Suvendra Vijayan,B.D.S., M.P.H., Department of Oral Pathology, Radiology and Medicine
Suvendra-Vijayan@uiowa.edu
phone: +1 (319) 335 7362
Veeratrishul Allareddy,B.D.S, M.S, Department of Oral Pathology, Radiology and Medicine
Suvendra Vijayan, B.D.S., M.P.H.
Email : Suvendra-Vijayan@uiowa.edu
Address : S386 Dental Science Building, The University of Iowa College of Dentistry, 801 Newton Rd. Iowa City, IA 52242
Published on : 12 Sep 2018
Dentin dysplasia is a rare autosomal dominant hereditary disorder affecting dentin formation in both primary and permanent dentitions. It is classified into type I: radicular dentin dysplasia and type II: coronal dentin dysplasia. Dwarfism is condition due to a hormonal defect of anterior pituitary or reduced tissue response to growth hormone. An interesting case of a 14-year-old patient with dwarfism and dentin dysplasia is presented here. A person is classified as a dwarf if they are under 147 cm in height, as an adult. Achondroplasia, caused by activating point mutations in fibroblast growth factor receptor 3 (FGFR3), accounts for about 70% of all cases of dwarfism.
After a thorough English language search of literature in PubMed, it was ascertained that there is no published literature wherein there has been a case of dentin dysplasia reported along with dwarfism.
Dentin dysplasia, a rare anomaly, is an autosomal dominant hereditary disturbance in dentin formation affecting either the primary or permanent dentitions. It is prevalent in approximately one patient in every 100,000.1 It was first reported by Ballschmiede 1, 2 in 1920 as rootless teeth and in 1929 Rusthon3, 4 coined the term Dentin Dysplasia.. Witkop5 classified Dentin dysplasia into type I: radicular dentin dysplasia, and type II: coronal dentin dysplasia.. Dwarfism is a condition due to a hormonal defect of the anterior pituitary or reduced tissue response to growth hormone 6. There are no known cases of dentin dysplasia with dwarfism presented in the literature. There are cases of Seckel syndrome reported in the literature which have some overlapping features with the presented case, especially regarding poor post-natal growth and abnormalities of teeth7, however this patient had normal cognitive functions and had no other abnormalities
A CBCT scan of a 14-year-old patient with dwarfism was referred for general evaluation of the dentition. Radiographically, the overall size of the craniofacial bones was significantly smaller, which was consistent with the patient’s stunted skeletal growth and overall size. The teeth were markedly smaller in size, the morphology of the crowns though smaller was relatively normal in size but the roots were much shorter, blunted, and consistent with dentin dysplasia. Portions of the teeth were grossly broken down with little evidence of pulp chambers. A supernumerary tooth was present in the mandible between the central incisors. The morphologic features of the dentition appeared to be characteristic of dentin dysplasia. This could be due to secondary effects of dwarfism, which along with the skeletal deformations may also be impacting the dentition.
An autosomal dominant abnormality, dentin dysplasia, resembles dentinogenesis imperfecta. Classification for dentin dysplasia was based on Shields’ classification for heritable human dentine defects 8. Shields’ classification characterized dentin defects into 2 types of dentin dysplasia (DD-I and DD-II), and 3 types of dentinogenesis imperfecta (DGI-I, DGI-II, and DGI-III). DD-I or radicular type characterized by marked changes in the root morphology of the teeth and DD-II or coronal type where the changes are more prominent in the crown and pulp chamber of the teeth.5, 8. Clinically in DD-I the crowns of primary and permanent have a normal appearance but radiographically the roots in permanent teeth tend to be short with a crescent shaped pulpal remnant and total pulpal obliteration in primary dentition. In DD-II some of the features are similar to DGI-II. The teeth structures look normal with a thistle-tube deformity and pulp stones in the pulp chamber. The root length is normal but bulbous crowns with cervical constriction similar to DGI-II are
Dwarfism is a condition due to a hormonal defect of anterior pituitary or reduced tissue response to growth hormone 6. A person is classified as a dwarf if they are under 147 cm in height, as an adult. Achondroplasia causes about 70% of all cases of dwarfism caused by activating point mutations in fibroblast growth factor receptor 3 (FGFR3) 6, 10. It is usually identified by a set of anomalies most notable short stature. There is a 50% chance that a child might have the condition if the parent has it. It also occurs due to sporadic genetic mutation in 75-80% of affected cases 11. Factors affecting achondroplasia may be parental age along with genetic mutation. Clinically, individuals will have short stature, with above average head size, small midface and flat nasal ridge. Intellectual ability is not hindered and there is no sex or gender predilection. The condition can be identified during antenatal screening. There is no pharmacological treatment.
Dentin dysplasia with dwarfism case report has not been reported in literature. Case reports on Seckel syndrome which has some overlapping features to the current case report are present7. One of the main difference is that intellectual ability is not hindered in the current individual whereas intellectual abilities are affected in individuals with Seckel syndrome.
Normal skull of 15y2m old (A) (120.79mm) vs skull of 14y11m old with dwarfism (B) (90.16mm) Measurement from right superior orbital foramen to inferior border of mandible at midline
Coronal view of the impacted supernumerary tooth
CBCT panoramic reconstruction showing morphology of the teeth