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| ORIGINAL ARTICLE |
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| Year : 2012 | Volume
: 18
| Issue : 1 | Page : 24-27 |
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Demarking and identifying points-reliable criteria for determination of sex from external ear
Prashant E Natekar, Fatima M De Souza
Department of Anatomy, Goa Medical College, Bambolim, Goa, India
| Date of Web Publication | 10-Jul-2012 |
Correspondence Address:
Prashant E Natekar
Department of Anatomy, Goa Medical College, Bambolim, Goa - 403202
India
 Source of Support: None, Conflict of Interest: None  | Check |
DOI: 10.4103/0971-7749.98292
Introduction: The anatomy of the external ear is clinically and surgically important as it is related to the vital structures in the neck. The morphometric measurements of the external ear were undertaken to determine the sex of an individual. These findings also suggest that this study will have a role in plastic and reconstructive surgery; identification of dysmorphic features in various chromosomal disorders. Aim: The present study will enlighten us to determine the sex from the external ear and provide an insight in determining the variations in sex from the external ear with 100% accuracy. It may also serve as a guideline before surgical intervention in otoplasty so as to resculpt or reshape the ear. Materials and Methods: The subjects were 100 healthy male and 100 healthy female medical students of age group 18-25 years of Goa Medical College, Bambolim, Goa, having no history of any diseases or other genetic disorder or heredity diseases. The anatomical landmarks used for this research study were the right and left a) ear length b) ear length above tragus c) ear length below tragus d) tragus length e) ear breadth f) concha length g) concha breadth h) lobule height i) lobule width of the external ear. Results: The measurement procedure proved to be easy and it did not show any discomfort to the participants. Ear length below tragus, lobule height and lobule width were larger in females than males. This method was made applicable to all the parameters except for ear length below tragus, lobule height and lobule widths since these parameters were greater in females than males. Conclusion: In this study, we could determine the sex from the external ear in a large percentage. The parameters were of little value when subjected to demarking point analyses. However, for a larger population the mean values for the above parameters from different regions will have significantly different values and hence, DPs are to be worked out separately for the different regions. These DPs are much simpler to apply than multivariate discriminant functional techniques for identification of sex with certainty. Keywords: Concha, Demarking Points, External Ear, Lobule, Tragus
How to cite this article:
Natekar PE, De Souza FM. Demarking and identifying points-reliable criteria for determination of sex from external ear. Indian J Otol 2012;18:24-7 |
How to cite this URL:
Natekar PE, De Souza FM. Demarking and identifying points-reliable criteria for determination of sex from external ear. Indian J Otol [serial online] 2012 [cited 2023 Mar 21];18:24-7. Available from: https://www.indianjotol.org/text.asp?2012/18/1/24/98292 |
| Introduction | |  |
The human ear is the most defining feature of the face. The human auricle has a complex shape and yet the basic component of the normal structure of auricle is constant among the individuals. It is well known that the human bones are of great importance in providing us the skeletal differences between the sexes for anthropological and medico legal purpose. Several studies have been attempted to identify the sex from hip bones. [1],[2],[3] Studies on various bones like clavicle [4] humerus, [5] radius, [6] ulna, [7] femur, [8] tibia, [9] and fibula [10] have been identified with 100% accuracy.
From the aesthetic vantage point, the auricle usually is inconspicuous and is often taken for granted unless it is unduly prominent or deformed. The ear that sticks out too much is often the focus of ridicule wherein the people stare at the deformity. Physicians have used the auricle as a harbinger of underlying pathology, psychologists as a clue of personality disorder, criminologists as a means of racial discrimination. The anatomy of the external ear has been described in many texts, [11],[12],[13] yet the information about the differences between males and females has been lacking, which is essential for the plastic and reconstructive surgery [14],[15],[16],[17],[18] and also for medico legal importance. However, no studies are being carried out regarding the sexing of the external ear, though, various metrical parameters of the external ear have been evaluated. [19]
| Objectives | | |
The main objective of this present study is to enlighten us and provide an insight in determining the variations in sex from the external ear with 100% accuracy.
| Materials and Methods | | |
This study was carried out in 100 healthy male and 100 healthy female medical students of age group 18-25 (mean age 22 years) of Goa Medical College, Bambolim, Goa, having no history of any diseases or other genetic disorder or heredity diseases. Informed consent of the students was obtained. The measurements of the following parameters were as evolved by Natekar and De Souza (2006) measured in millimeters with digital vernier caliper of japanese company Mitutoyo with an accuracy of 1/10 mm. Least count of vernier caliper = 0.05 mm. The parameters shown in [Figure 1] are as follows:
- Ear length: Uppermost of pinna to the lowermost point of lobule (L1-L2)
- Ear length above tragus: Uppermost point of pinna to tragion (L3-L4)
- Ear length below tragus: From intertragic incisure to the lower most point of lobule (L5-L6)
- Tragus length: From tragion to intertragic incisure (L7-L8)
- Ear breadth: From root of the ear to maximum convexity of the helix (L10-L9)
- Concha length: From cymba concha to intertragic incisure (L11-L12)
- Concha breadth: Posterior margin of the tragus to the maximum concavity of the antihelix (L13-L14)
- Lobule height: From lower point of attachment of the external ear to the head (otobasion inferior) to the caudal extension of the ear lobe free margin (subaurale) (L15-L16)
- Lobule width: From the most caudal attachment of the ear lobule to the head and to the outermost maximum transverse width of the ear lobule (L17-L18)
In the present study, each of the above parameter range from mean, standard deviation and identification points (IPs) were calculated in millimeters.
Identification points (IPs): The range of the male and female external ear for each parameter overlaps, the end points (limiting points) of the overlapping regions are "Identification Points."
Calculated range: The mean + 3 Standard deviation (SD) will determine the range of the above parameters. [20]
Demarking points (DPs): The limiting points determined on the basis of calculated range, are the "Demarking Points." [21]
| Observation and Results | | |
It has been observed from [Table 1] that when all the parameters were statistically analyzed to find the range, mean and standard deviation, most of the parameters were larger in males as compared to females. However, ear length below tragus, lobule height and lobule width were larger in females than males which were also statistically significant. It was also observed that in most of the parameters which were statistically significant when subjected to identification point analysis for sex determination, they showed a high percentage of differences between males and females. As seen in [Table 2], the ear length (right) of males was in the range of 61.52-62.77, while that of females (right) was 58.01-59.32. No male ear length (right) was less than 59.32 and no female ear length (right) was less than 61.52. Therefore, 59.32 served as an identification point (IP) for males and 61.52 served as an I.P. for females. However, ear lengths between 59.32 and 61.52 are not sexed. This similar method was made applicable to all the parameters in [Table 1] except ear length below tragus, lobule height and lobule width where the DPs were reversed since the female parameters were greater than the males. | Table 1: Range, Mean, SD and IP of the various parameters of the external ear in millimeters
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 | Table 2: Demarking points for the various parameters of the external ear in millimeters
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In [Table 2], the calculated range was obtained using the formula mean + 3 SD. All the parameters except ear length below tragus, lobule height and lobule width (left and right) were larger in males than females. As seen in [Table 2], the calculated range (mean + 3 SD) of ear length (right) of males was 52.55-71.75, while that of female (right) was 48.67-68.66. No male ear length (right) was less than 52.55 and no female ear length (right) was greater than 68.66. Therefore, 68.66 served as demarking point (DP) for males and 52.55 served as a demarking point for females. However, ear lengths between 52.55 and 68.66 could not be sexed. This method was made applicable to all the parameters except for ear length below tragus, lobule height and lobule widths since these parameters were greater in females than in males and the DPs were reversed.
| Discussion | | |
Ear sticks out from the head but when it excessively protrudes it is quite ridiculous. Children are usually nicknamed as "Dumbo" or "Mickey mouse". The Chinese believe that long ears predict longevity. [22]
Determination of sex of an individual based on human skeleton is well established. However, no data is available for identification of sex from the external ear. In our present study by IP analysis as seen in [Table 1], it has been observed that we could determine the sex from the external ear in a large percentage, since the overlapping range where the sex could not be determined was small. However, in [Table 2], it has been observed that all the parameters were of little value when subjected to demarking point analyses, since the percentage of ears identified by the demarking point analyses is low. This might be due to the fact that the overlapping data was larger between the two sexes. This analysis by limiting points holds good only for that particular sample and may not provide correct identification of the sex when applied to some other unknown sample of the same area, population or race. The reason for this may be that the biological variables may show vide variations, which the limiting points may not cover even if the sample size is large. In order to overcome this problem 3 SD were added and subtracted to the mean value (+ 3 SD) which will provide us the range of 99.75% of population of that area. Although our data reveals that the identification of sex from external ear by DPs was less in number, it was 100% accurate. The demarking point analyses have an advantage that it is not necessary that all the parameters of the external ear should cross the DPs before the sex can be identified. However if a single parameter crosses the DP it means that the sex can be identified with 100% accuracy.
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[Figure 1]
[Table 1], [Table 2]
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