A Comparative Evaluation between Cheiloscopic Patterns and Terminal Planes in Primary Dentition.

OBJECTIVE: To assess the correlation between different cheiloscopic patterns with the terminal planes in deciduous dentition.
MATERIALS AND METHODS: Three hundred children who are 3-6 years old with complete primary dentition were recruited, and the pattern of molar terminal plane was recorded in the pro forma. Lip prints of these children were recorded with lipstick-cellophane method, and the middle 10 mm of lower lip was analyzed for the lip print pattern as suggested by Sivapathasundharam et al. The pattern was classified based on Tsuchihashi and Suzuki classification.
RESULTS: Type II (branched) pattern was the most predominant cheiloscopic pattern. The predominant patterns which related to the terminal planes were as follows: Type IV (reticular) and Type V (irregular) pattern for mesial step, Type IV (reticular) pattern for distal step, and Type I (complete vertical) pattern for flush terminal plane. No significant relationship was obtained on gender comparison.
CONCLUSION: Lip prints can provide an alternative to dermatoglyphics to predict the terminal plane in primary dentition. Further studies with larger sample size are required to provide an insight into its significant correlations.

Introduction

Childhood is the mirror in which the propensities of adulthood are reflected; similarly, the type of occlusal characteristics in primary dentition predicts the occlusal relationship of the succedaneous dentition.[1] The understanding of the anteroposterior changes which occur in between the primary and permanent dentition is crucial, particularly for the clinicians involved in interceptive and preventive orthodontics.[2] The terminal plane in deciduous dentition is widely known to have some important bearing on the development of a normal occlusal relationship in the permanent dentition,[3] as any development of malocclusion primarily starts with the deciduous dentition. Cheiloscopy is one of the analytical tools that are used in forensic dentistry. Studies were performed to assess the link between these lip prints and permanent occlusal relationship,[456] but its association with terminal plane of primary dentition has not been reported. Hence, this study was aimed to assess the correlation between different cheiloscopic patterns with the terminal planes in deciduous dentition.

Materials and Methods

The present study was conducted among a total of 300 children who were aged 3–6 years attending the Department of Pediatric and Preventive Dentistry. Ethical clearance was obtained from institutional review board. The purpose and procedures of the study were explained to the parents/guardians, and informed consent was obtained to participate in the study. Inclusion criteria were children with completely erupted primary dentition. Exclusion criteria were previous history of orthodontic treatment, initiation of first transitional period, previous history of burn or chemical injury or lesions on lips, different molar relationships on either side of the same individual, children with grossly decayed teeth or proximal caries or premature extraction of primary teeth affecting the molar relation, and uncooperative children. Two calibrated examiners (two of the authors) were trained to assess the molar relationships based on the classification given by Baume,[7] as mesial step, distal step, and flush terminal plane. Examination was done using a mouth mirror and recorded in the pro forma. Under each terminal plane, 100 children were taken so as to standardize the number of children under each group; thereby, the results can be closely related to the patterns obtained.

Lip print was recorded using the lipstick-cellophane technique as proposed by Sivapathasundaram et al.[8] which provides good clarity and accuracy.[9] Matte finish lipstick was applied with disposable cotton buds as suggested by Amith et al.[10] Children were asked to rub their lips gently against one another and then to keep their lips in rest position. The glue part of the cellophane sheet is placed over the lips. After few seconds, the cellophane sheet with lip print was carefully removed and was stuck onto a bonded white paper [Figure 1]. Lip print was checked for clarity, and if any smudging of the print was noticed, the procedure was repeated once again. Children were asked to wipe off the remnant lipstick using wet tissue paper.

Figure 1

Method to record lip prints

The collected lip prints were analyzed using a magnifying glass by a forensic specialist who was not involved in the collection of prints and also was not disclosed about the terminal planes, thereby blinded from the data obtained. The analyst read the lip prints based on the classification given by Suzuki and Tsuchihashi in 1971.[11]

Type I: Clear-cut vertical grooves that run across the entire lips

Type I’: Similar to Type I, but do not cover the entire lip

Type II: Branched grooves

Type III: Intersected grooves

Type IV: Reticular grooves

Type V: Grooves do not fall into any of the types, i.e., Type I–IV, and cannot be differentiated morphologically.

The middle part of the lower lip (10-mm wide) was taken as the study area, similar to the study by Sivapathasundharam et al.[8] Lip print pattern was determined by counting the highest number of patterns in the above-mentioned region.

Statistical analysis

The data values were tabulated and subjected to statistical analysis. For comparison of proportions between all the groups and also between genders, Chi-square test was applied. Fisher's exact test was used when any expected cell frequency <5 was obtained. SPSS version 22.0 (SPSS Inc., Chicago, IL, USA) was used to analyze the data. A P < 0.05 is considered as statistically significant.

Results

The mean age of the children was 4.99 ± 0.67 years. For the children having mesial step, 61% were females and 39% were males. Among the children having distal step, 55% were females and 45% were males. In children having flush terminal plane, 43% were females and 57% were males. Type II (branched) pattern is the most predominant cheiloscopic pattern which was equally distributed among children with primary dentition. An increase in Type IV (reticular) and Type V (irregular) patterns was seen in children with mesial step. Type IV (reticular) pattern was seen in higher frequency in distal step. Among children with flush terminal plane, Type I (complete vertical) pattern was predominantly seen [Table 1]. There was no statistically significant relationship seen in all three molar patterns when compared with the cheiloscopic patterns (P = 0.345). On comparing between genders, no statistically significant relationship was noted [Table 2].

Table 1

Cheiloscopic distribution in primary dentition

Table 2

Gender comparison on distribution of cheiloscopic pattern in primary dentition

Discussion

Every human is distinct and unique in the pattern of characteristics they exhibit. Lip prints are lines and fissures that appear as wrinkles and grooves in the zone of transition between the inner labial mucosa and the outer skin of human lip. The examination of these fissures is referred to as “cheiloscopy.”[812] Although its existence was noticed as early as 1902, its importance did not reach the researchers until it was found in a scene of murder. These patterns, as they are analogous to the prints that are found in the palms and digits, gained popularity for sex determination in the field of forensics. The development of lip, alveolus, and palate occurs at the same period, i.e., 24th week of intrauterine life and also from the same embryonic origin. Any factor that tends to affect the development of a particular structure will ultimately affect all the other structures that develop along with it. Hence, there is a possibility for the developmental changes that occur in relation to alveolus to be reflected in the cheiloscopic patterns. This was the basis of analyzing the terminal plane of primary molars with the different cheiloscopic patterns.

Cheiloscopic patterns were analyzed for skeletal malocclusions, but the literature search shows no studies relating to terminal planes in primary dentition. This study is an initial attempt to relate them as the terminal plane of the primary second molars plays a significant role in determining the occlusion of the permanent dentition.[313] Chukwudi et al. showed that 68.7% of individuals initially having a flush terminal plane relationship resulted in a Class I molar relationship, 61.1% of individuals who initially had a mesial step relationship became a Class I molar relationship, while 27.8% resulted in a Class III relationship.[14] Since the primary dentition provides the framework and foundation for proper eruption and alignment of the permanent dentition, the prediction of the terminal planes can help the pediatric dentist in maintaining a favorable plane which may get affected by other environmental factors such as dental caries.

The results of the current study have helped us to predict certain patterns which might be related to specific terminal planes. In our study, among cheiloscopic patterns, Type II (branched) pattern was predominant among all the children. This was in accordance to the study done by Raghav et al.[4] and Madhusudan et al.,[15] who reported the same predominance in individuals with complete permanent dentition. The patterns that were seen predominantly in children with mesial step are both Type IV (reticular) and Type V (irregular) patterns, with the predominant pattern seen in children with distal step being Type IV (reticular) pattern and for flush terminal plane being Type I (complete vertical) pattern.

These results have provided an insight into specific cheiloscopic patterns which could be used as an anatomical tool, thereby helping to predict the future terminal plane of the primary dentition. This could help the dental practitioner to establish necessary measures to ensure no further loss of space occurs which could worsen the situation, if any. Since we could not elicit any statistical significance, we acknowledge that further studies with larger sample size are required to provide a more accurate prediction of the relationship. If this association can be proved on a larger scale, it can help as a non-invasive marker to predict the developing malocclusion which can be prevented, intercepted, or guided to achieve ideal occlusion in future.

Conclusion

Within the limitations of this study, we could conclude that Type II (branched) pattern was the most predominant cheiloscopic pattern. The predominant patterns which related to the terminal planes were as follows: Type IV (reticular) and Type V (irregular) patterns for mesial step, Type IV (reticular) pattern for distal step, and Type I (complete vertical) pattern for flush terminal plane.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.