Masseter muscle gene expression in human malocclusion subjects with and without posterior facial asymmetry. Homo sapiens

Non-syndromic facial asymmetry is commonly found in dentofacial deformity populations with skeletal malocclusions. Asymmetry of this type may result from imbalanced growth and function of both the jaw and associated muscles. Among the multiple genes that interact to affect the craniofacial musculoskeletal complex during pre and postnatal growth and development, NODAL signaling pathwy (NSP) genes are active in adult skeletal muscle and may be key factors in development, growth and maintenance of facial asymmetry. It is of interest to determine whether expression of NODAL pathway genes might differ in masseter muscles between individuals with malocclusion that have facial asymmetry and normal symmetry. Human Transcriptome 2.0 GeneChips (HTA2.0) were used to examine global gene expression in masster muscles between malocclusion subjects with posterior facial asymmetry and with normal facial symmetry. Overall design: Eleven patients undergoing orthoganthic surgery were selected for comparison of masseter muscle gene expression on microarrays. Two subjects had posterior facial asymmetry (one with class II open bite and one with class III open bite malocclusion) and nine subjects had normal facial symmetry (three with class II open bite, two with class III open bite and four with class II deep bite malocclusion). RNA representative of total gene expression in masseter muscles of the malocclusion subjects with and without posterior facial asymmetry was prepared for labeling and hybridization on HTA2.0 chips. The two subjects with facial asymmetry clustered separately from eight other malocclusion subjects by a principle component analysis (PCA), even though one had a class II and the other a class III malocclusion. Sample 4L_Open_II is from a subject who has sleep apnea. Data from 4L_Open_II clustered independent of the asymmetry group and the eight other subjects of the symmetry group by PCA and was not included in analysis of differential expression with facial symmetry. Masseter muscles are paired jaw muscles (i.e. right and left masseter). In some cases, there was not sufficient quantity/quality of RNA from one side, thus the other side was used. Please note that the following information is provided in the 'source name' field of each sample record; subject ID number; either left or right masseter; J CRANIOFAC SURG_ID# corresponding to the data presented in the manuscript

非综合征性面部不对称常见于伴有骨性错颌畸形的牙颌面畸形人群中。此类不对称可由颌骨及其附属肌肉的生长与功能失衡引发。在产前及产后生长发育过程中，诸多相互作用的基因共同调控颅面肌骨复合体，其中NODAL信号通路（NODAL signaling pathway, NSP）基因在成人骨骼肌中呈活跃表达状态，可能是面部不对称发生、生长及维持的关键调控因子。本研究旨在探究伴面部不对称的错颌畸形个体与面部对称个体的咬肌（masseter muscle）中，NODAL通路基因的表达是否存在差异。本研究采用人类转录组2.0基因芯片（HTA2.0），检测伴后部面部不对称的错颌畸形受试者与面部对称受试者的咬肌全基因表达谱。整体实验设计：选取11例接受正颌外科（orthognathic surgery）手术的患者，通过基因芯片比较其咬肌的基因表达情况。其中2例受试者存在后部面部不对称（1例为安氏Ⅱ类开颌错颌畸形，1例为安氏Ⅲ类开颌错颌畸形），剩余9例受试者面部对称（3例为安氏Ⅱ类开颌，2例为安氏Ⅲ类开颌，4例为安氏Ⅱ类深覆颌错颌畸形）。提取伴或不伴后部面部不对称的错颌畸形受试者咬肌中代表全基因表达的RNA，用于标记后在HTA2.0芯片上进行杂交实验。通过主成分分析（PCA）可知，2例面部不对称受试者的样本与其余8例错颌畸形受试者的样本各自聚类，尽管二者分别为安氏Ⅱ类与安氏Ⅲ类错颌畸形。样本4L_Open_II来自1例阻塞性睡眠呼吸暂停患者。经PCA分析，该样本的聚类结果与面部不对称组及其余8例对称组受试者均无关联，因此未纳入面部对称性相关的差异表达分析。咬肌为成对存在的颌骨肌肉（即左侧咬肌与右侧咬肌）。部分样本中单侧咬肌的RNA提取量或质量不足，因此采用对侧咬肌的样本进行实验。请注意，每个样本记录的"样本来源名称"字段包含以下信息：受试者编号、左侧或右侧咬肌、以及与本文手稿中数据对应的《颅面外科杂志》（J CRANIOFAC SURG）编号。