Evaluating the Effectiveness of Cranial Molding for Treatment of Positional Plagiocephaly Using Finite Element Analysis

Abstract

Evaluating the Effectiveness of Cranial Molding for Treatment of Positional Plagiocephaly Using Finite Element AnalysisMaziyar KeshtgarSince the advent of recommendations for placing infants in the supine position during sleep to reduce the incidence of sudden infant death syndrome, clinicians have noted an increase in the frequency of cranial asymmetry due to deformation of suture sections of the infants' skulls as a result of constant concentrated stress in one area at the back of their head.This specific form of cranial deformation is known as positional plagiocephaly and its rate of occurrence has increased from 0.3% in 8.2% within the past 30 years.Current treatments and methodologies for preventing and correcting positional plagiocephaly such as stretching exercises, bedding pillows, and cranial molding are not optimized for effectiveness and comfort. Literature surrounding the implementation of these methodologies or devices often assesses the relative effectiveness of each treatment through statistical means, or studies complications associated with their use. There is a lack of quantified mechanical analysis for determining the effectiveness of each treatment or engineered solutions.In this study, a finite element model was created and validated to study the effect of wearing a cranial helmet, as the most effective non-surgical device for treatment of positional plagiocephaly, on reducing concentrated stress from the back of the baby's head during sleep.The results from this model were then compared to two other finite element models with a healthy baby sleeping in supine position on a pillow, and a patient diagnosed with a severe case of positional plagiocephaly sleeping on the flat side of his head in supine position. The geometries representing the head of the babies in these models are the refined 3D laserv scanned file of a patient's head contour at Hanger Clinic as well as the cavity inside the cranial helmet that was used for treatment of the baby.After successfully assigning section and contact properties to different regions of the models, applying proper loading and boundary conditions, and performing mesh convergence studies for each of the three models, the average Von Mises stress values of each of the 13 different suture segments of each model were summarized in tables and evaluated using mathematical and qualitative methods.The stress value data obtained from different suture regions of the model with the cranial helmet resulted in the smallest standard deviation among all three populations which supports that wearing the cranial helmet helps to reduce stress concentrations. Use of the cranial helmet during sleep also showed a significant decrease of the average Von Mises stress within the posterior fontanelle by 90% compared to the healthy baby sleeping in supine position and 73.4% compared to the deformed head sleeping on the flat surface of the head.The major limitations of this study are correlated with the simplifying assumptions and geometries in generating and validating t...

Parental Adherence to Cranial Remolding Orthotic Treatment of Infants with Positional Cranial Deformities: A Qualitative Content Analysis

“…Regular visits during treatment can reduce the problems and worry and give the parents a better understanding of treatment results (1,11). Parents generally cease therapy once they are satisfied with the infant's appearance and before reaching anthropometric proportion and symmetry criteria, which results in their refusal to return to the treatment team (13). Increased infant age and higher manual skills increase their ability to open the CRO, which can interrupt the treatment process (14).…”