"Examining the link between tooth agenesis and papillary thyroid cancer: is there a risk factor?" Observational study.

BACKGROUND: Mutations in one or multiple genes can lead to hypodontia and its characteristic features. Numerous studies have shown a strong genetic influence on the occurrence of hypodontia, and identified several genes, including AXIN2, EDA, FGF3, FGFR2, FGFR10, WNT10A, MSX1, and PAX9, that are directly associated with dental agenesis and carcinogenesis. The objective of this study was to investigate the occurrence and pattern of tooth agenesis, microdontia, and palatally displaced canine (PDC) in women diagnosed with papillary thyroid cancer (PTC), compared to a control group of women without any malignancy or thyroid disease. MATERIALS AND METHODS: This case-control study was carried at the Department of Orthodontics, School of Dental Medicine University of Zagreb, and Department of Oncology and Nuclear Medicine Sestre Milosrdnice University Hospital Centre. The study involved a clinical examination and evaluation of dental status, panoramic X-ray analysis, and assessment of medical and family history of 116 female patients aged 20-40 with PTC, as well as 424 females in the control group who were of similar age. RESULTS: The prevalence of hypodontia, microdontia, and PDC was statistically higher in women with PTC than in the control group. The prevalence rate of hypodontia was 11.3% in the experimental group and 3.5% in the control group. The experimental group showed a higher occurrence of missing upper lateral incisors, lower left central incisors, and all the third molars (except the upper left) compared to the control group. Women with PTC showed the prevalence of PDC significantly higher than the control group (3.5%, 0.7%, p = 0.002). The probability of hypodontia as a clinical finding increases 2.6 times, and microdontia occurs 7.7 times more frequently in women with PTC. CONCLUSION: Our study suggests a possible link between odontogenesis and PTC. The absence of permanent teeth may increase the likelihood of PTC in women. Leveraging the age-7 orthopantomogram to identify women at high risk for PTC within a critical early detection window could significantly improve oral health outcomes and PTC prognosis through proactive interventions.

Clinical analysis of nonsyndromic oligodontia phenotypes.

OBJECTIVES: To provide references, this study investigated the clinical characteristics of patients with nonsyndromic oligodontia. METHODS: The information of 178 patients with oligodontia was collected, including histories, oral examinations, and panoramic radiographs. Tooth agenesis characteristics were calculated and evaluated. All the data were statistically analyzed with SPSS 24.0 software. RESULTS: No significant difference in the number of missing teeth was found between sexes nor between the right and left sides, and congenitally missing teeth affected the maxillary arch (P<0.05). The highest prevalence of tooth agenesis was observed in the mandibular second premolars. In the maxillary arch, the most common pattern of tooth agenesis was agenesis of the bilateral first and second premolars. The agenesis of the bilateral second premolars was observed in the mandibular arch. The prevalence of a symmetric pattern between the right and left quadrants was significantly higher than that of matched patterns between the maxillary and mandibular antagonistic quadrants. Approximately 16.85% of patients with nonsyndromic oligodontia were affected by other tooth-related anomalies. CONCLUSIONS: The common patterns of tooth agenesis were successfully identified in patients with nonsyndromic oligodontia. Dentists need to provide multidisciplinary treatments for patients with nonsyndromic oligodontia because of variations in occluding and full-mouth tooth agenesis patterns.

Prenatal onset GAPO syndrome with a novel ANTXR1 variant in an Indian child: Expansion of the phenotype & literature review.

GAPO syndrome is a rare genetic condition caused by bi-allelic variants in ANTXR1 gene & is an abbreviation for its core features - growth retardation, alopecia, pseudo-anodontia & optic atrophy. Certain additional features involving various other systems have been reported over the years & contribute to the expanding spectrum of this evolving phenotype. We report GAPO syndrome in a 3.75 year old Indian female child, who presented with some unique features such as sagittal craniosynostosis with scaphocephaly & bilateral choroid plexus cysts, alongside the core phenotype. We also report a novel frameshift variant in our patient & offer first evidence for the prenatal onset of some features.

Compound heterozygous WNT10A missense variations exacerbated the tooth agenesis caused by hypohidrotic ectodermal dysplasia.

BACKGROUND: The aim of this study was to analyse the differences in the phenotypes of missing teeth between a pair of brothers with hypohidrotic ectodermal dysplasia (HED) and to investigate the underlying mechanism by comparing the mutated gene loci between the brothers with whole-exome sequencing. METHODS: The clinical data of the patients and their mother were collected, and genomic DNA was extracted from peripheral blood samples. By Whole-exome sequencing filtered for a minor allele frequency (MAF) ≤0.05 non-synonymous single-nucleotide variations and insertions/deletions variations in genes previously associated with tooth agenesis, and variations considered as potentially pathogenic were assessed by SIFT, Polyphen-2, CADD and ACMG. Sanger sequencing was performed to detect gene variations. The secondary and tertiary structures of the mutated proteins were predicted by PsiPred 4.0 and AlphaFold 2. RESULTS: Both brothers were clinically diagnosed with HED, but the younger brother had more teeth than the elder brother. An EDA variation (c.878 T > G) was identified in both brothers. Additionally, compound heterozygous variations of WNT10A (c.511C > T and c.637G > A) were identified in the elder brother. Digenic variations in EDA (c.878 T > G) and WNT10A (c.511C > T and c.637G > A) in the same patient have not been reported previously. The secondary structure of the variant WNT10A protein showed changes in the number and position of α-helices and ß-folds compared to the wild-type protein. The tertiary structure of the WNT10A variant and molecular simulation docking showed that the site and direction where WNT10A binds to FZD5 was changed. CONCLUSIONS: Compound heterozygous WNT10A missense variations may exacerbate the number of missing teeth in HED caused by EDA variation.

Absent meibomian glands and cone dystrophy in ADULT syndrome: identification by whole exome sequencing of pathogenic variants in two causal genes TP63 and CNGB3.

BACKGROUND: Ectrodactyly is a rare congenital limb malformation characterized by a deep median cleft of the hand and/or foot due to the absence of central rays. It could be isolated or depicts a part of diverse syndromic forms. Heterozygous pathogenic variants in the TP63 gene are responsible for at least four rare syndromic human disorders associated with ectrodactyly. Among them, ADULT (Acro-Dermato-Ungual-Lacrimal-Tooth) syndrome is characterized by ectodermal dysplasia, excessive freckling, nail dysplasia, and lacrimal duct obstruction, in addition to ectrodactyly and/or syndactyly. Ophthalmic findings are very common in TP63-related disorders, consisting mainly of lacrimal duct hypoplasia. Absent meibomian glands have also been well documented in EEC3 (Ectrodactyly Ectodermal dysplasia Cleft lip/palate) syndrome but not in ADULT syndrome. METHODS: We report a case of syndromic ectrodactyly consistent with ADULT syndrome, with an additional ophthalmic manifestation of agenesis of meibomian glands. The proband, as well as her elder sister, presented with congenital cone dystrophy.The molecular investigation was performed in the proband using Whole Exome Sequencing. Family segregation of the identified variants was confirmed by Sanger sequencing. RESULTS: Two clinically relevant variants were found in the proband: the novel de novo heterozygous missense c.931A > G (p.Ser311Gly) in the TP63 gene classified as pathogenic, and the homozygous nonsense pathogenic c.1810C > T (p.Arg604Ter) in the CNGB3 gene. The same homozygous CNGB3 variation was also found in the sister, explaining the cone dystrophy in both cases. CONCLUSIONS: Whole Exome Sequencing allowed dual molecular diagnoses: de novo TP63-related syndromic ectrodactyly and familial CNGB3-related congenital cone dystrophy.

Characterization of novel MSX1 variants causally associated with non-syndromic oligodontia in Chinese families.

BACKGROUND: MSX1 (OMIM #142983) is crucial to normal dental development, and variants in MSX1 are associated with dental anomalies. The objective of this study was to characterize the pathogenicity of novel MSX1 variants in Chinese families with non-syndromic oligodontia (NSO). METHODS: Genomic DNA was extracted from individuals representing 35 families with non-syndromic oligodontia and was analyzed by Sanger sequencing and whole-exome sequencing. Pathogenic variants were screened via analyses involving PolyPhen-2, Sorting-Intolerant from Tolerant, and MutationTaster, and conservative analysis of variants. Patterns of MSX1-related NSO were analyzed. MSX1 structural changes suggested functional consequences in vitro. RESULTS: Three previously unreported MSX1 heterozygous variants were identified: one insertion variant (c.576_577insTAG; p.Gln193*) and two missense variants (c. 871T>C; p.Tyr291His and c. 644A>C; p.Gln215Pro). Immunofluorescence analysis revealed abnormal subcellular localization of the p.Gln193* MSX1 variant. In addition, we found that these MSX1 variants likely lead to the loss of second premolars. CONCLUSION: Three novel MSX1 variants were identified in Chinese Han families with NSO, expanding the MSX1 variant spectrum and presenting a genetic origin for the pathogenesis detected in patients and their families.

Shaken adult syndrome due to ocean wave: an autopsy case.

Severe intracranial trauma during torture or assault is reportedly caused by shaken adult syndrome. However, intracranial traumas caused by natural forces, excluding human factors and collision impact, are extremely rare. We report an autopsy case of shaken adult syndrome caused by ocean wave forces. A man in his 40s without any medical history was washed away by a wave during recreational fishing. He was found approximately 500 m away from the fishing point drifting on the ocean in a state of cardiopulmonary arrest and was confirmed dead, with no response to cardiopulmonary resuscitation, 3 h after the accident. The autopsy revealed no mechanical trauma to the entire body surface, including the head. Both lungs were inflated, and pleural effusion was observed. The brain was swollen and congested, and subarachnoid hemorrhage was observed in the interhemispheric fissure and the convexity of the parietal occipital lobe. Macroscopic and microscopic hemorrhage spots were found in the brain, and the results of the blood alcohol test and urinary toxicological screening were negative. The cause of death was determined as drowning. This case demonstrates a rare but notable mechanism of injury observed in immersed bodies.

Associations across 22 dental and craniovertebral anomalies or variations, sagittal skeletal relationships, and vertical growth patterns: a comprehensive epidemiological study of 43 dentoskeletal traits.

INTRODUCTION: Despite researchers' recent interest in identifying links between some dental and craniovertebral abnormalities, there are many important, unassessed gaps in our knowledge of this matter. In addition, previous samples were small. This large study aimed to examine, for the first time, the occurrence/severity of numerous dental and skeletal anomalies or variations and their correlations with each other and with growth patterns. METHODS: This epidemiological study was conducted on pretreatment radiographs of 1194 patients from 3 cities (815 females). Skeletal sagittal skeletal relationships and vertical growth patterns were determined. The occurrence/severity were assessed for: cervical vertebral fusion (CVF), atlas posterior arch deficiency (APAD), ponticulus posticus (PP), sella turcica bridging (STB), hypodontia, oligodontia, hyperdontia, missing of maxillary laterals, microdontia, macrodontia, root dilaceration, odontoma, taurodontism, dental fusion, dental gemination, enamel pearl, permanent molar ankylosis, primary molar ankylosis, dens in dente, dens invaginatus, dental impaction, ectopic eruption, and dental transposition. Incidental findings were recorded as well. Concurrent anomalies, sex dimorphism, and correlations across variables were examined statistically, adjusting for the false discovery rate (α = 0.05). RESULTS: Prevalence was calculated for 43 dentoskeletal traits/anomalies (22 abnormalities/variations [plus their severities/types] as well as 21 incidentally found traits/anomalies). Dental impaction may be more common in hyperdivergent and severer cases of sella bridging; also, primary molar ankylosis was associated with missing teeth. Dental impaction was associated only with STB and not with PP, APAD, or vertebral fusion. The only association observed among the four skeletal anomalies was seen between APAD and CVF. Merely the variables 'sagittal skeletal relationships, vertical growth patterns, PP, and APAD' showed sexual dimorphism; of these, only vertical growth pattern and APAD remained sexually dimorphic after adjusting for the FDR; still, the other two remained marginally significant and worth further evaluations. Sex dimorphism did not exist in concurrent abnormalities. The skeletal Class III was associated with the concurrent occurrence of craniovertebral, dental, and dentoskeletal abnormalities. Skeletal Class I was associated with fewer occurrences of concurrent dental anomalies. Vertical growth patterns were not associated with concurrent dental or dentoskeletal anomalies. However, the hyperdivergent pattern was associated with fewer cases of concurrent craniovertebral abnormalities. CONCLUSIONS: STB and hyperdivergent pattern were associated with dental impaction. However, APAD, CVF, or PP were not associated with dental impaction. APAD was associated with CVF. Sexual dimorphism existed conclusively in the case of vertical growth patterns and APAD. Concurrent abnormalities (dental, skeletal, and dentoskeletal) were associated with skeletal Class III.

Count Me in, Count Me out: Regulation of the Tooth Number via Three Directional Developmental Patterns.

Tooth number anomalies, including hyperdontia and hypodontia, are common congenital dental problems in the dental clinic. The precise number of teeth in a dentition is essential for proper speech, mastication, and aesthetics. Teeth are ectodermal organs that develop from the interaction of a thickened epithelium (dental placode) with the neural-crest-derived ectomesenchyme. There is extensive histological, molecular, and genetic evidence regarding how the tooth number is regulated in this serial process, but there is currently no universal classification for tooth number abnormalities. In this review, we propose a novel regulatory network for the tooth number based on the inherent dentition formation process. This network includes three intuitive directions: the development of a single tooth, the formation of a single dentition with elongation of the continual lamina, and tooth replacement with the development of the successional lamina. This article summarizes recent reports on early tooth development and provides an analytical framework to classify future relevant experiments.

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.

A service evaluation of the multidisciplinary team approach to hypodontia.

Introduction Patients with hypodontia can be seen by a multidisciplinary team clinic (MDT) for treatment planning at the University Dental Hospital of Manchester (UDHM). The MDT consists of orthodontics, restorative dentistry and oral surgery colleagues.Aims and methods A retrospective case-note analysis was conducted on 558 hypodontia patients seen on Manchester Hypodontia Clinic (MHC) between 2016-2022 to assess service utilisation and treatment planning outcomes.Results The average age of patients attending the MHC was 16 (range 8-50). The distribution of mild, moderate and severe hypodontia in the sample was 28%, 37% and 35%, respectively. Most common treatments proposed were fixed appliances, extractions, implants and resin-bonded bridges. Out of 558 patients seen for consultation on the MHC, 365 (65%) were accepted for treatment. The average number of visits for treatment was 15.5 (range: 1-55). The average number of did not attend/was not brought appointments, patient cancellations and hospital cancellations were 0.8, 1.4 and 1.8, respectively.Conclusion Hypodontia patients referred to UDHM are triaged by consultants in orthodontics or restorative dentistry, and if MDT planning is required, they are booked onto the MHC. There are sufficient patients with complex cases of moderate and severe hypodontia to justify a regular MDT hypodontia clinic.

New observation of severe tooth malformation in a female patient with ectodermal dysplasia due to the EDA splice acceptor variant c.742-2A>G.

BACKGROUND: Ectodermal dysplasias are inherited disorders, which are characterized by congenital defects in two or more ectodermal structures such as skin, sweat glands, hair, nails, teeth, and mucous membranes. METHOD: Here, we describe a new observation of significant oligodontia in a female patient with the EDA gene variant c.742-2A>G. RESULTS: The results strongly suggest that the EDA gene variant c.742-2A>G is pathogenic. The oligodontia in the proband was exceptionally severe. CONCLUSION: We demonstrate that the very rare splice acceptor variant EDA c.742-2A>G is associated with severe oligodontia even in females. Our study points that this variant is pathogenic. An early identification of this variant is crucial for planning adequate treatment and follow-up in time by a multidisciplinary team.

Prevalence and association of dental anomalies and tooth decay in Italian childhood cancer survivors.

The aim of this cross-sectional study was to assess the prevalence and severity of dental anomalies according to age at cancer treatment and type of antineoplastic protocol using the Modified Dental Defect Index (MDDI) and to explore the association between MDDI scores and caries experience in Italian childhood cancer survivors (CCS). A total of 88 CCSs (age range 6-20 years) treated with chemotherapy and/or radiotherapy for malignant diseases and in remission from at least 2 years were consecutively recruited from March 2019 to July 2022. All participants were examined for dental caries and enamel defects in the permanent dentition according to the decayed-missing-filled teeth (DMFT) index and the Aine rating scale. Dental abnormalities were diagnosed using panoramic radiographs and graded for severity according to the MDDI. The MDDI values were categorized as normal (MDDI, 0), moderately abnormal (1 ≤ MDDI < 16), and severely abnormal (MDDI ≥16). None of the enrolled children had normal MDDI score. MDDI and DMFT values were higher in CCSs submitted to cancer treatment before 5 years of age, while no statistically significant association was found with anticancer protocols. A significant positive correlation emerged between DMFT and MDDI values (p < 0.001). CCSs with moderately abnormal disturbances had statistically significant lower DMFT scores (p < 0.001) than those with severe dental abnormalities. These findings suggest that children in remission from malignant diseases with MDDI values ≥16 have poorer dental health and should be strictly monitored by dental specialists.

An Improvised Approach For Regaining Mouth Opening And Managing Tooth Wear In Oral Sub-Mucous Fibrosis.

This case report demonstrates the full mouth prosthetic rehabilitation of a patient with generalised compensated tooth wear and oral sub-mucous fibrosis (OSMF). A 50- year-old female with advanced tooth wear and concomitant OSMF presented to the clinic. She was managed in a sequential manner using an occlusal splint, extractions of hopeless teeth, root canal treatment of strategically important teeth, surgical crown lengthening of abutment teeth, and dental implants to replace missing dentition, followed by crown and bridgework to rehabilitate the dentition. All procedures were done on the principles of re-organised occlusal intervention. The outcome was a functional dentition with an aesthetic smile and a satisfied patient. The regaining of mouth opening among OSMF subjects is a challenge. The usual management is prescribing muscle stretching exercises, drugs, or surgery. In the present case, we managed to achieve significant improvement in mouth opening with occlusal splints. The use of such occlusal orthotics has never been reported.

Rehabilitation with implant-supported overdentures in preteens patients with ectodermal dysplasia: A cohort study.

INTRODUCTION: Hypohidrotic ectodermal dysplasia (HED) patients suffering of oligo-anodontia require early dental treatment to improve oral functions and reduce social impairment. The aim of this study was to evaluate the skeletal growth, implant and prosthetic survival rate, success, and complications after the rehabilitation with a maxillary denture and an implant-supported overdenture provided by a sliding bar in case of severe hypodontia/anodontia related to HED. MATERIALS AND METHODS: This retrospective cohort study began in 2009. Nine patients over 7 years old with HED and associated oligo-anodontia who presented at the University of Bologna for dental treatment were included in the study. They were first treated with conventional dentures and then with a maxillary denture and an implant-supported overdenture with a sliding bar connected to two implants placed in the anterior mandible. The subjects treated were followed for 3-12 years. In each case, orthopanoramic and lateral cephalometric radiographic exam were taken before implant placement and annually after prosthetic load. Vertical and transverse dimensions of the mandible in the symphysis area at implant sites were taken on the lateral cephalometric radiography at the time of implant placement and after 5 years from the prosthetic loading to assess the presence or absence of an anterior mandibular growth. Biologic and mechanical complications were also recorded at every visit. RESULTS: A mandibular vertical growth under the implant apex, at the implant neck, and a sagittal growth of the symphysis after 5 years from the prosthetic loading were observed and measured. Implant and prosthetic success and survival rates were 100% after 8.1 years (mean) follow-up period. No complications were reported except in one patient, where the repositioning of a retentive cap on the counter bar in the superstructure was necessary after 3 years from the prosthetic loading. CONCLUSIONS: The present study suggests that the growth of the mandible near implant sites continues even after their positioning. Implants can be successfully placed and provide support for prosthetic rehabilitation in preteens patients with HED.

Autotransplante dentário: da previsibilidade à técnica cirúrgica e resultados do tratamento / Dental Autotransplantation: from predictability to surgical technique and treatment results

Objetivo: apresentar o relato de duas pacientes com agenesias dentárias em que cinco dentes autotransplantados foram utilizados como modalidade de tratamento. Além disso, objetiva-se mostrar questões sobre a técnica cirúrgica, suas indicações e previsibilidade. Relato de caso: Neste estudo, foram relatados 5 casos de autotransplante dentário em duas pacientes jovens, em que a equipe realizou os procedimentos e o acompanhamento clínico e radiográfico por 5 e 7 anos. Devido à alta sensibilidade da técnica, foram seguidos princípios previamente estabelecidos na literatura envolvendo o autotransplante dentário. Durante o período de acompanhamento, os dentes se mantiveram em posição e em função e as pacientes não apresentavam queixas associadas. Considerações finais: a técnica do autotransplante dentário, quando bem indicada e executada, é capaz de promover resultados bastante satisfatórios, sendo uma ótima alternativa reabilitadora, com taxas de sucesso elevadas e custos reduzidos. No entanto, critérios em relação aos sítios doadores e receptores e a habilidade do cirurgião devem ser levados em conta para o sucesso do técnica.

Objective: presenting the report of two patients with tooth agenesis in which five autotransplanted teeth were used as a treatment modality. Furthermore, the aim is to show questions about the surgical technique and its indications and predictability. Case report: In this study, 5 cases of dental autotransplantation were reported in two young patients, in which the team performed procedures and had clinical and radiographic follow-up for 5 and 7 years. Due to the high sensitivity of the technique, principles previously established in the literature involving dental autotransplantation were followed. During the follow-up period, the teeth remained in position and function and the patients had no associated complaints. Final considerations: the dental autotransplantation technique, when well indicated and executed, is capable of achieving very satisfactory results, being a great rehabilitative alternative, with high success rates and reduced costs. However, criteria regarding donor and receptor sites and the surgeon's skill must be taken into account for the success of the technique.

Phenotypic characteristics of taurodontism and a novel WNT10A variant in non-syndromic oligodontia family.

OBJECTIVE: Variants in wingless-type MMTV integration site family member 10A (WNT10A) have been proposed to be the most common cause of non-syndromic oligodontia (NSO). The goal of the present study was to identify the novel WNT10A variants in Chinese families with NSO. DESIGN: Clinical data were collected from 39 families with oligodontia admitted to the Hospital of Stomatology Hebei Medical University (China) from 2016 to 2022. Whole-exome sequencing (WES) and Sanger sequencing were performed to identify WNT10A variants in three families with non-syndromic oligodontia. Amino acid conservation analysis and protein conformational analysis were conducted for the WNT10A variant. Genotype-phenotype analysis was performed on the previously reported WNT10A variants related to NSO. RESULTS: We found a novel heterozygous WNT10A variant c.1127 G>A (p.Cys376Tyr) and two reported heterozygous variants c.460 C>A (p.Leu154Met) and c.511 C>T (p.Arg171Cys). Structural modeling showed that the novel WNT10A variant was located in a highly conserved domain, which led to structural damage of WNT10A protein. In addition, we found that the phenotype of the WNT10A variants affected the maxillary second premolars, followed by the mandibular second premolars, and rarely affected the maxillary central incisor. Herein, it is the first time to report that NSO patients with WNT10A monoallele mutation carry taurodontism phenotype and 6.1% prevalence of taurodontism in WNT10A-related NSO patients. CONCLUSIONS: Our results demonstrated that the novel variant c.1127 G>A (p.Cys376Tyr) of WNT10A causes NSO. The present study expanded the known variation spectrum of WNT10A and provided valuable information for genetic counseling of families.

A comparative retrospective study on the prevalence and therapeutic treatment of dental agenesis between healthy children and children with systemic disease or congenital malformation.

BACKGROUND: Dental agenesis (DA) in the permanent dentition is one of the most common dental anomalies, with a prevalence up to 2-10%. Therefore, the aim of this retrospective study was to investigate the prevalence and therapeutic treatment of DA in healthy children (HC) compared to children with systemic disease or congenital malformation (SD/CM). METHODS: Out of 3407 patients treated at the Department of Paediatric Dentistry of the Justus Liebig University Giessen (Germany) between January 2015 and December 2020, a total of 1067 patients (594 female, 473 male) aged between 4.5 and 18 years were included in this study due to DA. Besides the patients' general medical history and therapeutic treatments, panoramic radiographs were analysed. RESULTS: In contrast to the HC group with 9.7% DA, the SD/CM group showed a significantly higher prevalence of DA (19.8%; p < 0.05). The latter group was further classified into children with ectodermal dysplasia (4.4%), down syndrome (8.2%), cleft lip and palate (4.4%), intellectual disability/developmental delay (16.4%), and other genetic/organic diseases without intellectual disability (45.9%). Regarding therapeutic treatments, the HC group (59.5%) was significantly more often treated with an orthodontic gap opening compared to the SD/CM group (42.6%; p < 0.05), followed by orthodontic gap closing 36.5% in the HC group and 22.9% in the SD/CM group (p < 0.05), whereas no treatment was predominantly performed in the SD/CM group (37.7%) compared to the HC group (4%; p < 0.05). Furthermore, 50% in the SD/CM group required general anaesthesia for therapeutic treatment (vs. 8.1% in the HC group; p < 0.05). CONCLUSIONS: Children with SD/CM suffered more often from DA compared to HC that underlines multi- and interdisciplinary treatment of utmost importance. Furthermore, due to intellectual disability, common treatment methods can be complicated by insufficient compliance. This fact underlines the importance of an early attempt to establish the necessary cooperation enabling children with SD/CM to receive therapy.

Associations between missing teeth and the risk of cancer in Korea: a nationwide cohort study.

BACKGROUND: Poor dental health is correlated with an increased risk of cancer. Using a nationwide population cohort database, we investigated which cancer is highly associated with poor dental health and which dental indicator mostly influences cancer risk. METHODS: This study was conducted using the National Health Checkups (NHC) and National Health Insurance System (NHIS) database in Korea. NHC in Korea includes dental examinations. We retrieved subjects who underwent NHC between 2002 and 2003 and their medical information in NHIS database was followed until December 31,2015. RESULTS: Data for 200,170 who participated in the NHC between 2002 and 2003 were analysed. During the maximum follow-up period of 13 years, 15,506 (7.75%) subjects were diagnosed with cancer. The median time to cancer diagnosis after the dental examination was 87 months (range, 51-119 months). The proportion of people with missing teeth was higher in the cancer-diagnosed group than in the non-diagnosed group (26.27% vs. 22.59%, p < 0.001). Among several dental health factors, missing teeth were significantly associated with higher cancer risk. Subjects with missing teeth showed a 12% increased cancer risk compared to those without missing teeth (odds ratio [OR] 1.12, 95% confidence interval [CI], 1.08-1.16). The risk was significantly higher, especially in lung, head and neck, pancreatic, liver, biliary, and esophageal cancers (OR 1.27 [95% CI, 1.14-1.41], 1.32 [95% CI, 1.13-1.55], 1.27 [95% CI, 1.02-1.58], 1.24 [95% CI, 1.1-1.4], 1.28 [95% CI, 1.03-1.6], 1.4 [95% CI, 1.04-1.88], respectively). CONCLUSIONS: Missing teeth were the most important dental indicator associated with cancer risk. Korean adults with missing teeth should be cautious about the risk of several cancers, particularly head and neck, lung, gastrointestinal, hepatobiliary, and pancreatic cancer.

Analysis of congenital deciduous teeth absence and its permanent teeth phenotype.

OBJECTIVES: This study aimed to investigate the clinical characteristics of congenital deciduous teeth absence and its permanent teeth performance type by using panoramic radiographs. METHODS: A total of 15 749 panora-mic radiographs of 3-6-year-old children with deciduous dentition were collected from January 2020 to December 2021. The incidence of congenital deciduous teeth absence was observed, and the abnormality of permanent teeth was recor-ded. SPSS 24.0 software was used for statistical analysis. RESULTS: The incidence of congenital deciduous teeth absence was 2.54% (400/15 749), which was found in 217 girls and 183 boys, and the difference between the genders was statistically significant (P=0.003). The absence of one and two deciduous teeth accounted for 99.75% (399/400) of the subjects. In addition, 92.63% (490/529) of mandibular deciduous lateral incisor was congenitally absent, 44.80% (237/529) of deciduous teeth was absent in the left jaw, and less than 55.20% (292/529) was absent in the right; the difference between them was statistically significant (P=0.017). The absence of 96.41% (510/529) deciduous teeth in the mandibular was significantly more than that of 3.59% (19/529) in the maxillary, and the difference between was statistically significant (P=0.000). Furthermore, 68.00% (272/400) and 32.00% (128/400) of deciduous teeth were absent in unilateral and bilateral, respectively, and the difference was statistically significant (P=0.000). Four types of congenital deciduous teeth absence with permanent teeth were observed as follows: 1) 73.91% (391/529) of permanent teeth was absent; 2) 20.60% (109/529) of permanent teeth was not absent; 3) the number of fused permanent teeth accounted for 4.91% (26/529); 4) the number of supernumerary teeth was 0.57% (3/529). CONCLUSIONS: Although the absence of congenital deciduous teeth is less common than that of permanent teeth, it affects deciduous and permanent teeth to some extent. Dentists should pay attention to trace and observe whether abnormalities are present in the permanent teeth and take timely measures to maintain children's oral health.