Thrombocytopenia-Absent Radius (TAR): Case report of dental implant and surgical treatment

Abstract

Thrombocytopenia-absent radius (TAR) syndrome is a congenital malformation in which affected individuals present reductions in the number of platelets, hypoplasia, or absence of radial bone unilaterally or bilaterally. Hematologic, skeletal, cardiac (particularly tetralogy of Fallot and septal-atrial defects), and gastrointestinal anomalies are most commonly associated with TAR syndrome. Skeletal changes result in a higher risk of dental and craniofacial trauma in patients with the syndrome. Thus, it is important for the dentist to be aware of the characteristics of TAR syndrome and its clinical management for better care of these patients. The objective of this study is to describe a case report of a 26-year-old patient with TAR syndrome with a history of trauma and root fracture of tooth 11 and alveolar bone ridge. During anamnesis, root fractures requiring the extraction of the 11 tooth, alveolar bone ridge fracture in the adjacent region, and dental trauma were observed. A hematological evaluation and blood and radiological examinations were performed. Osseointegrated implant was performed using the guided surgery and flapless technique, as well as prosthetic rehabilitation in the affected region. This report discusses the importance of careful planning, such as the use of incisions and conservative surgery, techniques for alveolar ridge preservation, gingival manipulation, and prosthesis confection. The patient was attended by a hematologist throughout the treatment. Key words: TAR syndrome, absent radii and thrombocytopenia, dental implants, oral surgery.

Thrombocytopenia With Absent Radii Syndrome With an Unusual Urological Pathology: A Case Report

“…The thrombocytopenia that develops in TAR syndrome is HMT, platelet hypoproduction caused by insufficient numbers of megakaryocytes, the precursors to platelets, in the bone marrow [7]. The etiology of the HMT in these patients is hematopoietic stem cells, which do not appropriately respond to thrombopoietin and impaired maturation of the megakaryocyte progenitor cells in the bone marrow [7]. Thrombocytopenia may be present at birth among those with TAR syndrome, with 95% of those with the condition developing significant thrombocytopenia within four months of birth [4].…”

“…The mechanism of the exacerbation is reported to be direct immunoglobulin E (IgE) immune-mediated or secondary to increased GI bleeding due to loss of coagulation proteins [11]. It is important that healthcare professionals treating those with TAR are aware of its impact on platelet count and act accordingly when performing surgical procedures [7].…”

“…Immediately after birth, approximately 50% of infants with TAR syndrome have symptomatic thrombocytopenia, and by four months of life, 90% will be symptomatic [6]. TAR syndrome has also been found to increase the occurrence of anomalies within hematologic, cardiovascular [4], gastrointestinal, and skeletal systems [7]. Cardiovascular anomalies may include tetralogy of Fallot or atrial septal defects [4].…”

“…Cardiovascular anomalies may include tetralogy of Fallot or atrial septal defects [4]. Skeletal anomalies may result in a higher risk of dental and craniofacial trauma in this patient population [7]. It has been reported that more than 60% of those with TAR syndrome have accompanying cow's milk protein allergy (CMPA) [8].…”