Objective To explore the diagnosis and differential diagnosis of spinal muscular atrophy with respiratory distress type Ⅰ (SMARD1). Method The clinical data, results of gene detection, and follow-up information of a girl diagnosed with SMARD1 were retrospectively analyzed, and related literatures were reviewed. Results The girl was born by cesarean section due to oligohydramnios. After birth, she was transferred to neonatology department for poor feeding and response, and diagnosed with neonatal sepsis, infectious shock, disseminated inravascular coagulation and atypical purulent meningitis. She was discharged after one month of treatment. However, at 2 months old, she presented contracture of ankle joint, abnormal liver function, and myocardial damage. At 6 months old, she had obvious reduced muscular tension and development retardation. At 8 months old, the SMA gene was detected and it was normal. At 9 months old, The panel gene of peripheral neuropathy was detected and found 2 heterozygosis mutations in IGHMBP2 gene, exon8 c.1061-2A>G and exon12 c.1708C>T, which came from her father and mother respectively. Locus of exon12 c.1708C>T has been reported to be associated with the disease, and the other is a shear mutation. The diagnosis of SMARD1 was confirmed by the clinical and gene detection. The girl, 2-year-old now, suffered with recurrent respiratory tract infections, but had no respiratory distress or no respiratory failure yet. Conclusion The clinical phenotype of SMARD1 is complex and diverse. This case is the first domestic case comfirmed by gene detection.

In the orthodontics process, intervention and sliding of an orthodontic bracket during the orthodontic process can arise large response of the labio-cheek soft tissue. Soft tissue damage and ulcers frequently happen at the early stage of orthodontic treatment. In the field of orthodontic medicine, qualitative analysis is always carried out through statistics of clinical cases, while quantitative explanation of bio-mechanical mechanism is lacking. For this purpose, finite element analysis of a three-dimensional labio-cheek-bracket-tooth model is conducted to quantify the bracket-induced mechanical response of the labio-cheek soft tissue, which involves complex coupling of contact nonlinearity, material nonlinearity and geometric nonlinearity. Firstly, based on the biological composition characteristics of labio-cheek, a second-order Ogden model is optimally selected to describe the adipose-like material of the labio-cheek soft tissue. Secondly, according to the characteristics of oral activity, a two-stage simulation model of bracket intervention and orthogonal sliding is established, and the key contact parameters are optimally set. Finally, the two-level analysis method of overall model and submodel is used to achieve efficient solution of high-precision strains in submodels based on the displacement boundary obtained from the overall model calculation. Calculation results with four typical tooth morphologies during orthodontic treatment show that: ① the maximum strain of soft tissue is distributed along the sharp edges of the bracket, consistent with the clinically observed profile of soft tissue deformation; ② the maximum strain of soft tissue is reduced as the teeth align, consistent with the clinical manifestation of common damage and ulcers at the beginning of orthodontic treatment and reduced patient discomfort at the end of treatment. The method in this paper can provide reference for relevant quantitative analysis studies in the field of orthodontic medical treatment at home and abroad, and further benefit to the product development analysis of new orthodontic devices.
Humans ; Periodontal Ligament/physiology* ; Orthodontic Wires ; Cheek ; Ulcer ; Tooth ; Finite Element Analysis