DISP1 deficiency: Monoallelic and biallelic variants cause a spectrum of midline craniofacial malformations.

PURPOSE: DISP1 encodes a transmembrane protein that regulates the secretion of the morphogen, Sonic hedgehog, a deficiency of which is a major cause of holoprosencephaly (HPE). This disorder covers a spectrum of brain and midline craniofacial malformations. The objective of the present study was to better delineate the clinical phenotypes associated with division transporter dispatched-1 (DISP1) variants. METHODS: This study was based on the identification of at least 1 pathogenic variant of the DISP1 gene in individuals for whom detailed clinical data were available. RESULTS: A total of 23 DISP1 variants were identified in heterozygous, compound heterozygous or homozygous states in 25 individuals with midline craniofacial defects. Most cases were minor forms of HPE, with craniofacial features such as orofacial cleft, solitary median maxillary central incisor, and congenital nasal pyriform aperture stenosis. These individuals had either monoallelic loss-of-function variants or biallelic missense variants in DISP1. In individuals with severe HPE, the DISP1 variants were commonly found associated with a variant in another HPE-linked gene (ie, oligogenic inheritance). CONCLUSION: The genetic findings we have acquired demonstrate a significant involvement of DISP1 variants in the phenotypic spectrum of midline defects. This underlines its importance as a crucial element in the efficient secretion of Sonic hedgehog. We also demonstrated that the very rare solitary median maxillary central incisor and congenital nasal pyriform aperture stenosis combination is part of the DISP1-related phenotype. The present study highlights the clinical risks to be flagged up during genetic counseling after the discovery of a pathogenic DISP1 variant.

Truncating and zinc-finger variants in GLI2 are associated with hypopituitarism.

Variants in transcription factor GLI2 have been associated with hypopituitarism and structural brain abnormalities, occasionally including holoprosencephaly (HPE). Substantial phenotypic variability and nonpenetrance have been described, posing difficulties in the counseling of affected families. We present three individuals with novel likely pathogenic GLI2 variants, two with truncating and one with a de novo missense variant p.(Ser548Leu), and review the literature for comprehensive phenotypic descriptions of individuals with confirmed pathogenic (a) intragenic GLI2 variants and (b) chromosome 2q14.2 deletions encompassing only GLI2. We show that most of the 31 missense variants previously reported as pathogenic are likely benign or, at most, low-risk variants. Four Zn-finger variants: p.(Arg479Gly), p.(Arg516Pro), p.(Gly518Lys), and p.(Tyr575His) were classified as likely pathogenic, and three other variants as possibly pathogenic: p.(Pro253Ser), p.(Ala593Val), and p.(Pro1243Leu). We analyze the phenotypic descriptions of 60 individuals with pathogenic GLI2 variants and evidence a morbidity spectrum that includes hypopituitarism (58%), HPE (6%) or other brain structure abnormalities (15%), orofacial clefting (17%) and dysmorphic facial features (35%). We establish that truncating and Zn-finger variants in GLI2 are associated with a high risk of hypopituitarism, and that a solitary median maxillary central incisor is part of the GLI2-related phenotypic variability. The most prevalent phenotypic feature is post-axial polydactyly (65%) which is also the mildest phenotypic expression of the condition, reported in many parents of individuals with systemic findings. Our approach clarifies clinical risks and the important messages to discuss in counseling for a pathogenic GLI2 variant.

Orthodontic evaluation of children and adolescents with different types of Foetal Alcohol Syndrome Disorders.

OBJECTIVE: To assess general and oral health status, including the presence of malocclusion and orthodontic treatment needs, in children and adolescents with FASD in relation to different types of this disorder. SETTING AND SAMPLE POPULATION: A total of 67 participants (29 males and 38 females) aged 2.5-17.8 years with confirmed diagnosis of FASD were included. MATERIALS AND METHODS: The participants were divided into three subgroups: foetal alcohol syndrome (FAS), partial foetal alcohol syndrome (PFAS) and alcohol-related neurodevelopmental disorders (ARND). General health, oral health status, history of dental trauma, presence of dysfunctions or parafunctions, and occlusion were examined. Additionally, the Index of Orthodontic Treatment Need (IOTN) index was calculated. Selected variables were compared to the results obtained from a national monitoring survey on the oral health conditions in Poland. RESULTS: In children and adolescents with FASD, a number of systemic anomalies including alimentary, neurological and musculoskeletal disorders were present. Dysfunctions and parafunctions such as mouth breathing and thumb sucking were frequently recorded. Children with FASD had an increased prevalence of distal occlusion and crossbite compared to the general population. Malocclusions were more often identified in the FAS group. No significant differences in the IOTN between different FASD groups were found. Borderline need for orthodontic treatment was more frequent in children with FASD compared to controls. CONCLUSION: Early screening for the presence of dysfunctions/parafunctions and malocclusions in children with FASD is recommended, so that orthodontic prophylaxis and state-funded orthodontic care programmes for these children are implemented.

Solitary Median Maxillary Central Incisor Syndrome: A Case Report of a Unique Dental Anomaly.

Solitary median maxillary central incisor (SMMCI) syndrome is complex and usually develops 35-38 days postconception during the intrauterine period. A noteworthy discovery is that just one central incisor in the maxillary alveolus, found exactly on the centerline, is present in both deciduous and permanent dentitions with other congenital anomalies. Around one in every 50,000 live babies exhibits this abnormality. This report describes the case of a 13-year-old female patient with SMMCI syndrome with a complaint about an unsightly appearance due to a single large upper front tooth. We underline the importance of increasing clinician awareness of SMMCI syndrome and the need for a multidisciplinary approach to its care.

Solitary Median Maxillary Central Incisor Syndrome: A Case Report.

Aim: This report intends to present a case of solitary median maxillary central incisor syndrome (SMMCI) and its multidisciplinary team approach for diagnosis of other associated anomalies, with special emphasis on their management. Background: Solitary median maxillary central incisor syndrome is a unique developmental condition characterized by only maxillary central incisor and a series of developmental defects, appearing as a syndrome. The appearance of a single incisor may take place due to the union of two incisor teeth or the absence of tooth germs. The mechanism of the fusion is still uncertain. Case description: A 9-year-old female child reported with a chief complaint of pain in the right lower back tooth for the past 10 days. The presence of a single maxillary central incisor was an incidental finding. Then a detailed history and multidisciplinary evaluations revealed the diagnosis of SMMCI syndrome. Conclusion: The effort in diagnosing and managing this syndrome had a strong impact on the child's life of which the parent was highly motivated and got a better understanding of associated problems of overall development. Clinical significance: In SMMCI syndrome, the patient requires a multidisciplinary health team in order to improve their quality of life. It is of greater importance to diagnose the syndrome and treatment of these median line deformities. How to cite this article: Balasubramanian S, Haridoss S, Swaminathan K. Solitary Median Maxillary Central Incisor Syndrome: A Case Report. Int J Clin Pediatr Dent 2022;15(4):458-461.

Osteogenic distraction to treat solitary median maxillary central incisor (SMMCI) syndrome: a case report.

Solitary median maxillary central incisor (SMMCI) syndrome is a rare developmental disorder characterized by a single symmetrical maxillary central incisor. Only a small number of cases with comprehensive dental treatment have been reported in the literature. No surgical treatment has been proposed before. We report the case of an 8-year-old girl who presented SMMCI syndrome associated with an Angle class II occlusion and a maxillary transverse deficiency. After the failure of two rapid maxillary expansions, a surgical option was proposed: osteogenic maxillary distraction. The distraction, associated with multi-bracketed fixed orthodontic treatment, created enough space to place a prosthetic central incisor without dental extractions. Osteogenic distraction is an interesting option to treat patients with SMMCI.

Solitary Median Maxillary Central Incisor Syndrome: An Exploration of the Pathogenic Mechanism.

This study aimed to identify the genetic cause of one Chinese family with solitary median maxillary central incisor (SMMCI) and explore the relationship between genotype and its phenotype. One Chinese family with clinical diagnosis of SMMCI was collected. Single Nucleotide Polymorphism (SNP) array was performed and identified variation was confirmed by whole-genome sequencing (WGS). The reported chromosomal abnormalities and pathogenic genes in patients with SMMCI in literature were reviewed and summarized. The proband was an 8-year-old boy presenting a typical solitary median maxillary central incisor with a range of other phenotypic anomalies, including ptosis. SNP array revealed a 14.3 Mbp heterozygous deletion at chromosome 18p11.32-p11.21 in the proband but not in the unaffected parents. WGS further confirmed the identified deletion. 194 genes were involved in the chromosome region. Among them, 12 genes had been shown to be associated with diseases, including TGIF1, a reported SMMCI gene. The de novo 18p deletion resulted in SMMCI in the present study. Our results provide new genetic evidence that structural abnormality in chromosome 18p contributes to solitary median maxillary central incisor.

Solitary Median Maxillary Central Incisor: A Case Report with 3-Year Follow-Up and Literature Review.

A solitary median maxillary central incisor (SMMCI) is a rare anomaly that can occur alone or be associated with other systemic abnormalities. Early diagnosis of SMMCI is crucial as it might indicate the presence of an associated congenital or developmental abnormality. The prevalence of live-born children with SMMCI is determined to be 1:50,000 and is more common among females. The purpose of this paper was to report an unusual case of a 9-year-old girl with SMMCI who had no growth deficiency or any other systemic involvement. Since pediatricians and dentists are the first professionals to evaluate an SMMCI's patient in most cases, it is important that they be aware of the possibility of other related systemic problems that require systemic care. Appropriate treatment, diagnosis, and referral should also include neuropediatric evaluation, genetic testing, and craniofacial profile analysis along with multidisciplinary approach.

Solitary median maxillary central incisor syndrome: A rare entity.

Solitary median maxillary central incisor (SMMCI) syndrome is a complex disorder and a rare dental anomaly, which is estimated to occur in approximately 1:50,000 live births. It is a unique developmental abnormality which involves the central incisor tooth germs, occurring with or without systemic involvement; hence, its early diagnosis is of great importance. The objective of this study was to discuss a case of SMMCI syndrome and various dental treatment alternatives available in management of such cases. Due to the possible association of this syndrome with other developmental problems, an early diagnosis and management becomes important. Moreover, when it is associated with other developmental malformation and defects, the management becomes multidisciplinary.

Single median maxillary central incisor syndrome and variant in SMO gene associated with SHH pathway.

Solitary median maxillary central incisor syndrome (SMMCI) is a rare congenital oronasal-dental midline anomaly. The aim of this paper is a presentation of a patient with SMMCI without other visible dentofacial anomalies, with a potentially new molecular etiology consisting of a gene-gene reaction and conservative therapeutic approach to nasal obstruction. Potentially pathogenic variants in the SMO gene (p.Gly422Glu) and in P2RY13 gene (p.Trp205*) inherited from the probant's father, and in the PLD2 gene (p.Gln319fs), inherited from the mother were found. A multidisciplinary approach is necessary for the management of patients with SMMCI, including a genetic consultation with genetic tests.

Solitary Median Maxillary Central Incisor due to Nasal Pyriform Aperture Stenosis in Fetus: The First Prenatal Ultrasound Case Report.

BACKGROUND: The single median incisor is a rare dental abnormality that could be isolated or could be part of many different syndromes or syndromic association with poor prognosis. CASE DESCRIPTION: We report the first prenatal ultrasound description of a 31-year-old patient, gravida 1, para 0, whose male fetus was diagnosed at 25 weeks' gestation with a single median incisor suggestive of nasal pyriform aperture stenosis in Montpellier University Hospital (France). A fetal magnetic resonance imaging (MRI) performed at 30 weeks' gestation retrieved no intracranial midline cerebral anomalies and confirm nasal pyriform aperture stenosis suspicion. Amniocentesis, performed at 31 weeks, found a normal fetal karyotype (46XY) and a normal comparative genomic hybridization (CGH) array. After term vaginal delivery, clinical and radiological examination confirmed the diagnosis of an isolated single median maxillary central incisor linked to nasal pyriform aperture stenosis. CONCLUSION: Prenatal diagnosis of a single median incisor due to nasal pyriform aperture stenosis is feasible and enables close postnatal follow-up. HOW TO CITE THIS ARTICLE: Fuchs F, Chadelle M, Captier G, et al. Solitary Median Maxillary Central Incisor due to Nasal Pyriform Aperture Stenosis in Fetus: The First Prenatal Ultrasound Case Report. Int J Clin Pediatr Dent 2020;13(3):295-298.

Solitary median maxillary central incisor, holoprosencephaly and congenital nasal pyriform aperture stenosis in a premature infant: case report. / Incisivo central único de la línea media del maxilar, holoprosencefalia y estenosis congènita del orificio nasal anterior en un recién nacido prematuro: a propósito de un caso.

Solitary median maxillary central incisor syndrome is a rare disorder involving midline abnormalities such as holoprosencephaly, nasal cavity anomalies, cleft palate-lip, hypotelorism, microcephaly, and panhypopituitarism. Congenital nasal pyriform aperture stenosis is a lethal cause of neonatal respiratory distress due to narrowing of the pyriform aperture anteriorly and it can be confused with choanal atresia. In this report, we present a newborn infant with solitary median maxillary central incisor syndrome accompanied by other abnormalities including holoprosencephaly, nasal pyriform aperture stenosis, microcephaly and panhypopituitarism. Chromosomal analysis showed heterozygous SIX3 gene deletion at 2p21 region resulting in a more severe form of holoprosencephaly.

El síndrome del incisivo central único de la línea media del maxilar es un trastorno raro que implica anomalías de la línea media, como holoprosencefalia, anomalías de las fosas nasales, fisura palatina, labio leporino, hipotelorismo, microcefalia y panhipopituitarismo. La estenosis congénita del orificio nasal anterior es una causa mortal de dificultad respiratoria neonatal debido al estrechamiento del orificio nasal anterior, y podría confundirse con la atresia de coanas. En este informe, presentamos el caso de un recién nacido con síndrome del incisivo central único de la línea media del maxilar acompañado de otras anomalías, tales como holoprosencefalia, estenosis del orificio nasal anterior, microcefalia y panhipopituitarismo. El cariotipado mostró una deleción heterocigota en el gen SIX3 en la región 2p21, que produjo una forma más grave de holoprosencefalia.

Less known aspects of central hypothyroidism: Part 2 - Congenital etiologies.

Central hypothyroidism (CH) occurs approximately in 1:50,000, and therefore is expected to be one thousand times rarer compared with primary hypothyroidism. Despite its rarity in the general population, it is much more common in certain disorders, in which it is frequently associated with other pituitary hormone deficiencies. The aim of this paper is to provide an updated review on the frequency of congenital CH, which is <1:50,000, and on its etiology, disregarding CH caused by other genetic defects, such as mutations of transcription factors involved in pituitary organogenesis or mutations of the genes encoding TRH or TRH receptor.

Congenital nasal pyriform aperture stenosis in association with solitary median maxillary central incisor: unique radiologic features.

Solitary median maxillary central incisor (SMMCI) coexists in 34%-65% of patients initially diagnosed with congenital nasal pyriform aperture stenosis. SMMCI, a genetic syndrome, warrants consideration for further screening because of its high prevalence of other diagnostic possibilities-specifically central defects, like nasal obstruction and hypothalamo-pituitary axis abnormalities. We report on a presentation of SMMCI with congenital nasal pyriform aperture stenosis which highlights the unique radiologic features and notes the relationship between these two central associated findings in the literature.

Incisivo central único de la línea media del maxilar, holoprosencefalia y estenosis congènita del orificio nasal anterior en un recién nacido prematuro: a propósito de un caso / Solitary median maxillary central incisor, holoprosencephaly and congenital nasal pyriform aperture stenosis in a premature infant: case report

El síndrome del incisivo central único de la línea media del maxilar es un trastorno raro que implica anomalías de la línea media, como holoprosencefalia, anomalías de las fosas nasales, fisura palatina, labio leporino, hipotelorismo, microcefalia y panhipopituitarismo. La estenosis congénita del orificio nasal anterior es una causa mortal de dificultad respiratoria neonatal debido al estrechamiento del orificio nasal anterior, y podría confundirse con la atresia de coanas. En este informe, presentamos el caso de un recién nacido con síndrome del incisivo central único de la línea media del maxilar acompañado de otras anomalías, tales como holoprosencefalia, estenosis del orificio nasal anterior, microcefalia y panhipopituitarismo. El cariotipado mostró una deleción heterocigota en el gen SIX3 en la región 2p21, que produjo una forma más grave de holoprosencefalia.

Solitary median maxillary central incisor syndrome is a rare disorder involving midline abnormalities such as holoprosencephaly, nasal cavity anomalies, cleft palate-lip, hypotelorism, microcephaly, and panhypopituitarism. Congenital nasal pyriform aperture stenosis is a lethal cause of neonatal respiratory distress due to narrowing of the pyriform aperture anteriorly and it can be confused with choanal atresia. In this report, we present a newborn infant with solitary median maxillary central incisor syndrome accompanied by other abnormalities including holoprosencephaly, nasal pyriform aperture stenosis, microcephaly and panhypopituitarism. Chromosomal analysis showed heterozygous SIX3 gene deletion at 2p21 region resulting in a more severe form of holoprosencephaly.

Concomitant solitary median maxillary central incisor and fused right mandibular incisor in primary dentition.

Solitary median maxillary central incisor (SMMCI) is a unique developmental anomaly in primary dentition. It involves central incisor tooth germs and may or may not be associated with other anomalies. Its presence, concomitant with fusion of right mandibular incisors has not previously been reported. A 5-year-old girl was presented with a single symmetrical primary maxillary incisor at the midline, with the absence of labial frenulum, an indistinct philtrum and a prominent midpalatal ridge. There was an associated fused tooth in the right incisor region and radiographic examination confirmed only one maxillary central incisor in both the dentitions. Family history revealed that the father of the girl also had a similar anomaly providing probable evidence of etiological role for heredity in SMMCI.

Solitary median maxillary central incisor in association with hemifacial microsomia: A rare case report and review of literature.

Solitary median maxillary central incisor (SMMCI) is a rare dental anomaly. It is estimated to occur in 1:50,000 live births. The SMMCI tooth differs from the normal central incisor in that the crown form is symmetric and it develops and erupts precisely in the midline of the maxillary dental arch in both primary and permanent dentitions. Presence of SMMCI with hemifacial microsomia (HFM) is a very rare clinical condition. We report a case of HFM in a male of Indian origin who presented with SMMCI in both primary and permanent dentitions. The association of HFM with SMMCI may be due to defective development of neural crest cells and/or lack of space in maxilla.

Dental trauma clinically mimicking single central incisor syndrome / Traumatismo dentário mimetizando clinicamente a síndrome do incisivo central único

PURPOSE: This paper presents a clinical case in which a patient was missing a median central incisor due to trauma but was referred for orthodontic treatment because of suspicions of solitary median maxillary central incisor (SMMCI) syndrome. CASE DESCRIPTION: A 12-year-old female patient visited the clinic with concerns about the appearance of her teeth. An oral examination revealed the presence of a single central incisor that was located on the midline and was adjacent to the maxillary lateral incisors. The patient reported two episodes of dental avulsion (of teeth 11 and 21) that had occurred approximately four years earlier. Tooth 11 was replanted; however, it was subsequently extracted due to pain. A panoramic radiograph and cephalometric analysis revealed a history of unsuccessful root canal treatment on tooth 21, a straight profile and symmetrical facial features. Tooth 21 was extracted, followed by the traction of the maxillary teeth in the mesial direction and the esthetic transformation of the lateral incisors into central incisors and the canines into lateral incisors. CONCLUSION: Dental trauma followed by tooth loss may mimic solitary median maxillary central incisor syndrome.

OBJETIVO: Apresentar um caso clínico de ausência de um incisivo central perdido por traumatismo e encaminhado ao ortodontista com suspeita de apresentar síndrome do incisivo central único (SMMCI). DESCRIÇÃO DO CASO: Paciente gênero feminino, 12 anos com queixa da aparência de seus dentes. Ao exame intrabucal observou-se a presença de um incisivo central único localizado na linha média sem espaçamentos em relação aos incisivos laterais superiores. A paciente relatou dois episódios de avulsão dos dentes 11 e 21, cerca de quatro anos antes. No entanto, devido a sintomas de dor após reimplante, o dente 11 foi extraído. A radiografia panorâmica e análise cefalométrica revelou a presença de tratamento insatisfatório do canal radicular do dente 21, um perfil reto e padrão de equilíbrio facial. Extração do dente 21 foi realizada, com tração posterior dos dentes superiores na direção mesial, seguido pela transformação estética dos incisivos laterais em incisivos centrais e dos caninos em incisivos laterais. CONCLUSÃO: O traumatismo seguido de perda dentária pode mimetizar um quadro de síndrome do incisivo central único.

Síndrome do incisivo central superior solitário: relato de caso / Solitary median maxillary central incisor syndrome: case report

INTRODUÇÃO: a presença de um incisivo central superior solitário é um evento bastante incomum na população. A prevalência da chamada Síndrome do Incisivo Central Superior Solitário (SICSS) é verificada em 1:50.000 nascimentos, sendo registrado um maior acometimento no sexo feminino. Essa alteração no desenvolvimento da oclusão dentária é caracterizada por más formações estruturais, sobretudo na região de linha média do paciente. O diagnóstico precoce e o tratamento adequado dessa síndrome são de grande importância, pois essa condição talvez seja um indicativo de que o paciente pode apresentar outras más formações congênitas severas, não devendo ser a SICSS considerada uma simples anomalia dentária. Os procedimentos ortodônticos, nesses casos, variam dependendo do grau de comprometimento das estruturas ósseas da maxila, da oclusão em si, e principalmente da sutura palatina mediana. OBJETIVO: discutir, baseado em evidências científicas, aspectos importantes relacionados à SICSS, bem como apresentar um caso clínico de paciente do sexo feminino com SICSS, que foi submetida a tratamento ortodôntico na Clínica Odontológica Integrada Infantil da Universidade Federal de Santa Maria / RS. CONCLUSÃO: pela análise crítica da literatura, verifica-se ser muito importante o diagnóstico correto e precoce acerca dessa síndrome, visto que há possibilidade da mesma estar associada a outros problemas de desenvolvimento. Além disso, o paciente acometido pela SICSS deve ser assistido por uma equipe multidisciplinar de saúde, de forma a otimizar os resultados clínicos e devolver-lhe qualidade de vida.

INTRODUCTION: The presence of a single median maxillary central incisor is an uncommon event in the population. The prevalence of the Solitary Median Maxillary Central Incisor (SMMCI) syndrome is about 1:50,000 live births, occurring more in women. This alteration in the development of the dental occlusion is characterized by structural malformations, over all in midline region of the patient. The early diagnosis and the adequate treatment of this syndrome are of great importance, therefore this condition can be an indication that the patient can present other severe congenital malformations, not having to consider the SMMCI a simple dental anomaly. The orthodontic procedures, in these cases, vary depending on the degree of involvement of bone structures of the maxilla, the occlusion in itself, and mainly of the midpalatal suture. OBJECTIVES: To discuss, based on scientific evidence, important aspects related to the SMMCI and present a clinical case of female patient with SMMCI, which was submitted to orthodontic treatment in the Children's Dental Integrated Clinic of the Federal University of Santa Maria - RS/Brazil. CONCLUSION: According to the critical analysis of literature, it is very important to correctly early diagnose this condition, since there is the possibility of this syndrome to be associated with other problems of development. Moreover, the patients affected by SMMCI should be attended by a multidisciplinary health team in order to optimize the clinical results and recover the quality of life of these patients.