Personal identification basically refers to the process of determining an individual’s unique identity. A crucial component of forensic science is human identification. Establishing the victim’s identity is the first step in gathering information about them. In the living individuals, identification relies upon the distinct morphological features that are unique to each person. In the case of skeletal remains, the process becomes complicated and requires more meticulous examination. ¹

The measurement of living body proportions in order to understand physical variances is known as anthropometry. ^{2 , 3} The main aspects of individual’s identification are age, sex, and stature. ^{4 – 6} The assessment of stature from various bodily parts, including the hands, trunk, foot, extremities, and vertebrae, has been the subject of numerous studies. ⁷ Given the possibility that not all of these body parts may be found at the crime scene for forensic investigation, it becomes essential to utilize other body parts like the cranial and facial region for identification purposes. ^{1 , 8 , 9}

Human ears are the most distinctive facial characteristics, and their structure can reveal an individual’s age and sex. ^{10 – 12} An effective method for estimating stature is the examination of ear morphological dimensions, such as auricle dimension and pinna breadth, as well as measurements of ear lobular span and ear lobule width. ^{13 – 15}

Some research papers have shown variation in ear shapes, ¹⁶ varied types of helices and tragus, classification of Darwin’s tubercles, and varied types of ear lobes. The types of ear shape are oval, triangular, rectangular, and round. The helix of the ear can take various forms, including flat, gently curved at the edges, broadly covering the scapha, or the more common rolled form. The different lobule shapes are tongue-shaped, triangular, arched, square. The various types of earlobe attachment are classified as free, partially attached, and attached ^{17 – 20} ( Figures 1, 2, 3, 4).

Many research papers have found that external ear proportions vary among individuals, and the external ear dimensions are considerably larger in males in addition, ²¹ the ear shows a bilateral asymmetry. Few studies also indicate that the configuration and proportion of the ear can show craniofacial reconstruction in forensic examination. Numerous studies have also reported an association between stature and external ear measurements.

Therefore, the goal of the study is to examine the correlation between the external ear measurements and height, as well as to identify the morphological variation between individual.

The study was conducted on 385 adult male individuals, aged between 18-50 years. The participants were students and professionals of MAHE, Manipal. A total of eight measurements were taken from both ears. The measurements included auricle length, auricle breadth, lobule length, and lobule breadth using a standard caliper, and stature was taken using measuring tape. Participants with deformed ears and female participants (wearing earrings), and also male participants wearing earrings are excluded. Written informed consent was taken from the participants before taking the measurements.

Each participant was made to stand barefoot, and the stature was measured using the measuring tape. The participants were made to sit and then the 8 measurements were taken using the digital calliper ( Figures 5, 6).

The data was analysed using Jamovi version 2.4.11. The mean and standard deviation were calculated for all the parameters. Correlation between the stature and the parameters was tested using Spearman’s rank correlation. Linear regression was performed to determine the statistically significant difference between all the parameters and stature.

From Table 1, the mean and standard deviation of different parameters are age (24.7 ± 6.78), stature (172 ± 6.90), left ear length (6.14 ± 0.462), left ear width (3.22 ± 0.321), left lobule length (2.16 ± 0.350), left lobule width (1.99 ± 0.334), right ear length (7.55 ± 28.6), right ear width (3.24 ± 0.305), right lobule length (2.07 ± 0.336), right lobule width (1.98 ± 0.330). Here, the right ear parameters show a higher mean and standard deviation than the left ear parameters, except for the lobule length and lobule width, where the left side values are higher than the right.

From Table 2, the result show that in males, the left ear length (R ²= 0.0780, p<0.001), left lobule length (R ²= 0.00734, p=0.093), left lobule width (R ²= 0.0112, p=0.038), right ear length (R ²= 0.0660, p=0.072), right ear width (R ²= 0.0144, p=0.019), right lobule length (R ²= 0.00886, p=0.065), right lobule width (R ²= 0.0157, p=0.014) and left ear width (R ²=0.00380, p=0.227), among all these parameters left ear length, right ear length shows a statistically significant difference between the stature.

From Table 3, the result show that in males, the left auricle length (r= 0.279), left ear width (r= 0.109), left lobule width (r= 0.113), right auricle length (r= 0.279), right ear width (r= 0.130), right lobule width (r= 0.120) shows moderate positive correlation with the stature, while the left lobule length (r= 0.096), right lobule length (r= 0.077) shows weak positive correlation with the stature.

From Table 4, the mean age of the 385 individuals was 23 years. The participants were then divided into two groups based on age: those ≤ 23 years and those ≥ 23 years. that is lesser than or equal to 23 years of age and greater than or equal to 23 years of age. The two age groups were compared across the eight parameters. The median [IQR] value is taken for all the eight parameters between the two age groups to find which parameter has a significant difference among the individuals based on different age. Among the age ≤23, the left ear length (6.14[5.65-6.31]), left ear width (3.31[3.19-3.39]), left lobule length (1.97[1.81-2.24]), left lobule width (2.05[1.86-2.18]), right ear length (6.06[5.55-6.17]), right ear width (3.43[3.11-3.49]), right lobule length (1.95[1.81-2.20]), right lobule width (2.16[1.80-2.27]) and among the age ≥23, the left ear length (6.21[5.92-6.40]), left ear width (3.29[3.10-3.50]), left lobule length (2.19[1.90-2.35]), left lobule width (2.15[2.02-2.32]), right ear length (6.14[5.76-6.32]), right ear width (3.29[3.15-3.45]), right lobule length (2.04[1.87-2.43]), right lobule width (2.20[2.01-2.31]).

Based on the result, the right ear length and left lobule width show a significant difference among the individuals with respect to age. The result shows that as age increases, the right ear length and left lobule width will show a significant difference from person to person.

Human identification is very important in many traumatic events. The main aim of a forensic anthropologist when dealing with bones is to find out the gender, height, years of living, and race. ^{22 – 24} The determination of height is necessary in forensic investigation in cases like mutilated human remains or a highly decomposed body. There are several benefits of using somatological dimensions of the outer ear for identification purposes. ¹⁹ Therefore, the goal of the research was to estimate the stature from the morphological variation of the external auricle and also to evaluate the morphological differences among persons.

In the study by Abdelaleem SA et al., ²⁵ a positive correlation was found between all measurements of both ears and stature in both sexes. However, the findings are not in agreement with our study. Archana Kumar et al., ¹³ reported no significant difference for both auricle dimensions in males, which differs from the present findings. In our study, there was a significant difference in left ear length and right ear length with stature.

The key findings of the paper are as follows:

Using the Spearman’s rank correlation, the present study revealed that there is an positive correlation between left auricular length (r=0.279, p<0.001) and right ear span (r=0.279, p<0.001) with height.

Estimation of height from the outer auricle dimensions in this paper was performed by using linear regression analysis. The present study revealed that left ear length (R ²=0.078), p-value (<0.001) was the best predictable variable to determine the stature, which is in concordance with the findings of Taura MG et al., ²⁶ who reported that left ear width (R ²=0.086) was the best predictor along with right auricle length (R ²=0.082) and left ear length (R ²=0.074).

Using the Mann-Whitney U test, the right ear length and left lobule width showed a significant difference between the individuals based on age. The right ear length for age group ≤23 (6.06[5.55-6.17]), ≥23 (6.14[5.76-6.32]) and left lobule width for the age group ≤23 (2.05[1.86-2.18]), ≥23 (2.15[2.02-2.32]) showed greater difference in the median [IQR] between the two age group. This indicates that right ear length and left lobule width exhibit morphological variation with age, rather than due to random causes.

This study proves the significance of external ear measurement as a unique tool used in forensic investigation for the estimation of stature from the morphological variation of the ear, in cases of mutilated bodies found in crime scenes, personal identification is important, and when other body parts are not available, then using the ear measurements, we can estimate the stature. ^{27 , 28} It could also be beneficial in different fields including forensic anthropology, forensic science.

The ethical approval IEC No. 397/2024 was granted by “The Institutional Ethics Committee (ICE) of Kasturba Medical College and Kasturba Hospital Manipal” on 13th August 2024. The data were kept completely undisclosed, and no participant identifiers were used. The CTRI approval number is CTRI/2024/10/075400.

Written informed consent was taken from all the participants. No minors were included in the study.