Peg-shaped Maxillary Lateral Incisors Research Articles

The Prevalence of Peg-shaped Maxillary Permanent Lateral Incisors in the Turkish Population

Aim The development of human dentition is influenced by a complex interplay of diverse factors spanning epigenetic, environmental, physical, chemical, biological, and genetic realms. Variations in the morphology and dimensions of upper lateral incisors have been documented, commonly resulting in a reduction in mesiodistal size, a phenomenon often referred to as "peg-shaped laterals". This study aimed to explore the prevalence of peg-shaped maxillary permanent lateral incisors while investigating potential correlations with gender and laterality. Material and method The study comprised 1076 Turkish individuals, aged between 18 and 75, who sought treatment at the Istanbul University Restorative Dentistry Clinic. Prior to examination, participants provided voluntary consent by completing consent forms. To ensure precision and consistency, all examinations were conducted by a single clinician with a minimum of twenty years of clinical experience. Patient selection adhered to predefined inclusion and exclusion criteria. Anamnestic data, encompassing age, gender, past dental history, general health status, and intraoral examination findings, were documented. Examinations focused on the anterior region, specifically between the maxillary canine teeth. Results Peg-shaped incisors were noted in 7.2% of cases (n=77), with 54 cases being unilateral and 23 bilateral. Among the cases, 7.4% (n=52) were observed in females and 6.7% (n=25) in males. A total of 97 peg-shaped incisors were identified in both left and right maxillary lateral incisors. Conclusion The research took place in Istanbul, Türkiye, a cosmopolitan metropolis. Expanding such investigations to various regions within Türkiye would yield a richer and more comprehensive dataset, enhancing the study's significance.

Is there an association between molar incisor hypomineralization and developmental dental anomalies? A case-control study

BackgroundThe aim of this study was to determine whether there is any association between molar incisor hypomineralization and developmental dental anomalies.MethodsTwo pediatric dentists evaluated panoramic radiographs of 429 children aged 8–14 years with molar incisor hypomineralization (study group) and 437 children without molar incisor hypomineralization (control group) in terms of developmental dental anomalies. Twelve different developmental dental anomalies were categorized into four types: size (microdontia, macrodontia); position (ectopic eruption of maxillary permanent first molars, infraocclusion of primary molars); shape (fusion, gemination, dilaceration, taurodontism, peg-shaped maxillary lateral incisors); and number (hypodontia, oligodontia, hyperdontia) anomalies.ResultsNo significant difference was observed in the frequencies of developmental dental anomalies between the study and control groups in total, females, and males (p > 0.05). A statistically significant difference was found between the distribution of developmental size, position, shape, and number anomalies between the study and control groups (p = 0.024). The most common anomaly in both groups was hypodontia (6.3% and 5.9%, respectively). There was a significant difference between the study and control groups in terms of subtypes of shape anomaly in all children and females (p = 0.045 and p = 0.05, respectively).ConclusionsWhile a significant difference was observed between the distributions of types of developmental dental anomalies between individuals with and without molar incisor hypomineralization, there was no difference in terms of the frequency of developmental dental anomalies.

Aesthetic Rehabilitation of Peg-Shaped Maxillary Permanent Lateral Incisors: Ultraconservative Approach

Aesthetic Rehabilitation of Peg-Shaped Maxillary Permanent Lateral Incisors: Ultraconservative Approach

Comparisons of Dental Anomalies in Orthodontic Patients with Impacted Maxillary and Mandibular Canines.

To assess the presence and possible associations between the type of dental anomalies and maxillary and mandibular canine impactions in orthodontic patients treated for canine impaction, panoramic radiographs of orthodontic patients treated for canine impaction were assessed for the presence of associated dental anomalies. A random sample of orthodontic patients without canine impaction matched for age and gender served as controls. Descriptive and exact inferential statistics were implemented in order to assess potential associations between canine impaction and dental anomalies. A total of 102 orthodontic patients with 70 maxillary (MaxCI) and 32 mandibular (ManCI) canine impactions were assessed. The control group included 117 orthodontic patients. Dental anomalies were present in more than 50% of patients with impacted canines and in 20% of the controls. Tooth agenesis was significantly more common in the MaxCI group when compared to the ManCI group, while supernumerary teeth and canine transmigration were registered more often in the ManCI group. When compared to the control group, peg-shaped maxillary lateral incisors and tooth agenesis were significantly more prevalent in the MaxCI group, while canine transmigration, supernumerary teeth, the agenesis of mandibular incisors and tooth transpositions were significantly more prevalent in the ManCI group. The impaction of other teeth was significantly more common in both canine impaction groups when compared to the controls. The prevalence of dental anomalies in orthodontic patients with impacted canines was higher than in orthodontic patients without canine impaction. Different types of tooth anomalies were found in the MaxCI and ManCI groups.

Features of Dental Anomaly Patterns in Finnish children as seen in panoramic radiographs at the late mixed stage

Objective To describe the prevalence of the developmental abnormalities involved in Dental Anomaly Patterns (DAP) and investigate their co-occurrence in an age cohort of children with late mixed dentition. Material and Methods Retrospective, register-based study focused on 1315 panoramic radiographs of children aged 8.5-10.5 years. The features examined were absent teeth, peg-shaped maxillary lateral incisor, delayed dental age, infraocclusion of primary molars, transposition and distal angulation of unerupted mandibular second premolar. Results Feature involved in DAP was detected in 29.8% of the children, most common being infraocclusion of primary molars (17.5%), followed by absent teeth (8.4%), delayed dental age (7.6%), distal angulation of unerupted mandibular second premolar (7.3%), peg-shaped maxillary lateral incisor (2.4%) and transposition (0.5%). Two DAP features occurred together in 4.7% of children, while three occurred in 0.7%. Infraocclusion (p=.040) and absent teeth (p=.001) occurred more commonly in girls. Phenotypic variations in maxillary lateral incisor more often occurred together (p=.004). Absent teeth, peg-shaped maxillary lateral incisor and delayed dental age more often occurred together (p<.01) as did transposition and absent teeth (p=.016). Conclusion Almost third of the children had dental developmental abnormalities involved in DAP. Absent teeth, peg-shaped lateral incisors and delayed dental age more often occurred together.

Association between maxillary canine impaction and other dental anomalies: radiological study of a mixed dentition children’s cohort from an orthodontic clinic

PurposeTo investigate the significance of association between maxillary impacted canines and various dental anomalies.MethodsFiles of 874 orthodontic patients were evaluated for the presence of maxillary impacted canines. From this sample, a group of 97 patients (39 males and 58 females) with at least 1 impacted maxillary canine consisted the study group. This group was compared to a control group of 97 patients (42 males and 55 females) that was created by random selection from the initial sample without maxillary canine impaction. The impaction diagnosis was made from the panoramic radiographs. Chi-square test was used to perform the analysis for significant associations. Stepwise discriminant analysis, binary logistic regression and classification tree were used to identify best combinations.ResultsStatistically significant difference was found for peg-shaped maxillary lateral incisors and infraoccluded deciduous molars. The presence of peg-shaped upper lateral incisors arises the probability of impacted canine to 83.3%, a distal displaced unerupted second premolar to 63.16% and the impaction of any other teeth to 80% as showed by the classification tree.ConclusionsThe presence of peg-shaped maxillary lateral incisors and infraocclusion of deciduous molars can be considered major valuable early risk indicators for maxillary canine impaction, because they manifest before the maxillary canine eruption. Special consideration should be given on distal displaced unerupted second premolar and the impaction of any other teeth. Patients with these dental anomalies are candidates for future interceptive treatment for canine eruption.

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.

Three-dimensional digital evaluation of tooth symmetry and volume in patients with missing and peg-shaped maxillary lateral incisors

This study aimed to evaluate the 3-dimensional tooth crown symmetry and the crown volumes of maxillary and mandibular teeth in patients with unilateral or bilateral missing or peg-shaped maxillary lateral incisors. Six groups were established for the possible clinical variations in patients with unilateral missing or peg-shaped maxillary lateral incisors, bilateral presence of these tooth anomalies, and a control group (CG) with normal lateral incisors. The study was conducted on digital dental models of 132 patients. The morphologic symmetry of the antimere teeth was investigated using 3-dimensional deviation analysis. Volumes of contralateral teeth were compared within and among groups for the maxilla and mandible. Furthermore, volumes of teeth were compared in missing and peg-shaped quadrants and quadrants of CG. Intergroup differences were tested using one-way analysis of variance and Kruskal-Wallis tests, whereas paired t and Wilcoxon tests were used for parametric and nonparametric variables, respectively, for intragroup comparisons. Significant deviations in symmetry of antimere teeth were not detected (P>0.05). The volumes of mandibular central and lateral incisors in missing or peg-shaped lateral incisor groups were smaller than in the CG (P<0.05). Per quadrant analysis, volumes of the maxillary central incisor and mandibular central incisors, canines, and first molars in quadrants with missing or peg-shaped lateral incisors were smaller than in the control quadrants (P<0.05). Neither unilateral nor bilateral presence of missing or peg-shaped maxillary lateral incisors affected the morphologic symmetry of antimere teeth but did affect tooth volume, especially in the mandibular arch.

Sella turcica bridging and ponticulus posticus calcification in subjects with different dental anomalies

This study aimed to evaluate and compare the bridging and dimensions of the sella turcica and calcification of the ponticulus posticus in subjects with different dental anomalies. Pretreatment recordsof orthodontic patients with palatally impacted canines (n=95), mandibular second premolar agenesis (n=45), maxillary lateral incisor agenesis (n=75), tooth transpositions (TT, n=25), peg-shaped maxillary lateral incisors (n=30), and third molar agenesis (TMA, n=145) were analyzed and compared with the control group (CG) consisting of 145 subjects with skeletal Class I malocclusion and no dental anomalies. The length, diameter, and depth of the sella turcica were calculated for each patient. The degree of sella turcica bridging was scored as type I, II, and III, whereas the extent of ponticulus posticus was classified as Class I, II, and III. Only decreases in the length and diameter of the sella turcica in subjects with TT were found to be statistically significant. Although type II bridging frequency was found to be significantly lower in subjects with mandibular second premolar agenesis, maxillary lateral incisor agenesis, TT, and TMA, type III bridging frequency was found to be significantly higher only in subjects with TMA. The decrease in Class I calcificationfrequencies and the increase in Class II calcification frequencies were found to be significant in subjects with palatally impacted canines, TT, and TMA compared with the CG. In addition, the presence of Class III calcification was found to be significantly more frequent in subjects with TMA than in the CG. Although type II and type III bridging frequencies were found to be higher than in previous studies because of the higher type II bridging frequency in the CG, type II bridging frequency was found to be insignificant. Furthermore, an increased frequency of ponticulus posticus calcification was observed in subjects with palatally impacted canines, TT, and TMA.

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

This study aimed to analyze the impact of different maxillary lateral incisor width ratios on the perception of smile esthetics among orthodontists and laypersons. 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. 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. 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. 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.

Prevalence of Peg-Shaped Lateral Incisors in Non-Syndromic Subjects: A Multi-Population Study

Objective: To evaluate the prevalence and gender-wise distribution of peg-shaped maxillary permanent lateral incisors among populations in Saudi Arabia representing different geographical locations (Saudi, Jordan, Egypt, Syria, Philippine, Pakistan, India and Bangladesh). Material and Methods: Panoramic radiographs of 9945 patients attending outpatient university dental clinics of College of Dentistry, Jouf University, Saudi Arabia between February 2014 and January 2018 were collected from the archives randomly. Two calibrated investigators examined the data, which were collected from the dental radiology department archives with prior permission from the authorities. The anomalies of maxillary lateral incisors (right and left) were investigated. Results: Among all geographic locations, the prevalence of peg laterals was more in males in comparison to females except in Pakistani and Philippine populations. Among the Saudi population, peg laterals' prevalence was more in case of right lateral incisor than the left incisor. Conclusion: A higher prevalence of peg laterals was found in Saudi. Conclusion: A higher prevalence of peg laterals was found in Saudi region, followed by Egypt. Among all geographic locations, the prevalence of peg laterals was higher in males than females except for Pakistan and Philippines populations. Among Saudi population prevalence of peg laterals was found to be higher in case of right lateral incisor when compared to the left.

Prevalence of dental anomalies in a sample of orthodontic Egyptian patients using orthopantograms

Objective The aim of this cross-sectional study was to investigate the prevalence of dental anomalies in a sample of Egyptian orthodontic patients. Patients and methods This is a retrospective study where 435 digital orthopantograms taken of patients, ranging in age from 14 to 30 years with a mean age of 19 years were studied. The patients were presented for treatment at a private practice in Cairo during the period from 2017 to 2019. The orthopantograms were reviewed for impactions (including and excluding third molars), congenitally missing teeth or hypodontia (including and excluding third molars), ectopic eruption, microdontia (peg-shaped and small-sized maxillary lateral incisors), rudimentary 8's, root dilacerations and supernumerary teeth. Results Excluding third molars, the number of patients that had at least one dental anomaly was 183 or 42.1%. The prevalence of patients with impacted teeth was 66 (15.2%), while the prevalence of congenitally missing teeth was 44 (10.1%). Equal prevalence between males and females was recorded for impacted maxillary permanent canines (M = 16, F = 16) and congenitally missing maxillary permanent canines (M = 1, F = 1). The least prevalence were microdontia (n = 15, 3.4%), dilacerated roots (n = 8, 1.8%) and supernumerary teeth (n = 8, 1.8%). Rudimentary wisdom teeth count was 12 (2.8%) out of the total sample with only maxillary third molars being affected. The prevalence of impacted third molars was 25% (n = 109, M = 27, F = 82). The prevalence of congenitally missing third molars (at least one missing third molar) was 19.3% (n = 84, M = 22, F = 62). Females showed higher prevalence than males for all anomalies except for impacted mandibular permanent canines where males were higher than females (M = 9, F = 5), impacted upper incisors and upper first premolars (M = 1, F = 0) and supernumerary teeth (M = 6, F = 2). The prevalence of patients with impacted permanent second molars was 4.6%. Conclusions Excluding third molars, the most common dental anomaly was impaction followed by teeth agenesis. The most prevalent impaction was the maxillary permanent canine and the most congenitally missing teeth were the maxillary lateral incisors. Root dilacerations and supernumerary teeth were the least common anomalies. Congenitally missing and impacted third molars constitute a large segment of dental anomalies and must be evaluated separately. A large variation exists between the different populations regarding the prevalence of the various anomalies.

New perspective for evaluation of tooth widths in patients with missing or peg-shaped maxillary lateral incisors: Quadrant analysis.

Missing or peg-shaped maxillary lateral incisors can affect the mesiodistal dimensions of the dentition. The pretreatment casts of patients with bilateral (BMLI, n=35) or unilateral (UMLI, n=29) missing maxillary lateral incisors or bilateral peg-shaped maxillary lateral incisors (BPLI, n=16) were evaluated. The mesiodistal widths of all permanent teeth except the second and third molars were measured, and the sums of total and quadrant tooth widths were calculated. The results were compared with a control group (n=32) with normal maxillary lateral incisors. A quadrant analysis was performed by comparing the quadrants with lateral incisor agenesis, peg-shaped lateral incisors, and normal lateral incisors with each other. Statistical analysis was performed by 1-way analysis of variance followed by Tukey and Tamhane tests. In the BMLI and BPLI groups, significant reductions in individual tooth widths and total tooth widths were seen. The size discrepancies were the greatest in the maxillary central incisors and decreased gradually from the incisors to the molars. Compared with the control group, the tooth-size discrepancy was more pronounced in the BPLI group followed by the BMLI and UMLI groups. Due to the variability in clinical presentations of the UMLI group, the association with the reduction of the tooth sizes was not significant. But the quadrant analysis showed that in quadrants with a missing or peg-shaped lateral incisor, the teeth were significantly narrower than in quadrants with normal incisors; this indicates the importance of the contralateral side in unilaterally affected patients during analysis. Bilateral missing or peg-shaped maxillary lateral incisors were significantly associated with reduction of individual mesiodistal tooth widths as well as their total and quadrant sums. Patients with a unilaterally missing lateral incisor should be analyzed individually with quadrant analysis, since the variability in the contralateral side would affect the traditional analysis results.

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

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. 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. 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%. As children with peg-laterals have a higher incidence of other dental anomalies, careful consideration is needed when planning diagnosis and treatment.

Dental anomalies in an orthodontic patient population with maxillary lateral incisor agenesis.

ABSTRACTIntroduction: The purpose of this study was to evaluate the prevalence of dental anomalies in a subpopulation of orthodontic patients with agenesis of maxillary lateral incisors (MLI). Methods:The material of the present study included the records of the 1964 orthodontic patients. Panoramic radiographs and dental casts were used to analyze other associated eight dental anomalies, including agenesis of other teeth, dens invaginatus, dens evaginatus, peg shaped MLI, taurodontism, pulp stone, root dilaceration and maxillary canine impaction. Results: Out of the 1964 patients examined, 90 were found to have agenesis of MLI, representing a prevalence of 4.6%. The most commonly found associated-anomalies were agenesis of other teeth (23.3%), peg-shaped MLIs (15.6%), taurodontism (42.2%), and dilacerated teeth (18.9%). Conclusion:Permanent tooth agenesis, taurodontism, peg-shaped maxillary lateral incisor, and root dilacerations are frequently associated with maxillary lateral incisor agenesis.

Prevalence of Maxillary Permanent Canine Impaction in Relation to Anomalous Lateral Incisors

ABSTRACT Objective: The aim of this study was to document the prevalence of maxillary permanent canine impaction in relation to anomalous adjacent lateral incisors in a Turkish population. Materials and Methods: Pretreatment orthodontic records of 68 subjects (27 male, 41 female) with palatal or buccal impaction of one or both permanent maxillary canines were included in this study. Localization of the impacted permanent canines was determined by using cone-beam computed tomography images and classified as buccal or palatal impaction. Maxillary lateral incisors were recorded as normal, small, peg shaped, impacted, or missing using 3-dimensional digital models. The percentage of the total sample in each group was calculated, and the significance of the relationship between canine impaction and anomalous lateral incisors was examined with the Pearson χ2 test at a significance level of 0.05. Results: The overall prevalence of peg-shaped maxillary permanent lateral incisors was found to be 18.3%. Impaction of...

English

This clinical report describes an interdisciplinary approach for the coordinated treatment of a patient diagnosed with peg-shaped maxillary lateral incisors, short clinical crowns, excessive gingival display, and orthodontic malocclusion. The patient's specific esthetic expectations for the anterior maxilla were successfully met through phased treatment, including orthodontic tooth movement, and porcelain laminate veneers. Porcelain laminates can mimic the translucency of natural tooth structure and can provide colour and contour stability with minimal risk of gingival irritation, provided that proper oral hygiene and plaque control are maintained.Such coordinated interdisciplinary evaluation and treatment are necessary for improved aesthetic results in maxillary anterior areas aesthetically compromised in several aspects.

Investigation of the peg-shaped maxillary lateral incisors in a Turkish orthodontic subpopulation

Aim: The following study aims to investigate the prevalence and distribution of the peg-shaped maxillary lateral incisors in a Turkish orthodontic subpopulation. Materials and Methods: A study sample consisted of 2925 patients of which 1746 were females and 1179 were males with aged range from 10 to 18 years; (mean age, 13.40 ± 1.9 years) were retrospectively examined using panoramic radiographs, dental cast and pre-treatment records for the presence of the peg-shaped maxillary lateral incisors. Pearson's Chi-square and Fisher exact tests were used for statistical comparisons. Results: Peg-shaped maxillary lateral incisors were found in 2.15% of the patients (63/2925; 41 females and 22 males) with no statistically significant difference between the genders. However, females had more peg-shaped maxillary left lateral incisors compared with the males ( P = 0.007). It was almost equally distributed as bilateral (1.09%, 32/2925) or unilateral (1.06%, 31/2925). Conclusion: It was found to be 2.15% (63 out of 2925 patients) with no gender difference except for the peg-shaped maxillary left lateral incisors. Clinicians should be aware of this anomaly prior to treatment for possible complications.

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.

Prevalence of peg-shaped maxillary permanent lateral incisors: A meta-analysis

The aim of this meta-analysis was to gain more insight into the prevalence of peg-shaped maxillary permanent lateral incisors and their associations with race, population type, sex, and sidedness. Electronic searches and supplementary hand searches initially yielded 3337 records. After applying inclusion and exclusion criteria, 30 articles about 36 studies were included. The overall pooled prevalence estimate was calculated with a random-effects model. An estimated risk ratio was used for sex comparison. The overall prevalence of peg-shaped maxillary permanent lateral incisors was 1.8%. No publication bias was found. The occurrence rates were higher in Mongoloid (3.1%) than in black (1.5%) and white (1.3%) patients, and in orthodontic patients (2.7%) than in the general population (1.6%) and dental patients (1.9%). Women were 1.35 times more likely than men to have peg-shaped maxillary permanent lateral incisors. The prevalence rates of unilateral (0.8%) and bilateral peg-shaped maxillary permanent lateral incisors were approximately the same. However, among the unilateral lateral incisors, the left side (0.4%) was twice as common as the right side (0.2%). In addition, contralateral lateral incisor hypodontia was seen in 55.5% of the subjects with unilateral lateral incisors. The prevalence of peg-shaped maxillary permanent lateral incisors varies by race, population type, and sex. The prevalence rates were higher among Mongoloid people, orthodontic patients, and women. Although the prevalence of unilateral and bilateral lateral incisors was the same, the left side was twice as common as the right side. Subjects with unilateral peg-shaped maxillary permanent lateral incisors might have a 55% chance of having lateral incisor hypodontia on the contralateral side.