Folate intake, markers of folate status and oral clefts: An updated set of systematic reviews and meta-analyses.

BACKGROUND: There has been a longstanding debate about the role of folate in the etiology of orofacial clefts (OFCs). Studies of different measures of nutritional intake or folate status have been done to investigate the possible role of folate in the prevention of OFC. Only one knowledge synthesis has attempted to bring together different types of evidence. The aim of the present work was to update it. METHODS: Evidence for associations between OFC and dietary folate, supplement use, folic acid fortification, biomarkers of folate status, and variants of MTHFR (C677T and A1298C) were included. Potentially eligible articles were systematically identified from PubMed, Medline, Embase, and Web of Science (2007-2020) and combined using random-effects meta-analysis when appropriate. Quality assessments were conducted using the Newcastle-Ottawa scale and Cochrane's risk of bias tool. RESULTS: Sixty-four studies published since the previous knowledge synthesis were identified, with eight of these identified through a supplementary search from October, 2018 to August, 2020. There was an inverse association between folic acid-containing supplement use before or during pregnancy and cleft lip with or without cleft palate (CL/P) (OR 0.60, 95% CI 0.51-0.69), with considerable between-study heterogeneity. The prevalence of CL/P showed a small decline post-folic acid fortification in seven studies (OR 0.94, 95% CI 0.86-1.02). No association was found between OFC and genetic markers of folate status. The coronavirus-19 pandemic has threatened food availability globally and therefore there is a need to maintain and even enhance surveillance concerning maternal intake of folate and related vitamins. CONCLUSIONS: The risk of non-syndromic OFC was reduced among pregnant women with folic acid-containing supplements during the etiologically relevant period. However, high heterogeneity between included studies, incomplete reporting of population characteristics and variation in timing of exposure and supplement types mean that conclusions should be drawn with caution.

Anomalies of the oral cavity in newborns.

Examination of the oral cavity should be an essential part of the newborn assessment. Early detection of congenital disorders is essential to begin appropriate medical or surgical therapy and to prevent complications that could profoundly affect a child's life. The present review aims to describe the main anomalies of the oral cavity in infants and provide images in order to help the physician in current clinical practice.

Incidence of Egyptian Live Births of Cleft Lip and/or Palate in Cairo, Luxor, Aswan and New Valley Governorates: A Survey Study in 237,783 Children

Objective: To evaluate the prevalence, cleft types distribution and etiological risk factors among newly born babies with cleft lip and/or palate (CL±P) in four governorate of the Arab Republic of Egypt, beginning the 1st of January 2013 till the 31st of December 2013. Material and Methods: Total 237,783 newly born babies from Cairo (162174), Aswan (42880), Luxor (32729), and New Valley (877) governorate in the Arab Republic of Egypt were included in this study. Incidence of CL±P babies per 1000 births was calculated in each district for the four studied governorates. Percentage distribution of cleft types within each governorate. Chi-square test was used for determining significance of difference of incidence and percentages within and between the governorates. Results: The mean prevalence value of CL±P in the four Egyptian studied governorates was 0.40/1000. The highest percentage of cleft type was cleft lip and palate followed by cleft lip and isolated cleft palate. The highest etiological risk factor was maternal passive smoking in the four studied governorates followed by consanguineous marriage and medicine intake during pregnancy. Conclusion: These data provided a picture of the prevalence of CL±P in four different governorate of Egypt and also provided a useful reference for cleft types distribution and etiological risk factors of CL±P data in Egypt and internationally.

Congenital dilatation of the submandibular duct.

Congenital dilatation of the submandibular duct also known as imperforate submandibular duct is a rare condition of unknown etiology, clinically characterized as a well-defined, fluctuant swelling in the floor of the mouth, and microscopically defined as a cystic cavity covered with pseudostratified columnar epithelium consistent with a dilated salivary duct. A 1-month-old female presented with a translucent, smooth cystic swelling in the floor of the mouth causing breastfeeding difficulty. The lesion was surgically excised and microscopically, a cystic cavity lined with pseudostratified columnar epithelium was observed. The final diagnosis was congenital dilatation of the submandibular duct. Dentists and otolaryngologists should consider congenital dilatation of the submandibular duct when evaluating fluctuant swelling in the floor of the month of infants.

Comportamiento de la oclusión dentaria en pacientes operados de cirugía ortognática / Behavior of dental occlusion in patients undergoing orthognathic surgery

Introducción: la cirugía ortognática corrige las alteraciones del componente esquelético en las anomalías dentomaxilofaciales. Estas deformidades provocan deficiente relación de los huesos maxilares, afectando la oclusión dentaria y sus funciones. Objetivo: identificar el comportamiento de la oclusión dentaria en pacientes que fueron intervenidos por cirugía ortognática. Materiales y Métodos: se realizó un estudio observacional descriptivo con el objetivo de identificar características oclusales en pacientes intervenidos por cirugía ortognática. Se utilizaron las variables: relación de molares, guías de función lateral, tipo de masticación, interferencias oclusales en movimiento de protrusión y de lateralidad. Resultados: se observaron pacientes con relación de molares en mesioclusión, lo cual es un indicio de recidiva de la neutroclusión que había sido alcanzada. La intervención quirúrgica de mayor incidencia fue la retroposición mandibular acompañada de centralización. Existió una gran mejoría de la función masticatoria. La mayoría de los pacientes, se encontraban libres de interferencias oclusales. Conclusiones: los examinados se encontraron entre los grupos de edades de 24 a 38 años, y el sexo femenino predominó con un 60,5 %. El 13, 2 % de los sujetos presentaron mesioclusión, con mayor incidencia en los casos intervenidos con retroposición y centralización de la mandíbula. Predominó la función canina en los movimientos de lateralidad. La mayoría de los pacientes se encontraban libres de interferencias oclusales, representando el 71,1 % de los pacientes estudiados.

Introduction: the orthognatic surgery corrects the alterations of the skeletal component in dentomaxillafacial anomalies. These deformations cause deficient relations of the maxillary bones, affecting the dental occlusion and its functions. Objective: to identify dental occlusion behavior in patients undergoing orthognatic surgery. Materials and methods: an observational, descriptive study was carried out with the objective of identifying oclussal characteristics in patients who underwent orthognatic surgery. The used variables were: molars relation, guides of lateral functioning, kinds of chewing, occlusive interferences in protrusion movements and in movements of laterality. Results: patients were found with molars relation of mesiooclussion, which is an indication of recidivism in the achieved neutroclussion. The surgical intervention with higher incidence was mandibular retro positioning accompanied by centralization. There it was a great improvement of the chewing function. Most of the patients were free of oclussal interferences. Conclusions: the assessed patients were in the age-groups from 24 to 38 years, and female sex predominated with 60.5 %. 13.2 % of the subjects had mesiocclusion, with higher incidence in the cases surgically treated with jaw retroposition and centralization. The canine tooth function in the lateral movements predominated. Most of the patients were free from occlusive interferences, being 71.1 % of the studied patients.

Comportamiento de la oclusión dentaria en pacientes operados de cirugía ortognática / Behavior of dental occlusion in patients undergoing orthognathic surgery

Introducción: la cirugía ortognática corrige las alteraciones del componente esquelético en las anomalías dentomaxilofaciales. Estas deformidades provocan deficiente relación de los huesos maxilares, afectando la oclusión dentaria y sus funciones. Objetivo: identificar el comportamiento de la oclusión dentaria en pacientes que fueron intervenidos por cirugía ortognática. Materiales y Métodos: se realizó un estudio observacional descriptivo con el objetivo de identificar características oclusales en pacientes intervenidos por cirugía ortognática. Se utilizaron las variables: relación de molares, guías de función lateral, tipo de masticación, interferencias oclusales en movimiento de protrusión y de lateralidad. Resultados: se observaron pacientes con relación de molares en mesioclusión, lo cual es un indicio de recidiva de la neutroclusión que había sido alcanzada. La intervención quirúrgica de mayor incidencia fue la retroposición mandibular acompañada de centralización. Existió una gran mejoría de la función masticatoria. La mayoría de los pacientes, se encontraban libres de interferencias oclusales. Conclusiones: los examinados se encontraron entre los grupos de edades de 24 a 38 años, y el sexo femenino predominó con un 60,5 %. El 13, 2 % de los sujetos presentaron mesioclusión, con mayor incidencia en los casos intervenidos con retroposición y centralización de la mandíbula. Predominó la función canina en los movimientos de lateralidad. La mayoría de los pacientes se encontraban libres de interferencias oclusales, representando el 71,1 % de los pacientes estudiados. (AU)

Introduction: the orthognatic surgery corrects the alterations of the skeletal component in dentomaxillafacial anomalies. These deformations cause deficient relations of the maxillary bones, affecting the dental occlusion and its functions. Objective: to identify dental occlusion behavior in patients undergoing orthognatic surgery. Materials and methods: an observational, descriptive study was carried out with the objective of identifying oclussal characteristics in patients who underwent orthognatic surgery. The used variables were: molars relation, guides of lateral functioning, kinds of chewing, occlusive interferences in protrusion movements and in movements of laterality. Results: patients were found with molars relation of mesiooclussion, which is an indication of recidivism in the achieved neutroclussion. The surgical intervention with higher incidence was mandibular retro positioning accompanied by centralization. There it was a great improvement of the chewing function. Most of the patients were free of oclussal interferences. Conclusions: the assessed patients were in the age-groups from 24 to 38 years, and female sex predominated with 60.5 %. 13.2 % of the subjects had mesiocclusion, with higher incidence in the cases surgically treated with jaw retroposition and centralization. The canine tooth function in the lateral movements predominated. Most of the patients were free from occlusive interferences, being 71.1 % of the studied patients.(AU)

Selected clinical features of the head and neck in women with Turner syndrome and the 45,X/46,XY karyotype.

INTRODUCTION: A 45,X/46,XY karyotype in women with Turner syndrome (TS) is very rare. The presence of a Y chromosome in the karyotype causes phenotypic differences and increased risk for neoplastic disease, compared to TS-women with other karyotypes. Our study addresses an issue: non-genital phenotypic differences between TS-patients with a Y-chromosome of their karyotype and TS-women without it. MATERIAL AND METHODS: Results from patient history/physical examinations of the head and neck of eight TS-women and the 45,X/46,XY karyotype were compared with those observed in 164 TS-women and 30 controls. The heights of TS-groups: 142.5 ± 7.2 and 144.9 ± 7.2 cm were lower than controls (165.2 ± 6.6 cm). Participants were examined from 1995 to 2014. RESULTS: Among 28 study parameters, 15 were more frequently observed in TS women with the 45,X/46,XY karyotype compared to controls. Only abnormalities in the oral cavity and a history of childhood lymphoedema, differed significantly in the TS groups. CONCLUSIONS: With respect to the head and neck, the patient history and physical examination results of TS-women and the 45,X/46,XY karyotype and TS and other karyotypes revealed similar differences compared to controls. Compared to others TS patients, 45,X/46,XY individuals might more frequently have oral cavity soft tissue abnormalities and more rarely a history of childhood lymphoedema. (Endokrynol Pol 2017; 68 (1): 47-52).

Tratamento primário da deformidade labial e nasal nas fissuras labiais e labiopalatinas unilaterais / Primary treatment of lip and nasal deformity in unilateral cleft lip or cleft lip and palate

Introdução: A fissura labiopalatina é a deformidade congênita mais frequente dentre as malformações craniofaciais, afetando principalmente o lábio superior, nariz e palato. A realização da queiloplastia associada à rinoplastia primária em tempo único é uma tendência. Avaliamos a correlação entre a gravidade da fissura, a idade cirúrgica e a qualidade estética do resultado pós-operatório. Métodos: Foram avaliados 26 pacientes com fissuras labiais ou labiopalatinas unilaterais, com idades entre 3 e 12 meses, operados pela técnica de queilorrinoplastia de Göteborg/McComb. Foi feita uma avaliação fotográfica do pré e pós-operatório por cinco cirurgiões plásticos separadamente e os dados analisados. Resultados: A idade média de realização do procedimento foi de 6,5 ± 3,15 meses, sendo que somente sete pacientes (26,9%) foram operados na idade de 3 meses preconizada pelo protocolo. Foi encontrada correlação entre a gravidade da fissura e a qualidade dos resultados, ao mesmo tempo em que não foi encontrada associação entre a idade da cirurgia e os resultados. Todos os casos do estudo foram considerados ótimos ou satisfatórios. Conclusões: A utilização de uma técnica de queiloplastia que seja de fácil reprodutibilidade, com bons resultados estéticos, e que possa ser utilizada em conjunto com outras técnicas de tratamento primário do nariz é uma boa opção a ser adotada por centros de tratamentos deste tipo de paciente. A gravidade da fissura é um fator importante na qualidade dos resultados. Quanto mais grave a fissura os resultados tendem ser piores. A idade da cirurgia, neste estudo, não teve correlação com a qualidade nos resultados.

Introduction: Cleft lip and palate, the most frequent congenital craniofacial deformity, mainly affects the upper lip, nose, and palate. One possible treatment is single-stage lip repair with primary rhinoplasty. Here we assessed the correlations among cleft severity, surgical age, and aesthetic results. Methods: A total of 26 patients with unilateral cleft lip or cleft lip and palate aged 3-12 months underwent surgical lip repair associated with the Göteborg/McComb rhinoplasty technique. Steps before and after surgery were separately evaluated by five plastic surgeons using pictures and the data were analyzed. Results: The average patient age at surgery was 6.5 ± 3.15 months, and only seven patients (26.9%) underwent surgery at 3 months of age as recommended by the protocol. Cleft severity and results quality were associated, whereas surgical age and aesthetic results were not correlated. Results in all cases were considered optimal or satisfactory. Conclusions: The lip repair technique, which presents good reproducibility and aesthetic results and can be used with other primary treatment techniques for the nose, should be adopted by treatment centers managing cleft lip and palate. Cleft severity is an important factor in results quality; the greater the severity, the worse the results. In the present study, surgical age was not correlated with results quality.

Lingual frenulum and malocclusion: An overlooked tissue or a minor issue.

CONTEXT: Tongue-tie (more formally known as ankyloglossia) is a congenital anomaly characterized by an abnormally short lingual frenulum, which may restrict mobility of the tongue tip impairing its ability to fulfill its functions. The clinical significance of ankyloglossia is varied; rarely symptomatic to a host of problems including infant feeding difficulties, speech disorders, malocclusions, and others. AIMS: The need of this study was to evaluate the occurrence and severity of tongue-tie and its association with the type of malocclusions in two populations and also to correlate the various malocclusion traits with the grades of tongue-tie. SUBJECTS AND METHODS: A total of 700 school children in the age group of 9-17 years were examined for the presence of tongue-tie, 350 from regular schools and 350 from special schools. The presence was evaluated, measured, and graded into Grades I-V according to Kotlow's method. The malocclusion was assessed according to Angle's classification. Severity of crowding was assessed by Little's irregularity index in each case. Various other malocclusion traits were visually assessed, in relation to the positions of the teeth. STATISTICAL ANALYSIS USED: Spearman's rank correlation method was used to test the relationship between type of malocclusions, grades of tongue-tie and severity of crowding. Significance was considered at the (P < 0.05) level. RESULTS: Statistically significant differences were seen between grades of tongue-tie and Angle's types of malocclusion and Spearman's correlation between them showed negative correlation. The Spearman's correlation showed a negative correlation between tongue-tie grades and severity of crowding. CONCLUSIONS: As the grade of tongue-tie increased, its association with Classes I and II malocclusion decreased. The lower grades of tongue-tie are associated with increased lower incisor crowding. Shorter, tight frenulums are more associated with maxillary constriction, anterior open bite, and spacing of the lower anteriors.

Congenital intra-oral adhesions: a surgical approach to cleft palate lateral synechia syndrome.

An array of genetic syndromes has been associated with intra-oral adhesions in neonates. The primary medical issues arise from airway obstruction, feeding difficulties and poor oral development, specifically with cleft palate lateral synechia syndrome (CPLSS). Despite this, a paucity of data exists for the clinical management of intra-oral adhesions in this population. We report the cases of a father and daughter diagnosed with CPLSS who presented with respiratory and feeding difficulties at birth undergoing surgical correction. Early surgical ligation of intra-oral bands allows for a stabilization of the airway, improved feeding and oral development with a good long-term outcome.

Imaging of the oral cavity.

The oral cavity is a challenging area in head and neck imaging because of its complex anatomy and the numerous pathophysiologies that involve its contents. This challenge is further compounded by the ubiquitous artifacts that arise from the dental amalgam, which compromise image quality. In this article, the anatomy of the oral cavity is discussed in brief, followed by a description of the imaging technique and some common pathologic abnormalities.

Oropharyngeal teratoma, oral duplication, cervical diplomyelia and anencephaly in a 22-week fetus: A review of the craniofacial teratoma syndrome.

BACKGROUND: Oropharyngeal teratoma may occur by itself or together with other craniofacial malformations, most commonly cleft palate. Oropharyngeal teratoma may be also seen in association with frontonasal dysplasia and/or various degrees of craniofacial duplication. The nosology of these sporadic disorders is poorly defined. CASE AND REVIEW: We report on a 22-week fetus with a protruding nasopharyngeal teratoma, partial oral duplication, anencephaly, multiple costo-vertebral segmentation defects, and cervical diplomyelia. A review of the literature identified 48 patients published from 1931 to 2013 with co-existing clefting and duplication anomalies of the cephalic pole. Thoracic and abdominal midline anomalies were reported 13 times. CONCLUSION: The term "craniofacial teratoma syndrome" is introduced to define this phenotype as a recognizable developmental field defect of the cephalic pole. Developmental pathogenesis is discussed with a focus on pleiotropy and stereotaxis. The observation of midline findings suggestive of holoprosencephaly in a few previously reported cases suggests a role for the sonic hedgehog signaling pathway in this malformation pattern.

Lábio duplo bilabial / Bilabial double lip

O lábio duplo é uma entidade rara, com poucos relatos, que geralmente afeta o lábio superior, sendo de fácil diagnóstico clínico. Pode ter origem congênita ou adquirida. O tratamento cirúrgico é indicado por queixa estética ou funcional, de simples execução. Este relato refere-se a um caso de lábio duplo bilabial em paciente do sexo masculino de 14 anos, em que foi realizada correção cirúrgica por motivação estética do paciente, com ótimo resultado dos pontos de vista estético e funcional.

There are few published reports on double lip, a rare entity that usually affects the upper lip, and that is easily diagnosed clinically. It may be congenital or acquired. Surgical treatment is indicated for aesthetic or functional complaints, and is simple to implement. This report describes a case of bilabial double lip in a 14-year-old male patient, in whom surgical correction was carried out for aesthetic reasons, with excellent aesthetic and functional results.

Reconstrução de lábio utilizando o retalho randomizado cervical do músculo platisma / Lip reconstruction with cervical platysma muscle randomized flaps

INTRODUÇÃO: A reconstrução cirúrgica da deformidade labial exige bom conhecimento anatômico e técnica cirúrgica. Fatores como localização da lesão, extensão, profundidade e tratamento inicial adequado constituem variáveis que são analisadas em conjunto para a estratégia cirúrgica mais apropriada. O retalho de Tsur é definido como randomizado do músculo platisma que pode ser elevado do pescoço como tubo unipediculado ou bipediculado, dependendo do tamanho e da localização da perda de substância. Pode incluir área pilosa cervical e ser utilizado em defeitos de plano parcial ou total do lábio. MÉTODO: Foram operados três pacientes com perda de substância labial extensa. Foi utilizado retalho bipediculado em dois casos e unipediculado em um caso. RESULTADOS: No primeiro paciente, foi liberado um dos pedículos do retalho cervical no 15º dia do pós-operatório. Após 30 dias, o outro foi liberado após integração completa ao lábio superior. A partir deste, retalhos ao acaso foram confeccionados para reconstrução do lábio inferior, columela e ponta nasal. O segundo paciente evoluiu com necrose da porção central do retalho, sendo realizada confecção de leito de ancoragem próximo à comissura. Apresentou melhora da continência salivar. O terceiro paciente evoluiu bem, sendo liberado o retalho lingual utilizado para reconstruir o lábio superior após 3 semanas. CONCLUSÃO: A reconstrução com o retalho de Tsur mostrou-se útil nos casos de reconstrução total do lábio superior e inferior, além de ser ótima alternativa na situação de impossibilidade de utilização do retalho microcirúrgico e de permitir um resultado estético aceitável com recuperação da função mastigatória e da fala adequadas, apesar da complexidade inicial dos casos.

INTRODUCTION: Surgical reconstruction of lip deformities requires proper anatomical knowledge and surgical techniques. Factors such as location, extent, depth, and appropriate initial treatment of the lesion are parameters that are simultaneously analyzed to identify the most suitable surgical strategy. The flap described by Tsur is defined as a platysma muscle randomized flap, and can be raised from the neck as a unipedicled or bipedicled tube, depending on the size and location of the loss of substance. This may include the hairy cervical area, and it can be used in defects of the partial or total plane of the lip. METHOD: Three patients with extensive loss of lip substance underwent surgery. A bipedicled flap was used in two cases, and a unipedicled flap in one case. RESULTS: In the first patient, one pedicle of the cervical flap was released on the 15th postoperative day. After 30 days, we released the other, after full integration into the upper lip. From this, flaps were randomly made for the reconstruction of the lower lip, columella, and nasal tip. The second patient developed necrosis of the central portion of the flap, and the recipient bed was anchored next to the commissure. The patient showed improved salivary continence. The third patient progressed well, and the tongue flap used to reconstruct the upper lip was released three weeks later. CONCLUSION: Reconstruction with a Tsur flap was useful in cases of total reconstruction of the upper and lower lip, in addition to being a great alternative in situations in which it was impossible to use microsurgical flaps. This technique also allowed the achievement of satisfactory aesthetic outcomes, and resulted in the recovery of masticatory function and appropriate speech, despite the initial complexity of the cases.

A rare case of ankyloglossia and bilateral fusion of mandibular incisors.

Dental anomalies may occur both in primary and permanent dentitions. Abnormalities in tooth size, shape, and structure result from disturbances during the morphodifferentiation stage of development. They are observed frequently during routine dental examinations and might be associated with a syndrome. Dentists must be familiar with the prevalence of such anomalies, as early diagnosis can prevent complications such as compromised aesthetics, space loss, midline shift, and carious exposure. This article describes a rare presentation of bilaterally fused permanent mandibular central and lateral incisors, along with ankyloglossia and fluorosis in a 22-year-old man with the chief complaint of "dirty teeth."

Oral manifestations of hereditary nonpolyposis colorectal cancer syndrome: a family case series.

INTRODUCTION: Hereditary nonpolyposis colorectal cancer is a colorectal cancer syndrome characterized by the development of colorectal cancer and extracolonic tumors, and this syndrome has an autosomal dominant mode of inheritance. To our knowledge, our study was the first to find dento-osseous anomalies and the second to observe Fordyce granules in a family with individuals with hereditary nonpolyposis colorectal cancer. CASE PRESENTATIONS: Twenty members of one Brazilian family with individuals with hereditary nonpolyposis colorectal cancer were analyzed according to the presence of colorectal cancer and the occurrence of Fordyce granules and dento-osseous anomalies. Their average age was 29.6 (range 7 to 53 years) years. Medical examinations of this family with hereditary nonpolyposis colorectal cancer were performed at the Coloproctology Division of our hospital. Then, all individuals were referred to our Oral Care Center for Inherited Diseases for intraoral examinations to verify the presence of Fordyce granules. Dental panoramic radiographs were done in order to describe dento-osseous anomalies on applying the Dental Panoramic Radiograph System. Of the 20 family members, four were diagnosed with hereditary nonpolyposis colorectal cancer and all four presented Fordyce granules in their upper lip, but only one of these four patients (Case 2) had a significant dento-osseous anomaly. CONCLUSIONS: Our familial study verified the presence of Fordyce granules in all individuals diagnosed with hereditary nonpolyposis colorectal cancer, and the presence of significant dento-osseous anomalies in one of these cases. However, the relationship between oral manifestations and hereditary nonpolyposis colorectal cancer should be further investigated.

Targeting of Slc25a21 is associated with orofacial defects and otitis media due to disrupted expression of a neighbouring gene.

Homozygosity for Slc25a21(tm1a(KOMP)Wtsi) results in mice exhibiting orofacial abnormalities, alterations in carpal and rugae structures, hearing impairment and inflammation in the middle ear. In humans it has been hypothesised that the 2-oxoadipate mitochondrial carrier coded by SLC25A21 may be involved in the disease 2-oxoadipate acidaemia. Unexpectedly, no 2-oxoadipate acidaemia-like symptoms were observed in animals homozygous for Slc25a21(tm1a(KOMP)Wtsi) despite confirmation that this allele reduces Slc25a21 expression by 71.3%. To study the complete knockout, an allelic series was generated using the loxP and FRT sites typical of a Knockout Mouse Project allele. After removal of the critical exon and neomycin selection cassette, Slc25a21 knockout mice homozygous for the Slc25a21(tm1b(KOMP)Wtsi) and Slc25a21(tm1d(KOMP)Wtsi) alleles were phenotypically indistinguishable from wild-type. This led us to explore the genomic environment of Slc25a21 and to discover that expression of Pax9, located 3' of the target gene, was reduced in homozygous Slc25a21(tm1a(KOMP)Wtsi) mice. We hypothesize that the presence of the selection cassette is the cause of the down regulation of Pax9 observed. The phenotypes we observed in homozygous Slc25a21(tm1a(KOMP)Wtsi) mice were broadly consistent with a hypomorphic Pax9 allele with the exception of otitis media and hearing impairment which may be a novel consequence of Pax9 down regulation. We explore the ramifications associated with this particular targeted mutation and emphasise the need to interpret phenotypes taking into consideration all potential underlying genetic mechanisms.

Lateral facial cleft associated with accessory mandible having teeth, absent parotid gland and peripheral facial weakness.

Transverse facial cleft is a very rare malformation. The Tessier no. 7 cleft is a lateral facial cleft which emanates from oral cavity and extends towards the tragus, involving both soft tissue and skeletal components. Here, we present a case having transverse facial cleft, accessory mandible having teeth, absent parotid gland and ipsilateral peripheral facial nerve weakness. After surgical repair of the cleft in 2-month of age, improvement of the facial nerve function was detected in 3-year of age. Resection of the accessory mandible was planned in 5-6 years of age.