Prevalence and distribution of dental anomalies: a comparison between maxillary and mandibular tooth agenesis

Prevalence and Distribution of Dental Anomalies in Schoolchildren in Kuwait

OBJECTIVE

Dental anomalies (DA) can affect paediatric patients' aesthetics, function, and psychological well-being. There is a lack of data about the prevalence of DA in children in Kuwait. This study aimed to investigate the prevalence and distribution of DA amongst schoolchildren aged 8 to 12 years.

METHODS

A retrospective study was conducted using panoramic digital radiographs of children who attended a single dental center. All radiographs were evaluated by 2 calibrated and trained examiners.

RESULTS

DA were present in 110 (20.1%) out of the 546 panoramic radiographs examined: 53.6% in females and 46.4% in males. The mean age of children with DA (9.83 ± 1.29) was similar to that of children with no anomalies (9.96 ± 1.46). The most prevalent anomaly was dental agenesis (9.3%), followed by taurodontism (6.6%) and ectopic eruption (EE, 2%). DA were more common in the maxilla (58.2%) compared to the mandible (41.8%, P = .042). Congenitally missing teeth were significantly more frequent in the mandible (56.9%) than in the maxilla (43.1%, P = .003). EE was significantly more common in the maxilla (90.9%) than in the mandible (9.1%, P = .024). Microdontia and root dilacerations were only present in males, whilst supernumerary teeth, transposition, and impacted teeth were noted in females only.

CONCLUSIONS

The prevalence of DA amongst schoolchildren in Kuwait was considered to be relatively high. Certain DA were associated with gender. The significant prevalence of DA highlights the need for early diagnosis using panoramic radiographs, particularly during the ages of 9 and 10, in order to ensure effective patient management.

Altering maternal calcium and phosphorus dietary intake induces persistent sex-specific changes in the dentition of the offspring

BACKGROUND

The maternal diet is essential to offspring development, but the specific effects on tooth morphology are still unknown. The aim of this study was to evaluate the effects of altering maternal calcium (Ca) and phosphorus (P) supplementation during gestation and lactation on offspring dentition.

METHODS

Pregnant mice were fed an experimental diet containing a threefold increase in Ca and a threefold decrease in P compared to the standard mouse chow diet at embryonic Day 0.5 (E0.5). Offspring mice were maintained on standard or experimental diets from post-natal Day 0 to weaning, then fed control diets until 6 weeks of age. Six-week-old offspring heads were collected and scanned using micro-computed tomography. Dental morphometrics of offspring maxillary and mandibular first and third molars (n = 5-6 per diet/per sex) were determined. A two-way ANOVA test was employed to verify the existence of any significant differences between groups. The significance level was set at P < .05.

RESULTS

A two-way ANOVA revealed a statistically significant interaction between the effects of diet and sex on the upper and lower dentition. Moreover, experimental diet-fed female offspring exhibited smaller molars with shorter mesiodistal width and larger pulp chambers relative to controls, while experimental diet-fed male offspring possessed larger molars with wider mesiodistal width and smaller pulp chambers.

CONCLUSION

Our findings reveal that altering the maternal and offspring dietary Ca:P ratio during gestation, lactation and weaning led to significant, sex-specific changes in the offspring dentition. The differences in dentition appeared to be correlated with the sex-specific changes in the craniofacial skeleton.

Reduced bone dimension in patients affected by oligodontia: A retrospective study on maxillary and mandibular CBCT

AIM

Oligodontia (OD) is a rare developmental condition characterized by the absence of six or more teeth. Dental implant placement may be challenging due to anatomical factors. This study aims to evaluate the alveolar bone dimensions in OD patients compared with controls.

MATERIALS AND METHODS

On maxillary and mandibular cone-beam computed tomography (CBCT), bone height and width were measured at every tooth and edentulous site. The distance to the inferior alveolar nerve was also measured. Fifty-three OD patients (40 maxillary and 32 mandibular CBCT) and 82 controls (51 maxillary and 31 mandibular CBCT) were compared using mixed models.

RESULTS

Compared with those in OD patients, maxillary permanent teeth and edentulous sites showed significantly higher mean height in control patients (incisive-canine site height: +2.12 mm; edentulous incisive-canine site height: +4.46 mm [p > .001]). For the mandibular permanent teeth, mean height was higher in controls than in OD patients at the incisive-canine (+3.82 mm [p > .001]) and premolar areas (+2.06 mm [p > .001]). Only edentulous incisive-canine sites were significantly different between controls and OD patients (mean: +0.52 mm [p > .001]). Changes in alveolar nerve position were observed in case of molar agenesis.

CONCLUSION

Maxillary and mandibular bone dimensions are reduced in OD patients compared with controls both in sites with permanent teeth and in edentulous areas.

Tooth agenesis: An overview of diagnosis, aetiology and management

Patients with one or more developmentally absent teeth are routinely encountered in dental practice. Tooth agenesis can be associated with significant functional, aesthetic and psycho-social problems. The present article provides an overview of the prevalence and aetiology of tooth agenesis, as well as the condition's clinical characteristics and management options with reference to the evidence base. A timely diagnosis can facilitate the appropriate planning and management which might not be straightforward, and patient care will likely require multi- and inter-disciplinary input. It is critical that dental care practitioners are aware of the clinical characteristics and management options for tooth agenesis.

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

BACKGROUND

The aim of this study was to determine whether there is any association between molar incisor hypomineralization and developmental dental anomalies.

METHODS

Two 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.

RESULTS

No 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).

CONCLUSIONS

While 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.

Availability of Third Molars as Donor Teeth for Autotransplantation to Replace Congenitally Absent Second Premolars in Children and Young Adults

The aim of the study was to assess the presence and distribution of third molars (M3) regarding their autotransplantation in patients with congenital absence of second premolars (PM2). Additionally, M3 development in relation to patients' age and gender was investigated. Panoramic radiographs of non-syndromic patients with at least one congenitally absent PM2 were used to assess the localization and number of missing PM2 and the presence or absence of M3 (minimum age 10 years). The alternate logistic regression model was applied to analyze associations between the presence of PM2 and M3. A total of 131 patients with PM2 agenesis were identified (82 females, 49 males). At least one M3 was present in 75.6% and all M3 were present in 42.7% of patients. A statistically significant association between the number of PM2 and M3 agenesis was found; the effects of age and gender were not significant. More than half of M3 in patients between 14-17 years old had completed ¼ of their root development. The congenital absence of maxillary PM2 was associated with the absence of maxillary PM2, M3, and no correlation was found in the mandible. In patients with PM2 agenesis, at least one M3 is often present and can be considered as a donor tooth for autotransplantation.

FEM Analysis of Individualized Polymeric 3D Printed Guide for Orthodontic Mini-Implant Insertion as Temporary Crown Support in the Anterior Maxillary Area

Either due to trauma, extraction or congenital factors, the absence of teeth has aesthetic, functional, financial and psychological consequences. The aim of the current study is to assess an individualized polymeric 3D printed digitally planned surgical guide designed to achieve precision and predictability in non-standard mini-implant orthodontic cases. Twenty-seven patient records with missing anterior teeth were selected from the database of a private clinic in Timisoara, Romania. Based on the analysis of the cases included in the research, a surgical guide for the insertion of mini-implants as provisional crown support was designed. An FEM simulation was performed using the Abaqus numerical analysis software. Finite element simulation revealed the maximum displacements and stresses that occur in the surgical guide. Mini-implant supported provisional crowns can be a simple and low-cost method to increase patient self-esteem and compliance with the orthodontic treatment. Computer aided mechanical simulation is a useful tool in analyzing different polymeric surgical guide designs before being used in clinical situations in order to avoid failure.

Dental anomalies in an Albanian orthodontic sample: a retrospective study

BACKGROUND

To evaluate the prevalence and the distribution of dental anomalies in an Albanian orthodontic sample.

METHODS

For this retrospective study, a sample of panoramic radiographs (PR) of n. 779 (456 F and 323 M, mean age of 15.1 ± 5.5 years) Albanian subjects with no genetic syndromes or craniofacial malformations (e.g., cleft lip/palate), history of extraction, trauma or previous orthodontic treatment drawn from the archives of the University Dental Clinic Our Lady of Good Counsel, was examined. The inclusion criteria were: subjects from 8 to 30 years of age, good quality of PRs in order to allow the assessment of crown and root development. For different dental anomalies, both the prevalence and the association were evaluated by using Chi-square test (p < 0.05).

RESULTS

24.4% of the sample had at least one dental anomaly and 4.6% had more than one. The following dental anomalies were most prevalent: hypodontia (9.8%), dental impaction (7.6%), and ectopic eruption (5.3%). No statistically significant correlation was found between males and females (p > 0.05).

CONCLUSIONS

The most common anomalies in this group are found to be those of number and position, and only radiological investigations can reveal either of these anomalies. Early diagnosis of dental anomalies can contribute to prevent their complications and to establish the most suitable therapy to achieve a functional occlusion.

Non-syndromic hypodontia of maxillary lateral incisors and its association with other dental anomalies

BACKGROUND

Tooth agenesis (TA) is the developmental absence of one or more teeth and is the most common craniofacial disorder in humans. Maxillary lateral incisor agenesis (MLIA) is a specific subtype of TA and can have esthetic, functional, and psychosocial implications for patients. The aim of this study was to evaluate the prevalence of MLIA amongst patients with non-syndromic tooth agenesis, as well as its association with other dental anomalies.

MATERIALS AND METHODS

The dental records of 240 patients with non-syndromic congenitally missing teeth treated at the University of Alabama at Birmingham Department of Orthodontics were reviewed. Dolphin Imaging software was used to identify missing teeth, microdonts, peg laterals, impactions, and transpositions. Data were analyzed using chi-square or Fisher's exact test. All the tests were two-sided at the significance level of 0.05 (SAS 9.4).

RESULTS

In the patient cohort, MLIA prevalence was 37.5% (second most common) and no gender or ethnic differences were identified. We also observed the bilaterally missing lateral incisors more frequently than the unilateral presentation (p = 0.0006). Additionally, 62.5% of patients with unilateral MLIA displayed a contralateral tooth that was a peg (p = 0.0001); however, no association was found with other microdonts. Furthermore, of the 90 patients missing at least one maxillary lateral incisor, 42.2% were missing another tooth type and 10% of MLIA patients also had an impacted tooth (mainly maxillary canines). However, these were not statistically significant. Finally, no transposed teeth were found in our patients.

CONCLUSIONS

This study found that maxillary lateral incisors were the second most frequently missing teeth. When clinicians diagnose congenital absence of a maxillary lateral incisor, the patient should be evaluated for other missing teeth, peg lateral incisors, or potential impactions, especially maxillary canines.

A simple method for quick evaluation of the anterior tooth ratio: an observational study

Background

An ideal relationship of anterior teeth is closely related to postoperative function, stability, and aesthetics. Therefore, it is necessary to estimate the proportion of anterior teeth when communicating with patients about possible treatment plans and outcomes. This study aimed to establish a simple method for assessing the proportion of anterior teeth and to identify the standard ratio value to provide references for clinical work.

Methods

Five hundred fourteen patients were divided into derivation, standard, and validation datasets. We first deduced our novel simplified anterior tooth ratio (SATR) by finding the key teeth with the derivation datasets, then established standard values by measuring the standard models, and finally validated the diagnostic performance of SATR. Independent sample t-test was used to select key teeth. Pearson’s correlation analysis and linear regression analysis was used to test and verify the correlation between SATR and the anterior Bolton ratio. Chi-square test and diagnostic test were used to verify the diagnostic results using SATR. P values of < 0.05 were considered statistically significant.

Results

Patients with an abnormal anterior Bolton ratio were more likely to have variations in the maxillary and mandibular lateral incisors. Therefore, the ratio of maxillary and mandibular lateral incisors was chosen as a simple way to assess the anterior tooth ratio and was defined as SATR (simplified anterior tooth ratio). A positive correlation was observed between SATR and anterior Bolton ratio (r = 0.702, p < 0.001), with the linear regression equation as follows: y = 0.503 + 0.328x, x = SATR, y = anterior Bolton ratio. The standard value of SATR was established (85.69% ± 3.57%) and proven reliable in clinical practice.

Conclusions

The ratio of maxillary and mandibular lateral incisors can be used to estimate the anterior tooth ratio, which showed high reliability and efficiency.

Infraocclusion: Prevalence, Characteristics, and Associated Dental Anomalies in Arabian Children

Aim. To analyze the distribution and characteristics of infraocclusion among Arabian children in primary dentition and its associated dental anomalies. Methods. A radiographic analysis was performed retrospectively using digital panoramic radiographs of children attending the pediatric dental clinic of College of Dentistry, Majmaah University, Saudi Arabia, from January 2019 to May 2021. The panoramic radiographs were analyzed to assess the distribution and characteristics of infraocclusion and its associated dental anomalies. Descriptive statistics were used for comparisons using SPSS version 21.0 (IBM Corp., Armonk, N.Y., USA). The chi-square test was used to compare percentages. Results. Among the study population (542), only 40 children reported infraocclusion of 65 primary molars. Infraocclusion was common in males (90%) and very frequent in the mandibular arch ( $n=48$ teeth). In the primary dentition, unilateral infraocclusion (62.5%) was very frequent than bilateral presence (37.5%). Single molars were involved in 50% of the patients, while two, three, and four molars were involved in 42.5%, 2.5%, and 5% of cases. The mandibular second primary molar was frequently affected with infraocclusion, while the maxillary first primary molar was less commonly affected. In the mandibular arch, the second primary molar (28, 58%) was more commonly affected with infraocclusion than the mandibular first primary molars and maxillary primary and secondary molars ( $p<0.05$ ). The majority of the infraoccluded molars were mild (75%), followed by moderate (23.5%) and severe (1.5%). Hypodontia (12.5%) is frequently associated with infraocclusion, followed by supernumerary teeth (5%) and radix entomolaris of the first permanent mandibular molars (5%). Infraocclusion was more in the second primary molar mandibular arch, while in the maxillary arch, the first primary molars were commonly affected ( $p>0.05$ ). Conclusion. In Arabian children, infraocclusion was commonly observed in mandibular second primary molars. Unilateral infraocclusion is a mild type of infraocclusion frequent in Arabian children. Numerical anomalies such as hypodontia and supernumerary teeth are associated with infraocclusion.

Distribution of congenitally missing teeth and treatment options for the lower second premolars in patients referred to special care

OBJECTIVE

The aim was to evaluate the distribution of congenitally missing teeth and the treatment provided for congenitally missing lower second premolars in an eleven-year cohort of patients referred to a publicly funded source of specialist care.

MATERIAL AND METHODS

This was a retrospective, register-based cohort study. Search for patients referred to a publicly funded source of specialist care based on ICD10 diagnosis code K00.00 (partial anodontia) and treatment codes EBA00, EBA05, EBA10, EBA12, EBB10 and EBB20 during the period 1.1.2009-27.10.2019 yielded 232 patients (151 females, 81 males), of whom 218, born in 1941-2009, were eligible. Data collected from medical files were presented in the form of descriptive statistics and analysed using Fisher's exact test.

RESULTS

The 218 subjects possessed 876 congenitally missing teeth (males 307, females 569) (third molars excluded). The most common missing teeth were upper second premolars and lateral incisors, and lower second premolars and central incisors. No difference in laterality was found. Statistically significant associations were found between the choice of treatment and both the patient's age at referral and the patient's year of birth. Most common treatment for adult patients (age 18-56 years) was placement of an implant (67%), while autotransplantation (11%) was the preferred option for children at the mixed dentition stage (age 9-15 years).

CONCLUSIONS

The congenitally missing teeth most commonly involved in referrals of patients to publicly funded specialist care were lower second premolars. The most frequent treatment was insertion of an implant for adults and autotransplantation at the mixed dentition stage.

Confirmation of a Phenotypic Entity for TSPEAR Variants in Egyptian Ectodermal Dysplasia Patients and Role of Ethnicity

Ectodermal dysplasia (ED) are hereditary disorders characterized by the disturbance of the ectodermal development of at least two of four ectodermal tissues: teeth, hair, nails and sweat glands. Clinical classification of ED is challenged by overlapping features, variable expressivity, and low number of patients, hindering full phenotypic spectrum identification. Disease-causing variants in elements of major developmental pathways, e.g., Ectodysplasin/NFκB, Wnt, and Tp63 pathways, have been identified in fewer than half of ED phenotypes. Whole-exome sequencing (WES) was performed for ten Egyptian ED patients presenting with tooth agenesis, normal sweating, scalp hypotrichosis, and sharing characteristic facial features. WES was followed by in silico analysis of the effects of novel detected genetic variants on mRNA and protein structure. The study identified four novel rare pathogenic and likely pathogenic TSPEAR variants, a gene which was recently found to be involved in ectodermal organogenesis. A novel in-frame deletion recurred in eight patients from six unrelated families. Comparing our cohort to previously reported TSPEAR cohorts highlighted the influence of ethnicity on TSPEAR phenotypic affection. Our study expands the clinical and mutational spectrum of the growing TSPEAR associated phenotypes, and pinpoints the influence of WES and in silico tools on identification of rare disease-causing variants.

Melatonin-Medicated Neural JNK3 Up-Regulation Promotes Ameloblastic Mineralization

Introduction: Melatonin, an endogenous neurohormone, modulates the biological circadian rhythms of vertebrates. It functions have been reported in previous stomatological studies as anti-inflammation, antioxidant, osseointegration of dental implants and stimulation to dental pulp stem cells differentiation, but its role in ameloblastic differentiation and mineralization has been rarely studied. Objective: To reveal the effects of melatonin on the mineralization of ameloblast lineage cells (ALCs), and to identify the change in gene expression and the potential mechanism based on ribonucleic acid sequencing (RNA-seq) analysis. Method: ALCs were induced in melatonin-conditioned medium. After 7-days culture, Western blot, real-time PCR, alkaline phosphatase (ALP) activity test, RNA-seq were accordingly used to detect the change in molecular level. After 1-month odontogenic induction in melatonin medium, Alizarin Red-S (ARS) staining showed the changes of mineral nodules. Differentially expressed genes (DEGs), enrichment of functions and signaling pathways analysis based on Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) database were performed. The JNK3 antagonist (JNK3 inhibitor IX, SR3576) and β-arrestin1 (Arrb1) overexpression were applied to confirm the fluctuation of melatonin-medicated JNK3 and Arrb1 expression. Results: In this study, we found out melatonin contributed to the ameloblastic mineralization, from which we can observed the elevated expression of enamel matrix protein, and increased ALP activity and mineralized nodules formation. RNA-seq analysis showed the up-regulation of neural JNK3 and down-regulation of Arrb1 in ALCs. Meanwhile, phosphorylated JNK3 deficiency (phosphorylated JNK3 inhibitor---SR3576 added to culture medium) led to mineralization delay, and Arrb1 overexpression proved Arrb1 takes bridge between melatonin receptors (MTNR) and JNK3 in MAPK signaling pathway.

Congenitally missing second permanent molars in non‑syndromic patients (Review)

Hypodontia (tooth agenesis) is regarded as the most common congenital dental anomaly. The present review discusses the epidemiological characteristics of congenitally missing second permanent molars (CMSPMs) within a systematic review of the literature. The review was based on Pubmed library associated with the search of various scientific databases or academic resources, improved by hand search of reference lists. The terms ‘hypodontia’ or ‘anodontia’ in combination with ‘prevalence’ or ‘epidemiology’ were searched in the data sources for studies published between January 2001 and December 2020. Abstracts of non-English papers were also analyzed. The inclusion criteria were as follows: i) Study provided precise data about CMSPMs, even if no second permanent molar was reportedly missing; ii) the number of CMSPMs distributed by jaw was provided and iii) studies on subjects >3 years were used. The exclusion criteria were as follows: i) Studies on patients with history of trauma of the maxilla or the mandible, any type of syndrome affecting bone metabolism, metabolic disorders, previous extraction or tooth loss due to dental caries, cleft lip and palate; ii) studies performed on cohorts of patients with hypodontia and iii) studies reporting data including third molars, except for those that presented sufficient data to perform correct calculations. A total of 79 studies were selected, accumulating a population of 281,968 people, with an average sample size of 3,524.60±11,255.25. The prevalence of CMSPMs (IpHSPM) was 2.79±3.16% among all missing teeth (1.03±1.59% for upper CMSPMs and 1.76±2.32% for lower CMSPMs; P=0.011). There were no significant differences (P=0.250) in IpHSPM between men (1.59±1.52%) and women (2.13±1.67%). However, significant differences were recorded between continents. Furthermore, lower CMSPMs were found more frequently in orthodontic samples (P=0.033). The prevalence of CMSPMs is low compared with the overall prevalence of CM teeth. Despite the rarity of these anomalies, early detection is important to enable practitioners to plan and start treatment at the best time for optimal results.

The prevalence and management of patients with hypodontia: A cross -sectional study

BACKGROUND

Hypodontia is one of the most common anomalies in dentistry. Hypodontia has a negative impact on oral health-related quality of life with patients best seen in a multidisciplinary clinic to improve treatment outcomes.

AIM

To investigate the prevalence of hypodontia and its association with other dental anomalies, as well as malocclusion, and to investigate the treatment planned for patients attending the clinic and whether the type of missing teeth affected the proposed treatment.

MATERIALS AND METHODS

Analysis of consecutive patients attending the hypodontia clinic at a dental hospital between February and November 2020. A total of 100 patients who met the inclusion criteria were identified. Data collected included the following: age/sex; number and type of missing teeth; pre-treatment occlusion; presence of other dental anomalies; and planned treatment.

RESULTS

A total of 100 patients (55% female; age range = 7-41 years; mean age = 18 years) were included. Of the cohort, 47% had a class I skeletal relationship and participants were significantly less likely to have a class III skeletal or incisor relationship; 45% had another dental anomaly with the most common being microdontia. Space opening was the preferred treatment option for those managed by orthodontic treatment with resin-bonded bridges most likely to be used for restoration of spaces, 86%.

CONCLUSION

Lower second premolars were the most commonly missing teeth. Participants were significantly less likely to have a class III incisor or skeletal relationship than class I or II. Space opening was the favoured approach for orthodontic treatment, particularly for maxillary lateral incisors.

Evaluation of the effects of hypodontia on the morphology of craniofacial structures

OBJECTIVE

The study aimed to investigate the effects of hypodontia on the sagittal and vertical dimensions of the jaws, dentition and the related soft tissue.

MATERIALS AND METHODS

The hypodontia group included 111 patients whose growth was completed with one or more congenitally missing teeth (CMT). Sixty additional patients with skeletal and dental class I relationship, without CMT, and who completed growth, were included as the control group. The hypodontia group was divided into three subgroups according to the intermaxillary (maxillary or mandibular) location, intramaxillary (anterior or posterior) location and the severity of hypodontia (mild: 1-2 CMT or moderate: 3-6 CMT). Twenty-three measurements were performed on lateral cephalograms of the patients. The one-way and Kruskal-Wallis Analysis of Variance tests were used for the statistical analysis. The false discovery-rate analysis was applied for the multiple comparison adjustment.

RESULTS

No significant difference was found in the skeletal measurements between all hypodontia subgroups and the control (P > .05). Upper incisors were found to be retroclined in the anterior hypodontia group. The upper lip was found to be protruded in the mandibulary hypodontia group compared to the control (P < .05).

CONCLUSION

The mild-to-moderate hypodontia did not produce a significant skeletal effect. However, hypodontia can affect the incisors, especially when CMT is in the anterior region. Besides, the effects of severe hypodontia could not be evaluated due to the insufficient number of oligodontia patients.

Prevalence and patterns of tooth agenesis among patients aged 12-22 years: A retrospective study

Objective

This study aimed to establish the prevalence and patterns of nonsyndromic tooth agenesis in patients referred to a tertiary health care facility.

Methods

The intraoral records and panoramic radiographs of 9,874 patients aged 12–22 years were evaluated. The study group included 716 patients (371 male, 345 female) with non-syndromic agenesis of at least one tooth (except the third molars). The study data were assessed using descriptive statistics, chi-square test, and Mann–Whitney U test, while patterns were evaluated using a tooth agenesis code (TAC) tool.

Results

A total of 1,627 congenitally missing teeth, were found in patients with non-syndromic tooth agenesis, with an average of 2.27 missing teeth per patient. The prevalence of tooth agenesis was 7.25%, and the most commonly missing teeth were the left mandibular second premolars (10.17%). The age group comparison revealed no significant difference in the median number of missing teeth per patient according to the cutoff values for ages between 12 and 22 years. When the missing teeth were examined separately according to quadrants, 114 different tooth agenesis patterns (upper right quadrant = 28, upper left quadrant = 27, lower left quadrant = 31, and lower right quadrant = 28) were identified, and 81 of these patterns appeared only once.

Conclusions

This study highlights the benefits of applying the TAC tool in a large sample population. The application of the TAC tool in such studies will enable the development of template treatment plans by determining homogenous patterns of tooth agenesis in certain populations.

Dental Anomalies' Characteristics

The aim of this study was to characterize dental anomalies. The pretreatment records (photographs and radiographs) of 2897 patients (41.4% males and 58.6% females) were utilized to detect dental anomalies. The dental anomalies studied were related to number, size and shape, position, and eruption. A Chi-square test was carried out to detect associations between dental anomalies, jaw, and sex. A total of 1041 (36%) of the subjects manifested at least one dental anomaly. The prevalence of all dental anomalies was jaw-dependent and greater in the maxilla, except for submerged and transmigrated teeth. The most frequently missing teeth were the maxillary lateral incisor (62.3%) and the mandibular second premolars (60.6%). The most frequent supernumerary teeth were the incisors in the maxilla (97%) and the first premolars in the mandible (43%). Dental anomalies are more frequent in the maxilla and mainly involve the anterior teeth; in the mandible, however, it is the posterior teeth. These differences can be attributed to the evolutionary history of the jaws and their diverse development patterns.

The global distribution of permanent canine hypodontia: A systematic review

Objective

To systematically review studies on canine agenesis prevalence in different populations and continents, based on the jaw, sex, location, and associated dental anomalies.

Methods

Electronic and hand searches of English literature in PubMed, Web of Science, Scopus, OpenGrey, and Science Direct were conducted, and the authors were contacted when necessary. Observational studies (population-based, hospital/clinic-based, and cross-sectional) were included. For study appraisal and synthesis, duplicate selection was performed independently by two reviewers. Study quality was assessed using a modified Strengthening the Reporting of Observational Studies in Epidemiology checklist, with main outcome of prevalence of canine agenesis.

Results

The global population prevalence of canine agenesis was 0.30% (0.0-4.7%), highest in Asia (0.54%), followed by Africa (0.33%), and the least in Europe and South America (0.19% in both continents). Canine agenesis was more common in the maxilla (88.57%), followed by both maxilla and mandible (8.57%), and the least common was mandible-only presentation (2.86%). The condition was more common in females (female:male ratio = 1.23), except in Asia (female:male ratio = 0.88) and Africa (female:male ratio = 1). In Asia, unilateral agenesis was almost twice as prevalent as bilateral, but in Europe, the bilateral form was more common.

Conclusions

The overall prevalence of canine agenesis is 0.30%, with the highest prevalence in Asia, followed by Africa, Europe, and South America. The condition is more common in the maxilla than the mandible, and in females than males (except in Asia and Africa), with unilateral agenesis being more common in Asia and the bilateral form showing a greater prevalence in Europe.

Dissipating tooth-mass discrepancy caused by a set of mandibular incisor anomalies

Dental anomalies are complicating factors of orthodontic treatment, especially when 1 or more anterior teeth are affected. In this case report, a girl, aged 12.5 years with a retrognathic chin; number, size, and position anomalies of the mandibular incisors; and bilateral Class I molar relationship sought orthodontic treatment. Tooth-size ratio discrepancy was dissipated without extraction or prosthetic rehabilitation, and the initial molar relationship was maintained, as well as the straight soft tissue profile. Tipping of maxillary and mandibular incisors, crown torque of canines, restoration of anomalous incisor, and maxillary interproximal enamel reduction were key points for successful treatment. After 18 months, the orthodontic records showed stable results, excellent static and functional occlusion, and good smile esthetics and facial appearance, in addition to a high degree of patient satisfaction with the achieved results.

Maxillary incisor root morphology in patients with nonsyndromic tooth agenesis: A controlled cross-sectional pilot study

INTRODUCTION

This study aimed to investigate the association between root morphology of maxillary incisors and nonsyndromic tooth agenesis in patients compared with a control group without agenesis.

METHODS

This controlled cross-sectional pilot study (1:4) was performed with a random sample of 335 records from Brazilian applicants for orthodontic treatment, paired by sex and age. Panoramic and periapical radiographs were analyzed to diagnose tooth agenesis and to assess root morphology. The agenesis group (n = 67) included patients with nonsyndromic tooth agenesis, and the control group (n = 268) included patients without tooth agenesis. The statistical analysis included the Student t test and z test, conditional logistic regression, and odds ratio estimates.

RESULTS

Occurrence of root morphological changes was significantly higher among patients with agenesis (P <0.05). Significant morphological changes (short, blunt, apically bent, and pipette-shaped roots) were found in the roots of remaining teeth when comparing agenesis and control groups (P <0.05). Patients with agenesis were more likely to show root morphological changes (odds ratio, 74.23; 95% confidence interval, 16.93-325.46; P <0.001).

CONCLUSION

Patients with agenesis are more likely to present root morphological changes, which should be considered to minimize problems during orthodontic treatments.

Dental treatment considerations for a pediatric patient with incontinentia pigmenti (Bloch-Sulzberger syndrome)

Incontinentia pigmenti (IP) is a uncommon gene disorder, heritage with X-linked dominant mode. IP patients have a characteristic dentition varying from marked hypodontia to delayed eruption and conical crowns on both dentitions. A 5½-year-old girl, whose mother and younger sister were also diagnosed with IP, has the whirling-like pigmented skin lesion over her trunk and four extremities. Four primary teeth and multiple permanent tooth germs were found to be congenital missing. Dental considerations of further treatment were discussed with her parents including the preservation of primary molars, possible interim prosthesis in mixed or permanent dentition, full mouth rehabilitation with orthodontic and prosthodontic combined treatment, and implant therapy in adulthood. Early and longitudinal involvement of pediatric dentist to deal with the dental complications of IP can not only solve the esthetic problem and oral function but also maintain the oral health of children with IP to adulthood.

New model for dental age estimation: Willems method applied on fewer than seven mandibular teeth

Willems method measures the developmental stages of the seven left permanent mandibular teeth and is frequently used for dental age estimation. The aim of this study was to test its accuracy on a large sample of the Croatian population and to develop new models for estimation based on one to seven mandibular teeth. The developmental stages were evaluated on the digital, standardized orthopantomograms of 1868 Croatian children aged 5 to 16. Univariate regression was used for age estimation based on one tooth and regression with forward and backward elimination for selection of the best combination on two to six teeth. Tested in parallel with Willems method, the accuracy of the new models was assessed within intervals of ± 0.5, ± 1, ± 1.5 and ± 2 years and shows the percentage of correct estimations. Using Willems method, the average overestimation was 0.41 years for boys and 0.22 years for girls. Newly developed models that use two to seven teeth proved to be significantly more accurate (p < 0.001). The accuracy of age estimation increases significantly with the number of teeth in a model. Predictably, within the interval ± 0.5 years, a model with three teeth has 3% fewer accurate age estimations than a model including seven teeth. In both theory and practice, Willems method has been considered suitable for age estimation among Croatian children. However, these newly developed models significantly surpass its accuracy. Models using two to seven teeth represent a simple, reliable, and accurate method for age estimation, even in cases with missing mandibular teeth.

Association between agenesis and root morphology of anterior teeth

Abstract Introduction Tooth agenesis is likely to affect the root teeth and should be considerated in orthodontic tratament. Objective The aim of this study was to assess the association between agenesis and root morphology of anterior teeth. Material and method The anterior teeth of 51 individuals were evaluated on 102 periapical radiographs and then divided into three groups: Group 1 (n=16) – no tooth agenesis; Group 2 (n=17) – only third molar agenesis; and Group 3 (n=18) – tooth agenesis of premolars or lateral incisors. Root morphology of anterior teeth was evaluated and the roots were classified as short, blunt, apically bent, and pipette-shaped. Fisher’s exact test was used to compare root shapes, the chi-square test was used to obtain the distribution of sexes between the groups, and ANOVA was performed to compare the ages between the groups. The significance level was set at 5% for all analyses. Result There was significant difference in root shapes (P<0.05) between the groups. Blunt roots were the most prevalent in all groups, but their rate was higher in Group 3 (83%). Conclusion There was association between agenesis and root morphology of anterior teeth.

[Individual risk factors impact on the development of dentoalveolar anomalies in children]

Dental anomalies and deformities belong to the group of major dental diseases and are characterized by high prevalence. To reduce the incidence of dental anomalies, early detection of risk factors is necessary. AIM: to study the effect of individual risk factors on the development of anomalies in the dental-maxillary system during the period of early interchangeable bite. It was established that in the period of early replaceable bite, risk factors for development were found in 54.24% of the examined children. To assess the degree of influence of various factors on the development of anomalies in the dental system in children, absolute, relative, and attributive risk values were calculated for 254 children of 7 years old. The absolute risk of the occurrence of dental anomalies in children with artificial and early mixed feeding was 79.16%, and the absolute risk in children with natural feeding was 64.6%. The relative risk of tooth-jaw anomalies in children with artificial and early mixed feeding was 2.08. Attributable risk - 28.55%. For effective preventive measures, the group of controlled risk factors is of the greatest interest. These are factors that can be eliminated, weaken or increase the resistance of the child's body to their action. Eliminating the bad habits of sucking fingers and various items, the risk of anomalies in the dental system is reduced by 20.38%. Introduction to the diet of tough food reduces the likelihood of development of dental-maxillary anomalies in children by 16.86%. Thus, the studied risk factors influence the formation of the dental system.

What factors affect the severity of permanent tooth impaction?

BACKGROUND

The aim of this study was to investigate the association between the severity of permanent tooth impaction and a number of predefined factors, including tooth type, age, gender, tooth agenesis, microdontia of maxillary lateral incisor, and retained deciduous predecessors.

METHODS

A sample of 2979 dental patients, aged 15 to 40 years, was surveyed by two calibrated examiners for permanent tooth impaction (excluding third molars). On panoramic radiographs, the impacted teeth were initially ranked based on their vertical, horizontal, and angular positions, and the ranking was then analysed for distribution by the predefined factors. To test the age factor, patients were divided into younger (15 to 25 yr) and older (between 25 and 40 yr) age groups. The statistical significance of the ranked vertical, horizontal, and angular positions of impacted teeth by the investigated factors was determined using the Wilcoxon-Mann-Whitney U test.

RESULTS

The angular position of the impacted teeth was more severe in the older age group (P = 0.012) and in females (P = 0.018). The maxillary canine had more severe horizontal (P = 0.001) and angular (P = 0.003) impactions in females. Tooth agenesis was associated with less severe horizontal impaction (P = 0.041) in the mandibular second premolar. In addition, microdontia of the maxillary lateral incisor was associated with more severe horizontal impaction in general, and more severe horizontal (P = 0.024) and angular (P = 0.010) impaction of the mandibular second premolar in particular. Finally, our results showed that a retained deciduous predecessor was linked to a less severe vertical impaction of the mandibular second premolar (P = 0.030) and horizontal impaction of the maxillary second premolar (P = 0.037) but more severe angular impaction of the mandibular canine.

CONCLUSIONS

This study suggests that the more delayed the treatment, being a female, the presence of maxillary lateral incisor with microdontia, and retained lower deciduous canines might be associated with more severe position of the impacted teeth. Because the severity of tooth impaction would follow different patterns when considering the investigated factors, it is mandatory to include such factors during dental diagnoses and the planning of preventive or interceptive interventions for young patients.

Non-syndromic tooth agenesis patterns and their association with other dental anomalies: A retrospective study

OBJECTIVE

This study aimed to investigate the prevalence and the factors associated with non-syndromic tooth agenesis, besides identifying its pattern of occurrence.

STUDY DESIGN

Pre-orthodontic exams of 3400 subjects, aged 8-30 years, were selected from a radiographic center in Brazil. Panoramic and periapical radiographs were analyzed to verify the presence of tooth agenesis and other six dental anomalies. Descriptive statistics were calculated using the Tooth Agenesis Code tool and, to evaluate significant associations, a negative binomial regression model was constructed. Besides, unadjusted and adjusted prevalence ratios (PR) were calculated for the bivariate and the multivariate analysis.

RESULTS

Prevalence of tooth agenesis was 3.0% (n = 68) and 41 different phenotypic patterns were observed. Teeth most often symmetrically missing were maxillary lateral incisors (13.2%) and mandibular second premolars (8.8%). Females (PR = 3.49, CI 95% = 1.96-6.19) presented more tooth agenesis. Other dental anomalies, such as palatal displacement of maxillary canine and infraocclusion of primary molar were significantly more frequent (p < 0.001) in subjects with agenesis.

CONCLUSION

There was a strong relationship between tooth agenesis and gender and the association with other dental anomalies was significant, with the exception of the supernumerary teeth, which seems to be independent.

Associations between tooth agenesis and displaced maxillary canines: a cross-sectional radiographic study

Background

The aim of present study was to test the association between hypodontia and displaced maxillary canine when compared with a control group.

Methods

The study group was composed of 336 subjects with a mean age of 10.7 ± 1.2 years, presenting with at least one missing tooth. Exclusion criteria included syndromes, craniofacial malformations, extractions and trauma history and previous orthodontic treatment. The control group consisted of 336 subjects with a mean age of 10.7 ± 1.2 years, without agenesis. Stepwise multiple logistic regression using the backwards elimination and the Wald test method was performed to identify the best combination of hypodontia and displaced maxillary canine (P < 0.05).

Results

The most represented category in study group consisted in mild agenesis (86.9%); moderate and severe agenesis groups respectively represented the 11.7 and 1.4% of study group. Agenesis was diagnosed in both arches in 46 subjects. Maxillary hypodontia and mandibular hypodontia was respectively detected in 156 and 134 subjects. The most frequent missing teeth were mandibular second premolars (45.8%), lateral incisors (41.7%) and maxillary second premolars (17.8%). A significant correlation between agenesis and displaced maxillary canine was observed in the study group (P < 0.05). Only the agenesis of maxillary lateral incisors remained in the final model during backward stepwise deletion. Significant association between the severity of dental agenesis and prevalence of displaced maxillary canine was not assessed.

Conclusions

The outcomes revealed no difference related to the severity of dental agenesis and prevalence of displaced maxillary canine. Only the agenesis of maxillary lateral incisors should be considered directly connected with displaced maxillary canine.

Electronic supplementary material

The online version of this article (10.1186/s40510-018-0226-0) contains supplementary material, which is available to authorized users.

Dental anomalies: prevalence and associations between them in a large sample of non-orthodontic subjects, a cross-sectional study

Background

To analyze the prevalence and associations between dental anomalies detectable on panoramic radiographs in a sample of non-orthodontic growing subjects.

Methods

For this cross-sectional study, digital panoramic radiographs of 5005 subjects were initially screened from a single radiographic center in Rome. Inclusion criteria were: subjects who were aged 8–12 years, Caucasian, and had good diagnostic quality radiographs. Syndromic subjects, those with craniofacial malformation, or orthodontic patients were excluded and this led to a sample of 4706 subjects [mean (SD) age = 9.6 (1.2) years, 2366 males and 2340 females]. Sample was subsequently divided into four subgroups (8, 9, 10, and 11–12 year-old groups). Two operators examined panoramic radiographs to observe the presence of common dental anomalies. The prevalence and associations between dental anomalies were also investigated.

Results

The overall prevalence of dental anomalies was 20.9%. Approximately, 17.9% showed only one anomaly, 2.7% two anomalies, while only 0.3% had more than two anomalies. The most frequent anomalies were the displacement of maxillary canine (7.5%), hypodontia (7.1%), impacted teeth (3.9%), tooth ankylosis (2.8%), and tooth transposition (1.4%). The lower right second premolar was the most frequent missing teeth; 3.7% had only one tooth agenesis, and 0.08% had six or more missing tooth (Oligodontia). Mesiodens was the most common type of supernumerary tooth (0.66%). Two subjects had taurodontic tooth (0.04%). Tooth transpositions and displacement of maxillary canine were seen in 1.4 and 7.5%, retrospectively (approximately 69 and 58% were in the 8 and 9 year-old groups, retrospectively). Significant associations were detected between the different dental anomalies (P < .05).

Conclusions

The results of our study revealed significant associations among different dental anomalies and provide further evidences to support common etiological factors.

Electronic supplementary material

The online version of this article (doi:10.1186/s12903-017-0352-y) contains supplementary material, which is available to authorized users.

Patterns of non-syndromic permanent tooth agenesis in a large orthodontic population

OBJECTIVE

The aim of this study is to explore patterns of non-syndromic permanent tooth agenesis in a large orthodontic patient group.

DESIGN

A record review was performed in various orthodontic clinics to identify white patients with non-syndromic permanent tooth agenesis, excluding 3rd molars. Four hundred and fourteen subjects fulfilled the inclusion criteria.

RESULTS

In the 414 subjects with tooth agenesis, approximately 70% presented 1-2 missing teeth. Symmetric agenesis patterns were often observed in the sample (by jaw, by side, or crossed quadrants), with prevalence approaching 30% for cases with contralateral tooth agenesis within a jaw. In cases with 1 or 2 missing teeth, from the total number of potential tooth agenesis patterns in the sample, a certain part was evident, limiting the variation to 27.8% (44/158). In the entire sample, both in the maxilla and the mandible a certain incisor/premolar agenesis phenotype was observed in 59.0% of cases in isolated form.

CONCLUSIONS

Although there was variation in the tooth agenesis patterns, our findings suggest the involvement of particular genetic, epigenetic, and/or environmental factors in the formation of the entire dentition, which often lead to specific tooth agenesis phenotypes in cases where this process is disrupted. The present study provides a comprehensive categorization of orthodontic cases with tooth agenesis and can assist in planning future epidemiological and genetic studies.