Permanent Tooth Agenesis and Associated Dental Anomalies among Orthodontically Treated Children.

(1) Background: Tooth agenesis is one of the most common developmental dental anomalies often affecting the maxillary incisors area and premolar regions. (2) Purpose: The aim of this study was to assess the prevalence and distribution of permanent tooth agenesis and the associated dental abnormalities among orthodontically treated children. (3) Materials and Methods: This study was carried out utilizing 3000 pretreatment records of children who underwent orthodontic treatment, 1780 (59%) females and 1220 (41%) males, aged 10-25 years (mean age 15 years). Tooth agenesis and other dental anomalies were surveyed using their panoramic radiographs, according to gender, pattern, and location. The level of statistical significance was set at p < 0.05 using t-test or Chi-Square tests. (4) Results: The total number of missing teeth, excluding third molars, was 518 (17%) found in 326 (11%) children. The majority were the maxillary lateral incisors, which was 176 teeth (34%) (p < 0.05). Of them, 111 (63%) were in females, and 65 (37%) were in males. The second most common missing tooth was mandibular second premolars, which was 137 teeth (26%), followed by missing 73 (14%) maxillary second premolars. Impacted teeth had the highest associated dental anomaly prevalence (14.3%), while transposition showed the lowest anomaly prevalence (0.5%). (5) Conclusions: A prevalence of 11% for tooth agenesis was detected in this study. More teeth were missing in the maxilla compare with the mandible. A significant association was found between missing maxillary lateral incisors and missing premolars (p < 0.05). Associated dental anomalies included an increased number of peg-shaped maxillary lateral incisors, palatally displaced and impacted maxillary canines, ectopic teeth, and infra-occluded (submerged) primary second molars.

The esthetic challenge of a malpositioned peg-shaped lateral incisor and a missing contralateral maxillary tooth: report of a case.

A peg-shaped maxillary lateral incisor is an underdeveloped, small, malformed permanent tooth that erupts following the loss of a primary tooth. The maxillary lateral irregularly shaped incisor may be unilateral, on both sides of the central incisors, or accompanied by a missing lateral tooth on the contralateral side of the arch. Peg-shaped maxillary lateral incisors receive a great deal of attention, play a significant role in the displayed smile, and present a treatment challenge during all stages of a patient's life. Clinicians are called to plan the treatment and the timing from as early as the beginning of growth and development. Careful diagnosis may dictate postponing a treatment to later stages of life, especially if the tooth is malpositioned in the arch. The goal of this clinical report was to present a combined treatment for a case with a palatal malpositioned peg-shaped maxillary lateral incisor and a missing contralateral permanent maxillary lateral incisor, creating an esthetic challenge. Moving the malpositioned peg-shaped lateral tooth to the arch simplified and eased the final prosthetic treatment procedure, increasing the treatment predictability. The presented sequence of therapy further stresses the importance of incorporating minor tooth movement, without referring to a specialist, in the daily practice of a prosthodontic-oriented general clinic, by simple accessible means.

Evaluating the Prevalence and Distribution of Dental Anomalies in the Permanent Dentition of Patients Seeking Dental Care.

BACKGROUND:  Disturbances seen during tooth formation result in developmental dental anomalies presenting in the oral cavity. These anomalies manifest as discrepancies in the number, color, size, and shape of the teeth. These dental anomalies can either be acquired, congenital, or developmental. Their early detection and management are necessary as they affect aesthetics and occlusion. The study had the aim of gauging the prevalence of developmental anomalies in the permanent dentition of Indian subjects. METHODS: A total of 1192 participants recruited from the institute for study purposes, comprising males and females, were examined clinically and radiographically, and their dental casts were also evaluated. These subjects were assessed for anomalies in position, structure, number, and/or shape. Anomalies in the position include transmigration, transportation, and/or ectopic position; anomalies in the structure, including dentinogenesis imperfecta or amelogenesis imperfecta; anomalies in number, including hyperdontia or hypodontia; and anomalies in shape, including peg laterals, taurodontism, fusion, dens evaginatus, talon cusp, and/or microdontia. RESULTS: A statistically significant difference was seen in unilateral microdontia and dentinogenesis imperfecta between males and females, with attained p-values of 0.003 and 0.06, respectively. The results of the present study showed that 9.89% (n = 118) study subjects, whereas 1% (n = 12) study subjects had two dental anomalies in their permanent dentitions, with no subject presenting more than two dental anomalies, showing that various dental anomalies have a low prevalence in the Indian population. CONCLUSION: The present study has led to the conclusion that the prevalence of dental anomalies is low in Indian subjects. However, these anomalies should be detected and treated early to prevent them from causing further complications.

Esthetic and functional rehabilitation of peg-shaped maxillary lateral incisors: Practical recommendations.

Peg-shaped maxillary lateral incisors cause many functional and esthetic major consequences in affected patients. Their esthetic and functional rehabilitations are often multidisciplinary, involving different clinical procedures like periodontal, orthodontic, or prosthodontic procedures. No exhaustive protocol has been established to improve their comprehensive management by general dentists or specialists. The aim of this article is to elaborate a simplified clinical protocol of complete management of peg-shaped maxillary lateral incisors by a multidisciplinary team (general practitioners, orthodontists, and prosthodontists). A clinical case of two peg-shaped maxillary lateral incisors completely rehabilitated with multidisciplinary approaches including orthodontic treatment and restoration by veneers and direct composite resin, according to the established protocol. Extraoral, intraoral, and smile clinical analysis are crucial to ensure optimal rehabilitation. Treatment results previsualization via wax-up and/or mock-up play a key role in the communication between practitioner and patient to help the latter make decision. These options also facilitate the achievement of a multidisciplinary approach by accurately estimating the number of dental movements and the type of restorations that are most suitable to the presenting clinical situation.

The antennal scape organ of Scutigera coleoptrata (Myriapoda) and a new type of arthropod tip-pore sensilla integrating scolopidial components.

BACKGROUND: Centipedes are terrestrial, predatory arthropods with specialized sensory organs. However, many aspects of their sensory biology are still unknown. This also concerns hygroreception, which is especially important for centipedes, as their epicuticle is thin and they lose water rapidly at low humidity. Thus, the detection of humid places is vital but to date no definite hygroreceptor was found in centipedes. House centipedes (Scutigeromorpha) possess a peculiar opening at the base of their antenna, termed 'scape organ', that houses up to 15 cone-shaped sensilla in a cavity. Lacking wall and tip-pores, these socket-less sensilla may be hypothesized to function as hygroreceptors similar to those found in hexapods. RESULTS: The cone-shaped sensilla in the scape organ as well as nearby peg-shaped sensilla are composed of three biciliated receptor cells and three sheath cells. A tip-pore is present but plugged by a highly electron-dense secretion, which also overlays the entire inner surface of the cavity. Several solitary recto-canal epidermal glands produce the secretion. Receptor cell type 1 (two cells in cone-shaped sensilla, one cell in peg-shaped sensilla) possesses two long dendritic outer segments that project to the terminal pore. Receptor cell type 2 (one cell in both sensilla) possesses two shorter dendritic outer segments connected to the first (proximal) sheath cell that establishes a scolopale-like structure, documented for the first time in detail in a myriapod sensillum. CONCLUSIONS: The nearly identical configuration of receptor cells 1 with their long dendritic outer segments in both sensilla is similar to hexapod hygroreceptors. In Scutigera coleoptrata, however, the mechanism of stimulus transduction is different. Water vapor may lead to swelling and subsequent elongation of the plug pin that enters the terminal pore, thus causing stimulation of the elongated dendritic outer segments. The interconnection of receptor cell 2 with short outer dendritic segments to a scolopale-like structure potentially suits both sensilla for vibration or strain detection. Thus, both sensilla located at the antennal base of scutigeromorph centipedes fulfill a dual function.

Frequency Of Developmentally Malformed Permanent Maxillary Lateral Incisors In Patients Visiting The Three Teaching Dental Hospitals Of Peshawar.

BACKGROUND: The permanent maxillary lateral incisor (PMLI) shows morphological variations, in the form of different crown shapes such as peg-shaped, cone-shaped, barrel-shaped and canine-shaped. The frequency of developmentally malformed permanent maxillary lateral incisors varies among different populations. The aim of this study was to document the frequency of different shapes of developmentally malformed permanent maxillary lateral incisors in patients visiting the three teaching dental hospitals of Peshawar. METHODS: It was a cross-sectional study conducted in the Oral Diagnosis department of Peshawar Dental College, Sardar Begum Dental College, and Khyber College of Dentistry from 1st Sep 2018 to 15th June 2019. A total of 82 subjects were included that fulfilled the inclusion criteria. Shape of the malformed PMLI was determined using Computer-aided design/Computer-aided manufacturing software. Descriptive statistics including frequencies and percentages for observed developmental malformation and their types were computed and Chi-square test was applied to see the relation between various shapes and their occurrence with respect to site and position within the jaws. RESULTS: The peg shaped PMLI was seen in 81 (98.87%) patients and barrel shaped was present in 1 (1.22%) patient. The malformed PMLIs was found to be unilateral in 38 (46.3%) and bilateral in 44 (53.7%) patients, with more common presence on both sides 44 (53.7%) followed by right side 20 (24.4%) and left side 18 (22.0%). CONCLUSIONS: The subjects having predominant developmental malformation in case of permanent maxillary lateral incisor was peg-shaped permanent maxillary lateral incisor.

Family-based association study of genetic analysis of paired box gene 9 polymorphisms in the peg-shaped teeth in the Jordanian Arab population.

OBJECTIVE: The aim of this study is to genotype thirteen Single Nucleotide Polymorphisms (SNPs) within the paired box gene 9 (PAX9) in 36 Jordanian Arab families with peg-shaped teeth, and also to investigate the association between the PAX9 gene and peg-shaped teeth disorder. METHODS: Genomic DNA samples were extracted from families according to distinguished processes. Then, DNA was amplified by polymerase chain reaction technique (PCR) using specified primers for the exons of the PAX9 gene. In addition, single nucleotide polymorphisms analysis was conducted using the DNA sequencing genotyping method to identify specific single nucleotide polymorphisms in the PAX9 gene associated with peg-shaped teeth. RESULTS: Thirteen single nucleotide polymorphisms in the PAX9 gene (Chromosome 14q13.3) were used; seven of them (rs104894467, rs104894469, rs28933373, rs28933970, rs28933971, rs28933972, and rs7143727) were non-polymorphic, and the other six were polymorphic (rs2073244, rs2073246, rs2295222, rs4904155, rs4904210, and rs12881240). Both rs12881240 and rs2295222 SNPs showed significant association with peg-shaped teeth disorder (P < 0.05). Moreover, the haplotype genetic analysis revealed that there is a genetic association with peg-shaped teeth disorder susceptibility (P < 0.05) in the Jordanian families of Arab descent. CONCLUSION: Our findings exhibited significant variations compared to the data recorded from other countries.

Influence of maxillary lateral incisor width ratio on perception of smile esthetics among orthodontists and laypersons.

OBJECTIVE: This study aimed to analyze the impact of different maxillary lateral incisor width ratios on the perception of smile esthetics among orthodontists and laypersons. METHODS: A smile photograph of a male subject showing the lips and gingival margins was selected. The smile was standardized for maxillary central incisor width proportions and ideally perceived smile esthetics. The maxillary lateral incisor width was symmetrically modified in increments of ratios of the central incisor from a ratio of 4:10 to a ratio of 8:10. The images were analyzed by 283 laypersons and 83 orthodontists who ranked the level of attractiveness using a visual analog scale. RESULTS: There were significant differences between the esthetic perception of the five different width ratios, and between the orthodontists and laypersons in their evaluations of esthetics (P < 0.0004). There were no significant differences in esthetic evaluations between genders. CONCLUSIONS: For orthodontists, the most attractive width ratio was 5.7:10, while the highest ranked ratio among laypersons was 8:10, although laypersons ranked all ratios very similarly. Both groups ranked the width ratio of 4:10 the lowest. Orthodontists were more critical in their assessment of esthetics. CLINICAL SIGNIFICANCE: To what proportions or protocol should a peg-shaped maxillary lateral incisor or missing lateral, that is, to be replaced with an implant/crown be restored? This is an important clinical question that is often encountered by the orthodontist and the restoring dentist. The literature suggests that orthodontists and laypeople have different perceptions of smile esthetics, and it is important to have patient centered goals when treatment planning. Further research is necessary to identify the width ratio of which the lateral incisor is perceived to be esthetic as well as the ideal ratio to consider when restoring lateral incisors. This research assessed and compared the perception that orthodontists and laypeople have on smile esthetics regarding different width ratios of lateral incisors.

Novel EDAR mutation in tooth agenesis and variable associated features.

Tooth agenesis (TA) is the developmental absence of one or more permanent teeth. We report on 10 members of a Pakistani family afflicted with TA with variable associated features inherited in autosomal dominant fashion with full penetrance. The malformation is bilateral in the majority of cases, and hallmark feature is the absence of lateral and central incisors and canines whereas first and second premolars are involved less often. Affected individuals also have pronounced variable features associated with TA such as diastema between central incisors, overgrown labial frenum, peg-shaped lower incisors, delayed exfoliation, over-erupted upper incisors and malocclusion but have no other signs of ectodermal dysplasia. Through linkage analysis coupled with exome sequencing, we identified novel nonsense variant EDAR c.1302G>A, p.(Trp434*). The variant is deduced to create a premature termination codon that leads to the deletion of the 15 C-terminal residues. Heterozygous EDAR variants most commonly cause hypohydrotic ectodermal dysplasia, but recently one nonsense and 10 missense variants have been reported in nonsyndromic TA, some with few mild features of hypohydrotic ectodermal dysplasia. The phenotype in the family we present, the largest with EDAR-related TA reported to date, is highly variable and without any signs of ectodermal dysplasia.

Redefining the phenotypic spectrum of de novo heterozygous CDK13 variants: Three patients without cardiac defects.

Recently, 7 patients with de novo constitutional non-synonymous mutations in the CDK13 gene were ascertained through a trio exome analysis of a large cohort of 610 patients with congenital cardiac diseases. Despite another report describing 9 additional patients, the clinical spectrum of this condition has yet to be defined. Herein, we report 3 patients with heterozygous constitutional CDK13 mutations, who were ascertained through exome analysis of children with intellectual disability and minor anomalies, who lacked cardiac anomalies. Two patients had a c.2149G > A, p.Gly717Arg mutation, and one had a c.2525A > G, p. Asn842Ser mutation. A review of the previously described patients and those described herein has enabled the following points to be clarified. First, congenital heart diseases are not an essential feature (13/19). Second, nasal features may help syndromic recognition (14/16). Third, widely spaced and peg-shaped teeth may represent a previously unappreciated diagnostic clue for this newly identified syndrome. Here, we show that p.Gly717Arg represents a hotspot in addition to p.Asn842Ser. We suggest that this CDK13-related disorder may represent a clinically recognizable syndrome.

A Retrospective Study of Association between Peg-shaped Maxillary Lateral Incisors and Dental Anomalies.

OBJECTIVE: The purpose of this study was to investigate the prevalence of peg-shaped maxillary lateral incisors and the incidence of associated dental anomalies in children. STUDY DESIGN: We investigated the prevalence of peg-laterals and incidence of associated dental anomalies in 3,834 children aged 7-15 who visited the Department of Pediatric Dentistry from January 2010 to December 2015 and underwent panoramic radiographs. RESULTS: The prevalence of peg-laterals was 1.69% in boys, 1.75% in girls, and 1.72% overall. Among children with peg-laterals, the frequencies of associated dental anomalies were as follows: congenitally missing teeth, 31.8%; dens invaginatus, 19.7%; palatally displaced canines, 12.1%; supernumerary teeth, 7.6%; and transposition, 7.6%. CONCLUSION: As children with peg-laterals have a higher incidence of other dental anomalies, careful consideration is needed when planning diagnosis and treatment.

Mandibular incisor extraction treatment in Angle's Class I malocclusion with peg-shaped maxillary lateral incisors.

Accurate diagnosis and treatment planning are essential for obtaining ideal treatment result in cases involving mandibular incisor extraction. This case report describes a 15-year-old female with balanced soft-tissue profile, peg-shaped maxillary lateral incisors, and moderate mandibular anterior crowding treated with a mandibular incisor extraction. Ideal overbite and overjet were achieved. "Black triangle" formation was avoided due to the bodily movement of mandibular incisors and the use of uprighting springs for ideal axial inclination of mandibular incisors. A mandibular incisor extraction can be an effective treatment option in carefully selected clinical situations.

Dracula tooth: A very rare case report of peg-shaped mandibular incisors.

Microdontia is a term used to describe teeth which are smaller than normal. Peg-shaped teeth are type of microdontia, a developmental disturbances of teeth mainly due to congenital reasons. Most commonly affecting single teeth, that is maxillary lateral incisors. Incidence of peg shaped tooth in maxillary laterals are usually seen and reported. But in mandibular arch it is very rare. Present case, it affected all the incisors of mandibular arch and also the laterals of maxillary arch which is rarest of condition. This case report presents a non syndromic, peg shaped mandibular incisors in a 11 year old male patient.

Tricho-odonto-onycho-dermal dysplasia and WNT10A mutations.

We report on three novel (IVS2+1G>A splice site, c.1066G>T, and c.1039G>T, and one previously reported (c.637G>A) WNT10A mutations in three patients affected with odonto-onycho-dermal dysplasia (OODD; OMIM 275980). OODD is a rare form of autosomal recessive ectodermal dysplasia involving hair, teeth, nails, and skin, characterized by hypodontia (tooth agenesis), smooth tongue with marked reduction of filiform and fungiform papillae, nail dysplasia, dry skin, palmoplantar keratoderma, and hyperhidrosis of palms and soles. The novel IVS+1G>A splice site mutation is predicted to cause significant protein alteration. The other novel mutations we found including c.1066G>T and c.1039G>T are predicted to cause p.Gly356Cys and p.Glu347X, respectively. Barrel-shaped mandibular incisors and severe hypodontia appear to be associated with homozygous or compound heterozygous mutations of WNT10A. The name "tricho-odonto-onycho-dermal dysplasia" is suggested to replace "odonto-onycho-dermal dysplasia" because hair anomalies including hypotrichosis and slow-growing hair have been reported in numerous reported patients with this syndrome.

WNT10A mutations also associated with agenesis of the maxillary permanent canines, a separate entity.

Agenesis or isolated hypodontia of the maxillary permanent canines is a very rare dental anomaly. We report on nine unrelated Thai patients with this condition. Three of them had one affected parent. Three heterozygous missense mutations (p.Arg171Cys; p.Gly213Ser; and IVS2+1G>A) were identified in WNT10A in six patients. The p.Gly213Cys mutation was found in four patients. One of the patients who had p.Gly213Ser mutation also had peg-shaped (microdontia of the) maxillary lateral incisors with dens invaginatus. The mothers of two patients who carried the same mutation as their affected sons (p.Gly213Ser and p.Arg171Cys) had microdontia of the maxillary permanent lateral incisor. Our study has demonstrated for the first time that agenesis of the maxillary permanent canines is a distinct entity, associated with mutations in WNT10A. Inheritance appears to be autosomal dominant. Agenesis of the maxillary permanent canines may accompany by microdontia of the maxillary permanent lateral incisors and dens invaginatus of the maxillary permanent lateral incisors. Mutations could not be identified in the coding exons of WNT10A in three patients. They might be located outside the coding exons, including the promoter regions. However, it is likely that agenesis of the maxillary permanent canines is a heterogeneous disorder.

Modification of esthetics using a combined orthodontic and a prosthodontic approach: a case report.

A patient sometimes requires a multidisciplinary approach to correct the esthetics and to improve the occlusion. This case report describes the management of an adult female patient with a convex profile, proclined upper and lower anterior teeth, missing upper left lateral incisor and peg shaped upper right lateral incisor tooth through orthodontic and prosthodontic treatment.