Widening of incisor spacing is one of the symptoms of Mannoside Storage Disorder Type II. Mannoside Storage Disease Type II usually develops after the age of 2 years with normal physical and psychomotor development, progressive cerebral delay starting after the age of 2 years, frequent respiratory infections, ugly face, thick eyebrows, widened incisor spacing, bulging jaws, low anterior hairline, and mild bilateral deafness (most of which is sensory). Some patients may have allodynia. The following diseases may cause widened incisor spacing. 1.Mannosidosis Mannosidosis (mannosidosis) is a systemic disease caused by α-mannosidase deficiency. Clinical features similar to Hurler syndrome, no mucopolysacchariduria, but an increase in the mannose-containing components of the tissue. 2, endodontics Endodontics refers to diseases of the dental pulp tissue, including pulp inflammation, pulp necrosis and pulp degeneration. As the pulp tissue is surrounded by the hard tissues of the tooth, only through the apical foramen, lateral root canals and the outside world, acute inflammation of the pulp, vascular congestion, exudate accumulation, resulting in increased pressure in the pulp cavity, so that the nerve pressure, plus the stimulation of inflammatory exudate and make the pain extremely severe. 3.Osteoporosis Osteoporosis is a systemic bone disease, which is characterized by the decline of bone mass and destruction of the microstructure of the bone, manifested by the increased fragility of the bone, thus increasing the risk of fracture, even in the case of minor trauma or no trauma, fractures are also prone to occur. Osteoporosis is a chronic disease that is multifactorial. There are usually no specific clinical manifestations until a fracture occurs. The disease is more common in women than in men and is common in postmenopausal women and the elderly. With the increase in the elderly population in China, the incidence of osteoporosis is on the rise and is a health issue of concern in China and globally.