Pyknodysostosis - a report of two cases with a brief review of the literature

Abstract

Pyknodysostosis is a rare sclerosing bone disorder that has an autosomal dominant trait. It is characterized by short stature, brachycephaly, short and stubby fingers, open cranial sutures and fontanelle, and diffuse osteosclerosis, where multiple fractures of long bones and osteomyelitis of the jaw are frequent complications. We present a report of two cases of pyknodysostosis with evidence of long bone fractures and chronic suppurative osteomyelitis of the jaws in one of the cases. Some of the specific oral and radiological findings that are consistent with pyknodysostosis are reported, along with a brief review of the literature.

Orthognathic surgery in pycnodysostosis: a case report

“…The incidence is estimated to be 1.7 per 1 million births 1,2,5,10 . Multiple fractures of long bones and osteomyelitis, stridorous breathing and snoring due to a narrow chest and airway are frequent complications 5,6,10 .…”

“…The impaired bone vascularity, increases the probability of developing post-extraction osteomyelitis 1 . Treatment of osteomyelitis of the jaws in pycnodysostosis is difficult and may lead to large resections 2,7 .…”

“…This syndrome usually presents with typical craniomaxillofacial deformities, such as a dolicocephalic or brachiocephalic skull with prominent forehead, hypoplastic maxilla and mandible with micrognathia, and hypoplastic midface with exophthalmus, hypopneumatization of the maxillary sinuses, beaked nose, open and anterior cross-bite, obtuse mandibular angle, grooved palate, longer soft palate and narrowing of the airway 1-3,5-7,10 . Dental crowding, dental abnormalities and impaction are observed, as well as alterations in eruption [1][2][3]6 .…”

“…The disease has also been called Toulouse-Lautrec syndrome, after the French artist Henri de ToulouseLautrec who suffered from the disease 1 . Pycnodysostosis has an autosomal recessive inheritance [1][2][3][4][5][6][7][8][9][10] and is characterized by systemic high bone density due to decreased bone turnover [1][2][3][4][5][6][7]9 . In the 1990s, the defective gene responsible for pycnodysostosis was located in chromosome Iq21, offering accurate diagnosis, carrier testing and a more thorough understanding of this disorder 1,3,[5][6][7]10 .…”

“…Pycnodysostosis is usually diagnosed at an early age due to the typical phenotype with proportionate dwarfism and peculiar facies 1,3,5,6 . The diagnosis is sometimes made late, as a result of high susceptibility to long bone fractures and infections, because of the severe bone fragility resulting from increased bone density and impaired bone vascularity [1][2][3][4][5][6][7][8][9][10] .…”