OBJECTIVE: Coffin-Siris Syndrome (CSS) is a congenital disorder characterized by delayed growth, dysmorphic facial features, hypoplastic nails and phalanges of the fifth digit, and dental abnormalities. Tooth agenesis has been reported in CSS patients, but the mechanisms regulating this syndromic tooth agenesis remain largely unknown. This study aims to identify the pathogenic mutation of CSS presenting tooth genesis and explore potential regulatory mechanisms.
METHODS: We utilized whole-exome sequencing to identify variants in a CSS patient, followed by Sanger validation. In silico analysis including conservation analysis, pathogenicity predictions, and 3D structural assessments were carried out. Additionally, single-cell RNA sequencing and fluorescence in situ hybridization (FISH) were applied to explore the spatio-temporal expression of Sox4 expression during murine tooth development. Weighted Gene Co-expression Network Analysis (WGCNA) was employed to examine the functional role of SOX4.
RESULTS: A novel de novo SOX4 missense mutation (c.1255C > G, p.Leu419Val) was identified in a Chinese CSS patient exhibiting tooth agenesis. Single-cell RNA sequencing and FISH further verified high expression of Sox4 during murine tooth development, and WGCNA confirmed its central role in tooth development pathways. Enriched functions included cell-substrate junctions, focal adhesion, and RNA splicing.
CONCLUSIONS: Our findings link a novel SOX4 mutation to syndromic tooth agenesis in CSS. This is the first report of SOX4 missense mutation causing syndromic tooth agenesis.
CONCLUSIONS: This study not only enhances our understanding of the pathogenic mutation for syndromic tooth agenesis but also provides genetic diagnosis and potential therapeutic insights for syndromic tooth agenesis.

OBJECTIVE: 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.
目的: 应用曲面体层技术探讨少牙多牙症（CHH）的发生率和临床特征。方法: 收集2019年1月—2021年5月就诊的41 648例儿童口腔科患者的曲面体层片，纳入CHH患者145例，观察记录CHH的发生情况。应用SPSS 24.0软件统计分析所得的数据。结果: CHH的发生率为0.35%（145/41 648），男性（102例）多于女性（43例），性别间差异有统计学意义（P<0.001）。恒牙先天缺失特征：缺失1~2颗为主；最好发下颌侧切牙和下颌第二前磨牙；下颌恒牙先天缺失多于上颌恒牙先天缺失，二者差异有统计学意义（P<0.001）；左侧先天缺失与右侧先天缺失差异无统计学意义（P=0.84）。多生牙特征：数目1~2颗；多见于上颌前牙区；多为圆锥形；垂直倒置生长和垂直正位生长为主。结论: CHH是一种少见的混合牙齿数目异常，男性多于女性，恒牙先天缺失和多生牙的特征与单独发生的恒牙先天缺失/多生牙的特征相似，建议早期诊断和多学科治疗。.

本文报道1例以多数恒牙先天缺失、余留牙不齐为临床表现的患者的多学科联合诊疗过程。通过多学科联合诊疗确定前牙位置并进行美学设计，正畸治疗排齐牙列，调整修复间隙，并通过数字化设计预测种植位点，最终完成种植修复并获得良好的疗效。文内总结并探讨以正畸-种植修复为核心的多学科联合诊疗多数恒牙先天缺失患者过程中的诊疗要点。.

OBJECTIVE: 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.
目的: 研究和分析非综合征型多数恒牙先天缺失患者的牙齿缺失特征，为该类患者的临床诊断、治疗设计提供参考。方法: 收集178例非综合征型多数恒牙先天缺失病例，根据病史、口腔检查和曲面体层片等资料，研究分析牙齿缺失特征，应用SPSS 24.0统计软件对所得数据进行统计学分析。结果: 缺牙数目在性别、左右侧间无明显差异，上颌缺牙数明显高于下颌（P<0.05）。缺失率最高的牙位是下颌第二前磨牙。上颌最常见的缺牙模式为双侧上颌第一前磨牙、第二前磨牙联合缺失，下颌为双侧下颌第二前磨牙联合缺失。左右侧对称性分布的缺牙模式高于上下颌对称性分布。16.85%患者同时合并其他牙齿发育畸形。结论: 非综合征型多数恒牙先天缺失患者存在数种常见的缺牙模式，而咬合和全口缺牙模式变异较大，临床上应根据个体差异制定个性化的、多学科合作的治疗方案。.

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 β-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.

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.
CONCLUSIONS: 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.

Tooth agenesis is a common dental anomaly that can substantially affect both the ability to chew and the esthetic appearance of patients. This study aims to identify possible genetic factors that underlie various forms of tooth agenesis and to investigate the possible molecular mechanisms through which human dental pulp stem cells may play a role in this condition.
Using whole-exome sequencing of a Han Chinese family with non-syndromic tooth agenesis, a rare mutation in FGFR1 (NM_001174063.2: c.103G > A, p.Gly35Arg) was identified as causative and confirmed by Sanger sequencing. Via GeneMatcher, another family with a known variant (NM_001174063.2: c.1859G > A, p.Arg620Gln) was identified and diagnosed with tooth agenesis and a rare genetic disorder with considerable intrafamilial variability. Fgfr1 is enriched in the ectoderm during early embryonic development of mice and showed sustained low expression during normal embryonic development of Xenopus laevis frogs. Functional studies of the highly conserved missense variant c.103G > A showed deleterious effects. FGFR1 (c.103G > A) was overexpressed compared to wildtype and promoted proliferation while inhibiting apoptosis in HEK293 and human dental pulp stem cells. Moreover, the c.103G > A variant was found to suppress the epithelial-mesenchymal transition. The variant could downregulate ID4 expression and deactivate the TGF-beta signaling pathway by promoting the expression of SMAD6 and SMAD7.
Our research broadens the mutation spectrum associated with tooth agenesis and enhances understanding of the underlying disease mechanisms of this condition.

We aimed to investigate the association between oral health and cognitive function in a sample of older adults from a Chinese rural community.
The cross-sectional cognitive function of 677 individuals were assessed by Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA). A comprehensive profile of the oral health status was evaluated by questionnaire and clinical examination.
Multiple covariates-adjusted regression models demonstrated decayed teeth (DT) and decayed/missing/filled teeth (DMFT) were negatively associated with MoCA score (all p < 0.05). Calculus index (CI) and clinical attachment loss (CAL) were significantly associated with the lower MoCA, short-term memory and executive function score, respectively (all p < 0.05). Additionally, participants with missing teeth unrestored tend to get lower MMSE and MoCA scores (p < 0.05). The results also showed that increased DT and CI were modestly associated with higher odds of cognitive impairment (p < 0.05).
There is an association between oral health and global cognition. Poor periodontal status was strongly associated with worse global cognition performance, especially in the short-term memory and executive domain for the aging population.

Objective: To measure the crown conical degree of the remaining maxillary incisors in patients with congenital tooth agenesis, and to analyze the influence of different gene mutations on the crown conical degree of patients. Methods: Whole exome sequencing was performed on 85 patients with congenital tooth agenesis (50 males, 35 females, median age 19 years old) who visited the Department of Prosthodontics, Peking University School and Hospital of Stomatology from January 2019 to January 2023. The pathogenic gene was identified. The width of the crowns of the maxillary central and lateral incisors at the incisal 1/3 and gingival 1/3 were measured on the panoramic radiograph, and the ratio was defined as the crown conical degree. The smaller the ratio is, the more likely is the crown to be peg shaped teeth. The control group was matched by age and gender with 85 other patients with intact maxillary permanent incisors who were treated in the Department of Prosthodontics, Peking University School and Hospital of Stomatology from January 2019 to January 2023. The conical degree of the tooth agenesis group was compared with the control group by t-test, and the differences in the crown conical degree in different gene mutation groups were compared using one-way analysis of variance, and the multiple comparisons among gene groups were carried out using the LSD method. Results: Among the 85 tooth agenesis patients, the numbers of patients in each gene mutation group were 20 in ectodysplasin A (EDA) group, 8 in ectodysplasin A receptor (EDAR) group, 15 in wingless-type MMTV integration site family, member 10A (WNT10A) group, 16 in paired box 9 (PAX9) group, 10 in Msh homeobox 1 (MSX1) group, 10 in low-density lipoprotein receptor related protein 6 (LRP6) group, and 6 in bone morphogenetic protein4 (BMP4) group. The number of missing teeth were 1-27, median number 15 among the tooth agenesis patients. There was no significant difference in the conical degree between the left and right homonymous teeth in the congenital tooth agenesis group and the control group (P>0.05). The crown conical degree of maxillary central incisor and lateral incisor in the congenital missing teeth group (0.95±0.24, 0.90±0.22) was significantly smaller than that in the control group (1.12±0.09, 1.13±0.09) (t=-8.50, P<0.001; t=-11.47, P<0.001). In WNT10A mutants, the conical degree of lateral incisors (0.89±0.18) was less than that of central incisors (1.07±0.15)(t=3.68, P<0.001). The conical degree of central incisors and lateral incisors (0.70±0.23, 0.57±0.15) of EDA mutants was significantly lower than that in patients with other gene mutations (P>0.05). Conclusions: Compared with the normal control group, the remaining maxillary central and lateral incisors of the seven gene mutation groups of patients with congenital tooth agenesis all had different degrees of conical crown. Among them, the crown conical degree of maxillary central and lateral incisors of the EDA mutation was the most severe, and the WNT10A mutation affected the maxillary lateral incisors more specifically.
目的： 测量先天缺牙患者上颌余留切牙牙冠锥形程度，并分析不同基因突变对患者的牙冠锥形程度的影响。 方法： 回顾性纳入2019年1月至2023年1月就诊于北京大学口腔医学院·口腔医院修复科的85例先天缺牙患者（先天缺牙组），其中男性50例，女性35例，年龄3~57岁，中位年龄19岁。对所有患者进行全外显子组测序分析致病基因突变，并在曲面体层X线片上测量上颌中切牙及侧切牙在切1/3和龈1/3处的牙冠宽度，计算两者的比值得出牙冠锥形程度值，该值越小，代表该牙牙冠形态越类似锥形。根据先天缺牙组患者的年龄及性别匹配，选择2019年1月至2023年1月就诊于北京大学口腔医学院·口腔医院修复科，无牙齿发育异常相关疾病且上颌恒切牙完好的85例其他患者为对照组。对先天缺牙组与对照组的牙冠锥形程度值进行t检验，使用单因素方差分析比较不同基因突变组的牙冠锥形程度值的差异，使用LSD方法进行各基因组别间的多重比较。 结果： 85例先天缺牙组患者共有7种基因突变类型，包括外胚层发育不良A（ectodysplasin A，EDA）（20例）、EDA受体（EDA receptor，EDAR）（8例）、无翅型MMTV整合位点家族成员10A（wingless-type MMTV integration site family，member 10A，WNT10A）（15例）、配对盒9（paired box 9，PAX9）（16例）、Msh同源框1（Msh homeobox 1，MSX1）（10例）、低密度脂蛋白受体相关蛋白6（low-density lipoprotein receptor related protein 6，LRP6）（10例）和骨形态发生蛋白4（bone morphogenetic protein4，BMP4）（6例）。先天缺牙组患者的先天缺牙1~27颗，中位数15颗。先天缺牙组和对照组中左侧与右侧同名牙牙冠锥形程度值差异均无统计学意义（P>0.05）。先天缺牙组患者上颌中切牙和侧切牙牙冠的锥形程度值（0.95±0.24、0.90±0.22）均显著小于对照组（1.12±0.09、1.13±0.09）（t=-8.50，P<0.001；t=-11.47，P<0.001）。WNT10A突变患者的侧切牙锥形程度值（0.89±0.18）显著小于中切牙（1.07±0.15）（t=3.68，P<0.001）。EDA突变患者的中切牙和侧切牙锥形程度值（0.70±0.23、0.57±0.15）均显著小于其他基因突变者（P<0.05）。 结论： 与正常对照相比，本研究纳入的7种不同基因突变的先天缺牙患者的余留上颌中切牙、侧切牙均存在不同程度的锥形牙，其中EDA突变者的上颌中切牙、侧切牙牙冠锥形程度最严重，而WNT10A突变更特异性地影响上颌侧切牙的牙冠锥形程度。.

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.
METHODS: 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.