JSUR Journal

Introduction

Congenital ear anomalies refer to malformations or deformations of the ear [1]. Deformations can occur due to external forces during pregnancy or after birth, without altering the amount nor quality of the chondro-cutaneous tissue¹. Examples of deformities include prominent ears, helical rim anomalies, Stahl’s deformation (also known as “Spock ear”), cup or lop ear, and cryptotia. The incidence of auricular deformities ranges from 1 to 58% [2,3]. with self-correction rates varying from 30 to 84%, depending on the type of deformation. Prominent ears may even progress after birth [3-5].While ear deformations are generally neither harmful nor affect hearing, they can lead to low self-esteem and negative social feedback [6,7]. Surgical correction through otoplasty is possible when the ear is greater than 90% of the adult size, typically at the age of 5-6 years [8]. However, otoplasty has its cost and carries potential complications such as necrosis, wound infection, scar hypertrophy and keloid formation, hypersensitivity, and especially asymmetry [9]. To avoid surgical treatment, ear deformities can be treated conservatively with a patient-specific mold. This technique, first described by Matsuo et al., has been adjusted by other clinicians [10,11]. Initiation of treatment is recommended within the first six weeks of life when the pinna is most pliable, in conjunction with increased estrogen levels after birth 6. A patient-specific mold seems most effective, as standardized molds may be less suitable due to variety of ear shapes [12]. Studies [2,13-20] show that molding is a safe and effective method for treating congenital auricular deformities, however there is a lack of data on long-term outcomes and optimal timing and duration of treatment. The aim of the study is to investigate parents and surgeons’ satisfaction rates immediately after treatment, and parents’ satisfaction rate over time, to examine if molding prevents the need for future surgery. The study also explores the correlation between various factors, such as timing and length of treatment, type of deformity, gender, and the use of a splint.

Material and Methods

Infants with auricular deformities who received ear molding treatment at the Department of Maxillo-Facial Surgery in the Red Cross Hospital Beverwijk and Spaarne Gasthuis Haarlem, located in the Netherlands, were included. Referrals were made by pediatricians, midwives, general practitioners, or parents who noticed the deformities themselves. The inclusion period ranged from January 2017 to October 2022. Exclusion criteria encompassed systemic diseases, syndromes, and infants older than 6 weeks. Three surgeons of the team MKA Kennemer & Meer employed ear molding techniques, as described by Matsuo et al [10] and further popularized by Tan et al [6]. Steri-Strips (3M, St Paul, MN) strips were used in combination with a splint when necessary. The splint consisted of a soldering wire core segment enclosed within an 8 French polyethylene suction catheter (Figure 1). It was customized to maintain the ear in its correct position and secured to the helical rim using Steri-Strips (Figure 2). In cases with prominent ears, the ear was taped against the mastoid [6]. Parents were educated about the molding technique and instructed to reapply the devices if they came off. The duration of treatment was at least twice the age of the infants measured in days at the start of the treatment to ensure optimal results. For instance, an infant presented at the consultation at the age of 10 days would be treated for a total of 20 days. Upon completion of the treatment, satisfaction with the outcome was assessed by both the treating surgeon and the parents using a Likert 5-scale questionnaire. Feedback was provided for each pathology per ear. Each pathology received a single score, given either by the mother, father or both together. No distinction was made between the evaluations by the mother, father or both together. The scale ranged from “excellent” to “good,” “fair,” “poor,” and “very poor”. Treatment was deemed successful if the result was rated 3 or more. Between January 2023 and February 2023, all parents were interviewed about their satisfaction with their children’s ears and whether they considered the procedure successful over time. Parents were asked to rate the difficulty of the treatment, classifying it as simple, mediocre, or difficult. They were also inquired about any complications.

Figure 1: Materials used for the treatment: Steri-strips, soldering wire core segment enclosed within an 8 French polyethylene suction catheter, and a ruler for scale.

Figure 2: Example of treatment. (a) Stahl deformation before treatment. (b) Stahl deformation during treatment.

Ethical Approval

All procedures involving human participants were performed in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Declaration of Helsinki and its later amendments or comparable ethical standards. The study was approved by the institutional review board of the Spaarne Gasthuis Hospital in Haarlem, the Netherlands (nr 2022.0110) as well as the institutional review board of the Red Cross Hospital in Beverwijk, the Netherlands (nr. 24.027).

Statistical Method

Descriptive statistics were performed using IBM SPSS Statistics Version 29.0. We calculated frequencies and means (with standard deviations) by satisfaction scores. For dichotomous variables we calculated p-values using chi-square tests while we performed linear regression analyses for continues variables. P values below <0.05 were considered significant.

Results

A total of 50 infants with the age of four months or younger, having 70 auricular deformities of which 30 unilateral and 20 bilateral were included. 40 (45.5%) ears were prominent, 2 (2.3%) had helical rim anomalies, 15 (17.0%) Stahl’s deformation (‘Spock ear’), 31 (35.2%) were cup or lop ears, 0 cryptotia and 0 had other undefined deformations. 18 ears had multiple diagnoses (12 prominent and lop, 4 prominent and Stahl, 2 lop and Stahl). Treatment took place at a median age of 24 days with a range of 2 to 46 days. The duration of treatment was a median of 28 days (range 10 to 60). Helical rim anomalies were excluded from the analysis due to their low occurrence rate.

Outcome of Parents’ Satisfaction Directly after Treatment

After completion of the treatment, a total of 48 parents evaluated the outcome. The result of 34 (52%) ears were scored excellent, 13 (20%) good, 9 (14%) fair, 5 (8%) poor, 4 (6%) were very poor results and 3 were not assessed (Figure 3). For 2 ears with multiple deformities, the prominence was evaluated as good, but the lop deformity in one ear and the Stahl’s deformity in the other were scored as poor. The analysis indicated a significant association between a younger age at the start of treatment and a higher rate of satisfaction immediately after the procedure (p=0.03). Furthermore, a significant correlation was found between the male gender and a higher rate of satisfaction (p=0.047). However, there were no significant associations observed between the use of a splint and the duration of treatment with improved outcomes (p=0.39 and p=0.23, respectively). The results are presented in Table 1. Regarding specific deformities, neither prominent ears nor Stahl deformation demonstrated significant improved outcomes (p=0.69 and p=0.36, respectively). Conversely, lop ears showed a significant association with improvement (p=0.013). There was no statistically significant difference in satisfaction when comparing patients with only a Stahl deformity, only lob ears, only prominent ears, or a combination of these deformities (overall p=0.18). The results are presented in Table 2.

Figure 3: Examples of evaluated patients directly after treatment. (a) Prominent ear before treatment. (b) Prominent ear evaluated as excellent immediately after treatment. (c) Prominent ear before treatment. (d) Prominent ear evaluated as good immediately after treatment. (e) Lop ear before treatment. (f) Lop ear evaluated as fair immediately after treatment. (g) Lop ear before treatment. (h) Lop ear evaluated as poor immediately after treatment.

Additional factors; age, gender, splint, duration of treatment. Age and duration in days. The mean value for each factor is given with the standard deviation in brackets.

Table 1: Satisfaction of the parents directly after the procedure in correlation with additional factors.

Type of deformation; prominent, lop or Stahl ear. Combination involves two types of deformities.

Table 2: Satisfaction of the parents directly after the procedure in correlation with type of deformation.

Outcome of Surgeons’ Satisfaction Directly after Treatment

The assessment by the surgeons revealed that 29 ears (54.7%) were rated as excellent, 10 (18.9%) good, 8 (15.1%) fair, 3 (5.7%) poor, and in 3 ears (5.6%) surgeons rated the result very poor (see Table 2). Additionally, 15 ears were not assessed for the outcome. Notably, in two cases, the prominence of the ears was satisfactorily resolved, while the lop ear aspect remained unresolved. No significant associations were found between age and gender regarding the outcome (p=0.12 and p=0.096, respectively). Furthermore, the use of a splint and the duration of treatment did not exhibit a significant correlation with improved outcomes (p=0.81 and p=0.28, respectively). The results are presented in Table 3. Different types of deformations, including prominent ears, Stahl deformation, and lop ears, were not associated with better outcomes (p=0.80, p=0.07, and p=0.53, respectively). There was no statistically significant difference in satisfaction when comparing patients with only a Stahl deformity, only lob ears, only prominent ears, or a combination of these deformities (overall p=0.45). The results are presented in Table 4.

Additional factors; age, gender, splint, duration of treatment. Age and duration in days. The mean value for each factor is given with the standard deviation in brackets.

Table 3: Satisfaction of the surgeons directly after the procedure in correlation with additional factors.

Type of deformation; prominent, lop or Stahl ear. Combination involves two types of deformities.

Table 4: Satisfaction of the surgeons directly after the procedure in correlation with type of deformation.

Outcome of Parents’ Satisfaction at Follow-Up

After a median follow-up of 2 years (range: 4 months to 70 months), parents were surveyed regarding their satisfaction of their children’s ears. A total of 64 parents (91.4%) considered the procedure to be worthwhile. The majority of parents (74%) reported no changes since the completion of the procedure, while 12% noted further improvement, and 10% observed a worsening of the ears. Parents perceived the procedure as simple in 67% of cases, mediocre in 11%, and difficult in 21%. During the follow-up assessment, parents rated the results as excellent in 30 (46%) ears, good in 24 (34%) ears, fair in 5 (7%) ears, poor in 5 (7%) ears, and reported very poor results in 4 (6%) cases (see table 3). 26% reported complications such as loosening of the Steri-Strips, pain, or skin irritation. In 17% of cases, parents considered a surgical intervention. The age and gender of the infants, the use of a splint and the duration of therapy were not significantly related to improved outcomes (p=0.97, p=0.08, p=0.48 and p=0.42 respectively). The results are presented in Table 5. Among the different types of deformations, only lop ear deformity demonstrated a significant association with a improvement (p=0.03), while prominent ears and Stahl deformation did not show improvement (p=0.13 and p=0.53, respectively). The results are presented in Table 6.

Additional factors; age, gender, splint, duration of treatment. Age and duration in days. The mean value for each factor is given with the standard deviation in brackets.

Table 5: Satisfaction of the parents at follow-up and correlation with additional factors.

Type of deformation; prominent, lop or Stahl ear. Combination involves two types of deformities.

Table 6: Satisfaction of the parents at follow-up and correlation with type of deformation.