致密性骨发育不全骨发育障碍矮小症课件

A CASE REPORT CASE REPORT A 20 year old female patient had come with complaints of a swelling in the lower jaw for past 7 years. The patient had coarse facial features and a detailed history was elicited. The patient gave history of stunted growth. Frontal prominence was present since childhood. Birth history: Normal vaginal delivery. No history of any drug intake by mother during pregnancy Developmental history Normal developmental milestones & IQ was normal Family history No history of similar problem in siblings or family members Treatment history 12 years back she had a swelling over the upper jaw diagnosed as giant cell reparative granuloma for which maxillectomy was done. ON EXAMINATION A globular shiny swelling of bony consistency seen seen projecting from the lower jaw anteriorly. On general examination - Height : - Coarse facies - Frontal bossing - Long head dolichocephaly ( cephalic index : - Hypoplastic maxilla - Edentulous - High arched palate - Flattened mandibular angle - Short & stubby fingers - brachydactyly INVESTIGATIONS Normal hemogram USG abdomen & pelvis : Normal XRAY SKULL LAT VIEW XRAY CHEST PA VIEW XRAY SPINE XRAY PELVIS XRAY BOTH HANDS CT SCANOGRAM SCANOGRAM SHOWING MANDIBLE CT SKULL CT- SKULL BASE CT SHOWING MANDIBLE CT FEATURES B/L obtuse angle of mandible A lobulated bony mass without soft tissue swelling is seen arising from the Symphysis menti. Adjacent body of mandible appears irregular with hypodense areas Craniofacial bones appear sclerosed Wormian bone in squamoparietal suture Maxilla not imaged Dolichocephaly No frontal sinus / mastoid air cells Foramina in base of skull appear normal Mandible is edentulous The Diagnosis is PYKNODYSOSTOSIS PYKNODYSOSTOSIS Pyknodysostosis is a sclerosing bone disorder The name for this disease was coined by the French physicians Maroteaux and Lamy in 1962. They described the disorder in a report entitled “La pycnodysostose.“ Pyknos dense / thick / compact Dysostosis abnormal bone formation Abnormally dense bone is a hallmark of the disease. WHO IS THIS? Pyknodysostosis is a rare ( classified internationally as 2 star rare disease ) genetic disease of the bone. Its pattern of inheritance follows the classic rules of genetics Autosomal recessive No race / sex predilection French artist Henri de Toulouse-Lautrec of late 19th century was known to suffer from this disease and hence called as Toulouse Lautrec Syndrome. MOLECULAR GENETICS Lysosomal enzyme defect disease due to mutation of Cathepsin-K gene By Linkage analysis, the pyknodysostosis locus is located on 1q21 Cathepsin K deficiency is the cause. Cathepsin K is cysteine protease, important for osteoclasts that are responsible for bone resorption. Normal function of osteoclasts is impaired due to a lack of cathepsin K and there is a failure of bone resorption. Hence bone remodeling is affected as a result of which bones are abnormally dense and brittle causing repeated fractures RISK FACTORS Pyknodysostosis is a rare disease so that, if there is no family history of the disease, the risk for a child to have pyknodysostosis is very low. Parental consanguinity is an important predisposing factor as it is inherited autosomal recessively The parents of a child with pyknodysostosis have no signs of the disease themselves but they each carry a single edition of the pyknodysostosis gene. The overall risk of pyknodysostosis in the offspring of parents carrying the gene is 25% CLINICAL FEATURES Short stature ( adult males 150cm and females even shorter ) Proportional dwarfism Low circulating concentrations of insulin-like growth factor-1 (IGF-1) compared with normal age-matched short children with constitutional short stature Pituitary hypoplasia SKULL Frontal bossing Brachycephaly Persisting fontanelles into adult life ( soft spot ) Wormian bones Sclerosed skull base & orbital rims (“harlequin appearance” or “raccoon mask” sign) Ocular proptosis Small facial bones with small/absent sinuses Hypoplastic midface / maxilla Beaking of nose Mandible with obtuse angle with micrognathia CONTD Grooved palate Anterior cross bite Persistent decidual teeth Enamel hypoplasia Dental crowding Irregular permanent tooth / hypodontia THORAX Hypoplastic lateral end of clavicle of varying degree Sclerosed ribs SPINE Failure of fusion of neural arches Vertebral bodies resemble spools with large anterior and posterior defects Spondylolisthesis Scoliosis Sclerosed vertebrae PELVIS Coxa plana Dense cortices Medullary canal not completely obliterated HAND Wrinkled skin over back of fingers Flat & grooved nails Acro osteolysis with irregular fragments of distal phalanges Brachydactyly COMPLICATIONS Pathological fractures usually long bones of lower limb, mandible & clavicle Osteomyelitis of jaw Dental caries with poor oral hygiene Prone for cerebral demyelination TREATMENT Growth hormone replacement therapy (18 U/m2/week) divided in daily evening doses subcutaneousely increase IGF-1 concentration and improved linear growth velocity of long bones Early intervention to relieve dental crowding in pediatric patient to allow better alignment of primary and erupting permanent teeth. An ideal alignment will lead to easier dental hygiene and avoid osteomyelitis due to dental extraction later in life Treatment of pathological fractures & osteomyelitis DIFFERENTIAL DIAGNOSIS Osteopetrosis Cleido cranial dysplasia FEATURES PYKNO DYSOSTOSIS OSTEO PETROSIS CLEIDO CRANIAL DYSPLASIA BASE OF SKULL DenseDenseNormal / rarely dense CRANIAL SUTURES OpenNormalNormal PARANASAL SINUSES Unaerated