Primary Rugae Research Articles

Quantitative and Qualitative Analysis of Palatal Rugae Patterns in Bhopal Division: A Retrospective Cross-Sectional Study

ABSTRACT Objective: The goal of this investigation is to assess the palatal rugae patterns in male and female participants from the Bhopal Division population. Material and Methods: A randomly selected cohort of 104 individuals, consisting of 47 males and 57 females, was included in the study. Both metric and non-metric characteristics of the palatal rugae were documented and analyzed using two-sample t-tests and chi-square tests, with a significance threshold set at 5%. Results: No significant difference was observed in the total number of rugae between genders. However, the mean number of primary rugae was significantly higher in males (P = 0.038). In contrast, females exhibited a higher mean number of vertical (P < 0.001) and fragmentary rugae (P = 0.004), with these differences achieving statistical significance. Conclusion: The rugae pattern demonstrates potential as a gender-differentiating characteristic, serving as a supplementary method to traditional techniques such as cranial anthropometry and dental analysis.

Comparative Study of Palatal Rugae Patterns in Two Populations (Arabs - Asian and Indians)

Palatal rugae are anatomical structures present in the roof of oral cavity; there is a significant association between rugae forms & ethnicity. The aim of this study is to compare rugae patterns in two different populations: Arabs (Asian) & Indians. 80 female participants were included in this study: 40 Arabs & 40 Indians. In the dental clinic / college of dentistry at university of Ajman in UAE. It has been found that the primary rugae lengths was significantly more in Arabs 8.325±1.3 compared to Indians 5.575±1.2, the Arabs population showed predominant wavy shaped rugae [58%], while the Indians had straight shaped rugae [40%]. These differences of the shape & lengths of palatal rugae appear as a result of genetic & environmental factors.

Is palatal rugae a specific marker of dysmorphogenesis in patients with schizophrenia?

Background and ObjectivesSupporting the neurodevelopmental model of schizophrenia, minor physical anomalies (MPAs) are markers of abnormalities in early fetal development. The mouth seems to be a common region for the occurrence of MPAs in patients with schizophrenia. This study aimed to compare the palatal rugae patterns, according to their length, shape, and orientation, between patients with schizophrenia and controls in a blinded fashion. The palatal rugae patterns were also evaluated by sex, as its effect on neurodevelopment was relevant. MethodsDental stone models were fabricated from maxilla impressions of patients with schizophrenia (N = 105) and controls (N = 105). Based on their lengths, three types of palatal rugae were classified; primary, secondary, and fragmentary. Primary rugae were further categorized according to their shape and direction. ResultsThe most detected palatal rugae were the primary ones in both groups. The primary, secondary, and fragmentary rugae numbers in both groups were no different. There were significant differences in the shape and orientation of the primary rugae between the two groups. Curved (OR:1.76, p = 0.006), island (OR:2.97, p = 0.001) and nonspecific (OR:5.44, p = 0.004) primary rugae shape were found to be significant predictive variables for schizophrenia. Randomly oriented rugae numbers were higher in schizophrenics than controls (p = 0.018). The two sexes had different preferences in primary rugae shapes and directions compared to same-sex controls in patients with schizophrenia. ConclusionIdentifying subtle changes in the primary rugae pattern, which appear to be sex-specific, is consistent with impaired neurodevelopment in schizophrenia.

Evaluation of the Denture Impact on the Palatal Rugae: An Original Research.

The palatal rugae may alter their shape based on the various physical pressures that they had to endure. This study's objective is to assess the various alterations in the palatal rugae parameters among the complete denture wearers. Forty subjects in all were chosen for the study. The control group interventional groups had an equal number of participants who were further equally distributed based on gender. For all of the participants, mucostatic maxillary alginate imprints were taken, and gypsum castings were created. They were called at the scheduled intervals of 2, 6, and 12 months following the treatment. The models used during those recalls and all of the palatal rugae were examined under a microscope for quantity, length, form, orientation, and unifications. The unpaired t-test was used to statistically examine palatal rugae alterations. Following the wear of the dentures, the experimental group's primary, secondary, and fragmented rugae all gradually shrank in length. In terms of statistics, the alteration solely affected primary rugae and was significant (P < 0.001). After a year of wearing dentures, a minimal change in rugae's form was noticed in the denture groups, but it was statistically not substantial (P > 0.05). Due to the prolonged mechanical stress the dentures placed on the palatal rugae, complete denture users saw a significant reduction in the length of their primary rugae. Rugae number, orientation, and unification were among the other criteria that did not change during the course of the study. Analysis of the palatal rugae may not be useful in identifying people wearing full dentures. However, in forensic investigations, rugae may act as an adjunct to other methods like fingerprints and DNA analysis.

An Association of Morphological Characteristics of Palatal Rugae and Dental Malocclusion in an Adult Indian Population: A Cross-Sectional Study.

Introduction The formation of palatal rugae is completed in the early intrauterine stage, and because of their unique and permanent pattern in each individual, they can be utilized in forensics to identify a person. Objective The primary objective of this study was to determine an association between the rugae pattern and the dental malocclusion system described by Angle. Materials and methods A prospective cross-sectional, observational study was conducted on pretreatment dental casts of 400 subjects in an age range of 18-40 years. The samples were divided according to Angle's system of classification of malocclusion into Class I, Class II, and Class III. The number, length, pattern, and orientation of the three anterior-most primary rugae on both sides of the palatal region were studied. Results Significant differences were noted in the mean number of palatal rugae and mean lengths of rugae 1 and 2 on the right side (p < 0.001) and rugae 3 on the left (p < 0.001) side among the different malocclusion groups. Curved and wavy patterns were predominant, and significant differences were found among the groups (p < 0.05), whereas non-significant differences were observed in the rugae orientation between the groups on the right and left sides. Conclusions The current study showed significant differences in the length, number, and pattern of the palatal rugae among Angle's classes of malocclusion. Clinical implications Palatal rugae can be effectively used to identify dental malocclusion at an early stage and can, therefore, help intercept the developing malocclusion.

A Morphometric Analysis of Palatal Rugae Patterns in a Saudi Arabian Population.

Background Palatal rugae patterns are useful in the field of forensic dentistry. Ethnicity has a significant effect on the development and final morphological pattern of palatal rugae. This study focused on a morphological analysis of the palatal rugae in a Saudi population to determine if any differences based on age and gender could support identifying an individual. Materials and methods This cross-sectional study conducted at the College of Dentistry, King Saud bin Abdul Aziz University for Health Sciences, was undertaken to evaluate 496 dental casts from the participant database of Saudi nationals from Riyadh. The rugae were delineated using a sharp graphite pencil under adequate light and magnification. The rugae patterns were classified based on the length, shape, and direction of the rugae by two observers as per Thomas and Kotze's criteria. Results The asymptotic chi-square McNemar test indicatedbilateral symmetry for all the characteristics of the palatal rugae, except for the backward and forward directions of the rugae. Two-way analysis of variance (ANOVA) revealed a statistically significant interaction between the effects of age group and gender on the primary rugae count (F(3, 488) = 7.466, p <0.05)). In addition, age had a statistically significant effect on the fragmentary rugae (p <0.05), and gender had a statistically significant effect on the circular and backward patterns of the rugae (p<0.05). The females had a higher incidence of backward-directed rugae and the males had more circular rugae. No other significant difference was evident, based on gender. The logistic regression analyses showed a significant association between the circular (OR=1.298; 95% CI= 1.061-1.588)and backward (OR= 0.898; 95% CI= 0.828-0.975) palatal rugae and gender. Also, there was a significant association of the fragmentary palatal rugae (PR) (OR=1.274; 95% CI= 1.084-1.498) with the age group younger than 16 years. Conclusion In a Saudi Arabian ethnic group, the varying type of length of the palatal rugae patterns can be used to identify the age groupwhile the direction and shape can be used to determine gender, although with limited accuracy. Post-mortem identification may benefit from using them along with other reliable forensic tools. There is a need to conduct continued research on diverse populations and ethnic groups in order to evaluate the PR potential in forensic dentistry.

Evaluation of Palatal Rugae in Patients for Maxillary Dental Prostheses

Significance and importance of palatal soft tissue rugae increases many folds when replacement of missing maxillary teeth with conventional complete denture is part of treatment plane. Objectives: To quantify the shape and size of rugae in completely and partial edentulous arches in both males and females. Methods: A total of 200 patients were selected on the basis of inclusion and exclusion criteria and after obtaining informed consent, impression with Alginate impression material were made and poured to form dental casts. Pattern and shapes of rugae were delineated with graphite marker. Under a good source of light different shapes, thus outlined, were counted in number and measured in length, categorizing them in various shapes such as divergent, wavy, curved and straight. Age, arches were computed for frequency and measuring the mean with standard deviation. All data were computed by using SPSS (version 22). Results: Out of 200 patients, a male (n=89) to female (n=111) ratio of 0.80 was found with a mean age of 52.6 and standard deviation of 11.3. Partially edentulous cases were 51%, while the rest were completely edentulous. A total of 1367 rugae were found in both types of patients. Females had more number of rugae (n=773) than males (n=594). Similarly primary rugae were higher in numbers (n=1132) than secondary rugae (n=235) and the observed difference was statistically significant (p=0.001). Conclusions: It was concluded in this study that female and partially edentulous arches had more numbers of rugae as compared to males and completely edentulous arches respectively.

Assessment and Correlation of Dactyloscopy, Cheiloscopy, and Rugoscopy Among Individuals With Different Skeletal Malocclusion—A Cross-Sectional Study

Background and Objectives A probable association between dermatoglyphics and malocclusions related to skeletal discrepancy may exist as dermal ridges, and craniofacial structures develop from the same embryonic tissues during the same embryonic period. The study aims to assess and correlate the pattern of fingerprints, lip prints, and palatal rugae in individuals with malocclusions related to skeletal discrepancy. Materials and Methods The 180 samples collected in the study were divided into 3 groups based on cephalometric analysis into class I, II, and III malocclusion. The fingerprints, lip prints, and palatal rugae patterns were obtained for each participant and pattern analysis was done. Results Class I malocclusion with no skeletal discrepancy showed a statistically significant difference in the loop fingerprint patterns on all fingers except the first finger on the right and left hand, branched lip pattern, and straight palatal rugae pattern in primary rugae 1 and 4. Class II malocclusion related to skeletal discrepancy showed a statistically significant difference in the loop pattern on all fingers except in the fourth finger of the right hand which showed a whorl pattern, branched lip pattern, and straight palatal rugae pattern in primary rugae 1, 4, and 5. Class III malocclusion related to skeletal discrepancy showed a statistically significant difference in the loop pattern on all fingers except in the fourth finger of the right hand which showed an absence of arch pattern, vertical lip print pattern, and straight palatal rugae pattern in primary rugae 1. Conclusion Dermatoglyphics analysis can be used to indicate developing malocclusions related to skeletal discrepancies. at an early age, thereby aiding the development of treatment aiming to establish favorable occlusion. Prospective and various ethnic and racial-based studies would be valuable for the establishment of dermatoglyphic markers of malocclusion.

Palatal Rugae as an Indicator of Sexual Dimorphism

Introduction: Palatoscopy or palate rugoscopy has been studied over the years to identify its unique characteristics to utilize for the human identification process. The unique anatomical location of the palatal rugae provides stability which along with the uniqueness of the palatal rugae pattern can contribute in human identification. Despite its simplicity and reliability, the palatal rugae is unexplored in the Nepalese population. The objective of the present study is to identify the rugae pattern and assess its sexual dimorphism. Methods: This was a cross-sectional analytical study conducted in Tribhuvan University Dental Teaching Hospital (TUDTH). The characteristics of palatal rugae based upon number, length, shape, and unification were analyzed on 100 dental casts. The rugae patterns were marked with a black color graphite pencil under adequate illumination. The length of the rugae was measured with the help of a digital vernier caliper and brass wire. The independent sample T-test and Mann Whitney U tests were used to assess the sexual dimorphism. Results: The predominant type of rugae according to the size in both males and females was primary rugae. According to the shape of the rugae, the predominant type of rugae was wavy followed by curved, straight, diverging, converging, and circular in both the sexes. However, no significant difference was seen in the rugae pattern in males and females. Conclusion: Based on the findings of the present study, the use of palatal rugae for sex determination is not recommended.

Palatal rugoscopy as an adjunct for sex determination in forensic odontology (Sri Ganganagar population): A cross-sectional study of 100 subjects.

Introduction:Palatorugoscopy is the term used to study the rugae patterns. The word rugae came from the Greek word seam. Moreover, it relates the crisscrossing or joining or stitching of the parts of two biological structures during fetal differentiation. The aim of this study is to determine the gender difference in rugae pattern with regard to length, number, shape, unification and direction in the population of Sri Ganganagar, Rajasthan.Objective:The objective is to determine the gender difference in rugae pattern with regard to length, number, shape, unification and direction; to investigate the difference in division of rugae in males and females and to compare rugae pattern in males and females of different age group.Materials and Methods:This study included 100 subjects, in which 50 were males (Group A) and other 50 were females (Group B). After the formation of primary cast, all quantitative as well as qualitative characteristics of palatal rugae patterns were recorded. Mainly, two classifications were used in this study, Thomas et al. and Kapali et al.Statistical Analysis:Student t-test was used, and “P” value of <0.05 was considered statistically significant.Results:A statistically significant value was found in left-sided palatal rugae patterns depending upon the size, where we found that primary rugae were more in males. On comparing the angulation of palatal rugae patterns of left-sided rugae, a statistically significant value was found among the negative angulation which was higher in male subjects. Next, while comparing the angulation of palatal rugae of right side, we found a statistically significant value among zero (perpendicular rugae), which was more in male population. On comparing the unification of right-sided rugae patterns, we found that divergent rugae were more in male subjects.Conclusion:Palatal rugae patterns act as individualistic, and are unique patterns, and are helpful in determining the human gender. Further, more studies are required on palatal rugae patterns used in forensics on large population scale.

Genetic variants in bone morphogenetic proteins signaling pathway might be involved in palatal rugae phenotype in humans

This study investigated, if genetic variants in BMP2, BMP4 and SMAD6 are associated with variations in the palatal rugae pattern in humans. Dental casts and genomic DNA from 75 patients were evaluated. Each patient was classified as follows: total amount of rugae; bilateral symmetry in the amount, length and shape of the palatal rugae; presence of secondary or fragmentary palatal rugae; presence of unifications; predominant shape; and predominant direction of the palatal rugae. The genetic variants in BMP2 (rs1005464 and rs235768), BMP4 (rs17563) and SMAD6 (rs2119261 and rs3934908) were genotyped. Genotype distribution was compared between palatal rugae patterns using the chi-square test (alpha = 0.05). The allele A was associated with the presence of secondary or fragmentary rugae for rs1005464 (OR = 2.5, 95%CI 1.1–6.3; p = 0.014). Secondary or fragmentary rugae were associated with the G allele in rs17563 (OR = 2.1, 95%CI 1.1–3.9; p = 0.017). rs17563 was also associated with rugae unification (p = 0.017 in the additive model). The predominant shape (wavy) was associated with rs2119261 (p = 0.023 in the additive model). The left–right symmetry of the length of primary rugae was associated with rs3934908 in the recessive model (OR = 3.6, 95%CI 1.2–11.7; p = 0.025). In conclusion, genetic variants in the BMP pathway impacted on palatal rugae pattern.

Effect of Dentures on Palatal Rugae: An Investigation

Aims: The aim of this study is to evaluate the rugae pattern changes (rugae number, length, shape, direction, and unification) in completely edentulous patients treated with complete denture. Materials and Methods: A total of 100 subjects were selected for the study. The experimental group comprised 60 participants (30 males and 30 females) who had undergone complete denture treatment and the control group comprised 40 participants (20 males and 20 females) who were dentulous and patients with fixed partial denture treatment. Mucostatic maxillary alginate impressions were made for all the subjects, and casts were poured with gypsum. Patients were recalled at the regular intervals of 1, 6, and 18 months after the treatment. During those recalls, the same impression procedure was made, and all the palatal rugaes were observed for number, length, shape, direction, and unifications under magnifying lens. Changes in the palatal rugae were statistically analyzed using the unpaired t‑test. Results: A gradual decrease in the length was observed in primary, secondary, and fragmentary rugae for the experimental group after denture wearing (Group 1). Statistically, the change was significant (P &lt; 0.001) in primary rugae only. A slight change in rugae shape was also observed in the experimental group after 18 months period of denture wearing which is statistically insignificant (P &gt; 0.05). Conclusions: Significant decrease in primary rugae length in complete denture wearers was due to sustained mechanical stress posed by the dentures on palatal rugae. The other parameters such as rugae number, direction, and unification remained constant throughout the study. Palatal rugae analysis may not be helpful for human identification in complete denture wearers. Nevertheless, palatal rugae may serve as an adjuvant to other techniques such as DNA analysis and finger prints in forensic investigations.

Comparison of Palatal Rugae Pattern among Indian and Malaysian Population

Background: Tools for establishing identity is invaluable part of forensic sciences form the beginningof the profession. Odontology is one of such branches which in early days started in its crude form withidentification of different species and races within the species, currently is an individual subject withspecialist societies, journals and courses. Palatal rugae, was identified to be a potential tool for establishingidentity few centuries back itself but is not validated even today to be part of standard protocols. This is apilot study comparing two racial groups i.e., Indian and Malaysian with established parameters for palaterugae aiming at testing the feasibility of the parameters to be used in identification of individuals and racialgroups and also to provide preliminary data to make way to larger studies.Aims and Objectives: The aim of this pilot study is to explore the feasibility of palate prints as tool foridentification by, studying palate print in Indian and Malaysians and Comparison of plate Rugosity betweenIndians and Malaysians students for identification.Methodology: Study population was male Indian and Malaysian Medical and Dental students, age between18-25 years studying at Mangalore, India. Sample size 80 (40 in each group); were selected for studying ofPalatal Rugae. The palate impressions were collected using maxillary alginate cast. The parameters assessedwere: Total number of rugae, number of primary rugae (length- 5 to 10 mm), secondary rugae (3-5mm),fragmentary rugae (less than 3 mm). Comparison for two populations was done using non-parametric MannWhitney Test.Results: There were no statistically significant differences among the Indians and Malaysians in totalnumber and number secondary rugae in both sides more in Indians than Malaysians.There was statistically significant difference in number of the primary rugae and the fragmentary rugae,which in both sides were more in Indians than Malaysians.Conclusion: In conclusion, palatal rugae pattern are unique to an individual and their use in forensicidentification has been advocated and applied. Our study demonstrated significant difference in the numberof primary rugae on each side. It was more in Indians than Malaysians. This study demonstrated theuniqueness of rugae pattern in different individuals. Thus, it appears to be an effective &amp; reliable source ofidentification.

Stability of Palatal Rugae after Rapid Maxillary Expansion

Introduction: Palatal rugae or plicae palatine are uneven ridges made of connective tissue situatedbeneath the incisive papilla. DNA analysis, finger prints analysis, are the most common techniques usedfor establishing person’s identity but in situation where using these techniques are difficult palatal rugaecan be used as a second source of identification. However, some habits like prolonged thumb sucking andorthodontic treatment for long duration could affect the rugae pattern. Hence, this study aims to evaluate thechanges in transverse dimensions of palatal rugae in subjects treated with rapid maxillary expansionMaterial and Methods: The palatal rugae patterns were measured and compared to evaluate the morphometricchanges between pre-treatment cast (30 Pre-RME) and its post-treatment (30 Post-RME) counterpart. Allpre-and post-expansion dental casts were traced and the intermedial and interlateral dimensions of first,second and third rugae were measured. The statistical analysis was done using paired t test.Conclusion: The medial aspect of first primary rugae can be considered as a stable reference landmarkwhile the lateral and medial aspects of the 2nd and 3rd rugae are liable to changes in transverse dimension.Hence, for forensic identification the stability of palatal rugae in patients who had undergone rapid maxillaryexpansion still remains questionable

Prediction of Mandibular Growth Pattern Using Palatoscopy: A Retrospective Model Analysis

To predict and correlate mandibular growth pattern using palatoscopy (average, horizontal, and vertical). This retrospective study includes 120 archived maxillary casts. One key person and two examiners performed the study; the key person was responsible for coding and collecting casts and radiographs, as well as calibration of the examiners. The key person divided the samples into three craniofacial growth pattern groups (average, horizontal, and vertical) based on Frankfort-mandibular plane angle (FMA), SN-GoGn, and facial axis angle and distributed them to the blinded examiners. Rugae were studied using a modified Thomas and Kotze classification system. After the analysis, the results were decoded and analyzed with the corresponding cephalometric radiographs. Multinomial logistic regression was employed to predict the mandibular growth patterns with the following independent variables: Forwardly directed rugae, number of divergent rugae, predominant shape circular, predominant shape curved, primary rugae, predominant shape wavy, number of convergent rugae, and horizontally directed rugae. Palatal rugae patterns predict the growth pattern of the mandible. Considering the significant parameters and their correlation with mandibular growth pattern, prediction of mandibular growth patterns can be done noninvasively.

Anthropometric analysis of palatal rugae pattern, face form and arch form among Indian population at Moradabad, India

Purpose: To evaluate the correlation between the palatal rugae pattern, face form and arch form among Indian population at Moradabad, India. Materials and Methods: Alginate impressions of maxillary arch was made and cast was poured immediately with type III dental stone. A sharp graphite pencil was used for marking outline of the rugae on the cast. A digital caliper was employed for measurement of length of palatal rugae. Palatal rugae were analysed in accordance with Thomas and Kotze classification. Arch form of these models was determined with using 3M Unite template. For assessment of the face form, the subjects were seated in an upright position on the operator chair and the camera was stabilized on a tripod. Then photographs of the frontal profile were taken. These photographs were used for the analysis of the face form. The data was subjected to one way analysis of variance test and Post Hoc test. Results: The average number of primary rugae (10.76%) were found to be more predominant than secondary (2.12%) and fragmentary rugae (1.54%). The most predominant shape of palatal rugae were curved (42.19%) followed by wavy (32.71%), straight (17.37%) and circular (0.92%). Based on the direction of the rugae, forward rugae (54.27%) were found more common followed by backward rugae (37.26%) and perpendicular rugae (0.55%). Base on the unification of rugae pattern, diverging rugae (4.55%) were found to be more common than the converging rugae (1.57%). The most common face form was ovoid (72.4) % followed by tapered (24.4%) and square (3.2%). The most prevalent arch form was ovoid (62.2%) seen followed by the tapered (26.0%) and square (4.8%) arch form. It was found that there was significant correlation between the face form and arch form among the study subjects (p0.05). In term of arch form and face form, ovoid was the most common followed by tapered and square. Conclusion: Within the limitations of this study, it was concluded that there was significant correlation

Palatal rugae morphology is associated with variation in tooth number

This observational study compared palatal rugae morphology in adolescent subjects with normal tooth number and tooth agenesis. Maxillary dental study casts were used to compare rugae number, length and shape. Each study group contained 60 subjects (30 females and 30 males) mean age 13.4 (SD, 1.55) in control and 13.56 (SD, 1.54) years in tooth agenesis groups (p = 0.576). Mean number of missing tooth units in the tooth agenesis group was 2.1. Mean number of primary rugae in the whole sample was 4.35 (SD, 0.98) on the right and 4.33 (SD, 0.92) on the left with no significant differences (p = 0.236 and p = 0.404, respectively). However, the number of secondary rugae on the left (p = 0.006) and fragmentary rugae on the right (p = 0.004) was significantly increased in the tooth agenesis group. The shape of left primary rugae 2 and 3 also differed between groups, tending towards a wavy pattern in the control group and curved in the tooth agenesis group (p = 0.012 and p = 0.004, respectively). In addition, primary rugae 3 was more convergent (p = 0.008) whilst left primary rugae 3 and 5 were orientated in an antero-posterior direction (p = 0.04 for both rugae) in the tooth agenesis group. Subgroup analysis also identified significant associations between patterns of tooth agenesis and rugae number, in addition to shape of primary rugae. The identification of significant differences in rugae pattern between subjects with normal tooth number and agenesis suggests potential commonality in signal pathway disruption during establishment of these structures.

The Heritability of Palatal Rugae Morphology Among Siblings*†

Although there is clinical applicability of the palatal rugae as an identification tool in forensic odontology, controversy exists whether the palatal rugae patterns are stable or variable. The greater the genetic component, the higher the probability that palatal rugae patterns are stable. The aim of this study was to compare the palatal rugae morphology between full siblings and the proportion of variability due to genetic component. This cross-sectional study was conducted on digital models of 162 siblings aged 15-30years old. The palatal rugae patterns were assessed with Thomas and Kotze (1983) classification using Geomagic Studio software (3D Systems, Rock Hill, SC). The palatal rugae morphology between siblings showed significantly similar characteristics for total number of left rugae (p=0.001), left primary rugae (p=0.017), secondary rugae for right (p=0.024) and left sides (p=0.001), right straight rugae (p=0.010), and right convergent rugae (p=0.005) accounting for at least 6.25%-12.8% of the variability due to heredity. Despite the similarities found, the palatal rugae patterns showed significant differences between siblings of at least 46.9% (p=0.001). Zero heritability was found in 9 of the 14 rugae patterns. Meanwhile, total number of rugae, primary, backward, and convergent rugae showed moderate heritability (h2 >0.3) and total number of secondary rugae showed high heritability (h2 >0.6). In conclusion, despite the individuality characteristics, an appreciable hereditary component is observed with significant similarities found between sibling pairs and the palatal rugae patterns were both environmentally and genetically influenced.

Association of Rugae Pattern with Skeletal Malocclusion in Orthodontic Patients Visiting Tertiary Care Hospital

Background: The palatal rugae are special constructions that are inalterable in their position and pattern during the lifestyles of an individual. This imparts them an exceptional role in the forensic dentistry and may play potential role in malocclusion identification. This study was aimed to see association of rugae pattern with sagittal skeletal malocclusion in orthodontic patients visiting tertiary care hospital. Methods: This cross-sectional examination was completed on pretreatment records (lateral Cephalometric radiographs and maxillary dental casts) of 384 subjects at the orthodontic department of Ziauddin Dental Hospital, Karachi. The study duration was from January to July 2019. The samples were sub-divided into three sagittal skeletal groups based on ANB angle proposed by Steiner’s on lateral Cephalometric radiographs (Class I with ANB angle between 0° to 4°; Class II: ANB angle greater than 5°; Class III: ANB angle less than 0°). The shapes of three most-anterior primary rugae were then evaluated bilaterally using Kapali et al., Classification. Chi Square test was applied to find association of rugae pattern among sagittal skeletal malocclusions groups. Results: Circular and curved rugae shapes were the most prevalent in all skeletal malocclusions. The primary palatal rugae pattern was seen to be significantly different among three skeletal malocclusion groups (p&lt;0.05). The right and left sided palatal rugae pattern showed significant difference in all three skeletal malocclusion groups (p&lt;0.05). Conclusion: The present study showed no specific palatal rugae pattern associated with sagittal skeletal malocclusion. Further studies on larger sample and use of modern 3D technologies to scan the maxillary casts are required for results that are more precise.

Characteristics of Palatal Rugae Patterns as a Potential Tool for Sex Discrimination in a Sample of Iranian Children

Statement of the Problem: Palatal rugae have been considered equivalent to fingerprints, as they are unique to each individual. It has been shown that palatal rugae are associated with specific racial groups and are known to aid sex identification. Due to the lack of any published data on palatal rugae morphology on Iranian children, the present study was performed. Purpose: The present study aimed to investigate differences in the morphology of individual palatal in a sample of Iranian children. Additionally, it is intended to develop discriminant function to identify sex, based on rugae morphology. Materials and Method: A total of 120 pre-orthodontic casts were evaluated for different rugae patterns using the Thomas and Kotze classification. The casts were equally distributed between sexes with an age range of 6-12 years. Rugae length, shape, and associated morphology were recorded and the independent t-test and Chi-square test were used to compare the mean and relationship between the attributes. The discriminant function analysis was applied to the data in order to determine the applicability of palatal rugae patterns as an aid for sex identification. Results:While the total rugae count showed an insignificant difference between the males and females, the rugae count on the right side of the palates showed a significant difference (p= 0.046). The primary rugae were most common in both sexes, followed by the secondary and fragmentary rugae. The most prevalent rugae shape between both sexes was the wavy rugae followed by the curve and straight shapes in males and the straight and curve shapes in females. A significant difference was observed in the number of the curve rugae between the sexes. Discriminant function analysis allowed sex differentiation with an accuracy of 60.8%. Conclusion: Palatal rugae shapes are unique to each individual and could be used as a potential tool for sex identification. Further research on a larger sample is required to fully confirm the application of this method (e.g. in forensic medicine) as a complementary technique for sex identification.