Use of CBCT in the orthodontic diagnosis of a patient with pycnodysostosis.

Introduction. The Pycnodysostosis is an osteosclerosis genetically determined, autosomal
recessive, linked to deficiency of cathepsin K. It is characterized by short stature, massive skull,
hands and feet with short terminal phalanges, dysplastic nails. Oral and maxillofacial
manifestations include hypoplasia of the mandibule and maxillary sinus, obtuse mandibular gonial
angle deciduous teeth and permanent impacts, or malposition, frequent overcrowding, periodontal
lesions. Bone sclerosis is already detectable in X-rays during childhood, often present open
fontanelles and sutures, wormian bones; frequent pathological fractures.
Case Report: Patient male, Caucasian, age 9 years and 11 months suffer from Pycnodysostosis,
mutation of the gene in heterozygotes p.R241X, already followed at the Pediatric Endocrinology
Clinic of the Spedali Civili of Brescia. After evaluation at the Department of Maxillofacial Surgery of
the Spedali Civili of Brescia, for surgical reasons required a CBCT scanner with NewTom 3G, was
presented to our observation at the Department of Orthodontics of the Dental Clinic of the
University of Brescia.
Discussions and conclusions: CBCT findings including detailed information about the anatomy of
the upper and lower jaw, dental elements, their relationship with the surrounding anatomical
structures and the spatial position. The only radiographic examination currently available that
obtains 3D images and the volume of the life-size area, without exposing patient to dose of
radiation from a classic multi-layer CT is CBCT that, even through the 3D reconstructions with
dedicated programs can make a correct diagnosis, prognosis and treatment in patients with
maxillofacial dysmorphism. Through this examination is possible to obtain images from around the
skull that allow a complete orthodontic diagnosis, not only restricted to the area of surgical interest,
taking into account the reports of the dental arches to each other and with surrounding structures.