Study Design
Comparative cross-sectional study
Study Settings
The study was carried out in the college premises. The duration of the study was 1.5 years with data collected using a study proforma sheet.
Study Population
Individuals greater than 20 years in age with/without impaction of tooth/teeth were the respondents for the study.
Inclusion And Exclusion Criteria:
Inclusion criteria: Individuals aged more than 20 years and willing to participate in the study were included in the study.
Exclusion criteria: Individuals who were differently-abled / had amputated forelimbs/scar on phalanges of hands/ having impacted tooth other than the third molars/ impacted third molar with pathology,were excluded from the study.
Sampling Procedure and Data Collection
The statistical formula was used to compute the sample size and a total of 180 participants were involved in the study, of which individuals with impacted third molar/ partially erupted third molar / missing third molars with no history of extraction were included in the case group comprising of 90 subjects; whereas individuals who had the full complement of erupted teeth (32 number) were taken as controls comprising of 90 subjects. The sampling technique used was quota sampling. Measures have been taken with interval matching. The participants were given the PATIENT INFORMATION SHEET [in Appendix] and the procedure was comprehensively explained in his/her vernacular language.
The ink method was used to record the impression of fingerprints with blue duplicating ink. The materials used were: Magnifying glass (5x), Cotton applicator, Soap, Water, Tissue paper, and study proforma sheet.[ in Appendix]
To ensure a good quality dermatoglyphic print, the hands of the participants were washed with soap and water followed by drying using tissue paper to remove sweat, oil, and dirt from the fingertips. Subsequently, a small daub of blue duplicating ink was applied on the cotton applicator and the fingertip was smeared evenly with a thin layer of ink. The rolling impression technique was preferred to record the impression on the study proforma sheet. This method enables to record complete imprints by rolling the finger from one side to the other (nail to nail). [15, 16]
To attain a high-quality impression, each digit was pressed firmly on the proforma sheet with stable and adequate pressure. To avoid duplication, blocks made on the proforma sheet were numbered from 1-5 for the right hand starting from thumb to the little finger and 6-10 for the left hand starting from the thumb to the little finger.
For participants with missing tooth/teeth without any history of surgery/extraction of the same, an Orthopantomogram (OPG) X-RAY [in Appendix] was taken to confirm the presence of impacted teeth or congenitally missing tooth/teeth
Study Variables: Demographic variables were recorded. Impaction was taken as a dependant variable, along with that, all the versions of the fingerprints of all the fingers were taken as independent variables. All the fingerprints were taken as categorical variables which were divided into 5 categories: Loop Radial, Loop-Ulnar, Whorl-Plain, Whorl-Pocket, Whorl-Double loop, Arch-Plain.
Data Management and Analysis
The recorded prints were studied using a hand-magnifying glass under the forensic expert’s supervision. The patterns visualized were
WHORL PATTERN
It has a concentric design in which the majority of the ridges make circuits around the core. They are further divided into
i. Plain- concentric circles form the pattern around a core
ii. Doubleloop- two loops form an S-shaped pattern
iii. Accidental-irregular shaped pattern
iv. Central pocket loop- a loop with a whorl pattern at one end
LOOP PATTERN
It has ridges that are open and curve around only on the single extremity of the pattern and flow to the margin of the digit. They are further divided into
i. Radial- loop ends towards the radial side
ii. Ulnar- loop ends towards the ulnar side
ARCH PATTERN
It has ridges passing from one margin of the digit to the other with a distally bowed sweep. They are further subdivided into
iii. Plain- the wave in the centre is blunt/low in height
iv. Tented-the wave in the centre is sharp/high in height[17][ In Appendix ]
Statistical analysis was done using SPSS 20.0 software at a 5% level of significance. The impaction with gender and the pattern of dermatoglyphics with each finger was compared using the chi-square test. The prediction of impaction was analyzed using forward stepwise binary regression analysis. Impaction was taken as the dependent variable and the patterns of each finger of the individual were taken as the independent variables for prediction.
Ethical Consideration
The clearance from the Ethics Committee of the institution (Ethical Clearance Reference number 18061) was taken before commencement. All the participants signed an Informed Consent Agreement [in Appendix] before taking part.
After the completion of the study, the study proforma sheets would be burnt to dispose of the imprints considering the safety and legal facets.