Correlation between speech outcome and cephalometric dimensions in patients with diastrophic dysplasia.

Diastrophic dysplasia (DTD) is a recessively inherited form of osteochondrodysplasia, presenting with disproportionate short stature and multiple orthopedic problems. The clinical oral manifestations include either cleft palate or submucous cleft palate in at least half of the patients. Histological studies have shown alterations in growth plate, articular, laryngeal, tracheal, and ear cartilages. Mutations in the DTDST gene, which codes for the sulphate transporter membrane protein, are responsible for the disease. Thirty-three patients were studied for speech characteristics and their correlation with cephalometric dimensions. Hyponasality was observed in 13 and misarticulation of /R/, /S/, or /L/ sounds in 17 of the 33 patients. Neither of these correlated with the occurrence of palatal deformities. Hyponasality was atypical and did not correlate with the obtained nasalance scores. Cephalometric measurements reflecting the size of the orofacial area of the vocal tract were short in the DTD patients compared with those in the healthy controls. The specific speech characteristics in DTD probably result from both the altered size and shape of the vocal tract and the structural and functional abnormalities of the laryngeal and tracheal cartilages.

Craniofacial structure in diastrophic dysplasia--a cephalometric study.

Diastrophic dysplasia (DTD) is a well characterized, recessively inherited osteochondrodysplasia. Forty-eight patients with DTD were studied for craniofacial characteristics. Of these patients, 58% had cleft palate. A cephalometric analysis based on lateral cephalograms was performed. We observed a short anterior cranial base, vertical nasal bones, short and posteriorly positioned upper and lower jaws, increased anterior facial height, increase in the sagittal length of the body of the cervical vertebrae, and an abnormal dens of the second cervical vertebra. DTDST, in which mutations responsible for the disease occur, is a gene that codes for a sulphate transporter membrane protein. The craniofacial anomalies in DTD most likely result from deficient development and growth of cartilaginous structures and are probably due to defective sulfation of the proteoglycans of the cartilage.

Transverse facial morphology in patients with diastrophic dysplasia.

Diastrophic dysplasia (DTD) is a well-characterized, recessively inherited osteochondrodysplasia. Thirty-seven patients were studied for transverse craniofacial characteristics. Of these patients, 10 had cleft palate and 11 had submucous cleft palate. A cephalometric analysis based on posteroanterior (PA) cephalograms was performed: 16 landmarks were identified and digitized into a computer. Seven linear and four angular variables were calculated and the values compared with those of a matched control population. DTD patients differed from controls only in cases with cleft palate where the mesio-orbital, bigonial, and antegonial widths were large compared with controls. The present findings indicate that although the development and growth of cartilaginous structures are disturbed in DTD, the intramembranously developing bones and the appositional growth pattern do not seem to be primarily affected.

Phenotypic features of dentition in diastrophic dysplasia.

Diastrophic dysplasia (DTD) is a well-characterized, recessively inherited osteochondrodysplasia. The gene, DTDST, in which mutations are responsible for the disease, codes for a sulphate transporter protein. We studied 53 patients with earlier diagnosed DTD for special characteristics in the oral region. Clinical examination included impressions of dental arches, oral photographs, and panoramic radiographs. Palatal clefting was recorded. Congenitally missing teeth were evaluated and dental maturity calculated from the panoramic radiographs. Tooth crown size and length and breadth of dental arches were measured from the casts. Dental anomalies and orthodontical status were evaluated from the casts and oral photographs. The level of oral hygiene was evaluated with caries (DMF) and periodontal (GBI) indices. Cleft palate was recorded in 56% and hypodontia (excluding third molars) in 31% of the patients. Dental age was retarded. Dental arches were narrow and tooth crown size was reduced. The observed crown size reduction could result from the same factors that cause cleft palate and/or hypodontia, or from a lack of sulfation in the developing dental papilla. The typical malocclusion traits were crowding, lateral crossbite, and open bite, which we assumed to result from reduced growth potential of the dental arches. Despite crowding and limited flexion of the finger joints leading to a severe handicap, the level of oral hygiene was high and no need for auxiliary equipment for cleaning the teeth was noted.