero and can be associated with any situation that crowds the fetus and limits or restricts head movement prior to birth- multiple births, oligohydramnios, large infants, fibroids, and others (SEE the Science segment on this web page for more information on how these relate). CMT typically manifest as a head tilt to the side of the tight muscle, and head rotation to the side of the weaker muscle. This creates the “twisted” neck appearance from which torticollis is named. Of course, the longer the immobilization in utero the more persistent and severe the imbalance can become. A helpful analogy is to consider immobilizing one’s arm in a long-arm cast with your arm bent. The biceps muscle on the front of the arm is shortened and contracted, and the triceps on the back of the arm is stretched. Removing the cast after one week leaves only a minor amount of stiffness that will rapidly resolved with movement. If we leave the cast on for 4 weeks, the arm is much stiffer and it takes significantly longer to regain motion. After 12 weeks of casting, the arm is contracted and one may never regain full motion of the arm. Thus, the degree of imbalance, and importantly the time it takes to resolve, varies greatly and can range from a minor head rotation preference with otherwise normal passive motion (i.e., someone else moving the head) to a severe contracture that makes passive motion to the tight side nearly impossible. In the mild cases, the imbalance usually resolves quickly. This adds to the diagnostic confusion for many practicioners as most 8-9 month-old infants I see with plagiocephaly have already worked out the neck imbalance and have little clinical evidence of the prior torticollis. Howver, this does not mean they did not have CMT early in life. The observation of a head rotation preference is the hallmark of CMT.
The literature relating plagiocephaly to torticollis is inconsistent with regards to how they define and measure torticollis. For example, some studies define the presence of torticollis by restricted passive motion (examiner actively moving the infant’s head to one side of the other). Unfortunately, this definition is far too restrictive and does not capture very mild cases where the infant does not ACTIVELY move his/her head to each side equally. The most inclusive measure is active motion (what the infant can or prefers to do on his own) because if an infant prefers one side over the other because it is marginally more comfortable, that is what he/she will do left alone. Left unchecked, a persistent head rotation preference will lead to head flattening. Why? Consider that the infant head has weight and, therefore, it applied a force to the flat mattress on which it rests. Newton’s Law states that this force will be met with an equal and opposite force applied by the bed to the infant’s growing head. Growth will occur preferentially in area where there is no such resistance (i.e., every part that is not touching the mattress). As this process progresses, head growth redirects away from the point of contact and a flat spot develops. This is directly analogous to how a growing pumpkin gets flat as it grows on a field. A small pumpkin is not soft or malleable. Yet, as it grows against the hard ground, most growth is redirected away from the area of contact (and resistance) and a flat spot develops. Of course, as the pumpkin gets heavier, this process accelerates. That is why the largest pumpkins always have the most severe shape distortion. Turning back to our infant with torticollis, the more severe the neck imbalance, the more severe the head flattening that will develop as the increasing head weight leads to steady acceleration in head flattening. I often use the pumpkin analogy in the office with families as it helps them understand what happened, although I cannot deny that some parents do not appreciate equating their infants head shape to a pumpkin!
