The ontogeny of Robin sequence.

The triad of micrognathia, glossoptosis, and concomitant airway obstruction defined as "Robin sequence" (RS) is caused by oropharyngeal developmental events constrained by a reduced stomadeal space. This sequence of abnormal embryonic development also results in an anatomical configuration that might predispose the fetus to a cleft palate. RS is heterogeneous and many different etiologies have been described including syndromic, RS-plus, and isolated forms. For an optimal diagnosis, subsequent treatment and prognosis, a thorough understanding of the embryology and pathogenesis is necessary. This manuscript provides an update about our current understanding of the development of the mandible, tongue, and palate and possible mechanisms involved in the development of RS. Additionally, we provide the reader with an up-to-date summary of the different etiologies of this phenotype and link this to the embryologic, developmental, and genetic mechanisms.

Secuencia malformativa de Pierre Robin: informe de un caso y revisión de la literatura / Pierre Robin sequence: case report and literature review

Durante la infancia es muy frecuente encontrar alteraciones del desarrollo,las cuales derivan de una defi ciente formación de las estructurasanatómicas durante la embriogénesis. Puede encontrarse un sinnúmerode alteraciones del desarrollo que afectan la región bucal y maxilofacial.La gran mayoría de estas alteraciones han sido catalogadas como síndromes de orden genético; sin embargo, no todas pueden describirse como tales, pues existen anomalías del desarrollo que aparecen como consecuencia de una deficiente embriogénesis de la región facial, provocando alteraciones anatómicas y funcionales, pero que se apartan de componentes genéticos y cromosómicos específi cos. La secuencia malformativa de Pierre Robin es una de ellas, ya que esta condición es producida por una afección inicial, de la cual derivarán otras afeccionesadicionales a nivel del paladar y de la mandíbula que ocasionarán en elpaciente dificultad para la alimentación y respiración. Debido a que las alteraciones de esta condición afectan directamente la cavidad bucal,es crucial que el odontólogo se encuentre familiarizado con esta anomalía. El objetivo del presente artículo es describir las característicasque configuran esta entidad nosológica mediante la exposición de un caso clínico y revisión de la literatura.

During childhood, it is frequent to find development disorders whichare linked to the weak formation of anatomic structures duringembryogenesis. It is possible to find a plethora of developmentdisorders that aff ect the oral and maxillofacial region. The majorityof these disorders has been classifi ed as genetic malformations butnot all can be described as such. That is because some developmentdisorders appear as a result of a defi cient embryogenesis of the face,producing thus anatomic and functional malformations but that standapart from genetic and chromosomic specifi c components. The Pierre Robin sequence is one of them, given that this condition is producedby an initial disorder, followed by other disorders in the palate andjaw; provoking alimentary and breathing disabilities in the patient.Due to these disorders and their impact on the mouth, it is crucial thatdentists be familiarized with such anomalies. The aim of this article isto describe the key characteristics that defi ne this disease through thepresentation of a clinical case and a literature review.

Sequência de Pierre Robin: aplicação da técnica de distração osteogênica em pacientes como abordagem terapêutica / Pierre Robin sequence: application of the osteogenic distraction technique in patients as a therapeutic approach

Introdução: Pierre Robin, em 1923, descreveu a sequência das malformações e as correlacionou com os sinais clínicos de insuficiência respiratória, o que trouxe a constatação da necessidade de tratamento, muitas vezes urgente. A conduta terapêutica deve ser individualizada para cada caso e respeitar o quadro apresentado pelo paciente. Objetivo: O presente estudo consiste em uma revisão sobre a Sequência de Pierre Robin e sua abordagem terapêutica, através de distração osteogênica da mandíbula, com a finalidade de demonstrar a efetividade do procedimento. Método: Estudo descritivo de abordagem qualitativa tipo relato de caso. Resultados e conclusão: A aplicação da técnica possibilitou a correção das anormalidades craniofaciais, o que minimizou os prejuízos causados pela síndrome (AU)

Introduction: In 1923, Pierre Robin described and sequenced the malformations and correlated them with the clinical signs of respiratory failure, which eventually confirmed the need for treatment, often urgent. The therapeutic approach should be individualized for each case and must respect the patient's clinical picture. Aim: The present study consists of a review on the Pierre Robin sequence and its therapeutic approach through osteogenic distraction of the mandible in order to demonstrate the effectiveness of the procedure. Method: A descriptive study with a qualitative approach, case report type. Results and conclusion: The application of the technique made possible the correction of craniofacial abnormalities, which minimized the damage caused by the syndrome (AU)

Etiology and pathogenesis of robin sequence in a large Dutch cohort.

Robin sequence (RS) can be defined as the combination of micrognathia and upper airway obstruction/glossoptosis causing neonatal respiratory problems, with or without a cleft palate and either isolated or non-isolated. Pathogenesis varies widely. We hypothesize that optimal treatment depends on pathogenesis and therefore patients should be stratified according to diagnosis. Here, we evaluate diagnoses and (presumed) pathogeneses in an RS cohort. Medical records of all RS patients presenting between 1995-2013 in three academic hospitals were evaluated. Four clinical geneticists re-evaluated all information, including initial diagnosis. Diagnoses were either confirmed, considered uncertain, or rejected. If uncertain or rejected, patients were re-evaluated. Subsequent results were re-discussed and a final conclusion was drawn. We included 191 RS patients. After re-evaluation and changing initial diagnoses in 48 of the 191 patients (25.1%), 37.7% of the cohort had isolated RS, 8.9% a chromosome anomaly, 29.3% a Mendelian disorder, and 24.1% no detectable cause. Twenty-two different Mendelian disorders were diagnosed, of which Stickler syndrome was most frequent. Stratification of diagnoses according to (presumed) pathogenic mechanism in 73 non-isolated patients with reliable diagnoses showed 43.9% to have a connective tissue dysplasia, 5.5% a neuromuscular disorder, 47.9% a multisystem disorder, and 2.7% an unknown mechanism. We diagnosed more non-isolated RS patients compared to other studies. Re-evaluation changed initial diagnosis in a quarter of patients. We suggest standardized re-evaluation of all RS patients. Despite the relatively high diagnostic yield pathogenesis could be determined in only 59.7% (71/119), due to limited insight in pathogenesis in diagnosed entities. Further studies into pathogenesis of entities causing RS are indicated.

Rare syndromes of the head and face-Pierre Robin sequence.

Pierre Robin sequence (PRS) is an association of clinical features consisting of mandibular hypoplasia, cleft secondary palate, and glossoptosis leading to obstructive apnea and feeding difficulties. PRS can occur as an isolated condition or can be found in association with a range of other features in a number of conditions including Treacher collins and Stickler syndromes. The frequent association of the PRS triad suggests a common underlying developmental mechanism which impacts on each of these tissues. Isolated PRS is typically sporadic but when familial usually exhibits autosomal dominant inheritance. The term PRS is applied on the basis of the pattern of malformation rather than etiology and growing evidence indicates that the initiating genetic lesion is variable. Various chromosomal anomalies have been associated with PRS including loci on chromosomes 2, 4, and 17. Associations with genes including SOX9, a number of collagen genes and work with animal models suggest the phenotype derives from a cartilage defect during early facial growth. However, alternative theories have been proposed and these highlight the difficulty of characterising congenital anomalies of craniofacial development in which multiple etiologies can result in very similar phenotypes.

Caudal dysplasia, femoral hypoplasia-unusual facies syndrome and absent radius: a new association in infant of diabetic mother?

The Caudal dysplasia syndrome (CDS) and the femoral hypoplasia-unusual facies syndrome (FHUFS) have been reported to be more frequent among infants of diabetic mothers (IDMs). Infact, uncontrolled maternal diabetes is the most common cause of both the syndromes. Till now, there is no case report to suggest absent radius as a manifestation of IDMs. The authors report a rare case of newborn, who presented with features compatible with both CDS and FHUFS with an additional feature of absent radius, which is not reported in the literature so far. The possibility that all these features represent different manifestations of the same disorder is discussed here.

Pierre Robin syndrome: an update.

OBJECTIVES: 'Pierre Robin' is one of the most readily recognised eponyms in medicine, yet it is a poorly understood nonspecific grouping of malformations that has no prognostic significance. Previously known as 'Pierre Robin syndrome', the way this diagnostic entity is viewed is now undergoing change. It is the purpose of this paper to review previous thinking about Robin and provide an update on recent clinical observations. SOURCES OF DATA: A computerised literature search using MEDLINE, EMBASE, AJOL and OMIM was conducted for published articles up to March 2006. Mesh phrases used in the search were: Pierre Robin syndrome, Robin anomalad and Robin sequence (RS). RESULTS: This relatively uncommon association of micrognathia with cleft palate and upper airway obstruction which was initially thought to be a specific disease and entire treatment regimens established to deal with presumed problems is now understood to be a grouping of clinical findings that does not represent a distinct multiple anomaly syndrome. The condition is therefore now described as 'Pierre Robin sequence'. Evidence of distinct cytogenetic anomalies has also highlighted the aetiological heterogeneity associated with RS in recent times. CONCLUSION: Infants with Robin sequence can present with varied problems, some of them emergencies. Clinicians must be aware of the high prevalence of associated syndromes and the possible contribution of other syndromic features to the problems for proper patient care. Candidate loci and potential candidate genes are currently being proposed in the literature for RS.

Maternal smoking and environmental tobacco smoke exposure and the risk of orofacial clefts.

BACKGROUND: Smoking during pregnancy has been associated with orofacial clefts in numerous studies. However, most previous studies have not been able to assess the relation between maternal smoking and specific phenotypes (eg, bilateral clefts). METHODS: We examined the association between periconceptional maternal smoking, environmental tobacco smoke (ETS) exposure, and cleft lip with or without cleft palate (CLP) (n = 933) and cleft palate only (CPO) (n = 528) compared with infants with no major birth defects (n = 3390). Infants were born between 1 October 1997 and 31 December 2001, and exposures were ascertained from maternal telephone interviews for the National Birth Defects Prevention Study. We excluded infants who had a first-degree relative with an orofacial cleft. Effect estimates were adjusted for folic acid use, study site, prepregnancy obesity, alcohol use, gravidity, and maternal age, education, and race/ethnicity. RESULTS: Periconceptional smoking was associated with CLP (odds ratio = 1.3; 95% confidence interval = 1.0-1.6), and more strongly associated with bilateral CLP (1.7; 1.2-2.6), with a weaker association observed for CPO. Heavy maternal smoking (25+ cigarettes/day) was associated with CLP (1.8; 1.0-3.2), bilateral CLP (4.2; 1.7-10.3), and CPO with Pierre Robin sequence (2.5; 0.9-7.0). ETS exposure was not associated with CLP or CPO. CONCLUSIONS: This study confirmed the modest association between smoking and orofacial clefts that has been consistently reported, and identified specific phenotypes most strongly affected.

Secuencia de Pierre Robin / Pierre Robin sequence

La secuencia de Pierre Robin constituye un desafío diagnóstico antenatal, el cual se transforma en un desafío terapéutico posterior al nacimiento por la multiplicidad de presentaciones al asociarse con otros síndromes más o menos complejos que provocan problemas en las decisiones de los distintos actores llamados a evaluar la necesidad de corrección quirúrgica o manejo conservador de los niñosque se presentan en forma esporádica en nuestros hospitales. Esta revisión pretende actualizar en forma sucinta los conocimientos sobre patogenia, fisiopatología, manifestaciones clínicas y herramientas terapéuticas con que se cuenta para enfrentar este cuadro.

Fetal hydrocolpos leading to Pierre Robin sequence: an unreported effect of oligohydramnios sequence.

The presence of distal atretic vagina causing accumulation of fluid and mucus secretions in the proximal vaginal cavity resulted in fetal hydrocolpos. Obstructive uropathy developed gradually because of direct compression of hydrocolpos on bilateral lower ureters, resulting in oligohydramnios from decreased urine formation. Oligohydramnios inhibited normal mandibular development with resulting cleft palate and glossoptosis (Pierre Robin Sequence). The development of sequence of events in this case indicates Pierre Robin Sequence as another effect of Oligohydramnios Sequence arising out of deformational forces acting on cranio-facial structures.

Brainstem dysfunction: a possible neuroembryological pathogenesis of isolated Pierre Robin sequence.

UNLABELLED: Pierre Robin sequence (posterior U-shape cleft palate, glossoptosis, retrognathia) (PRS) is a frequent and heterogeneous neonatal condition of obscure origin. We show here that orodigestive and cardiorespiratory functional disorders are very frequent in PRS and that these functional disorders, as well as anatomical and embryological data, argue for the involvement of brainstem dysfunction in the pathogenesis of some cases of isolated PRS. A total of 66 infants consecutively admitted for isolated PRS were followed-up with observations and investigations focused on their orodigestive and cardiorespiratory disorders. Neonatal clinical examination and neonatal anatomical aspects of the three orofacial features of the sequence were evaluated. Feeding difficulties and respiratory disorders were recorded and infants were classified according to three grades of severity. The relation between functional severity grade and neonatal orofacial features was evaluated, as well as the relation between functional severity grade and specific criteria characterising oesophageal and laryngeal motility and cardiac orthoparasympathetic imbalance. In the first weeks of life, sucking and swallowing disorders (100%), excessive regurgitation (94%), upper airways obstruction (50%), and cardiac vagal overactivity (59%) were noted. Correlation of anatomical features with functional severity grades was poor except for extreme forms of glossoptosis and retrognathia. Specific anomalies of oesophageal motility, pharyngolaryngeal tone and parasympathetic cardiac regulation were described. These anomalies were more frequent in children with the two higher grades of functional severity. CONCLUSION: infants with Pierre Robin sequence have early and severe anomalies of orodigestive and cardiorespiratory function which do not appear to be related solely to anatomical features and which require proper medical management. We suggest a prenatal and neonatal brainstem dysfunction as a neuroembryological hypothesis to explain the onset of some cases of Pierre Robin sequence.

Actualización en el tratamiento ortopédico del síndrome de Pierre Robin / An update in the orthopedic treatment of Pierre Robin syndrome

Se describe el tratamiento ortopédico del niño que presenta la "secuencia de Pierre Robin" (anteriormente llamado Síndrome de Pierre Robin) el cual comienza a partir de la primera semana de vida. El tratamiento ortopédico se efectúa con una prótesis de acrílico, cuyo flanco vestibular va adosado al reborde alveolar superior, presentando a nivel del postdaming una prolongación posterior (tipo coleta) que coincide con la fisura. Gracias a ella, la lengua encuentra un punto de apoyo posterosuperior que le permite descender y adelantarse progresivamente solucionando en parte el micrognatismo mandibular y la glosoptosis característica de esta patología, logrando que el niño pueda ser alimentado con biberón. Este recurso terapéutico, sumado al uso de tetinas y chupetes anatómicos y a un tratamiento postural adecuado (posición supino-prono) permiten una correcta alimentación y mejora también los problemas respiratorios característicos de estos niños. El enfoque ortopédico es preparatorio para un exitoso cierre quirúrgico de la fisrua, que complementado con el tratamiento fonoaudiológico y el apoyo psicológico, permiten la rehabilitación de estos niños antes de la edad escolar, mediante un trabajo multi e interdisciplinario

Etiopathogenesis of isolated Robin sequence.

OBJECTIVE: To investigate the etiopathogenesis of isolated Robin sequence. DESIGN: A longitudinal and prospective study of children with isolated Robin sequence and no other associated syndromes or malformations. SETTING: The study was carried out at the Hospital de Reabilitação de Anomalias Craniofaciais (formerly the Hospital for Research and Rehabilitation of Cleft Lip/Palate), University of São Paulo, Bauru, SP, Brazil, which provides care for patients with lip/palate lesions throughout Brazil. PATIENTS: Forty-three children were initially included in the study, seven of whom were later found to be cases of Stickler syndrome and excluded. The remaining 36 children presenting only the anomaly triad of microretrognathia, glossoptosis, and cleft palate were followed up from the first month of life to 4 years of age with repetitive clinical and ophthalmological examination. MAIN OUTCOME MEASURE: A family history of cleft lip/palate was determined on the basis of information provided by the parents and, when possible, the affected relative was submitted to physical examination. RESULTS: A family history of cleft lip/palate was observed in 27.7% of cases, one case having a younger brother with only cleft palate but no microretrognathia or glossoptosis. Six cases of isolated cleft palate and three cases of cleft lip with or without cleft palate were present in distant relatives. Complete U-shaped cleft palate (wide cleft) was the most frequent type of cleft, which was present in 75% of cases. Only one case of incomplete cleft palate was observed, but U-shaped; 25% of the patients presented complete V-shaped cleft palate. CONCLUSIONS: We conclude that heredity could be a factor in the etiopathogenesis of isolated Robin sequence and suggest that cleft palate (usually complete and U-shaped) is the primary event in the determination of the triad of anomalies.

Atendimento da crianca portadora da sequencia de Pierre Robin / Attendence of the child carrier state of the sequence of Pierre Robin

Os autores descrevem a experiencia clinica no tratamento de criancas portadoras da Sequencia de Pierre Robin (fissura de palato, micrognatia e glossoptose) no Hospital de Pesquisa e Reabilitacao de Lesoes Labio-Palatais, da Universidade de Sao Paulo, Bauru-SP .

Pierre Robin sequence associated with amniotic band syndrome ultrasonographic diagnosis and pathogenesis.

A case of prenatal diagnosis of the Pierre Robin sequence is reported in which hydramnios and amniotic bands are present. The possible pathogenesis is discussed.