PMC:7490201 / 4455-9255 JSONTXT

{"project":"2_test","denotations":[{"id":"32924339-26928929-61522897","span":{"begin":1100,"end":1101},"obj":"26928929"},{"id":"32924339-22872837-61522898","span":{"begin":1877,"end":1878},"obj":"22872837"},{"id":"32924339-18176220-61522899","span":{"begin":2645,"end":2647},"obj":"18176220"},{"id":"32924339-11482615-61522900","span":{"begin":2841,"end":2843},"obj":"11482615"},{"id":"32924339-3492164-61522901","span":{"begin":3884,"end":3886},"obj":"3492164"}],"text":"METHODS\n\nPatients\nIn this retrospective chart review, we included 53 patients with positional plagiocephaly who received complete helmet therapy between December 2008 and June 2016. This study was conducted at an outpatient clinic in our institution. The inclusion criteria were as follows: patients diagnosed with positional plagiocephaly, patients with a cranial vault asymmetry index (CVAI) of \u003e 10 mm, patients whose parents had good compliance in recording their child's helmet use time, and patients who wore the helmet for \u003e 10 hours/day for \u003e 8 weeks. The exclusion criteria were as follows: patients with craniosynostosis or other syndromic diseases, patients who were lost to follow-up, and patients with incomplete medical records. Finally, 39 patients (23 males and 16 females) were included in the study.\n\nTherapy protocol\nHelmet orthoses manufactured by a single company (Gio Inc., Seoul, Korea) were used in this study. In accordance with the patients' head parameters such as anteroposterior, bitemporal, and diagonal distances measured using a calliper, a customized helmet was made.9 The helmet was composed of a plastic outer shell and soft inner foam with the thickness depending on the patients' current measurements. Every 2–4 weeks, the cranium was measured, and the helmet size was adjusted accordingly. Parents were instructed to educate their children on the use of the helmet as much as possible, and have their children wear the helmet for at least 10 hours a day. If the child could not follow this recommendation, the treatment was continued, but the patient was not included in the study. We defined the treatment end point as a CVAI difference of ≤ 3.5% or absolute CVAI difference of \u003c 5 mm, with consideration of the induction of prominent areas to be retained passively and flattened areas to grow rapidly into the hollow space in the helmet.5 After confirmation of the treatment end point, the helmet therapy was discontinued. However, if the total treatment period was \u003e 18 months, even if the treatment end point was not attained, the treatment was ended owing to patient compliance.\n\nOutcome analysis\nThe data recorded included age at commencement of treatment (months), age at completion of treatment, duration of treatment (months), daily use duration (hours), initial and final absolute diagonal differences (mm), and cephalic index. Diagonal distance was defined as the frontozygomatic-to-contralateral occipital (euryon) distance from both sides, and cephalic index was defined as the maximal length and breadth measured on the skull radiograph obtained at each period (breadth/length × 100) (Fig. 1).10 With these measurements, we calculated CVAI, defined as the absolute diagonal difference divided by the shorter diagonal distance (absolute diagonal difference/shorter diagonal distance × 100).11 We defined improvement rate as the difference in the CVAI values at the end and beginning of treatment, divided by the treatment duration. At the end of the helmet therapy, effectiveness was confirmed when the CVAI was ≤ 3.5%.\nFig. 1 Measuring cranial vault asymmetry index. Absolute diagonal difference is divided by shorter diagonal distances (× 100%). Diagonal A is distance from the FZr to the contralateral EUl and diagonal B is distance from the FZl to the contralateral EUr. (A) The severity of asymmetry is shown to be increasing from left to right. (B) Landmarks.\nFZr = right frontozygomatic point, EUl = left euryon point, FZl = left frontozygomatic point, EUr = right euryon point.\n\nStatistical analysis\nStatistical analysis was performed with the SPSS version 19.0 software (IBM Corporation, Armonk, NY, USA), with the level of significance set at P \u003c 0.05. Variables were eligible for entry into the multiple logistic regression model if they were significantly associated with the initial measurements at a P value of \u003c 0.25.12 For the analysis of the relative strength between two factors, the Spearman rank correlation test was used. Factors with values \u003e 0.5 were considered to have positive correlations, whereas those with values \u003c −0.5 were considered to have negative correlations. A receiver-operating characteristic (ROC) curve analysis was performed, and the area under the curve (AUC) was calculated to identify the effective cut-off values of the validated variables that could predict the effectiveness of helmet therapy. All the graphs were created using MedCalc 13 (MedCalc software, Ostend, Belgium).\n\nEthics statement\nThis study conforms to the principles of the Declaration of Helsinki. The study protocol was approved by the Institutional Review Board (IRB) of Asan Medical Center (approval No. 2017-0482). The need for informed consent was waived by the IRB of our hospital owing to the retrospective design of the study."}