Dentition Research Articles

Performance of dental pattern analysis system with treatment chronology on panoramic radiography

The present study was conducted to improve human identification based on dental pattern with adopting chronology of dental treatment within the system. Five hundred adult patients were randomly selected, and their initial and recent panoramic radiography images were assumed as antemortem (AM) and postmortem (PM) images, respectively. For each radiographic image, the dental pattern was analyzed. The analysis system was newly developed considering sequence of dental treatment in time order. AM and PM databases were constructed with information of dental patterns, patient age, and gender. For the PM database, age information was stored as the actual age ± 10 years, which was defined as the estimated age. According to dental pattern of PM record, the possible AM records were selected as candidates. Then candidates were sorted in order of dental pattern similarity to the PM record, and the rank of the true AM record was identified. The total 500 AM records were reduced to 14.5 ± 13.4 candidates in average when the dental pattern, gender, and estimated age were considered. When the candidates were sorted in order of similarity, the true AM record received an average ranking of 2.0 ± 2.6. When dental pattern and gender were considered, 46.7 ± 42.3 candidates were selected among 500 records and the true AM record was ranked at 3.0 ± 5.0, in average. The dental pattern analysis adopting dental treatment chronology was contributed to reduce the sample population. This method would become more efficient and comprehensive if the dental pattern analysis process is automatized in the near future.

Avaliação da prevalência de agenesia de incisivos laterais superiores dos pacientes da Faculdade de Odontologia do Centro Universitário da Serra Gaúcha

A agenesia dentária pode ser definida como a falta de desenvolvimento do dente, com a ausência de um até seis dentes, sendo bastante frequente nas dentições decídua e permanente. A etiologia está relacionada tanto à fatores genéticos quanto a ambientais. Quanto maior a contribuição genética na origem de uma alteração, menor a possibilidade de prevenir, assim, pior o prognóstico do tratamento. Com o diagnóstico precoce, consegue-se uma intervenção ortodôntica em uma época adequada. Objetivo: Avaliar a prevalência de agenesia de incisivos laterais superiores (ILS) em radiografias panorâmicas da Faculdade de Odontologia do Centro Universitário da Serra Gaúcha. Métodos: estudo transversal de prevalência realizado no laboratório de Interpretação Radiográfica da FO-FSG envolvendo radiografias panorâmicas realizadas nos anos de 2015 a 2017. Foram registrados dados relativos ao número do prontuário do paciente, idade, sexo do indivíduo, a presença ou não de agenesia, o dente ausente, a presença ou não de diminuição de tamanho e apresentação de anomalia conoíde. Resultados: Nas amostras aplicou-se o teste Qui-quadrado para a heterogeneidade. Verificou-se que o gênero e a agenesia não estão significativamente associados (p<0,05). Conclusão: Os indivíduos com agenesia de ILS, não apresentam diferenças entre os lados e os gêneros. Constata-se que a agenesia bilateral do ILS, é mais frequente do que a agenesia unilateral.

Clinical effect and safety of orthodontic treatment in prosthodontics

Objective To study the clinical application and safety of orthodontic treatment in oral repair. Methods From August 2014 to September 2017, eighty patients with dentition defect admitted in the department of stomatology of Yanzishan Mine Hospital of Datong Mining Group co, LTD were selected.By using digital random table method, eighty patients were randomly divided into two groups, with 40 cases in each group.The control group was directly treated with oral repair, and the observation group was given orthodontic treatment before oral repair treatment.The clinical efficacy, speech function score and recovery time, chewing efficiency and recovery time, gingival crevicular bleeding index, plaque index and X-ray projection measurement indicators of the two groups were compared, and the satisfaction and adverse reactions of the two groups were compared. Results The total effective rate of the observation group was 97.50%(38/40), which was higher than that of the control group [85.00%(32/40)](χ2=3.914, P<0.05). After treatment, the scores of language function[(8.49±1.56)points], masticatory efficiency [(83.94±12.66)%] in the observation group were significantly higher than those in the control group[(7.18±1.45)points, (70.12±13.57)%](t=3.890, 5.445, all P<0.05). The recovery time of language function [(17.19±5.41)d], and the recovery time of masticatory efficiency [(20.81±4.87)d] in the observation group were shorter than those of the control group[(24.37±7.02)d, (27.54±6.95)d](t=5.124, 5.016, all P<0.05). After treatment, the plaque index (1.14±0.36), gingival sulcus bleeding index(1.96±0.64) of the observation group were lower than those of the control group [(1.51±0.40), (2.73±0.87)](t=4.348, 4.509, all P<0.05). The SNA angle [(71.24±4.98)°], the SNB angle [(72.85±1.07)°] in the observation group were less than those in the control group[(76.59±5.40)°, (74.13±1.39)°](t=4.606, 4.615, all P<0.05). In terms of satisfaction, the overall satisfaction rate of the observation group was 95.00%, which was higher than 80.00% of the control group (χ2=4.114, P<0.05). The overall incidence rate of adverse reactions of the observation group(2.50%) was lower than that of the control group(17.50%)(χ2=5.000, P<0.05). Conclusion Orthodontic treatment before dental repair in patients with dentition defect can effectively improve the effect of oral repair, improve the speech function and masticatory efficiency of patients, improve the dentition and maxillofacial malformation, and make the patients more satisfied.And it is safe and reliable, can reduce adverse reactions. Key words: Mouth diseases; Tooth loss; Tooth prepararation, prosthodontic; Orthodontics, corrective; Mouth rehabilitation; Treatment outcome; Patient stisfactive

First Record of Petinomys setosus (Rodentia: Sciuridae: Pteromyini) from Lao PDR

The first known occurrence of Petinomys setosus in Lao People's Democratic Republic (PDR) was recorded from a single specimen collected at Na Mouang village in Vientiane province, which is approximately 240 km from its nearest known distribution in northwestern Thailand. We describe the morphological and cranial features of this specimen and discuss its occurrence in Lao PDR. The focal Laos specimen is similar in pelage color to those from northwestern Thailand, particularly on the dorsal and ventral surfaces of the body, gliding membrane, face, and tail. The cranio-dental characters (bullae and dental patterns) are also similar.

Can Dentition Aid in Estimation of Handedness?

Handedness is challenging to estimate on skeletonized human remains when muscular markers of it are not available. This preliminary study anthropometrically explores if human teeth could be used to aid in identification of handedness. The dental data for this research is collected from a total of fifty (N=50) living adult volunteers with good dental health of which thirty‐nine (N=39) were right handed and eleven (N=11) left‐handed. Non‐invasive anthropometric data collected via digital dental caliper consists of the Maxillary and the Mandibular quadrants in which permanent incisors and canines were analyzed. The study reconfirms that males on average have larger teeth than females. The lateral incisors were not taken into consideration as they show minimal variations across the quadrants. The left‐handed males measure slightly larger central Maxillary incisors and canines at the left and the right quadrant than the right‐handed males. The left‐handed females have smaller central incisors than the right‐handed females on the Maxillary quadrants, but slightly larger central incisors on the Mandibular quadrants. Mandibular right quadrant central incisors are slightly larger among the left‐handed than they are among the right‐handed individuals of both sex.Support or Funding InformationSWCThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Shear Bond Strength of Resin Cement to Saliva-Contaminated Metal Alloys after Various Surface Treatments

The bonding ability of resin cement to metal alloys of conventional dental restorations is critical for the retention and long-term survival rate. Contaminated saliva during try-in process which is resistant to simple water rinsing could reduce bond strength. Surface treatment before cementation might have an important role in optimizing resin-metal bond strength. The purpose of this study was to study the effect of surface pretreatment on the shear bond strength of dental base metal alloys after saliva contamination using a self-adhesive resin cement. Forty dental wax patterns (7-mm diameter) were made and cast with dental base metal alloy (Argeloy N.P. (V)). Cast metal specimens were embedded in PVC tube using self-curing acrylic resin and then flattened with 600-grit silicon carbide paper. PVC tube holders were specifically designed for the shear bond strength test device. Forty resin composite specimens were prepared in plastic mold (diameter of 3 mm and depth of 3 mm). The resin composite specimens were treated with sandblasting. Fifty-μm aluminum oxide particle was blasted for 10 seconds from the distance of approximately 5 mm perpendicular to the bonding surface. Metal alloy specimens were immersed in artificial saliva for 1 minute and rinsed with water-spray for 15 seconds. The specimens were also air-dried for 15 seconds. Specimens were divided into four groups, which received one of the following surface treatments: (1) No surface treatment (Control), (2) 37% phosphoric acid, (3) 37% phosphoric acid and then rinsed with 70% ethyl alcohol, and (4) 70% ethyl alcohol. After rinsing and drying, the resin composite specimens were cemented with Panavia SA Cement (Kuraray Noritake Dental Inc., Okayama, Japan) at the center of metal alloy specimens followed by the manufacturer’s instruction. Before testing, the specimens were stored in distilled water at 37oC for 24 hours. For testing, specimens were dried and mounted to universal testing machine (EZ-S, Shimadzu Co., Kyoto, Japan) at the crosshead speed of 1 mm/minute. Failure loads was recorded in Newton (N) and then analyzed to Mega Pascal (MPa). The highest shear bond strength was observed for group 2 and 3. The failure mode in all the materials was adhesive failure which occurred at the resin-metal interface. Within the limitations of this study, phosphoric acid was effective in removing saliva contamination and enhancing bond strength at the resin-dental base metal interface.

Three-Dimensional Geometric Morphometric Analysis of Treeshrew (Scandentia) Lower Molars: Insight into Dental Variation and Systematics.

Scandentia (treeshrews) is an order of small-bodied Indomalayan mammals generally agreed to be a member of Euarchonta with Primates and Dermoptera (colugos). However, intraordinal relationships among treeshrews are less well understood. Although recent studies have begun to clarify treeshrew taxonomy using morphological and molecular datasets, previous analysis of treeshrew dentition has yielded little clarity in terms of species-level relationships within the order. However, these studies made use of character-based methods, scoring traits across the dental arcade, which depend on there being clear differences among taxa that can be encapsulated in coding schemes. Geometric morphometrics has the potential to capture subtler shape variation, so it may be better for examining similarities among closely related taxa whose teeth have a similar bauplan. We used three-dimensional geometric morphometrics on a sample of treeshrew lower second molars and compared the patterns of variation to the results of previous studies. We captured 19 landmarks on a sample of 43 specimens representing 15 species. Using specimen-based principal components analysis and between-group principal component analysis, the two treeshrew families (Tupaiidae and Ptilocercidae) were well separated in morphospace. Moreover, several treeshrew species plot in morphospace according to the clades established in previous molecular work, with closely related species plotting closer to one another than to more distantly related species, suggesting that dental morphology can be useful when studying relationships among treeshrews. As most extinct treeshrews are known only from teeth, understanding morphological patterns in treeshrew molars is important for future work on the evolutionary history of Scandentia. Anat Rec, 302:1154-1168, 2019. © 2019 Wiley Periodicals, Inc.

A new genus and species of extinct ground shark, †Diprosopovenator hilperti, gen. et sp. nov. (Carcharhiniformes, †Pseudoscyliorhinidae, fam. nov.), from the Upper Cretaceous of Germany

ABSTRACTWe describe a new genus and species of extinct ground shark, †Diprosopovenator hilperti, gen. et sp. nov. (Elasmobranchii, Carcharhiniformes), based on a single incomplete skeleton with dentition recovered from basinal marine late Cenomanian (Metoicoceras geslinianum ammonite zone) organic-rich deposits of northern Germany. The new carcharhiniform is characterized by a unique combination of dental morphologies, indicating close architectural resemblance to the family Scyliorhinidae (catsharks). However, the very distinct tooth root morphology readily separates the new taxon from all other scyliorhinids. The extinct Cretaceous carcharhiniform †Pseudoscyliorhinus (represented by †Ps. schwarzhansi and †Ps. reussi) shares tooth root morphologies and vascularization patterns with †Diprosopovenator, gen. nov. We hypothesize that these two sharks form part of an extinct group of carcharhiniforms characterized by a distinct root morphology (viz., low hemiaulacorhize roots with very flat and strongly flared basal faces protruding below the crown labially and mesiodistally and with a well-developed central labiobasal notch). Consequently, we propose a new family of Late Cretaceous carcharhiniforms, †Pseudoscyliorhinidae, fam. nov., to include the new taxon, as well as †Pseudoscyliorhinus. †Pseudoscyliorhinidae, fam. nov., shows a wide European distribution during the Late Cretaceous, ranging from the early Cenomanian to the late Campanian. The longevity of Scyliorhinidae, with a fossil record extending back into the Middle Jurassic, however, remains ambiguous and unresolved; therefore, it may be best to regard the assignment of fossil taxa to Scyliorhinidae as currently uncertain pending further taxonomic work.

Paediatric Orthodontics Part 1: Anterior open bite in the mixed dentition.

The correction of anterior open bite in the mixed dentition: treatment or over-treatment? Early treatment of the anterior open bite is a common, widespread treatment, which involves sometimes multiple clinical procedures: active orthodontic treatment and correction of the dysfunctional habits with a large waste of financial and biological costs. Therefore, also considering the significant possibility of self-improvement in the pre-pubertal phase, active early treatment should not aim to the active correction of the AOB, but only to other aspects of the malocclusion and to the interception of dysfunctional habits.

Quantitative heterodonty in Crocodylia: assessing size and shape across modern and extinct taxa.

Heterodonty in Crocodylia and closely related taxa has not been defined quantitatively, as the teeth rarely have been measured. This has resulted in a range of qualitative descriptors, with little consensus on the condition of dental morphology in the clade. The purpose of this study is to present a method for the quantification of both size- and shape-heterodonty in members of Crocodylia. Data were collected from dry skeletal and fossil specimens of 34 crown crocodylians and one crocodyliform, resulting in 21 species total. Digital photographs were taken of each tooth and the skull, and the margins of both were converted into landmarks and semilandmarks. We expressed heterodonty through Foote’s morphological disparity, and a principal components analysis quantified shape variance. All specimens sampled were heterodont to varying degrees, with the majority of the shape variance represented by a ‘caniniform’ to ‘molariform’ transition. Heterodonty varied significantly between positions; size undulated whereas shape was significantly linear from mesial to distal. Size and shape appeared to be primarily decoupled. Skull shape correlated significantly with tooth shape. High size-heterodonty often correlated with relatively large caniniform teeth, reflecting a prioritization of securing prey. Large, highly molariform, distal teeth may be a consequence of high-frequency durophagy combined with prey size. The slender-snouted skull shape correlated with a caniniform arcade with low heterodonty. This was reminiscent of other underwater-feeding tetrapods, as they often focus on small prey that requires minimal processing. Several extinct taxa were very molariform, which was associated with low heterodonty. The terrestrial peirosaurid shared similarities with large modern crocodylian taxa, but may have processed prey differently. Disparity measures can be inflated or deflated if certain teeth are absent from the tooth row, and regression analysis may not best apply to strongly slender-snouted taxa. Nevertheless, when these methods are used in tandem they can give a complete picture of crocodylian heterodonty. Future researchers may apply our proposed method to most crocodylian specimens with an intact enough tooth row regardless of age, species, or rearing conditions, as this will add rigor to many life history studies of the clade.

Reassessment of a large lamniform shark from the Upper Cretaceous (Santonian) of Italy

To date, only a few partially articulated chondrichthyan specimens are known from the Upper Cretaceous marine fossil record of northern Italy. Here, we re-evaluate the taxonomic status and geological age of selachian remains originally discovered during the 19th century from the Castellavazzo locality. The described specimen is largely embedded in matrix with minute exposure of joined and moderately deformed sequentially stacked vertebral centra. Computed tomography (CT) image-data obtained of the specimen enabled the identification of potential cranial-cartilage elements located in close proximity to teeth and are here interpreted as remnants of the jaws. Based on tooth and vertebral morphology the specimen is in all likelihood an adult lamniform shark with a measured 3.5 m length. Using ordinary least-squares regression analysis (OLS) and proportion-based calculations, we estimated a total-length (TL) of 596.27 and 632.5–672.64 cm respectively. We prefer the size estimation derived through OLS bivariate regression; however, in the present analysis, reliance on a small sample size (n = 11) and evidence for differential scaling between taxa impose limitations on the precision of our size prediction. Planktonic foraminifera examined from the surrounding matrix of the slab preserving shark vertebral centra and teeth indicate a Santonian age (Dicarinella asymetrica zone). Although, the specimen could not confidently be assigned beyond the ordinal-level, the sheer centrum size, gross dental morphology, and depositional environment, are indicative of a pelagic apex-predator comparable to coeval lamniforms, with a specific resemblance towards cretoxyrhinids, reported from elsewhere along the peri-Tethyan shelf of Europe and Western Interior Seaway of North America. Finally, the re-emergence of this historical specimen, here re-described using cutting-edge techniques, is of great importance as it contributes to the otherwise poor record of extinct lamniform shark skeletons.

Mosaic dental morphology in a terminal Pleistocene hominin from Dushan Cave in southern China

Recent studies reveal high degrees of morphological diversity in Late Pleistocene humans from East Asia. This variability was interpreted as complex demographic patterns with several migrations and possible survival of archaic groups. However, lack of well-described, reliably classified and accurately dated sites has seriously limited understanding of human evolution in terminal Pleistocene. Here we report a 15,000 years-old H. sapiens (Dushan 1) in South China with unusual mosaic features, such as large dental dimensions, cingulum-like structures at the dentine level in the posterior dentition and expression of a “crown buccal vertical groove complex”, all of which are uncommon in modern humans and more typically found in Middle Pleistocene archaic humans. They could represent the late survival of one of the earliest modern humans to settle in an isolated region of southern China and, hence, the retention of primitive-like traits. They could also represent a particularity of this group and, hence, reflect a high degree of regional variation. Alternatively, these features may be the result of introgression from some late-surviving archaic population in the region. Our study demonstrates the extreme variability of terminal Pleistocene populations in China and the possibility of a complex demographic story in the region.

Large deadfalls of the ʻginsuʼ shark Cretoxyrhina mantelli (Agassiz, 1835) (Neoselachii, Lamniformes) from the Upper Cretaceous of northeastern Italy

Cretoxyrhina mantelli was a large pelagic lamniform shark geographically widespread during the Late Cretaceous, and well known because of several nearly complete skeletons from the Western Interior Seaway of North America. Here we report 15 partial skeletons belonging to lamniform sharks from the ‘lastame’ lithozone of the Upper Cretaceous Scaglia Rossa Formation of the Lessini Mountains (northeastern Italy). Seven partial but articulated skeletons include tooth sets that allow a confident attribution to Cretoxyrhina mantelli based on dental morphologies. We review the taxonomic history of C. mantelli, evidencing that the taxon was erected by Agassiz (1835) and tracing back four of the original syntypes. Based on calcareous plankton biostratigraphy, the rock in which the Italian skeletal remains are embedded is constrained to the middle-upper Turonian. Total length estimates of the specimens suggest that the sample includes the largest specimen of Cretoxyrhina mantelli (615–650 cm estimated total length) known to date. The placoid scale morphology indicates that C. mantelli most likely was a fast swimmer with a similar ecology as the extant white shark, Carcharodon carcharias. The associated skeletal elements of the specimens represent large chondrichthyan deadfalls and the cadavers decayed on the seafloor where they remained exposed for several months, as indicated by bioerosional traces, some of which are interpreted as a product of bone-eating worm activities and other bioerosional traces with Gastrochaenolites-like structure. The Cretoxyrhina mantelli remains described herein provide new information about the ʻlastameʼ vertebrate assemblage, which seemingly was strongly dominated by chondrichthyans, especially lamniform sharks.

Occurrence of Maxillary Central Diastema between Tooth-supported and Implant-supported Prostheses: a 5-year Clinical Follow-up.

A 27-year-old patient with a history of maxillary anterior tooth trauma presented with a maxillary central diastema between tooth- and implant-supported prostheses that had been in use for 5 years. The all-ceramic crowns were placed in 2012 after rigorous occlusal adjustment. Evaluations were carried out at 0, 2, 3, 4 and 5 years post restoration. The central diastema between the natural teeth and the implant-supported prosthesis on teeth 11 and 12 was first observed 2 years after implantation. After 5 years, the distance was found to have increased, with anterior occlusion and esthetic changes having taken place. The following possible causes were discussed: occlusal problems, anterior traumatic effects, the possible impact of guided bone regeneration (GBR) on the adjacent natural teeth and natural movement. More predictive information should be given to patients with implant-supported prostheses and natural teeth so that they are fully informed of the impact of any necessary clinical compromise and are aware of the modifications that may occur to their natural dentition.

A new lophocyonid, Izmirictis cani gen. et sp. nov. (Carnivora: Mammalia), from the lower Miocene of Turkey

Lophocyonids are one of the more enigmatic groups of Carnivora in the European Miocene fossil record. Lophocyonids are clearly distinguished from other Feliformia by their peculiar lophodont dental morphology. For this reason, the systematic relationships of the family have been controversial. Here we describe and interpret dental remains from the early Miocene of Sabuncubeli, Turkey, which we attribute to a new genus and species: Izmirictis cani. The phylogenetic analysis allows us to include Izmirictis within a monophyletic group, Lophocyonidae new rank, characterized by the molarization of the anterior premolars (P3 and p4), the lophodont adaptation of the molar dentition and the complex morphology of the incisors. The phylogenetic analysis shows a close relationship between Izmirictis and primitive hyaenids (represented herein by Protictitherium). The divergence between Lophocyonidae and Hyaenidae is estimated by biochronological data to have occurred during the early Miocene (MN2). Dental microwear analysis, although limited by poor dental enamel preservation, indicates that the pronounced lophodonty in Izmirictis cani could be connected to a herbivorous feeding habit.http://zoobank.org/urn:lsid:zoobank.org:pub:8D75382D-6C22-41C1-A47F-BA3EAF766881

Informativeness of dental morphology in ancestry estimation in African Americans.

Our objective is to assess the informativeness of dental morphology in estimating biogeographic ancestry in African Americans. The data are 62 dental morphological traits scored as nondichotomized and dichotomized in 797 individuals, 992,601 SNPs from 271 individuals, and 645 STRs from 177 individuals. Each dataset consists of Africans, Europeans, and African Americans. For each dataset, we summed Fisher Information (FI), then used STRUCTURE to estimate ancestry. Total FI was highest for SNPs, followed by STRs, nondichotomized dental traits, and dichotomized dental traits. For both genetic datasets, Africans and Europeans fell into two distinctive clusters with low 90% credible regions for individual ancestry estimates. In African Americans, membership in the African cluster was 76.4% and 80.4% for SNPs and STRs, respectively. For the dental data, all Africans and Europeans had appreciable membership in both clusters and comparatively high 90% credible regions for individual ancestry estimates. Nonetheless, African Americans had consistently higher membership in the same cluster in which Africans had high membership. African American membership in this cluster was significantly higher for the nondichotomized form than for the dichotomized. FI potentially provides a useful gauge of the effectiveness of dental and genetic data for ancestry estimation. The comparatively high FI of nondichotomized dental traits suggests data in this form may be better suited for studies of admixture than dichotomized data. Because of high error in individual ancestry estimates, dental morphological data may be unable to distinguish differences in ancestry among individuals within admixed populations.

Noninvasive interdisciplinary treatment of a dischromic partially worn dentition.

According to the classic concepts of prosthodontics the treatment of a patient presenting severely worn and dischromic dentition would involve a complex and demolitive treatment including periodontal surgery, endodontic therapy, posts and cores, and crowns; nowadays these problems can be solved with noninvasive procedures that allow preservation of dental and periodontal tissues. This article describes the interdisciplinary team approach (orthodontist, dental technician, prosthodontist) for the treatment of a patient showing attrition of the mandibular incisors in a deep bite relationship, contraction of the posterior sextants of both arches, diastemas in the anterior region of the maxilla, and highly dischromic teeth. The gingival tissue levels and the tooth malposition were corrected by orthodontic therapy, the abraded and the healthy dischromic teeth were restored with 20 additional veneers (the molars were the only teeth not involved in the restorative phase); tooth structure, tooth vitality, and bone level were maintained. No provisional restorations were delivered and no anesthesia was necessary either for tooth preparation or final impression. A protocol is shown to treat in a conservative and comfortable manner the structural and esthetic problems in a patient presenting highly dischromic teeth, worn mandibular incisors, and diastemas on the maxillary sextant.

Augmentation/Transplantation in Periodontally Compromised Dentition

Augmentation/Transplantation in Periodontally Compromised Dentition

Analysis of rugae pattern morphology and their comparative differences in a Jazan population sample

Background: Palatal rugoscopy offers an excellent, reliable, and economical method for forensic identification in natural disasters or any other case that involves unknown remains where the death toll is extremely high. Their protective location, early complete development, stability, and singularness for each individual make this analysis of forensic useful. Objectives: The objective is to study the predominant rugae pattern among the Jazan population sample and to analyze the morphological differences in the number, types, size, and contour of various palatal rugae both intraindividual (within an individual) and interindividual (between individuals). Materials and Methods: A total of 110 patients (55 males and 55 females) in the age group of 20–35 years representing a pure ethnic Saudi population were selected based on a criterion of having an ideal natural dentition. Maxillary study models for all subjects were made from maxillary impressions. The rugae pattern recorded on cast was compared with intraoral high-magnification photographs for consistency and verification. Different types and orientation (to mid-palatine raphe) of rugae were then evaluated for the number, size, type, and contour (direction). Mean, standard deviation, and frequencies were calculated as the percentages of each type of rugae. Statistical analysis was done by using two-sample t-test and Chi-square tests at a significance level of 5%. Results: No differences in rugae pattern and rugae orientation was found between sexes, however, both pattern and direction differed in Saudi population when compared with other studies done on other population. Conclusion: The study concludes that no sexual dimorphism exists in rugae pattern and their orientation between male and female patients among the Saudi population.

Multivariate analysis of nonmetric traits in permanent anterior teeth: A forensic overview

Introduction: Dental morphology is a highly heritable characteristic, also stable with time and has a fairly high state of preservation. Nonmetric dental traits have a crucial role in ethnic classifications of a population which helps in forensic racial identification purposes. Aims and Objectives: The objective of the study is to determine the frequency and variability of possible nonmetric tooth traits using extracted permanent anterior teeth from Kerala population for discerning racial ethnicity. Materials and Methods: This qualitative, cross-sectional study was carried out using 1761 extracted intact permanent anterior teeth collected from different dental clinics situated all over Kerala. Results: The most common trait noted was shoveling in both incisors and canines with maximum expression in 11 (69.12%) followed by 21 (62.94%). Double shoveling and lingual tubercle prevalence in canines (12.64% and 10.18%) were more than incisors (6.09% and 7.55%). In canines, the expression percentage of palatal fossae, lingual fossae, and distal accessory ridge was 31.13, 18.49, and 10.56, respectively. Conclusion: The results showed a higher degree of shoveling trait in this population. This research suggested new elements of invaluable ethnographic tooth traits value to understand racial ethnicity of Kerala population.