Mutations in SNRPB, encoding components of the core splicing machinery, cause cerebro-costo-mandibular syndrome.

Cerebro-costo-mandibular syndrome (CCMS) is a developmental disorder characterized by the association of Pierre Robin sequence and posterior rib defects. Exome sequencing and Sanger sequencing in five unrelated CCMS patients revealed five heterozygous variants in the small nuclear ribonucleoprotein polypeptides B and B1 (SNRPB) gene. This gene includes three transcripts, namely transcripts 1 and 2, encoding components of the core spliceosomal machinery (SmB' and SmB) and transcript 3 undergoing nonsense-mediated mRNA decay. All variants were located in the premature termination codon (PTC)-introducing alternative exon of transcript 3. Quantitative RT-PCR analysis revealed a significant increase in transcript 3 levels in leukocytes of CCMS individuals compared to controls. We conclude that CCMS is due to heterozygous mutations in SNRPB, enhancing inclusion of a SNRPB PTC-introducing alternative exon, and show that this developmental disease is caused by defects in the splicing machinery. Our finding confirms the report of SNRPB mutations in CCMS patients by Lynch et al. (2014) and further extends the clinical and molecular observations.

Heterogeneity of mutational mechanisms and modes of inheritance in auriculocondylar syndrome.

BACKGROUND: Auriculocondylar syndrome (ACS) is a rare craniofacial disorder consisting of micrognathia, mandibular condyle hypoplasia and a specific malformation of the ear at the junction between the lobe and helix. Missense heterozygous mutations in the phospholipase C, ß 4 (PLCB4) and guanine nucleotide binding protein (G protein), α inhibiting activity polypeptide 3 (GNAI3) genes have recently been identified in ACS patients by exome sequencing. These genes are predicted to function within the G protein-coupled endothelin receptor pathway during craniofacial development. RESULTS: We report eight additional cases ascribed to PLCB4 or GNAI3 gene lesions, comprising six heterozygous PLCB4 missense mutations, one heterozygous GNAI3 missense mutation and one homozygous PLCB4 intragenic deletion. Certain residues represent mutational hotspots; of the total of 11 ACS PLCB4 missense mutations now described, five disrupt Arg621 and two disrupt Asp360. The narrow distribution of mutations within protein space suggests that the mutations may result in dominantly interfering proteins, rather than haploinsufficiency. The consanguineous parents of the patient with a homozygous PLCB4 deletion each harboured the heterozygous deletion, but did not present the ACS phenotype, further suggesting that ACS is not caused by PLCB4 haploinsufficiency. In addition to ACS, the patient harbouring a homozygous deletion presented with central apnoea, a phenotype that has not been previously reported in ACS patients. CONCLUSIONS: These findings indicate that ACS is not only genetically heterogeneous but also an autosomal dominant or recessive condition according to the nature of the PLCB4 gene lesion.

Commissuroplasty for macrostomia: surgical technique and long-term aesthetic and functional results assessment.

BACKGROUND: Macrostomia or lateral cleft lip is a rare congenital deformity. In this article we describe a surgical technique of macrostomia repair developed. The objective of this article is to assess the results of our surgical technique and to validate a method for macrostomia surgical result evaluation. METHODS: We included retrospectively patients with unilateral and bilateral macrostomia, operated from 1995 to 2014 in our department. First part of the study was a satisfaction questionnaire completed by patients. The second part was subjective evaluation of frontal photography (closed mouth, wide open and smiling) by surgeons and lay people with a questionnaire. Both group completed a second questionnaire within one to six months. RESULTS: Eighteen patients answered the questionnaire. The satisfaction for all patients were considered as very good for 38.9% (n = 7) of patients and good for 44.4% (n = 8). 21 patients were photographed, 5 isolated macrostomia, 13 macrostomia with minor facial asymmetry and 3 with a major asymmetry. Surgeons evaluated the result as very good for isolated macrostomia and good for syndromic macrostomia. Layperson evaluated the result as good in isolated macrostomia and macrostomia with minor facial asymmetry and average with major facial asymmetry. P < 0.0001. The evolution of the results between medical and non-medical assessors in our two questionnaires, were non-significant. CONCLUSION: In this study, we propose a new methodology to assess commissuroplasty surgical results, with a 3 type of evaluator: patients, surgeons and laypeople. We present a simple surgical technique, that allows good results in syndromic and isolated macrostomia.

Conservative management is effective in unicystic ameloblastoma occurring from the neonatal period: A case report and a literature review.

Unicystic ameloblastoma (UA), a benign odontogenic tumor of the jaw, represents less than a third of all ameloblastomas and seems less aggressive than other types of ameloblastoma. We present here the first case of UA that developed prenatally and was successfully managed in the early neonatal period with marsupialization and curettage performed carefully to avoid injury to the tooth germ. BRAF and SMO mutations were not detected. After 2 years of follow-up, complete reossification and normal eruption of deciduous teeth were noted, and there was no recurrence of UA. We recommend conservative treatment of UA in the pediatric population to avoid loss of and/or injury to the tooth germ, provided close follow-up is carried out all through the individual's growth for early detection of potential recurrences, growth impairments, or tooth eruption disorders. The intratumoral somatic mutational status of BRAF, SMO, RAS family, and FGFR2 may help determine personalized targeted treatment, particularly in case of recurrence.

Oral health related quality of life of children and adolescents affected by rare orofacial diseases: a questionnaire-based cohort study.

BACKGROUND: Rare diseases affecting the teeth, the oral cavity and the face are numerous, each of them present specific characteristics, and is a life-long condition. The aim of the study was to assess the association between Oral health-related quality of life (OHRQoL), and demographic characteristics, clinical and dental factors, and psycho-social characteristics to investigate that oral symptoms are not the main factors underlying a decrease in OHRQoL. MATERIAL AND METHODS: We conducted a national cohort study in French centres for rare diseases (RD) specialized in orofacial diseases. The inclusion criteria were: to have received care in RD centres over the last 5 years (2012-2017) and to have been between 6 and 17 years of age on September 1, 2017. Patients were invited to answer a questionnaire composed of socio-demographic, clinical and dental questions, psychosocial questions and then fill in the Child-OIDP Index. At the end of the questionnaire, a free space was left for the patient to add a verbatim comment to provide qualitative data. Thematic analysis was used to analyze the verbatim answers. RESULTS: Complete data were available for 110 patients. The sample included 44.5% boys and 55.5% girls. Ages ranged from 6 to 17 years old and 68.2% were between 6 to 12 years old and 31.8% were between 13 and 17 years old. Factor associated with a lower OHRQoL were: being a girl (p = 0.03), renouncement to dental care for financial reasons (p = 0.01), having syndromic disease (p = 0.01), having a problem with tooth shape and color (p = 0.03), feeling isolated, alone and different from other children (p = 0.003 and p = 0.02). Qualitative analysis highlighted very little recourse to psychological care and patients reported great anxiety and fear about the future. CONCLUSION: OHRQoL of children suffering from these diseases is impaired, especially from the psychosocial point of view but also from that of the course of treatment and access to care. There is a need to improve the legibility of care pathways and the financial coverage of treatments.

Management of rare diseases of the Head, Neck and Teeth: results of a French population-based prospective 8-year study.

BACKGROUND: In the last ten years, national rare disease networks have been established in France, including national centres of expertise and regional ones, with storage of patient data in a bioinformatics tool. The aim was to contribute to the development and evaluation of health strategies to improve the management of patients with rare diseases. The objective of this study has been to provide the first national-level data concerning rare diseases of the head, neck and teeth and to assess the balance between demand and supply of care in France. METHODS: Centres of expertise for rare diseases record a minimum data set on their clinical cases, using a list of rare Head, Neck and Teeth diseases established in 2006. The present analysis focuses on 2008 to 2015 data based on the Orphanet nomenclature. Each rare disease RD "case" was defined by status "affected" and by the degree of diagnostic certainty, encoded as: confirmed, probable or non-classifiable. Analysed parameters, presented with their 95% confidence intervals using a Poisson model, were the following: time and age at diagnosis, proportions of crude and standardized RD prevalence by age, gender and geographical site. The criteria studied were the proportions of patients in Paris Region and the "included cases geography", in which these proportions were projected onto the other French Regions, adjusting for local populations. RESULTS: In Paris Region, estimated prevalence of these diseases was 5.58 per 10,000 inhabitants (95% CI 4.3-7.1). At December 31st 2015, 11,342 patients were referenced in total in France, of whom 7294 were in Paris Region. More than 580 individual clinical entities (ORPHA code) were identified with their respective frequencies. Most abnormalities were diagnosed antenatally. Nearly 80% of patients recorded come to Paris hospitals to obtain either diagnosis, care or follow up. We observed that the rarer the disease, the more patients were referred to Paris hospitals. CONCLUSIONS: A health network covering a range of aspects of the rare diseases problematic from diagnostics to research has been developed in France. Despite this, there is still a noticeable imbalance between health care supply and demand in this area.

Evaluation of 5-year-old children with complete cleft lip and palate: Multicenter study. Part 2: Functional results.

BACKGROUND AND PURPOSE: Cleft surgery is marked by all the controversies and the multiplication of protocols, as it has been shown by the Eurocleft study. The objective of this pilot study is to start a comparison and analyzing procedure between primary surgical protocols in French centers. METHODS: Four French centers with different primary surgical protocols for cleft lip and palate repair, have accepted to be involved in this retrospective study. In each center, 20 consecutive patients with complete cleft lip and palate (10 UCLP, 10 BCLP per center), non syndromic, have been evaluated at a mean age of 5 [range, 4-6]. In this second part, maxillary growth and palatine morphology were assessed on clinical examination and on dental casts (Goslon score). Speech was also evaluated clinically (Borel-maisonny classification) and by Aerophonoscope. RESULTS: Veau-Wardill-Killner palatoplasty involves a higher rate of transversal maxillary deficiency and retromaxillary. The fistula rate is statistically lower with tibial periosteum graft hard palate closure but this technique seems to give retromaxillary. Malek and Talmant two-stage-palatoplasty techniques reach Goslon scores of 1 or 2. Considering speech, Sommerlad intravelar veloplasty got higher outcomes. CONCLUSIONS: Primary results. Extension to other centers required. The two-stage palatoplasty, including a Sommerlad intravelar veloplasty seems to have the less negative impact on maxillary growth, and to give good speech outcomes. LEVEL OF EVIDENCE: Therapeutic study. Level III/retrospective multicenter comparative study.

Defining a new aggressiveness classification and using NFATc1 localization as a prognostic factor in cherubism.

Cherubism is a rare genetic disease characterized by bilateral giant cell reparative granuloma of the jaws consisting of a fibrotic stroma with giant multinucleated cells (GMCs) and osteoclastic features. Cherubism severity is highly variable, and recurrence after surgery is the most important risk. Currently, there are no prognostic indicators. The aims of this study were to evaluate the osteoclastogenesis phenotype by histologic examination of nuclear factor of activated T cells 1 (NFATc1) localization and tartrate-resistant acid phosphatase (TRAP) activity and to correlate the results to disease aggressiveness to define prognostic indicators. Based on cherubism evolution 1 year after surgery, 3 classes of cherubism aggressiveness were identified: mild (group A), moderate (group B), and severe (group C). Histologically, in grade A and B cherubism lesions, GMCs were negative for both TRAP activity and NFATc1 nuclear localization. In contrast, in grade C cherubism lesions, GMCs were all positive for TRAP activity and NFATc1 nuclear localization and displayed osteoclast-like features. Other histopathologic findings were not different among the 3 groups. Our results establish that TRAP activity and NFTAc1 nuclear localization are associated with aggressive cherubism and therefore could be added to routine pathologic examination to aid in prognosis and management of the disease. The finding of NFATc1 nuclear localization in aggressive tumors supports the addition of anticalcineurin treatment to the therapeutic arsenal for cherubism.

Skeletal and soft tissue changes and stability in cleft lip and palate patients after distraction osteogenesis using a new intraoral maxillary device.

BACKGROUND: The authors have recently reported on the use of an internal maxillary distraction device. In this study, we report on the hard and soft tissue movements achieved with this intraoral distraction device, and the stability changes after distraction osteogenesis for maxillary hypoplasia in patients with cleft lip and palate. METHODS: Ten male patients with severe hypoplasia of the maxilla, with complete uni- or bilateral cleft lip and palate were included. The mean age of the patients at the time of operation was 11.91 years (±3.41). To evaluate the distraction process and stability, superimpositions on the preoperative lateral cephalograms were performed. The mean follow-up (FU) was 15.42 months (±3.94). RESULTS: Cephalometric measurements at all of the maxillary hard and soft tissue points improved significantly. Maxillary point A was advanced by 8.25 mm (±3.17; P < 0.001). After distraction soft tissue point A' had advanced 7.10 mm (±2.69; P < 0.001). The soft tissue to hard tissue ratio at point A was 0.86:1 after distraction. Maxillary horizontal relapse at point A was 14.1% at FU. Vertical relapse was not significant. CONCLUSION: This rigid intraoral distraction device can be successfully used in the correction of severe maxillary hypoplasia. The marked aesthetic improvement and low psychological encumbrance make this device viable for the treatment of cleft-related hypoplasia of the maxilla.

Osseous and dental outcomes of primary gingivoperiosteoplasty with iliac bone graft: A radiological evaluation.

Primary alveolar cleft repair has two main purposes: to restore normal morphology and normal function. Gingivoperiosteoplasty with bone grafting in mixed dentition has been a well-established procedure. We hypothesized that 1) performance of this surgery in deciduous dentition would provide favorable bone graft osseointegration, and 2) would improve the support of incisor teeth eruption, thereby avoiding maxillary growth disturbances. We conducted a retrospective study of clinical and tridimensional radiological data for 73 patients with alveolar clefts (with or without lip and palate clefts) who underwent gingivoperiosteoplasty with iliac bone graft in deciduous dentition. Pre- and post-operative Cone Beam Computed Tomography (CBCT) comparison allowed evaluation of the ratio between bone graft volume and initial cleft volume (BGV/ICV ratio), and measurement of central incisor teeth movements. This series of 73 patients included 44 males and 29 females, with a mean age of 5.5 years. Few complications were observed. Post-operative CBCT was performed at 7.4 months. The mean BGV/ICV ratio was 0.62. Axial rotation was significantly improved post-operatively (p = 0.004). Gingivoperiosteoplasty with iliac bone graft is safe when performed in deciduous dentition and results in a sufficient bone graft volume to support lateral incisor eruption and upper central incisor tooth position improvement.

The calcineurin inhibitor tacrolimus as a new therapy in severe cherubism.

Cherubism is a rare genetic disorder characterized by extensive growth of a bilateral granuloma of the jaws, resulting in facial disfigurement. Cherubism is caused by gain-of-function mutations in the SH3BP2 gene, leading to overactivation of nuclear factor of activated T cells, cytoplasmic 1 (NFATc1)-dependent osteoclastogenesis. Recent findings in human and mouse cherubism have suggested that calcineurin inhibitors might be drug candidates in cherubism medical treatment. A 4-year-old boy with aggressive cherubism was treated with the calcineurin inhibitor tacrolimus for 1 year, and clinical, radiological, and molecular data were obtained. Immunohistologic analysis was performed to compare preoperative and postoperative NFATc1 staining and tartrate resistant acid phosphatase (TRAP) activity. Real-time PCR was performed to analyze the relative expression levels of OPG and RANKL. After tacrolimus therapy, the patient showed significant clinical improvement, including stabilization of jaw size and intraosseous osteogenesis. Immunohistologic analyses on granuloma showed that tacrolimus caused a significant reduction in the number of TRAP-positive osteoclasts and NFATc1 nuclear staining in multinucleated giant cells. Molecular analysis showed that tacrolimus treatment also resulted in increased OPG expression. We present the first case of effective medical therapy in cherubism. Tacrolimus enhanced bone formation by stimulating osteogenesis and inhibiting osteoclastogenesis.

Infant Odontogenic Myxoma: a specific entity.

INTRODUCTION: In children, and specifically in infants, odontogenic myxomas are extremely rare. In infants, myxoma seems to display mostly the same clinical, radiological and pathological characteristics. This paper presents a series of odontogenic myxomas in infant patients. MATERIALS AND METHODS: Four infant patients were included in this retrospective study. The clinical, radiological and pathological presentation was characterized and the treatment analysed. RESULTS: All patients presented with a rapidly evolving paranasal swelling. CT-scan showed a maxillary homogeneous unilocular and intraosseous tumour. In all cases, pathological examination revealed a loose myxoid stroma within stellate and spindle shaped cells. All patients underwent conservative surgery through a vestibular approach. CONCLUSION: This patient series and a review of the literature demonstrates that odontogenic myxoma is specific in infant. We propose the name of Infant Odontogenic Myxoma for this entity.

Specificity of paediatric jawbone lesions: tumours and pseudotumours.

INTRODUCTION: Characteristics and epidemiology of jaw tumours have been described mostly in adults. Compared with their adult counterparts, childhood jaw tumours show considerable differences. The aim of this study was to describe the different jaw tumours in children, define diagnostic tools to determine their specificity and describe optimal treatment. METHODS: All children patients with jaw lesions, excluding cysts, apical granuloma and osteitis were included in our study between 1999 and 2009. The medical records were analyzed for clinical, radiological, and pathological findings, treatments and recurrences. RESULTS: Mean patient age was 10.9 years old, ranging from 2 months to 18 years old. Of the 63 lesions, 18 were odontogenic and 45 non-odontogenic lesions. 6% of all cases were malignant tumours; the mean age of presentation was 7.25 years old, [ranging from 0.2 to 18 years old]. Approximately 80% of the tumours developed after 6 years of age. Odontogenic tumours occurred more often after the age of 6. CONCLUSION: Compared with their adult counterpart, childhood jaw tumours show considerable differences in their clinical behaviour and radiological and pathological characteristics. Clinical features of some tumours can be specific to children. Tumourigenesis is related to dental development and facial growth. Conservative treatment should be considered.

PTCH1 mutation and local aggressiveness of odontogenic keratocystic tumors in children: is there a relationship?

Keratocystic odontogenic tumors (KCOTs) are locally aggressive jaw lesions that may be related to PTCH1 mutations in isolation or in association with nevoid basal cell carcinoma syndrome. We sought to clarify the role of PTCH1 mutation in KCOT aggressiveness. We assessed cyst pathological characteristics, Ki-67 immunostaining, and somatic and germinal PTCH1 mutation in 16 KCOTs from 10 unrelated patients. Ten PTCH1 mutations were identified in 16 tumors. All tumors with PTCH1 mutations presented the criteria of pathological aggressiveness. We also noted the presence of a chorionic epithelial structure apparently acting as a secondary germinal center in these same tumors. Ki-67 immunostaining was not associated with PTCH1 mutation. KCOTs harboring the mutation display a chorionic epithelial structure that acts as a secondary germinal center. Genetic and microenvironmental factors might interact to propel tumor development.

Highly conserved non-coding elements on either side of SOX9 associated with Pierre Robin sequence.

Pierre Robin sequence (PRS) is an important subgroup of cleft palate. We report several lines of evidence for the existence of a 17q24 locus underlying PRS, including linkage analysis results, a clustering of translocation breakpoints 1.06-1.23 Mb upstream of SOX9, and microdeletions both approximately 1.5 Mb centromeric and approximately 1.5 Mb telomeric of SOX9. We have also identified a heterozygous point mutation in an evolutionarily conserved region of DNA with in vitro and in vivo features of a developmental enhancer. This enhancer is centromeric to the breakpoint cluster and maps within one of the microdeletion regions. The mutation abrogates the in vitro enhancer function and alters binding of the transcription factor MSX1 as compared to the wild-type sequence. In the developing mouse mandible, the 3-Mb region bounded by the microdeletions shows a regionally specific chromatin decompaction in cells expressing Sox9. Some cases of PRS may thus result from developmental misexpression of SOX9 due to disruption of very-long-range cis-regulatory elements.

Bilateral macrostomia as an isolated pathology.

OBJECTIVE: Congenital macrostomia is a lateral orofacial cleft between the maxillary and mandibular components of the first branchial arch. Bilateral macrostomia is a poorly characterized malformation, with only 14 cases reported in the literature. The purpose of this study was to compare our experience with the world literature. METHOD: A retrospective analysis of 20 cases of bilateral congenital macrostomia was conducted; 6 cases were drawn from 2 maxillofacial surgery units and 14 cases from the world literature. Cases of bilateral congenital macrostomia were compared with cases of unilateral forms using a review of the literature post-1954. Among the six cases identified from the two maxillofacial surgery units, three were treated with linear sutures and three with Z-plasty. Subsequent aesthetic and functional results were analyzed. RESULTS: Compared to unilateral forms, bilateral macrostomia is more often isolated without ear or skin deformities. Moreover, there are a greater proportion of larger defects among cases with bilateral macrostomia when compared to unilateral macrostomia. Alimentation, phonation, and mouth opening were always normal. The two sides were always symmetric. Only one case presented with the complication of skin contractions during lip movement. CONCLUSION: The etiopathogenesis of bilateral macrostomia is unclear. Although over 50% of the reported cases of bilateral macrostomia are isolated, this condition presents a therapeutic challenge. In the case of bilateral forms, the surgeon must define the commissure position without a normal side. Repair thus requires extraoral landmarks and normal measurements.