Prevalence of dental agenesis in a sample of Italian orthodontic patients: an epidemiological study

EDA Variants Are Responsible for Approximately 90% of Deciduous Tooth Agenesis

Deciduous tooth agenesis is a severe craniofacial developmental defect because it affects masticatory function from infancy and may result in delayed growth and development. Here, we aimed to identify the crucial pathogenic genes and clinical features of patients with deciduous tooth agenesis. We recruited 84 patients with severe deciduous tooth agenesis. Whole-exome and Sanger sequencing were used to identify the causative variants. Phenotype-genotype correlation analysis was conducted. We identified 54 different variants in 8 genes in 84 patients, including EDA (73, 86.9%), PAX9 (2, 2.4%), LRP6 (2, 2.4%), MSX1 (2, 2.4%), BMP4 (1, 1.2%), WNT10A (1, 1.2%), PITX2 (1, 1.2%), and EDARADD (1, 1.2%). Variants in ectodysplasin A (EDA) accounted for 86.9% of patients with deciduous tooth agenesis. Patients with the EDA variants had an average of 15.4 missing deciduous teeth. Mandibular deciduous central incisors had the highest missing rate (100%), followed by maxillary deciduous lateral incisors (98.8%) and mandibular deciduous lateral incisors (97.7%). Our results indicated that EDA gene variants are major pathogenic factors for deciduous tooth agenesis, and EDA is specifically required for deciduous tooth development. The results provide guidance for clinical diagnosis and genetic counseling of deciduous tooth agenesis.

A Narrative Review of the Association between Dental Abnormalities and Chemotherapy

Dental abnormalities are often detected in childhood and are reported to occur with high prevalence in patients who have undergone cancer treatment or chemotherapy. We performed a literature search of PubMed from 2004 to 2024 using the terms "dental anomaly" and "panoramic examination", and 298 potentially relevant articles were found. Thirty-one articles about dental abnormalities matched the eligibility criteria and were extracted for this review. Although the prevalence of tooth agenesis and microdontia in the general population was reported to be approximately 10% and 3%, respectively, the prevalence in patients who had undergone cancer treatment or chemotherapy was higher in all surveys, suggesting that the treatment is related to the occurrence of dental abnormalities. It is important to continue long-term follow-up with patients not only during treatment but also after the completion of treatment. Dental professionals should provide information about dental abnormalities to patients, their guardians, and medical professionals, which may lead to improvement in the quality of life of patients.

Non-syndromic tooth agenesis in Latvian adolescent dental patients: a retrospective study with relevant literature review

AIM

To investigate the prevalence of tooth agenesis and associated dental anomalies in Latvian adolescent dental patients and compare it to other European countries.

DESIGN

Cross-sectional study of 2692 11-to-14-year-old patients (39.9% males and 60.1% females) attending Riga Stradins University Institute of Stomatology with panoramic radiographs taken between August 2020 and September 2021. Patients with any genetic syndromes were excluded. Data on tooth agenesis (excluding third molars) and other dental anomalies were recorded.

RESULTS

The prevalence of tooth agenesis in Latvian adolescent dental patients was 9.3% with no statistically significant difference between genders (χ2 test, p = 0.472). The most commonly missing teeth were mandibular second premolars, followed by upper lateral incisors and upper second premolars. There was a statistically significant association with the presence of other dental anomalies in tooth agenesis patients (p < 0.001).

CONCLUSIONS

This study found that the prevalence of non-syndromic tooth agenesis in Latvian adolescent dental patients was 9.3% with no statistically significant differences between the genders. Patients with tooth agenesis have a statistically significant possibility of the presence of other dental anomalies (p < 0.001).

Dental and jawbone abnormalities linked to amelogenesis imperfecta: A retrospective and analytic study comparing panoramic radiographs

BACKGROUND

Amelogenesis Imperfecta (AI) is a disorder of tooth development characterized by abnormal enamel formation. In order to detect other dental and jawbone abnormalities that could be associated with AI, a retrospective and analytic study was conducted comparing panoramic radiographs of AI and non-AI patients.

MATERIAL AND METHODS

Digital panoramic radiographs of 60 AI and 60 non-AI patients were examined. Abnormalities in dental number, size, shape, eruption, and in the shape of the dental arches were checked and blindly recorded by two experimented observers. Descriptive statistics using percentages and chi-square test with .05 level of significance value was used.

RESULTS

Prevalence of supernumerary teeth, dental agenesis, microdontia, taurodontism, radicular dilacerations, dental inclusions, temporary teeth persistence, and pulp calcifications was significantly higher in AI patients compared to control patients. Prevalence of periapical images, cysts, and hypercementosis was lower in AI patients compared to control patients, with no statistically significant difference. A significant prevalence of mandibular hypoplasia was also noted in AI patients.

CONCLUSION

In addition to enamel defect, panoramic radiography was useful in detecting other dental abnormalities and mandibular hypoplasia associated with AI and should therefore be systematically indicated for AI patients' care.

Patterns and sexual dimorphism of non-syndromic hypodontia among a French orthodontic population

OBJECTIVES

This retrospective study aimed to estimate the prevalence of non-syndromic congenitally missing teeth (CMT) and to explore the frequency of CMT patterns in a French orthodontic population. In addition, the study sought to assess sex-based differences in CMT patterns.

DESIGN

Panoramic radiographs of 4569 orthodontic patients between 9 and 21 years-old performed over a 16-year period (2006-2022) were examined to identify non-syndromic tooth agenesis, excluding third molars. A chi-square test or a Fisher exact test were used to determine the difference in the prevalence of tooth agenesis between sex and between arches.

RESULTS

Tooth agenesis was observed in 7.3% of the sample (7.9% for females and 6.6% for males). Approximately 86% of the included subjects presented 1 or 2 missing teeth. Single tooth agenesis was significantly more frequent in females than males (p = 0.002, χ2). In total, 23 of the 67 different patterns of CMT observed, were present more than once. 75.5% of male patients and 79.5% of female patients presented one or both missing lateral incisors or second premolars, rarely affected at the same time. This study showed no sex difference in the patterns of tooth agenesis.

LIMITATIONS

This study has limitations due to its retrospective nature and our findings apply solely to an orthodontic population from a white ethnic background.

CONCLUSIONS

Clinicians should be aware of this particular incisor/premolar phenotype regardless of biological sex. Issues associated with congenitally missing teeth can be managed more effectively with early teenage diagnosis.

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.

The phenotype and genotype of PAX9 mutations causing tooth agenesis

OBJECTIVES

The purpose of this study was to identify associations between PAX9 mutations and clinical features of non-syndromic tooth agenesis patients.

MATERIALS AND METHODS

Non-syndromic tooth agenesis patients were found to have mutations by whole exome sequencing (WES). Additionally, conservation analysis and three-dimensional structure prediction were also applied to identify mutated proteins.

RESULTS

Eight non-syndromic tooth agenesis probands were identified with PAX9 mutations (c.C112T; C.131_134del; c.G151A; c.189delG; c.305delT; c.C365A; c.394delG; c.A679C). All of the probands were missing more than six teeth (oligodontia). The mutations (c.131_134del,p.R44fs; c.189delG,p.T63fs; c.305delT,p.I102fs and c.394delG,p.G123fs) caused premature termination of the PAX9 protein. The c.C112T(p.R38X) mutation created a truncated protein. Bioinformatic prediction demonstrated that the three missense mutations change the PAX9 structure suggesting the corresponding functional impairments.

CONCLUSIONS

We reported that eight mutations of PAX9 caused non-syndromic tooth agenesis and analyzed the relationship between PAX9 mutations and non-syndromic tooth agenesis.

CLINICAL RELEVANCE

Our study revealed that PAX9 mutations might be the mutations most associated with non-syndromic tooth agenesis in humans, which greatly broadened the mutation spectrum of PAX9-related non-syndromic tooth agenesis.

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.

Retrospective study of concomitant hypodontia and hyperdontia in 145 subjects

OBJECTIVES

This study aims to investigate the incidence and clinical characteristics of concomitant hypodontia and hyperdontia (CHH) by performing panoramic radiographs.

METHODS

A total of 41 648 panoramic radiographs of pediatric patients who were admitted to the hospitals from January 2019 to May 2021 were reviewed, and 145 CHH patients were included in the study. The presence of CHH was recorded. SPSS 24.0 software was used for statistical analysis.

RESULTS

The prevalence of CHH was 0.35% (145/41 648). Males (102 cases) were obviously more than females (43 cases), and the difference between genders was statistically significant (P<0.001). The features of congenital permanent tooth loss in this group were predominantly 1 and 2 teeth missing and preferably mandibular lateral incisors and mandibular second premolars missing. The incidence of congenital permanent teeth loss was higher in the mandible than in the maxilla (P<0.001), but no difference was found in the distribution between left and right (P=0.84). The features of supernumerary teeth in this group were 1 and 2 teeth, mostly in the maxillary anterior area, mostly conical, mostly vertical inversion and orthotopic growth.

CONCLUSIONS

CHH is a rare mixed numeric dental anomaly characterized by congenital missing teeth and supernumerary teeth occurring in the same individual. CHH cases are higher in men than in women. The characteristics of their hypodontia and hyperdontia are similar to those of patients with congenital permanent tooth absence or supernumerary teeth. Early diagnosis of the condition and a multidisciplinary approach for management of such case is recommended.

Association between Hypodontia and Angle’s Malocclusions among Orthodontic Patients in Kathmandu, Nepal

Background. Disturbances during the early tooth development stages may result in the congenital absence of teeth. The purpose of this study was to assess the relationship between hypodontia and Angle’s malocclusions. Materials and Methods. The sample comprised 601 orthodontic patients’ pretreatment records (242 men and 259 women), selected from the achieved orthodontic records. Developmental anomalies of teeth affecting the number were examined on dental panoramic radiographs. Based on Angle’s classification, pretreatment dental casts were assessed and classified into different classes of malocclusion. The relationship between hypodontia and different classes of malocclusion was evaluated using the chi-square test. Results. The prevalence of tooth agenesis was 7.48%, that is, 45 out of 601 samples. There were a total of 72 (0.42%) missing teeth, excluding the third molars. The most frequent missing tooth was the maxillary lateral incisor (35, 48.61%), followed by the mandibular lateral incisor (14, 19.44%), the mandibular central incisor (6, 8.33%), the mandibular second premolar (5, 6.294%), and the maxillary second premolar (4, 5.55%). Hypodontia was more common in the upper jaw. Although hypodontia was mostly seen in Class I malocclusion patients (7.87%), followed by Class II malocclusion patients (6.99%) and least in Class III malocclusion patients. However, there was no significant difference in hypodontia among different classes of malocclusions (p = 0.352). Conclusion. The most frequently missing tooth was the maxillary lateral incisor, followed by lateral and central mandibular incisors and mandibular second premolars, while excluding the third molars. The present study did not find any association between various types of malocclusions and hypodontia.

Prevalence of Orthodontic Malocclusions in Healthy Children and Adolescents: A Systematic Review

The purpose of this study was to systematically review the literature regarding the prevalence of malocclusion and different orthodontic features in children and adolescents. Methods: The digital databases PubMed, Cochrane, Embase, Open Grey, and Web of Science were searched from inception to November 2021. Epidemiological studies, randomized controlled trials, clinical trials, and comparative studies involving subjects ≤ 18 years old and focusing on the prevalence of malocclusion and different orthodontic features were selected. Articles written in English, Dutch, French, German, Spanish, and Portuguese were included. Three authors independently assessed the eligibility, extracted the data from, and ascertained the quality of the studies. Since all of the included articles were non-randomized, the MINORS tool was used to score the risk of bias. Results: The initial electronic database search identified a total of 6775 articles. After the removal of duplicates, 4646 articles were screened using the title and abstract. A total of 415 full-text articles were assessed, and 123 articles were finally included for qualitative analysis. The range of prevalence of Angle Class I, Class II, and Class III malocclusion was very large, with a mean prevalence of 51.9% (SD 20.7), 23.8% (SD 14.6), and 6.5% (SD 6.5), respectively. As for the prevalence of overjet, reversed overjet, overbite, and open bite, no means were calculated due to the large variation in the definitions, measurements, methodologies, and cut-off points among the studies. The prevalence of anterior crossbite, posterior crossbite, and crossbite with functional shift were 7.8% (SD 6.5), 9.0% (SD 7.34), and 12.2% (SD 7.8), respectively. The prevalence of hypodontia and hyperdontia were reported to be 6.8% (SD 4.2) and 1.8% (SD 1.3), respectively. For impacted teeth, ectopic eruption, and transposition, means of 4.9% (SD 3.7), 5.4% (SD 3.8), and 0.5% (SD 0.5) were found, respectively. Conclusions: There is an urgent need to clearly define orthodontic features and malocclusion traits as well as to reach consensus on the protocols used to quantify them. The large variety in methodological approaches found in the literature makes the data regarding prevalence of malocclusion unreliable.

Correction of an adult Class III malocclusion through regaining of orthodontic space and an implant restoration

This case report describes the interdisciplinary treatment of a 23-year-old female with Class III malocclusion and a missing maxillary left second premolar. Treatment alternatives were discussed, and the selected treatment plan was presented to illustrate a way to gain space for the premolar implant restoration and correct Class III relationship through maxillary molar retraction followed by maxillary total arch protraction with a palatal temporary skeletal anchorage device. Esthetic anterior alignment and functional occlusal rehabilitation was achieved, and facial balance was maintained at the end of treatment. CLINICAL SIGNIFICANCE: Implant restoration in conjunction with regaining orthodontic space by a team of multidisciplinary dental specialists presents an effective treatment solution to permanent tooth agenesis. Class III malocclusion can be treated with a combination of maxillary protraction and mandibular retraction using temporary skeletal anchorage devices. The versatility of modified palatal C-plates presents greater clinical application when related side effects are controlled with solid understanding of their biomechanics.

Alveolar bone changes after molar protraction in young adults with missing mandibular second premolars or first molars

OBJECTIVES

To assess the changes in alveolar bone of the mandibular second molars following molar protraction and investigate the factors associated with the alveolar bone changes.

MATERIALS AND METHODS

Cone-beam computed tomography of 29 patients (mean age 22.0 ± 4.2 years) who had missing mandibular premolars or first molars and underwent molar protraction were reviewed. Alveolar bone level was measured as the distance from the cementoenamel junction at six points, buccal, lingual, mesiobuccal (MB), mesiolingual (ML), distobuccal (DB), and distolingual (DL), of the second molars at pretreatment (T0) and after molar protraction (T1). Factors associated with alveolar bone changes at the distal and mesial of the second molars were assessed.

RESULTS

Mean alveolar bone changes ranged from -1.2 mm (bone apposition) to 0.8 mm (bone resorption). The presence of a third molar impaction at T0 (P < .001), third molar angulation at T0 (P < .001), and Nolla's stage of third molar at T0 (P = .005) were significantly associated with alveolar bone level changes distal to the second molars. Treatment duration (P = .028) was significantly associated with alveolar bone level changes mesial to the second molar.

CONCLUSIONS

Patients with impacted third molars, third molars at an earlier stage of development, and mesially angulated third molars at pretreatment may have less alveolar bone resorption distal to the second molars following protraction. Patients with increased treatment time may have reduced alveolar bone resorption mesial to the second molars.

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.

Maxillofacial morphological characteristics in growing orthodontic patients with non-syndromic oligodontia

OBJECTIVE

Patients with oligodontia frequently show different types of malocclusions. However, how oligodontia affects the maxillofacial growth remains uncertain. This study aimed to investigate the maxillofacial morphological characteristics in growing patients with oligodontia.

SETTING AND SAMPLE POPULATION

The study subjects included 33 Japanese children with non-syndromic oligodontia (14 boys and 19 girls; mean age: 10.2 years) who visited the orthodontic clinic of Fukuoka Dental College Medical and Dental Hospital from 1999 to 2019.

MATERIALS AND METHODS

Cephalometric analyses were performed, and the variables measured in each subject were converted into Z scores in relation to the mean and standard deviation of the Japanese norms matched for growth stage. The one-sample t-test or Wilcoxon signed-rank test was performed to compare the mean scores in the patients with oligodontia with those of the Japanese norms.

RESULTS

Compared with the Japanese norms, patients with oligodontia showed a smaller convexity and larger A-B plane and SNB angles. The Frankfort-mandibular plane and gonial angles were smaller, whereas the height of the ramus was larger. The vertical height of the alveolar bone in the maxillary and mandibular incisors and molar areas was smaller in patients with oligodontia.

CONCLUSIONS

Patients with oligodontia showed Class III skeletal tendency with mandibular prognathism and flattened mandibular plane with a smaller gonial angle. These maxillofacial morphological features can be induced by a deficiency in the vertical growth of the alveolar bone in the maxillary and mandibular molar areas due to the lack of tooth germs.

Effect of Tooth Agenesis on Mandibular Morphology and Position

Congenital missing teeth (OMIM #106600) is the most common dental abnormality. The aim of the study was to evaluate the effects of tooth agenesis on the total mandibular length, length of the mandibular body and alveolar process, and the mandibular anteroposterior position. The material was obtained from the Department of Orthodontics, Medical University of Warsaw. The study group included 116 patients aged 9–18 years with a congenital absence of at least two permanent tooth buds in the maxilla and/or mandible (mean: 6.2 teeth missing/patient). All patients were Caucasians: 68 (59%) females and 48 (41%) males. The control group included 115 patients without tooth agenesis matched with the age and gender of the study group. A cephalometric analysis was performed, and it was focused on assessing anteroposterior mandibular measurements. This assessment was based on 17 measurements (12 linear and 5 angular). Statistical analysis of the cephalometric measurements between the study group and the control group showed significant changes regarding selected mandibular measurements. Tooth agenesis does not affect the total length of the mandible and the length of the mandibular body, but it might reduce the length of the mandibular arch length and result in a more retrusive mandibular position.

Radiographic evaluation of non-syndromic third molar agenesis in two Mediterranean populations

Background and aims

Third molar agenesis is a common finding across the world. Many studies have assessed third molar agenesis in different ethnicities and populations. However, there are no such studies in the Italian and Lebanese populations. Our study aims to evaluate the prevalence of third molar agenesis and study the pattern and distribution of agenesis in between genders in Italian and Lebanese Mediterranean populations and compare these findings with other global and Mediterranean populations' studies.

Methods

Retrospective chart review was conducted based on the history and orthopantomograms of adolescents aged 12 to 21 years to assess the agenesis of third molars in a sample of Italian and Lebanese populations by two experienced dental surgeons twice within 1 month. Descriptive and comparative tests were used to analyze the patterns of ageneses and make comparisons between the two samples.

Results

23.4% of the studied sample had at least one third molar agenesis; females were more likely to have two or more third molar agenesis than males, but neither sex predisposition for single third-molar agenesis was recorded. Both the Italian and Lebanese subgroups seemed to have similar results. The maxillary right third molar was the most common third molar to be absent. Two or more ageneses were more common than one third molar agenesis.

Conclusion

Our Mediterranean population results fall within the range reported in the literature and corroborate with the global average prevalence.

Sella Turcica Morphology on Cephalometric Radiographs and Dental Abnormalities-Is There Any Association?-Systematic Review

BACKGROUND

The sella turcica is a saddle-like structure in the middle cranial fossa on the intracranial surface of the sphenoid bone, visible on lateral cephalograms routinely conducted for orthodontic diagnosis. The development of facial structures follows similar traits to the sella turcica: glandular anomalies may be associated with functional disorders, e.g., altered hormonal levels, thus influencing dental development. The aim of this study is to find out if there is any association between the morphology of the sella turcica on cephalometric radiographs and the presence of dental abnormalities. (2) Methods: The search was conducted on 27 January 2021 in four search engines: Medline (PubMed Central), Scopus, Web of Science, Embase. The keywords used in the search strategy were as follows: "sella turcica" AND ("dental abnormalities" OR "dental anomalies" OR "malocclusion"). Since all the studies finally included were retrospective case-control studies, the Newcastle-Ottawa Quality Assessment Form for Case-Control Studies was applied. (3) Results: The search strategy identified 465 articles: 289 from PubMed, 121 from Scopus, 32 from Web of Science and 23 from Embase. Finally, 10 full-text papers were included into qualitative analysis. (4) Conclusions: Sella turcica bridging is very frequent among orthodontic patients. A clear association exists between dental abnormalities and sella turcica bridging.

Prevalence of hyperdontia, hypodontia, and concomitant hypo-hyperdontia

Background/purpose

Anomalies in human dentition are some of the most common occurrences of congenital abnormalities. Present study aimed to determine the prevalence of hypodontia, hyperdontia and concomitant hypo-hyperdontia (CHH) among patients attending the University of Nevada, Las Vegas (UNLV) School of Dental Medicine clinics.

Materials and methods

Retrospective search was conducted on patients’ clinical notes in AxiUm™. Search included using keywords such as “hypodontia”, “hyperdontia”, “supernumerary teeth” and “congenitally missing”. Panoramic radiographs were used to confirm the hyperdontia, hypodontia or CHH for patients attending the UNLV SDM clinics from 2010 to 2018. Collected data were analyzed using the chi-square test.

Results

1101 patients were populated using the keywords. From these populated patients, 186 had hyperdontia, 23 hypodontia, and 3 presented with CHH. The distribution of males and females was 54.7% and 45.3% respectively. Hispanics, African Americans, Asians, Caucasians and ethnically unspecified patients represented 43.39%, 14.25%, 3.30%, 8.02%, and 31.13%, respectively, of those patients with a dental anomaly. Hyperdontia was most common amongst Hispanic patients with 39.24%, followed by the unspecified patients at 32.8% as well as amongst males at 56.45% (P value of 0.03). Unidentifiable supplemental teeth were overall the greatest in number with the lower right premolars, tooth 44, being the most common. This was demonstrated in the Hispanic patients whereas within the African American patients a 4th molar was in excess.

Conclusion

Hispanic patient population has a significant link to dental anomalies, specifically hyperdontia while the presence of the fourth molar was prominent among African American patients.

Oral Rehabilitation of Hypodontia Patients Using an Endosseous Dental Implant: Functional and Aesthetic Results

Hypodontia often leads to limited bone availability of the alveolar ridges. Oral rehabilitation of severe hypodontia patients is challenging. In this retrospective study, we evaluated the functional and aesthetic results after dental implants in hypodontia patients, corroborated by Albrektsson implant success criteria. Over a period of 15 years (2000–2015), a total of 43 patients were diagnosed with hypodontia and 165 dental implants were inserted. Six patients who received 10 implants were lost in the follow-up. We examined 155 implants in 37 patients between December 2015 and May 2017. Besides family history, patients evaluated the general satisfaction, functionality, and aesthetics of the implants. Study subjects were between 17 and 44 years old (mean ± SD: 21.4 ± 5.6). Hypodontia patients were missing one to five teeth (n = 28), whereas patients diagnosed with oligodontia (≥6 missing teeth, n = 9). In this study, 24 patients (64.9%) with hypodontia had a positive family history; the remaining 13 patients had no family member with hypodontia. The final follow-up time ranged between 5 and 189 months after implant placement. Orthodontic treatment was performed in 32 patients (86%) before implant placement. Rehabilitation resulted in 62% of the cases being treated with 1–2 implants and 38% treated with 3–15 implants. However, out of 155 inserted dental implants, 18 implants failed to meet Albrektsson criteria, under which two implants were removed. Only autografts were used for bone augmentation with 97 implants. More than two-thirds of the patients showed high general satisfaction and masticatory function (69.4%) as well as phonetic ability (80.6%). The aesthetic outcome was rated as excellent by 17 patients (47.2%). The findings emphasize the importance of interdisciplinary treatment of hypodontia, leading to a satisfactory, functional, and long-term fixed prosthodontics using dental implants.

A systematic review of relative indications and contra-indications for prescribing panoramic radiographs in dental paediatric patients

PURPOSE

To systematically review the evidence of the diagnostic efficacy of panoramic radiographs (PRs) in the following six clinical situations: caries, acute dental infections, dental trauma, dental anomalies, Developmental disorders and pathological conditions in children. The research question posed by the EAPD was: "In which clinical situations and age groups is it indicated/contra-indicated to prescribe PRs in relation to these six clinical situations, in children".

METHODS

An electronic search of the following databases was conducted: MEDLINE via OVID, EMBASE via OVID, The Cochrane Oral Health Group's Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL), The Cochrane Database of Systematic Reviews (CDSR), the Database of Abstracts of Reviews of Effects (DARE) and the Cochrane Health Technology Assessment (HTA), to identify relevant studies published from 1990 to 2018. The systematic review was performed according to the PRISMA guidelines. Study screening, data extraction and risk of bias assessment of included studies was carried out independently and in duplicate using the QUADAS 2 tool.

RESULTS

The search resulted in 3420 potentially relevant studies, and following screening 175 full texts were obtained, of which 16 were finally included in the review. Meta-analysis was not possible for any of the aforementioned clinical situations, therefore the included studies were tabulated in terms of qualitative descriptive hierarchy of evidence for diagnostic.

CONCLUSION

Based on currently available evidence there is a need for high quality diagnostic accuracy efficacy studies to address important diagnostic tasks in these six clinical situations in children, as there is a lack of scientific evidence concerning PRs in children, as there would support the production of guidelines for prescribing PRs in children along with their relative indications and contra-indications.

A novel mutation of MSX1 inherited from maternal mosaicism causes a severely affected child with nonsyndromic oligodontia

Mutations of MSX1 have been associated with nonsyndromic hypodontia. To seek the causal gene mutation sites in a family with nonsyndromic oligodontia, whole-exome sequencing (WES) was performed to seek the causative locus of the family. The candidate mutation was further identified by Sanger sequencing afterward. Two mutations of MSX1 were found both in the proband and her mother. One novel heterozygous missense mutation (c.C667G, p.R223G) of MSX1 inherited from the asymptomatic mother with mosaic mutation was located in the highly conserved fragment of exon 2. The other was a synonymous mutation (c.C348T, p.G116G) in exon 1, which had been reported. The novel maternal heterozygous missense mutation (c.C667G, p.R223G) was likely to be the major reason for nonsyndromic oligodontia in the family. This is the first mosaic variant that has been recorded of the MSX1 gene. Our study expands the phenotype-genotype correlation associated with MSX1 variants. Our study also suggests that the determination of the mosaicism is essential for precise genetic counseling if a disease appears to arise de novo.

Evaluation of Implant Success in Patients with Dental Aplasia

Introduction

Dental aplasia is an anomaly in which the number of teeth is reduced. It is the most commonly occurring dental anomaly during tooth development. Treatment management of patients with dental aplasia is challenging.

Objectives

The aim of this retrospective clinical study was to analyze the survival and success rates of dental implants placed in hypodontic patients, rated with different criteria.

Methods

Forty-three patients were diagnosed with dental aplasia and treated with dental implants between November 2000 and February 2016. The variables assessed included the plaque level, bleeding on probing, probing depth, implant mobility, implant stability, and implant loss. To analyze the peri-implant bone level, a panoramic X-ray of each patient was taken. The results were compared with X-rays taken immediately after implantation.

Results

Thirty-seven patients (16 males; 21 females) participated in this study. In total, 155 implants (86 maxillary; 69 mandibular) were inserted. Two of the 155 implants failed; the in situ survival rate was 98.7%. The success rate according to the criteria of Buser et al. was 96.8%, and that according to the criteria of Albrektsson et al. was 88.4%.

Conclusion

The survival and success rates of dental implants in patients with congenitally absent teeth were very high and did not differ significantly from results achieved in an unaffected population. Dental implants are a reliable therapy for patients with dental aplasia.

Examination of craniofacial morphology in Japanese patients with congenitally missing teeth: a cross-sectional study

Background

The purpose of this cross-sectional study was to investigate the effects of congenitally missing teeth on craniofacial morphology and to characterize the features of maxillofacial morphology of oligodontia patients associated with individual skeletal maturity by assessment with the cervical vertebrae maturation (CVM) method.

Methods

A total of 106 non-syndromic Japanese patients with congenitally missing teeth (except for third molars) were selected and categorized into two groups according to the severity of congenitally missing teeth (hypodontia group, 1–5 missing teeth [n = 56]; oligodontia group, ≥ 6 missing teeth [n = 50]). A control group included orthodontic patients without either skeletal disharmony or congenitally missing teeth (n = 63). Subjects in oligodontia and control groups were further categorized into two subgroups on the basis of cervical stage (CS): stage I (CS2 or 3; n = 27 and n = 31, respectively) and stage II (CS4 or above; n = 23 and n = 32, respectively). Lateral cephalograms were analyzed by using eight angular and eight linear measurements. Z-scores were formulated on the basis of age and sex and were matched to the Japanese norm. Tukey tests and t tests were performed.

Results

Compared with the control group, the hypodontia group had significantly smaller U1 to FH plane angle and A-B plane angle; U1-L1 was significantly larger. The oligodontia group had significantly smaller ANS-Me, L1 to mandibular plane angle, and Ptm-A; U1-L1 was significantly larger. At stage I, the oligodontia group had significantly smaller ANS-Me, gonial angle, and ANS-U1. At stage II, the oligodontia group had significantly smaller U1 to FH plane angle, L1 to mandibular plane angle, Ptm-A, and Go-Pog; it also had significantly larger U1-L1.

Conclusions

The present study suggested that skeletal patterns differ along with the number of congenitally missing teeth and that, in oligodontia patients, skeletal patterns differ before and after growth peak. It is important to consider the skeletal characteristics of tooth agenesis patients when designing a treatment plan.