The genetic basis of dental anomalies and its relation to orthodontics

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.

Extraction of a Bi-Rooted Primary Maxillary Canine Tooth in a 9-Year-Old Saudi Boy: A Case Report

BACKGROUND Dental anomalies are common congenital disturbances that can occur as single findings or as components of specific syndromes. Primary bi-rooted canine teeth are rare dental anomalies that are more common in the maxilla. It is unusual for a child to have a bi-rooted maxillary canine, as this tooth is known for having a single long root, more than twice the length of the crown. The present report describes the extraction of a bi-rooted primary maxillary canine tooth in a 9-year-old Saudi boy. The report aims to contribute to a better understanding of the possible etiological factors of these rare conditions as well as to review the data available so far in the literature. CASE REPORT A 9-year-old Saudi boy presented to the clinic for an initial visit. The patient was medically fit. The chief complaint was "I have pain in my upper front left region". A thorough oral examination revealed that the upper left primary canine was carious. The panoramic radiograph showed that the former tooth was bi-rooted. The tooth was claimed to be non-restorable. Thus, we planned for extraction. The tooth was extracted in the subsequent visit. CONCLUSIONS The presence of bi-rooted primary canines is rare. Dentists should always assess the presence of any dental abnormality. Panoramic radiographs may give an initial sign of the existence of abnormal bi-rooted teeth, and the abnormality can be confirmed by taking intraoral radiographs. Although the data availability in the literature is limited, ethnicity and gender seem to have an impact on its prevalence.

Evaluation of Beta-Defensin 1 and Mannose-Binding Lectin 2 Polymorphisms in Children with Dental Caries Compared to Caries-Free Controls: A Systematic Review and Meta-Analysis

Background and objective: Some variants in defensin beta 1 (DEFB1) and mannose-binding lectin 2 (MBL2) genes can be associated with oral diseases. Herein, we designed a systematic review and meta-analysis to evaluate the association of DEFB1 (rs11362, rs1799946, and rs1800972) and MBL2 (rs7096206 and rs1800450) polymorphisms with the susceptibility to dental caries (DC) in children. Materials and methods: A systematic literature search was conducted in the PubMed/Medline, Web of Science, Scopus, and Cochrane Library databases until 3 December 2022, without any restrictions. The odds ratio (OR), along with a 95% confidence interval (CI) of the effect sizes, are reported. Analyses including a subgroup analysis, a sensitivity analysis, and funnel plot analyses were conducted. Results: A total of 416 records were identified among the databases, and nine articles were entered into the meta-analysis. A significant relationship was found between the T allele of DEFB1 rs11362 polymorphism and DC susceptibility, and the T allele was related to an elevated risk of DC in children (OR = 1.225; 95%CI: 1.022, 1.469; p = 0.028; I² = 0%). No other polymorphisms were associated with DC. All articles were of moderate quality. Egger's test in homozygous and dominant models demonstrated a significant publication bias for the association of DEFB1 rs1799946 polymorphism with DC risk. Conclusions: The results demonstrated that the T allele of DEFB1 rs11362 polymorphism had an elevated risk for DC in children. However, there were only few studies that evaluated this association.

Study of twenty non-metric dental crown traits using ASUDAS system in NCR (India) population

Background

The non-metric dental crown traits (NDCT) can vary within and between the geo-populations. These play a critical role in the ethnicity determination and help in identification of an individual. A commonly used system for scoring these dental traits is “Arizona State University Dental Anthropology System” (ASUDAS).

Aim and objectives

Our study aims to evaluate the frequency trend of twenty NDCT traits in the India, National Capital Region population using ASUDAS, and check for any significant sexual dimorphism for each trait.

Methods

The maxillary and mandibular dental casts from 200 patients (100 males+100 females, age 18–30 years) reporting to the dental OPD of a Government dental college were evaluated. Twenty dental crown traits were scored as per ASUDAS protocol in each dental cast by three investigators independently. NDCTs were tabulated and the chi-square test was performed for calculation of the P value.

Results

The results showed that the trait cusp number (83%) and lingual cusp variation (79%) were the two most frequent NDCTs and Y groove pattern (13%) and premolar accessory cusp-4 (12.5%) were the two least frequent traits observed. Shoveling of the upper lateral incisor (P=0.007), tuberculum dentale (P=0.049), mesial ridge (lingual) (P=0.034), and hypocone absence (P=0.001) were found to show statistically significant sexual dimorphism (P < 0.05). Although grade-wise expression of shoveling in upper lateral had statistically significant sexual dimorphism and the frequency of higher expression grades was found more in females, overall dichotomy of expression was not significant. Similarly, although an expression of grade-wise tuberculum dentale, mesial ridge (lingual) and hypocone absence had statistically significant sexual dimorphism, an overall dichotomy of expression was not significant.

Conclusion

The current study shows certain NDCTs like cusp number and lingual cusp variation have a significant association with the NCR population. Sexual dimorphism was not significant; hence, future studies should be planned on a large sample with sex pooled data for each precise location and ethnicity in all the regions of India. This can be further correlated with different facial forms and dental occlusal patterns, for correlation with abnormalities in jaws and teeth.

The Human Genetics of Dental Anomalies

The development of tooth is a highly complex procedure and mastered by specific genetic programs. Genetic alterations, environmental factors, and developmental timing can disturb the execution of these programs, and result in various dental anomalies like hypodontia/oligodontia, and supernumerary teeth, which are commonly seen in our clinical practice. Advances in molecular research enabled the identification of various genes involved in the pathogenesis of dental anomalies. In the near future, it will help provide a more accurate diagnosis and biological-based treatment for these anomalies. In this article, we present the molecular phenomenon of tooth development and the genetics of various dental anomalies.

Research algorithm for the detection of genetic patterns and phenotypic variety of non-syndromic dental agenesis

Introduction: Dental agenesis (DA), brings together the anodontia, oligodontia, hypodontia, characterized by a deficit in the development of a variable number of teeth. The objectives of the study were to illustrate the phenotypic variability of non-syndromic DA, to identify cases of DA with hereditary genetic transmission, and establish the mode of DA genetic pattern in these cases, together with the determination of DA prevalence in the population group study. Patients, Materials and Methods: The cross-sectional observational study was performed on a mixed population group, consisting of 861 Caucasian patients, between January 2018–December 2019. The clinical evaluation protocol of patients with DA, used to illustrate their phenotype, included the following stages: oral examination, photographic examination, and radiological examination. The evaluation protocol specific to the family genetic study of patients with DA, involved the following three stages: family survey, construction of the family tree and analysis of the pedigree structure. Results: The prevalence of DA in the population group was 2.78%. Regarding the phenotype, DA mainly affected the upper arch (50% of cases); bilateral DA had a significantly increased incidence (83.33% of cases) compared to unilateral form; in most cases (75%), a patient lacked one to two teeth, the lack of two teeth being the most common form (83.33% of cases); the upper lateral incisors were the teeth most frequently involved in DA (31.11% of the total missing teeth). Regarding the family genetic study, hereditary DA with autosomal dominant inheritance was present in 37.50% of cases. In the other cases (62.50%), isolated, sporadic forms of DA were registered, suggesting a spontaneous de novo mutation or a disorder of odontogenesis of a non-genetic nature. Conclusions: We consider that this study is of interest for current scientific research with applicability in dental medicine, by bringing actual information on the prevalence of non-syndromic DA in South-East Romania, the variety of phenotypic spectrum of DA for this geographic area, and the role of heredity in the DA genetic determinism in the studied population.

MACRODONTIA: A brief overview and a case report of KBG syndrome

Macrodontia is a dental condition where a tooth or group of teeth are abnormally larger than average. Functional and aesthetic discrepancies may arise in affected individuals resulting in lowering the quality of life. It has been noted that macrodontia is associated with several genetic and endocrine abnormalities. Among which, KBG syndrome is a rare genetic disorder characterized by developmental and dental abnormalities. This case report provides a brief overview of the significance of macrodontia, along with presenting a case of KBG syndrome with atypical features in a South African, 16-year-old female. The dental manifestations are often overshadowed by other more conspicuous and complex syndromic features. Recognition of both the clinical and oral changes that occur in KBG syndrome facilitates accurate diagnosis and appropriate management of this condition. The authors highlight the importance for clinicians to be cognizant of the clinical implications of macrodontia.

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.

Factors influencing different types of malocclusion and arch form-A review

AIM

This review intends to highlight malocclusion as a multifactorial issue and review the different factors that influence different types of malocclusion and arch form.

METHODS

An online article search was performed on the factors influencing malocclusion and arch form from January 1990 through April 2020. The search was performed within the Google, Rutgers library, PubMed, MEDLINE databases via OVID using the keywords mentioned in the PubMed and MeSH headings for the English language published articles January 1990 through April 2020, which evaluated different factors that influence malocclusion and arch form.

RESULTS

Of the 300 articles found in initial search results, 31 articles met the inclusion criteria set for this review. These 31 studies were directly related to the factors that impact malocclusion and different arch forms.

CONCLUSION

Genetic inheritance, genetic mutations, age, gender, ethnicity, dental anomalies like macrodontia, congenital diseases, muscular diseases, hormone imbalance, and human behaviour are all factors that influence malocclusion and arch forms. The elements within the individual's control like behaviours can aid in preventing malocclusion. However, it seems as if the underlying reason for most of these factors indicates that malocclusion is a by-product of genetics and pathology.

Root Dimensions in Patients with Mild Hypodontia and a Control Group

Objectives  The aim of this study was to compare root dimensions (length and mesiodistal widths) between subjects with mild hypodontia and an age- and sex-matched control group.

Materials and Methods  Root dimension measurements of all permanent teeth excluding third molars were made on standardly taken orthopantomograms of 50 individuals (25 hypodontia and 25 controls) attending the University of Sharjah Dental Hospital. The length and two mesiodistal widths were measured for each fully formed root. The length of the root was measured digitally by drawing a line from the midpoint and bisecting the mesiodistal cemento-enamel junction (CEJ) of the tooth and extended to its apex. The mesiodistal widths of each root were measured at the cervical region and at half way of and perpendicular to the length of the root.

Statistical Analysis  Two sample t -tests were used to compare root dimension measurements between the hypodontia and control groups.

Results  There were no significant differences between genders with regard to root length or widths measurements, and therefore genders were combined for further analysis. Patients with hypodontia have significantly shorter root lengths than controls for the upper central incisors, upper canines, first premolars, and lower first molars ( p < 0.05). Similarly, root width at the midpoint of the root was found to be less in hypodontia group than that in controls for the upper central incisors, lower first premolars, upper first molars, and all second premolars ( p < 0.05). Similar pattern of differences was found with regard to the root width at the cervical region ( p < 0.05).

Conclusions  Patients with hypodontia have shorter and narrower roots of the whole permanent dentition except the upper lateral incisors, lower incisors, lower canines, and all second molars when compared with controls. In effect, this may affect the orthodontic treatment planning and implant placement.

Remineralization, Regeneration, and Repair of Natural Tooth Structure: Influences on the Future of Restorative Dentistry Practice

Currently, the principal strategy for the treatment of carious defects involves cavity preparations followed by the restoration of natural tooth structure with a synthetic material of inferior biomechanical and esthetic qualities and with questionable long-term clinical reliability of the interfacial bonds. Consequently, prevention and minimally invasive dentistry are considered basic approaches for the preservation of sound tooth structure. Moreover, conventional periodontal therapies do not always ensure predictable outcomes or completely restore the integrity of the periodontal ligament complex that has been lost due to periodontitis. Much effort and comprehensive research have been undertaken to mimic the natural development and biomineralization of teeth to regenerate and repair natural hard dental tissues and restore the integrity of the periodontium. Regeneration of the dentin-pulp tissue has faced several challenges, starting with the basic concerns of clinical applicability. Recent technologies and multidisciplinary approaches in tissue engineering and nanotechnology, as well as the use of modern strategies for stem cell recruitment, synthesis of effective biodegradable scaffolds, molecular signaling, gene therapy, and 3D bioprinting, have resulted in impressive outcomes that may revolutionize the practice of restorative dentistry. This Review covers the current approaches and technologies for remineralization, regeneration, and repair of natural tooth structure.

Orthodontic management of a dental anomaly pattern (DAP) including mandibular canine transmigration: A case report: A challenging treatment but worth it!

Orthodontic technology has advanced to the point where management of cases with multiple dental anomalies should be within an orthodontist's daily armamentarium. A patient with bilateral agenesis of lower second premolars, delayed development, and transmigration of a mandibular canine was treated with the aid of hemisection, indirect/closed exposure, application of continuous force, targeted delivery, and strict attention to keeping the roots as much in bone as possible. This was accomplished without implants or flattening the facial profile, yet with excellent periodontal status and a fully functioning occlusion.

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.

Primary failure of eruption combined with bilateral transmigration of mandibular canines, transposition, torus palatinus, and class III incisor relationship: A rare case report

Eruption disorders are numerous varying from delayed to complete failure of eruption. Primary failure of eruption (PFE) is a rare condition that involves arrested eruption of teeth with the absence of local or general contributory factors. Another rare and clinically challenging phenomenon is canine transmigration which is the intra-osseous movement of impacted canines across the midline. This report presents the first case of combined failure of eruption of multiple teeth with bilateral mandibular canine transmigration, transposition of upper canine and the first premolar, torus palatinus, and class III incisor relationship in a 33-year-old asymptomatic and nonsyndromic female patient.

Clear double layer Bioplast feeding plate for neonates with cleft palate

An infant with cleft palate was referred to cleft clinic of the Orthodontic Department. The mother was concerned to feed the child because of the escape of milk from the nose. Intraoral examination revealed a large palatal cleft extending from hard to soft palate involving uvula. The impression was taken and dental cast obtained. A 3 mm soft and afterward a 1 mm hard Bioplast plate was pressed using Biostar device (Scheu-Dental Gmbh, Iserlohn, Germany) on the model. Finally, a hole was prepared on the anterior part to put a thread through it. The infant tolerated the plate immediately and encounters no difficulties during feeding. The inlaying soft Bioplast plates eliminate the risk of tissue irritation, whereas the covering hard Bioplast plate supplies endurance. The fabrication of the clear Bioplast feeding plate is easy and less time-consuming compared with acrylic plates and may be recommended in crowded and overloaded cleft centers.

Genetic background of supernumerary teeth

Supernumerary teeth (ST) are odontostomatologic anomaly characterized by as the existence excessive number of teeth in relation to the normal dental formula. This condition is commonly seen with several congenital genetic disorders such as Gardner's syndrome, cleidocranial dysostosis and cleft lip and palate. Less common syndromes that are associated with ST are; Fabry Disease, Ellis-van Creveld syndrome, Nance-Horan syndrome, Rubinstein-Taybi Syndrome and Trico–Rhino–Phalangeal syndrome. ST can be an important component of a distinctive disorder and an important clue for early diagnosis. Certainly early detecting the abnormalities gives us to make correct management of the patient and also it is important for making well-informed decisions about long-term medical care and treatment. In this review, the genetic syndromes that are related with ST were discussed.