Multidisciplinary orthodontic and prosthetic treatment of an eleven-year-old patient with a solitary median maxillary central incisor: A case report.

Solitary median maxillary central incisor syndrome (SMMCI) is a complex disorder consisting of multiple, mainly midline defects of development resulting from unknown factor(s) operating in utero about the 35th–38th day(s) from conception. It is estimated to occur in 1:50,000 live births. Aetiology is uncertain. Missense mutation in the SHH gene (I111F) at 7q36 may be associated with SMMCI. The SMMCI tooth differs from the normal central incisor, in that the crown form is symmetric; it develops and erupts precisely in the midline of the maxillary dental arch in both primary and permanent dentitions. Congenital nasal malformation (choanal atresia, midnasal stenosis or congenital pyriform aperture stenosis) is positively associated with SMMCI. The presence of an SMMCI tooth can predict associated anomalies and in particular the serious anomaly holoprosencephaly. Common congenital anomalies associated with SMMCI are: severe to mild intellectual disability, congenital heart disease, cleft lip and/or palate and less frequently, microcephaly, hypopituitarism, hypotelorism, convergent strabismus, oesophageal and duodenal atresia, cervical hemivertebrae, cervical dermoid, hypothyroidism, scoliosis, absent kidney, micropenis and ambiguous genitalia. Short stature is present in half the children. Diagnosis should be made by eight months of age, but can be made at birth and even prenatally at 18–22 weeks from the routine mid-trimester ultrasound scan. Management depends upon the individual anomalies present. Choanal stenosis requires emergency surgical treatment. Short stature may require growth hormone therapy. SMMCI tooth itself is mainly an aesthetic problem, which is ideally managed by combined orthodontic, prosthodontic and oral surgical treatment; alternatively, it can be left untreated.

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. 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. 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. 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. 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. 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.

Solitary Median Maxillary Central Incisor Syndrome (SMMCI Syndrome) is a rare developmental disorder consisting of morphological defects that mainly affect structures in the midline of the body. The aetiology of this syndrome has not been fully explained, and SMMCI syndrome is observed more frequently in females. The presence of a solitary median maxillary incisor in the midline of the maxilla is a typical trait in the stomatognathic system, and this anomaly is found in both deciduous and permanent dentition. Regarding developmental abnormalities accompanying a solitary incisor with an atypical structure, the most common ones include: lack of the frenulum of the upper lip, deformations in the nasal cavity and cranial base, heart defects, cleft lip and palate, and mental disability of various severity. <b>Aim.</b> The aim of this work is to present the characteristic traits of a solitary median maxillary central incisor syndrome on the basis of a case study of a 9-yearold female patient and the analysis of available literature. <b>Material and methods.</b> The literature review was performed using the PubMed database and the following key words: incisor, maxilla, syndrome, development, SMMCI syndrome. <b>Case report.</b> When the clinical examination and medical history were performed the patient was diagnosed with signs of solitary median maxillary central incisor syndrome. The outcomes of a computed tomography scan confirmed choanal stenosis. Except for allergies to animal hair and grass, the patient did not suffer from any systemic diseases. On the basis of a clinical examination and analysis of additional tests the following diagnosis was made: I skeletal class, complete distocclusion with incisor protrusion, partial lateral bilateral cross bite and dental abnormalities. <b>Summary.</b> Patients diagnosed with SMMCI syndrome often require complex care provided by specialists from various fields of medicine and dentistry, due to the possibility of coexistence of numerous developmental abnormalities involving different body structures.

Solitary median maxillary central incisor (SMMCI) syndrome (OMIM #147250) is a disorder characterized by developmental defects of midline structures with variable expressivity. It presents dentally as a single symmetrical central incisor in the midline position. This is a case report of a child with the isolated dental feature of a single maxillary central incisor, with no medical features of SMMCI syndrome. Under the management of a multidisciplinary dental team, a non-invasive approach was undertaken to improve aesthetics. This case report describes the dental options for managing SMMCI including a non-invasive option that has not previously been reported in detail. CPD/Clinical Relevance: Dentists should be aware of SMMCI and its potential medical sequelae.

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

Tooth agenesis is not a rare phenomenon. Most often, the tooth that shows agenesis is the maxillary lateral incisor or the third molars. Agenesis of maxillary central incisor is an extremely rare phenomenon. A case of congenital absence of maxillary central incisor in a 42-year-old, otherwise healthy individual is being presented. When one encounters a case, it is important that it is differentiated from the other serious form of the disease which is solitary median maxillary central incisor syndrome.

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. The presence of SMMCI with hemifacial microsomia (HFM) is a very rare clinical condition. We report a case of SMMCI in a female of African ethnic origin, who presented with SMMCI in permanent dentition with mild nasal stenosis. An early diagnosis of SMMCI is important, since it may be a sign for other severe congenital or developmental abnormalities. Therefore, systematic follow-up and close monitoring of the growth and development of SMMCI patients are crucial.

The present report follows the case of a young boy with solitary median maxillary central incisor (SMMCI) syndrome between the ages of 4 and 7 years. This condition is characterized by the presence of one single maxillary central incisor in the midline instead of two central incisors. No other developmental abnormalities involving growth or brain function were noted at, or subsequent, to birth. This report includes a discussion of the aetiology of SMMCI syndrome and its association with birth defects such as holoprosencephaly (HPE), CHARGE and VACTERL, as well as a discussion of the long-term prognosis and associated dental and medical issues for this particular patient

Orthodontic treatment for a patient with hypodontia involving the maxillary lateral incisors

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.

This is the first reported case of siblings with Solitary Median Maxillary Central Incisor (SMMCI) syndrome presenting with an erupted single symmetrical central maxillary midline incisor between normal central incisors. Usually only one central incisor is present. This case is also interesting as the tooth described could have been mistaken for a mesiodens, however, a mesiodens is not symmetrical and usually erupts between the maxillary central incisors and sits slightly to the right or left of the midline. CPD/Clinical Relevance: This case highlights the fact that SMMCI should not be considered as a simple dental anomaly because it may be associated with more complex craniofacial malformations.

A case of solitary median maxillary central incisor (SMMCI) syndrome with bilateral pyriform aperture stenosis and choanal atresia

IntroductionSolitary median maxillary central incisor (SMMCI) syndrome is a rare and complex disorder that occurs in 1:50,000 live births. The developmental defects are mainly located in the craniofacial midline, namely: the midline cleft lip palate or congenital nasal malformation. Some of the associated anomalies belong to the holoprosencephaly (failure of the prosencephalon to laterise) spectrum but associated anomalies outside the holoprosencephaly spectrum have also been described. In most severe phenotypes the survival rate is low. Genetic and environmental factors acting between the 35th and 38th day of pregnancy are associated with the anomaly. The relationship of SMMCI to genes implicated in the pathogenesis of holoprosencephaly is still discussed controversially. A SHH missense mutation identified 2001 by Nanni et al. may be associated with SMMCI. SMMCI is characterized by a mostly symmetric central incisor of normal size, located exactly in the midline of the maxilla.Case reportA 9.5-year-old girl was presented at the Department of Orthodontics, Dentofacial Orthopedics and Pedodontics of Charité Berlin by her father, who was concerned about the single maxillary central incisor. The patient had a non-contributory history. A traumatic loss of one central incisor was ruled out, but a solitary median maxillary central incisor was present in the primary dentition, too. Clinical examination showed dolichofacial, symmetric face with mild hypotelorism, indistinct philtrum and hypoplastic nose. The most striking finding was the presence of a single central incisor that was located in the midline of the maxilla. Additional intraoral findings were the "V"-shaped high palate with an unusual prominent midpalatal ridge and the absence of labial frenulum and incisive papilla. The patient was also evaluated by a geneticist and no mutations of the SHH gene could be identified. According to the CBCT-findings, the midline maxillary suture was fused and therefore rapid maxillary expansion is not a treatment option for this patient. Extractions of the solitary median maxillary central incisor and of 2 mandibular incisors and sub sequent orthodontic space closure was the orthodontic approach followed for this patient.ConclusionFor the clinician it is important to assure an early detection of SMMCI syndrome with consideration of the patient’s needs in term of dental and medical care. Moreover, a multidisciplinary pedodontic, orthodontic and prothodontic treatment plan is necessary to ensure a successful dental treatment. Patients’ and parents’ perception, treatment needs and concerns should be evaluated carefully. In addition, SMMCI is considered one of the microforms of the holoprosencephaly spectrum and it can be associated with more severe anomalies or with a more severe phenotype of holoprosencephaly in the next generation. Therefore, we would like to underline the fundamental role of the dentist in the early diagnosis by identifying and referring these patients to the clinical geneticist for a further evaluation.

Solitary median maxillary central incisor (SMMCI) syndrome is a complex disorder consisting of multiple, developmental defects involving midline structures of the head, which includes the cranial bones, the maxilla, and its container dentition (specifically the central incisor tooth germ), together with other midline structures of the body. SMMCI may appear as an isolated trait or in association with other midline developmental anomalies. We describe the case of a patient with SMMCI. He presented with a solitary median maxillary incisor, short stature, corpus callosum anomalies and a microform of holoprosencephaly (HPE), diabetes insipidus, and neurodevelopmental delay. The diagnosis was performed postnatally based on clinical features, radiological imaging, and a comprehensive genetic study. SMMCI can be diagnosed during the prenatal or neonatal periods or during infancy. Evaluation of the superior maxillary bone is important for prenatal diagnosis. Direct evaluation through bidimensional ultrasound or the use of multiplanar ultrasound or tridimensional reconstruction should be performed in cases of brain or face malformations. Early diagnosis can contribute to improved prenatal assessment and postnatal management.

Solitary median maxillary central incisor syndrome is a unique developmental abnormality, involving the central incisor tooth germs, occurring with and without systemic involvement. This syndrome has been recorded in association with many other midline developmental anomalies and several known syndromes. Its presence, together with oromandibular-limb hypogenesis syndrome type 1, has not previously been reported. A 3-year-old girl was presented with early childhood caries and a solitary median maxillary central incisor. She had a median submucosal cleft palate and severe micrognathia with hypoglossia. In addition, she had short stature, eating difficulty, and hearing and speech problems. Comprehensive dental treatment for severe early childhood caries was accomplished with a 3-month follow-up appointment to monitor the oral health. The multidisciplinary consultation important for further management has been established. The results suggested that when a solitary median maxillary incisor tooth presents, a paediatrician and a geneticist should be asked to carefully examine the patient for other craniofacial malformations and especially midline systemic problems.