Evolutionary Analysis Predicts Sensitive Positions of MMP20 and Validates Newly- and Previously-Identified MMP20 Mutations Causing Amelogenesis Imperfecta

Amelogenesis imperfecta (AI) designates a group of genetic diseases characterized by a large range of enamel disorders causing important social and health problems. These defects can result from mutations in enamel matrix proteins or protease encoding genes. A range of mutations in the enamel cleavage enzyme matrix metalloproteinase-20 gene (MMP20) produce enamel defects of varying severity. To address how various alterations produce a range of AI phenotypes, we performed a targeted analysis to find MMP20 mutations in French patients diagnosed with non-syndromic AI. Genomic DNA was isolated from saliva and MMP20 exons and exon-intron boundaries sequenced. We identified several homozygous or heterozygous mutations, putatively involved in the AI phenotypes. To validate missense mutations and predict sensitive positions in the MMP20 sequence, we evolutionarily compared 75 sequences extracted from the public databases using the Datamonkey webserver. These sequences were representative of mammalian lineages, covering more than 150 million years of evolution. This analysis allowed us to find 324 sensitive positions (out of the 483 MMP20 residues), pinpoint functionally important domains, and build an evolutionary chart of important conserved MMP20 regions. This is an efficient tool to identify new- and previously-identified mutations. We thus identified six functional MMP20 mutations in unrelated families, finding two novel mutated sites. The genotypes and phenotypes of these six mutations are described and compared. To date, 13 MMP20 mutations causing AI have been reported, making these genotypes and associated hypomature enamel phenotypes the most frequent in AI

Behavioral Modifications in Children after Repeated Sedation with Nitrous Oxide for Dental Treatment: A Retrospective Study

Sedation with nitrous oxide (N2O) has been widely used as a viable alternative to general anesthesia to perform dental treatments in uncooperative or anxious children. The purpose of this retrospective study is to assess if repeated sedations with N2O can improve collaboration of uncooperative children. The medical records of 650 children, aged between 3 and 14 years, who underwent at least two sedations, were consulted. Differences in the Venham score during the first sedation and subsequent sedations were collected. After removal incomplete records, 577 children’s records (309 males and 268 females) were analyzed. The Venham score decreased both during each sedation and with repeated sedations (p < 0.01 for both comparisons). In particular, a significant reduction of the Venham score was observed at the first contact with the dentist, with a mean score ranging from 1.56 ± 1.46 to 1.16 ± 1.37, comparing the first and the second sedation, and from 1.65 ± 1.43 to 1.06 ± 1.30, comparing the first with the third sedation (p < 0.01). The reduction in the Venham score was recorded in both healthy and physically impaired patients, and it was significantly greater in older children than in younger children (p < 0.01). In conclusion, uncooperative children with or without physical impairments can be successfully treated with N2O sedation in order to increase their confidence in dental procedures

L'hyperactivité avec déficit de l'attention (THADA) chez l'enfant (aspects bucco-dentaires)

STRASBOURG-Medecine (674822101) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Conscious Sedation in Dentistry for the Management of Pediatric Patients with Autism: A Narrative Review of the Literature

(1) Background: the variety of autism spectrum disorder makes the definition of guidelines for dental care a challenging task. The aim of this review was to evaluate the literature concerning the use of conscious sedation for dental treatments in pediatric autistic patients. (2) Methods: we searched MEDLINE/PubMed, EMBASE, Cochrane databases in order to identify pertinent studies. The search strategy was based on these areas of interest: autistic spectrum disorder, pediatric patients, dentistry, tranquilizing agents, and conscious sedation. (3) Results: the search yielded 177 non-duplicated articles, of which 24 articles were retrieved for full text review, and 2 were found to address our review aim. The first paper was a retrospective study that included 83 autistic patients sedated either with an oral premedication combined with nitrous oxide/oxygen inhalation or with nitrous oxide/oxygen inhalation alone; the second article was a prospective trial on the effectiveness of 0.3 mg/kg of oral diazepam with 0.5 mg/kg of oral midazolam in 13 sedated uncooperative autistic patients. (4) Conclusions: this review highlights the insufficiency of studies that can provide concrete indications for the dental treatment in conscious sedation of pediatric patients with autism. New studies are needed to better define the appropriate drugs, dosages, sedation level and evaluate patient cooperation

Manifestations dento-maxillo-faciales chez un enfant atteint d’une ß-thalassémie majeure traitée par greffe de cellules souches hématopoïétiques. A propos d’un cas

Cet article présente le cas d’un garçon de 8 ans atteint de ß-thalassémie majeure, affection qui représente une forme d’anémie héréditaire grave. Le traitement initial par transfusions répétées a entraîné le développement d’une hémochromatose sévère mettant en jeu le pronostic vital. Le patient a bénéficié d’une greffe allogénique de cellules souches hématopoïétiques, seul traitement curatif de la thalassémie majeure, mais il a rapidement développé une maladie du greffon contre l’hôte. Une prise en charge globale du patient a été réalisée dans le Département d’Odontologie Pédiatrique en raison des complications maxillo-faciales et bucco-dentaires importantes liées à ces deux affections. (Med Buccale Chir Buccale 2006 ; 12 : 163-70)

Inhalation Conscious Sedation with Nitrous Oxide and Oxygen as Alternative to General Anesthesia in Precooperative, Fearful, and Disabled Pediatric Dental Patients: A Large Survey on 688 Working Sessions

Aim. To evaluate the effectiveness and the tolerability of the nitrous oxide sedation for dental treatment on a large pediatric sample constituting precooperative, fearful, and disabled patients. Methods. 472 noncooperating patients (aged 4 to 17) were treated under conscious sedation. The following data were calculated: average age; gender distribution; success/failure; adverse effects; number of treatments; kind of dental procedure undertaken; number of dental procedures for each working session; number of working sessions for each patient; differences between males and females and between healthy and disabled patients in relation to success; success in relation to age; and level of cooperation using Venham score. Results. 688 conscious sedations were carried out. The success was 86.3%. Adverse effects occurred in 2.5%. 1317 dental procedures were performed. In relation to the success, there was a statistically significant difference between healthy and disabled patients. Sex and age were not significant factors for the success. Venham score was higher at the first contact with the dentist than during the treatment. Conclusions. Inhalation conscious sedation represented an effective and safe method to obtain cooperation, even in very young patients, and it could reduce the number of pediatric patients referred to hospitals for general anesthesia

Oral Manifestations and Complications in Childhood Acute Myeloid Leukemia

Acute myeloid leukemia (AML) is a heterogeneous group of diseases, whose classification is based on lineage-commitment and genetics. Although rare in childhood, it is the most common type of acute leukemia in adults, accounting for 80% of all cases in this age group. The prognosis of this disease remains poor (especially in childhood, as compared to acute lymphoblastic leukemia); however, overall survival has significantly improved over the past 30 years. The health of the oral cavity is a remarkable reflection of the systemic status of an individual. Identification of the signs and symptoms of oral lesions can act as a warning sign of hidden and serious systemic involvement. Moreover, they may be the presenting feature of acute leukemia and provide important diagnostic indicators. Primary oral alterations are identified in up to 90% of cases of acute myeloid leukemia and consist of petechiae, spontaneous bleeding, mucosal ulceration, gingival enlargement with or without necrosis, infections, hemorrhagic bullae on the tongue, and cracked lips. Poor oral hygiene is a well-known risk factor for local and systemic infectious complications. Oro-dental complications due to AML treatment can affect the teeth, oral mucosa, soft and bone tissue, and contribute to opportunistic infections, dental decay, and enamel discoloration. The treatment of acute myeloid leukemia is still associated with high mortality and morbidity. The management is multimodal, involving aggressive multidrug chemotherapy and, in most cases, allogenic bone marrow transplantation. Periodontal and dental treatment for patients with leukemia should always be planned and concerted with hematologists

Pain Experience and Behavior Management in Pediatric Dentistry: A Comparison between Traditional Local Anesthesia and the Wand Computerized Delivery System

Aim. To evaluate the pain experience and behavior during dental injection, using the Wand computerized delivery system versus conventional local anesthesia in children and adolescents. Methods. An observational crossover split mouth study was performed on 67 patients (aged 7 to 15 years), requiring local anesthesia for dental treatments in both sides of the dental arch. Patients received both types of injections in two separate appointments, one with the use of a Computer Delivery System (the Wand STA system) and one with the traditional syringe. The following data were recorded: pain rating; changes in heart rate; level of collaboration; patient satisfaction. The data were analyzed using ANOVA for quantitative outcomes and nonparametric analysis (Kruskal-Wallis) for qualitative parameters. Results. The use of the Wand system determined significantly lower pain ratings and lower increase of heart rate than the traditional syringe. During injection, the number of patients showing a relaxed behavior was higher with the Wand than with the traditional local anesthesia. The patient level of satisfaction was higher with the Wand compared to the conventional local anesthesia. Conclusions. The Wand system may provide a less painful injection when compared to the conventional local anesthesia and it seemed to be better tolerated with respect to a traditional syringe

Evolutionary Analysis Predicts Sensitive Positions of MMP20 and Validates Newly- and Previously-Identified MMP20 Mutations Causing Amelogenesis Imperfecta

International audienceAmelogenesis imperfecta (AI) designates a group of genetic diseases characterized by a large range of enamel disorders causing important social and health problems. These defects can result from mutations in enamel matrix proteins or protease encoding genes. A range of mutations in the enamel cleavage enzyme matrix metalloproteinase-20 gene (MMP20) produce enamel defects of varying severity. To address how various alterations produce a range of AI phenotypes, we performed a targeted analysis to find MMP20 mutations in French patients diagnosed with non-syndromic AI. Genomic DNA was isolated from saliva and MMP20 exons and exon-intron boundaries sequenced. We identified several homozygous or heterozygous mutations, putatively involved in the AI phenotypes. To validate missense mutations and predict sensitive positions in the MMP20 sequence, we evolutionarily compared 75 sequences extracted from the public databases using the Datamonkey webserver. These sequences were representative of mammalian lineages, covering more than 150 million years of evolution. This analysis allowed us to find 324 sensitive positions (out of the 483 MMP20 residues), pinpoint functionally important domains, and build an evolutionary chart of important conserved MMP20 regions. This is an efficient tool to identify new- and previously-identified mutations. We thus identified six functional MMP20 mutations in unrelated families, finding two novel mutated sites. The genotypes and phenotypes of these six mutations are described and compared. To date, 13 MMP20 mutations causing AI have been reported, making these genotypes and associated hypomature enamel phenotypes the most frequent in AI