Journal of Pharmacy And Bioallied Sciences

: 2015  |  Volume : 7  |  Issue : 6  |  Page : 504--508

Prediction of age and gender using digital radiographic method: A retrospective study

V Poongodi, R Kanmani, MS Anandi, CL Krithika, A Kannan, PH Raghuram 
 Department of Oral Medicine and Radiology, SRM Dental College, Chennai, Tamil Nadu, India

Correspondence Address:
Dr. R Kanmani
Department of Oral Medicine and Radiology, SRM Dental College, Chennai, Tamil Nadu


Aim and Objective: To investigate age, sex based on gonial angle, width and breadth of the ramus of the mandible by digital orthopantomograph. Materials and Methods: A total of 200 panoramic radiographic images were selected. The age of the individuals ranged between 4 and 75 years of both the gender - males (113) and females (87) and selected radiographic images were measured using KLONK image measurement software tool with linear, angular measurement. The investigated radiographs were collected from the records of SRM Dental College, Department of Oral Medicine and Radiology. Radiographs with any pathology, facial deformities, if no observation of mental foramen, congenital deformities, magnification, and distortion were excluded. Results: Mean, median, standard deviation, derived to check the first and third quartile, linear regression is used to check age and gender correlation with angle of mandible, height and width of the ramus of mandible. Conclusion: The radiographic method is a simpler and cost-effective method of age identification compared with histological and biochemical methods. Mandible is strongest facial bone after the skull, pelvic bone. It is validatory to predict age and gender by many previous studies. Radiographic and tomographic images have become an essential aid for human identification in forensic dentistry forensic dentists can choose the most appropriate one since the validity of age and gender estimation crucially depends on the method used and its proper application.

How to cite this article:
Poongodi V, Kanmani R, Anandi M S, Krithika C L, Kannan A, Raghuram P H. Prediction of age and gender using digital radiographic method: A retrospective study.J Pharm Bioall Sci 2015;7:504-508

How to cite this URL:
Poongodi V, Kanmani R, Anandi M S, Krithika C L, Kannan A, Raghuram P H. Prediction of age and gender using digital radiographic method: A retrospective study. J Pharm Bioall Sci [serial online] 2015 [cited 2021 Apr 18 ];7:504-508
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Full Text

Chronological age assessment is an important part of medico-legal practice. The procedures for age determination are complex and involve the consideration of many factors. Changes related to chronological age are seen in both hard and soft tissue [1],[2] among dental hard tissues and bone are extremely resistant to fire and are usually the only remains after an extended period of burial. As a result, forensic odontology has gained importance as a tool in identifying the skeletal/dental remains. As existing age-at-death estimation techniques have limited precision; researchers have sought to demonstrate age-related changes in the dental hard tissues. [1],[3] The bone remodeling is a continuous and complex process, which occurs through our life. During an individual's life, the morphological changes undergone by the mandible are thought to be influenced by dental status and the age of the patient. [4],[5] The various remodeling fields in the mandible, which undergo changes include the gonial region, antegonial region, condyle, and ramus. [4]

A number of methods for age determination have been proposed. These can be classified in four categories including clinical, histological, chemical and radiological analysis. In the living persons, any or all of the above methods can be used to determine age, in cases where actual age is not known or is to be confirmed. However, in case of a dead person, postmortem changes such as decomposition, mutilation or skeletonization may make identification progressively more difficult almost to the point of impossibility. [3] Dry skull's orthopantomography (OPG) are frequently used on scientific research or forensic investigations. Dental methods are considered to be a reliable tool when other identification methods fail. [6]

Digital OPGs are one of the best quality examinations when dry skull radiograph are necessary for scientific or forensic study [Figure 1]. However, when dealing with analog equipment, developing a panoramic film, which is intentionally exposed to light, and placed inside the cassette between the new film and the intensifying screen is used to achieve satisfactory radiographs. An exposure of 63 Kv and 06 mA should be selected, and an automatic processing machine can be used for enhanced results. [7] This study was conducted to understand the alteration by measuring gonial angle, width of the ramus, height of condyle and coronoid and to correlate with various parameters of age and sex in dentition status and to drive at regression equation.{Figure 1}

Source of data

This study was conducted in our outpatient department, SRM Dental College and Hospital, Chennai, India. The sample 760 digital OPG images were analyzed during the year of August 2013-October 2014 in which 200 images are selected for the study.

 Materials and Methods

A retrospective study was conducted using OPGs of 113 males and 87 females in the age group between >4 years and 75 years. Ideal OPGs of dentate radiographic images were selected for the study. The following are inclusion criteria optimal radiograph no pathologies, age >4-75 years, no magnification errors, no periodontal lesions, no missing teeth in mandibular arch, completely dentulous and exclusion criteria asymmetry in OPG images, unreadable and poor quality, presence of supernumerary teeth, orthodontic treatment, deep caries, Rct to the teeth near mental foramen, missing teeth, magnification and distortion. An OPG was taken in standard manner using VILLA system MEDICALI S.p.A (Owandy, France) (Rotograph Evo D for image acquisition, patient positioning, and exposure are made according to manufacturer's reference guide).

The image is measured using KLONK image measurement software version (Owandy, France) with tools of linear and angle measurement, before measuring digital OPG images are converted into DICOM images for various measurements in digital OPG. A single examiner measured the gonial angle by angular measurement tool by determining from two tangents which is drawn from inferior border of the mandible and posterior borders of condyle (i.e.,) (angle between the ramus and corpus of the mandible (x = ABC)) and height of the ramus is determined by two lines one from most cranial point of the condyle (Co) and the intersection point with the lower border of the ramus mandibulae(the gonial point [Go] Y = D + E), (another from most cranial point of the coronoid to the lower border of the ramus mandibiulae Z = F + E); width of the ramus determined by two lines, (for maximum width from below the sigmoid notch of outer border of condyle to inner coronoid border Wa1 = G + H), (for minimum width from lower border of condyle to external oblique line Wa2 = I + J) [Figure 1]. [7]

Statistical analysis

The data were analyzed by SPSS 10 for Windows (SPSS Inc., Chicago, USA) for Descriptive analysis - mean, median, standard deviation (SD), first quartile, third quartile (independent variables) angle of mandible, height of ramus of right (R) and left (L) sides; correlating age and gender (independent variables) measured for R and L side - Pearson correlation; linear regression coefficient by regression equation to determine predictive value; multiple linear regression analysis by fitted model equation to arrive at age and gender.


In this study, radiographic measurement of digital OPG images of 200 images consisting 113 (male), 87 (female) and statistical analysis were carried out using SPSS software 10. descriptive statistical analysis of mean, SD, 1 st Q, median, minimum, maximum, 3 rd Q for all the variables to better understand about the inter variable difference [Table 1] the table shows below descriptive statistics according to various parameters and there is a significance difference between all the parameters - gonial angle, height and width of the ramus of mandible of the right side similarly there is significance difference was also observed in respect to the left side, between the genders, regression equation is derived for 200 samples to predict the unknown age and gender X/Y = Constant + Beta value × Variable.{Table 1}

Regression coefficient analysis is performed for all the parameters to determining relationship between the dependent variables and the P < 0.005 shows highly significant for angle of mandible (R) <0.001, width of ramus MAX (R) <0.001, Angle of mandible (L) <0.001, width of mandible MAX < 0.001, (L) height of ramus CO-MB < 0.001 [Table 2]. Slopes determine the most predictive value for the various parameters. Regression coefficient for gender is carried out and the results shows significant variables in the gonial angle 0.002 and height of the ramus <0.001 in males and gonial angle <0.001 [Table 3] and height of the ramus 0.002 females [Table 4].{Table 2}{Table 3}{Table 4}


Human beings growth changes taking place from the beginning of prenatal life to senility. Hard tissues (bones and teeth) also undergo changes with growth, which can be a change in shape and/or fusion of ossification centers or after death, these changes remain stable and facilitate ease in estimation of age from hard tissue samples. [8],[9],[10] The identification of sex from human remains is of fundamental importance in forensic medicine and anthropology, especially in criminal investigations as well as in the identification of missing persons and in attempts at reconstructing the lives of ancient populations. The important aspect of forensic dentistry is to determine sex from fragmented jaws and dentition. [11] Detection of sex based on morphological marks is subjective and likely to be inaccurate, but methods based on measurements and morphometry are accurate and can be used in the determination of sex from the skull. [12],[13],[14] Mandibles were used for the analysis for two simple reasons - there is a lack of standards utilizing this element and also this bone is often recovered largely intact. [15]

The accuracy of panoramic radiography in providing anatomic measurements has been recognized. OPG has been widely used by the clinicians as an appropriate screening tool for the diagnosis of oral diseases. The main advantages of panoramic images are their broad coverage, low radiation dose, and less time required for image acquisition. [16] Furthermore, the contrast and brightness enhancement and enlargement of images provide an accurate and reproducible method of measuring the chosen points. [17],[18],[19] The limitations of this technique are magnification and geometric distortion, however, the vertical dimension in contrast to the horizontal dimension is altered less, and this technique is quite sensitive to positioning errors because of relatively narrow image layer. [16],[19] However, in our study, this limitation did not affect our results since all images were uniformly magnified. This study was performed to assess the radiographic measurements of gonial angle, height, and width of the ramus in predicting the age and gender.

The first amongst them was angle an increase in the size of the gonial angle was observed in this study. This is in agreement with the previous study. [1],[20] Who found a close positive association between gonial angle and age. This could be attributed to the muscular forces associated with mastication preserved the angle from any changes in the dentate individual and also increase in the size is also seen with bone remodeling, loss of teeth.

A reduction in the height of the body of the mandible was observed with increase in age has negative correlation and it is agreed with previous studies [19],[21] [Figure 2] it shows that bone resorption takes place during ageing. Various studies have investigated the sexual dimorphism of the mandibular ramus flexure using direct visual assessment [22] and the predictive accuracy of mandibular ramus sexual dimorphism. [22] {Figure 2}

Identification is significantly reliable in identifying gender dimorphism [Figure 3] which was in agreed with literature [19] and whereas contrast to previous study [23] conducted a study on dry adult mandibles of northern part of India and found that ramus expresses strong sexual dimorphism in this population. The overall prediction rate using five variables was 80.2%. The best parameters were coronoid height, condylar height, and projective height of ramus, and breadth measurements were not very dimorphic in their sample.{Figure 3}

Gonial angle ABC, height of ramus from CO-MB, width of ramus max G-H measurement was found to be the best parameter in the present study, which is consistent with other osteometric studies where breadth measurements were found to be very dimorphic. This is related to the differences in musculoskeletal development and to the differences related to a different growth trajectory in males and females. [12],[24],[25]


The mean values of the gonial angle and ramus height and width on the right side were slightly higher than those on the left side but the differences were not statistically significant. Males have higher values of the gonial angle, ramus height female. Gender differences in gonial angle were significant it has been established that socioenvironmental factors e.g. nutrition, food, climate; pathologies influence the development, and thus the appearance of bones. Numerous studies have demonstrated that skeletal characteristics differ in each population and have emphasized the need for population-specific osteometric standards for sex determination future direction toward by taking larger sample size and driving regression equation to predict the age and gender from dental records and regression slopes have most cluster in the second decade probably due to other factors, which influencing the growth pattern and finding those will lead in to reliable identification of age and gender.


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