Relationship between congenital malformation of the outer ear and hearing

Abstract

Background: There is no report on the relationship between congenital malformation of the outer ear and hearing, which makes it possible to predict the hearing level just based on microtia grades.

Aims/Objectives: To investigate the correlation between two types of congenital malformation of the outer ear [microtia and Outer Ear Canal Malformation (OECM)] and hearing, as well as the interrelationship among all three variables.

Material and methods: A total of 535 cases (598 ears) of congenital malformation of the middle and outer ear (CMMOE) with hearing data, out of which 319 cases (349 ears) microtia with available images and graded by I–V, 449 cases (482 ears) OECM graded by atresia, stenosis and normal, and 87 cases (87 ears) OEC atresia graded I–IV, 301 cases (301 ears) with materials of microtia, OECM and hearing at the same time were carried out correlation analysis. The Average Air-Conduction Threshold of pure tone (AACT) at 0.5–4 KHz was calculated corresponding to the ears with different malformation grades. The differences in AACT among different malformation grades, the correlation between malformation severity and AACT, as well as the relationship among microtia, OECM and AACT were analyzed. The one-way analysis of variance (ANOVA) was employed to compare the differences in AACT, Kendall’s tau-b rank correlation coefficient test was used for correlation analysis. A statistical significance level of p < 0 .05 was applied.

Results: Among the 349 ears with microtia, the corresponding AACT values for grades I to V were 61.6, 63.0, 69.9, 75.4, and 75.0 (dB HL), respectively. Comparing grade III to grades II or IV, both p < 0 .05. However, p > 0 .05 between grade I and II or between grade IV and V. The correlation coefficient between microtia grades and AACT r = 0.219, p < 0.05. Among the 482 ears of OECM, the distribution was as follows: 73.6% atresia, 19.1% stenosis, and 7.3% normal, the corresponding AACT values were 64.1, 61.7, and 52.5 (dB HL), respectively. Comparing normal to stenosis or atresia, both p < 0.05, while between atresia and stenosis p > 0.05. The correlation between OECM and AACT was r = 0.104, p < 0.05. The AACT values corresponding to grades I to IV of OEC atresia in the 87 ears were 59.9, 65.1, 71.1, and 64.1 (dB HL), respectively. Comparing these grades, all p > 0.05. The correlation between the degree of atresia and AACT r = 0.23, p < 0 .05. The correlation coefficients for 301 ears microtia to OECM, microtia to AACT, OECM to AACT were r = 0.339, r = 0.163 and r = 0.128 respectively, with all p < 0 .05.

Conclusion and significance: There are positive correlations among the degree of microtia, degree of OECM, and AACT values for each other, and so between the degree of OEC atresia and AACT, suggesting that as the severity of microtia or OECM increased, the AACT also tended to be higher, which make it possible to predict the hearing level and the degree of OECM based on microtia grades in clinical practice. Additionally, there are significant differences in AACT values in microtia grade III to grades II or IV, OEC normal to stenosis or atresia, while no differences in microtia grade I to II and grade IV to V, OEC stenosis to atresia, and among the grades I–IV of the OEC atresia.

Chinese Abstract

背景：目前尚无关于外耳先天畸形与听力之间的关系的报道。这使得根据小耳畸形等级即可预测听力水平。

目的：调查两种类型的外耳先天性畸形[小耳症和外耳道畸形 (OECM)] 和听力之间的相关性, 以及三者的相互关系。

材料与方法：先天性中耳和外耳畸形 (CMMOE) 535例（598耳）的听力数据, 其中 319例（349 只耳）小耳症并提供影像, 按 I 至 V 分级；449 例（482耳）OECM , 按闭锁、狭窄和正常分级；87 例（87 耳）OEC闭锁, 分级为I-IV 级；301 例（301 耳）同时具有小耳畸形、OECM 和听力, 接受相关性分析。对应不同畸形级别的耳

朵, 计算0.5-4KHz处纯音平均气导阈值（AACT）。分析了不同畸形级别AACT的差异、小耳畸形的严重程度和AACT之间的相关性, 以及小耳畸形、OECM和AACT之间的关系。 采用单因素方差分析 (ANOVA) 来比较 AACT的差异, Kendall的 tau-b 等级相关系数检测用于相关分析。 应用了统计显著性水平 p<.05。

结果：349只小耳症耳中, I～V级对应的AACT值分别为61.6、 63.0、69.9、75.4 和 75.0（dB HL）。 将 III 级与 II 级或 IV 级进行比较, 结果都是 p<.05。然而, I 级和 II

级之间或 IV 级和 V 级之间, p>.05。小耳畸形等级和 AACT 的比较系数是r=0.219, p<.05。 OECM 的 482 只耳中, 分布如下：73.6％闭锁, 19.1％狭窄, 7.3％正常, 相应的AACT值分别为64.1, 61.7, 和 52.5（dB HL）。 将正常与狭窄或闭锁比较, 结果都是 p<.05, 而比较闭锁和狭窄 , 则p >.05。 OECM 与 AACT 之间的相关性为

r=0.104, p<.05。亚洲行动计划87只耳中OEC闭锁I至IV级对应的值分别为59.9、65.1、71.1和64.1（dB）HL）。 比较这些等级, 所有 p>.05。 闭锁程度与闭锁程度的

相关性AACT亚洲行动计划87只耳中OEC闭锁I至IV级对应的值分别为59.9、65.1、71.1和64.1（dB）HL）。 比较这些等级, 所有 p>.05。 闭锁程度与闭锁程度的相关性AACT r=0.23, p<.05。 301只耳朵中, 小耳畸形与OECM、小耳畸形与AACT、OECM与AACT的相关系数分别为 r=0.339、r=0.163 和 r=0.128, 所有都是 p<.05。

结论及意义：小耳畸形程度、OECM 程度、AACT值之间存在正相关关系。OECM 和 AACT 值彼此相关, OEC 闭锁程度和 AACT 之间也是如此。这表明随着小耳症或 OECM 严重程度的增加, AACT 也趋于升高, 这使得临床上可以根据小耳畸形等级和

OECM程度来预测听力水平。 此外, III级至II级和IV级、小耳畸形的AACT值存在显着差异, OEC 正常至狭窄或闭锁的AACT值也存在显着差异, 而小耳畸形 I 至 II 级和 IV 至 V 级, OEC 狭窄至闭锁, 以及 OEC 闭锁的 I-IV 级的AACT值无差异。

Keywords:

• Microtia
• Outer ear canal malformation (OECM)
• Average air-conduction threshold of pure tone (AACT)
• Correlation

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No potential conflict of interest was reported by the author(s).

Correction Statement

This article has been corrected with minor changes. These changes do not impact the academic content of the article.

Additional information

Funding

This work was supported by National Clinical Medical Center Special Project: YiHui Zou 202100003. National Logistics Support Department Special Family Planning Project: YiHui Zou 22JSZ14.