Master of Science Program in Geriatric Dentistry and Special Patients Care (International Program), Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand; Genomics and Precision Dentistry Research Unit, Department of Physiology, Faculty of Dentistry, Chulalongkorn University.
Genomics and Precision Dentistry Research Unit, Department of Physiology, Faculty of Dentistry, Chulalongkorn University.
Oral Surg Oral Med Oral Pathol Oral Radiol. 2021 Jun;131(6):694-701. doi: 10.1016/j.oooo.2021.01.003. Epub 2021 Jan 9.
Dentinogenesis imperfecta (DI) requires dental treatment. This study investigated the characteristics of DI teeth associated with osteogenesis imperfecta (OI) and COL1A2 mutations.
Whole exome and Sanger sequencing were performed. Three primary teeth (called "OIDI teeth") obtained from 3 unrelated COL1A2 patients were investigated and compared with 9 control teeth from age-matched healthy individuals using colorimetry, micro-computed tomography, Knoop microhardness, energy dispersive X-ray spectroscopy, scanning electron microscopy, and histology.
All patients were identified with heterozygous glycine substitutions in COL1A2. The COL1A2 mutations, c.1531G>T and c.2027G>T, were de novo, whereas c.3106G>C was inherited. OIDI1, 2, and 3 teeth had a substantial decrease in dentin microhardness and lightness. OIDI2 enamel microhardness was significantly reduced, whereas OIDI1 and 3 had enamel microhardness comparable to that of control individuals. The OIDI1 pulp cavity was large; OIDI2 was narrow; and OIDI3 was obliterated. OIDI1 and 3 had significantly higher carbon levels than those in control individuals. Numerous ectopic calcified masses, sparse and obstructed dentinal tubules, dentin holes, and collagen disorientation were observed.
OIDI teeth had reduced lightness and variable pulp morphology. Weak dentin, mineral disproportion, and abnormal ultrastructure could contribute to the brittleness of OIDI teeth and adhesive restoration failure. Here, we expand the phenotypic spectrum of COL1A2 mutations and raise awareness among dentists seeing patients with OI.
牙本质发育不全（DI）需要进行牙科治疗。本研究调查了与成骨不全症（OI）和 COL1A2 突变相关的 DI 牙的特征。
进行了全外显子组和 Sanger 测序。对 3 名 COL1A2 患者的 3 颗原发性牙齿（称为“OIDI 牙齿”）进行了研究，并与 9 颗来自年龄匹配的健康个体的对照牙齿进行了比较，使用比色法、微计算机断层扫描、Knoop 显微硬度、能量色散 X 射线光谱、扫描电子显微镜和组织学。
所有患者均被鉴定为 COL1A2 中的杂合甘氨酸取代。COL1A2 突变 c.1531G>T 和 c.2027G>T 是新生的，而 c.3106G>C 是遗传的。OIDI1、2 和 3 牙齿的牙本质显微硬度和明度显着降低。OIDI2 牙釉质显微硬度显着降低，而 OIDI1 和 3 的牙釉质显微硬度与对照个体相当。OIDI1 牙髓腔较大；OIDI2 较窄；OIDI3 被阻塞。OIDI1 和 3 的碳水平显着高于对照个体。观察到大量异位钙化肿块、稀疏和阻塞的牙本质小管、牙本质孔和胶原错位。
OIDI 牙齿明度降低，牙髓形态可变。弱牙本质、矿物质比例失调和异常超微结构可能导致 OIDI 牙齿的脆性和粘合修复失败。在这里，我们扩大了 COL1A2 突变的表型谱，并提高了牙医对 OI 患者的认识。
