Arrested Root Development Research Articles

Long-term adverse effects on dentition in children with poor-risk neuroblastoma treated with high-dose chemotherapy and autologous stem cell transplantation with or without total body irradiation.

Chemo- and radiotherapy may have injurious effects on developing teeth. In this long-term follow-up study among poor-risk neuroblastoma (NBL) survivors our aims were: (1) to assess both the type and extent of the side-effects of the anticancer treatment on tooth development; and (2) to develop an index for expressing total damage to the permanent dentition. We studied the dental development from panoramic radiographs (PRG) of 18 long-term survivors treated under the age of 6 years with high-dose (HD) chemotherapy and autologous stem cell transplantation (ASCT) for poor-risk NBL. The myeloablative therapy was either HD chemotherapy and fractionated total body irradiation (TBI) of 10-12 Gy (TBI group, n = 10) or HD chemotherapy only (non-TBI group, n = 8). A defect index (DeI) was developed to describe the damage to the permanent dentition. The DeI was also tested in 18 healthy adolescents. All NBL patients had disturbances in dental development including short roots, arrested root development, microdontia and tooth aplasia. After TBI, 9/10 patients had very severe root defects, in contrast to none in the non-TBI group. All children in the TBI group had 2-12 (mean 6.6) missing permanent teeth, while 2/5 in the non-TBI group (3/8 excluded due to young age) had two and four missing permanent teeth, respectively. Microdontia was found at equal frequency in both groups. The mean value of the DeI was 70.0 (range 28-117) in the TBI group, 15.2 (range 4-34) in the non-TBI group (P<0.001, Mann-Whitney U test) and 1.8 (range 0-15) in healthy adolescents. Disturbances in dental development may compromise occlusal function in poor-risk NBL patients after ASCT, especially when TBI is included in the conditioning regimen. Long-term dental follow-up and rehabilitation is required.

Pulp revascularization of replanted immature dog teeth after different treatment methods.

The purpose of the present study was to determine the effect of topical treatment with doxycycline and/or the application of unfilled resin to the anatomical crown on the occurrence of revascularization in reimplanted dog teeth. Ninety-six teeth in 4 young mongrel dogs were used. Eighty one teeth were atraumatically extracted and divided into four groups. Group 1, 17 teeth were kept dry for 5 min and then replanted. Group 2, 21 teeth were soaked with a freshly prepared solution of doxycycline (1 mg/20 mL saline) for 5 min before replantation. Group 3, 23 teeth were soaked with the doxycycline solution for 5 min, and then replanted. The crowns were coated with 2 layers of light cured unfilled resin. Group 4, 20 teeth were kept dry for 5 min, and then replanted. The crowns were treated as with the teeth in Group 3. Three months after surgery, radiographic evaluation revealed that 27 teeth had continued root development and 32 teeth showed arrested root development with periradicular pathosis. The remaining 17 teeth, which had arrested root development but no signs of periradicular pathosis, were all histologically evaluated for final assessment. The occurrence of revascularization according to treatment group was 29.4%, 60%, 60%, 36.8% in Group 1, 2, 3, and 4, respectively. A multiple logistic regression analysis in SAS indicated there was no significant association between vitality and dog (P = 0.7564). Soaking for 5 min in doxycycline significantly increased the revascularization rate (P = 0.024) while the addition of resin to the crown did not result in an increased incidence of pulp revascularization (P = 0.823).

Replantation of 400 avulsed permanent incisors. 3. Factors related to root growth

Four hundred avulsed and replanted permanent incisors were examined for pulpal and periodontal healing. In 30 teeth, root formation was incomplete at the time of injury. Two teeth were excluded from the study due to nonphysiological extraalveolar storage (i.e. homemade saline). Of the 28 remaining replanted incisors, 7 showed subsequently completed root development, 8 partially completed root development and 13 arrested root development. Completed root development subsequent to replantation was found to be significantly related to pulpal revascularization, being rare in cases with pulp necrosis (5 of 15 teeth) and frequent after pulpal healing (11 of 13 teeth) (p = 0.01). Root development was not found to be significantly related to the extraalveolar storage period; but occurred slightly more frequently when the dry storage period was less than 45 min. (p = 0.13). Ingrowth of bone and formation of an internal periodontal ligament (PDL) was found in 6 teeth and was related to arrested root formation in cases with pulpal healing. The explanatory factor for these findings appeared to be damage to the Hertwig's epithelial root sheath.

Dentofacial development in long-term survivors of acute lymphoblastic leukemia: A comparison of three treatment modalities

Ninety-seven children who were diagnosed with acute lymphoblastic leukemia before 10 years of age and treated with chemotherapy alone, chemotherapy plus 1800-cGy cranial irradiation (RT), or chemotherapy plus 2400-cGy RT were evaluated for effects of therapy on dentofacial development. All patients were seen at least 5 years postdiagnosis. Dental abnormalities were determined from panoramic radiographs, and craniofacial evaluations were made from lateral cephalometric radiographs. Ninety-one (94%) of all patients and 41 (100%) of patients younger than 5 years of age at diagnosis had abnormal dental development. The severity of these abnormalities was greater in children who received treatment before 5 years of age and in those who received RT. Observed dental abnormalities included tooth agenesis, arrested root development, microdontia, and enamel dysplasias. Craniofacial abnormalities occurred in 18 of 20 (90%) of those patients who received chemotherapy plus 2400-cGy RT before 5 years of age. Mean cephalometric values of this group showed significant deficient mandibular development. The results of this study suggest that the severity of dentofacial-developmental abnormalities secondary to antileukemia therapy are related to the age of the patient at the initiation of treatment and the use of cranial RT.

多数歯埋伏を伴った大理石骨病の１例

Osteopetrosis is a rare disorder characterized by symmetrical systemic sclerosis of skeletal bone which gives rise to susceptibility to fracture and osteomyelitis. Frequently dentition development is affected. A case of osteopetrosis in a 20-year-old female including various forms of dentition disorders i.e., impaction of 765 678 E3 B3, distorted crowns of 5 5, enamel hypoplasia of 43 3 4 4, arrested root development of 35, curved roots of 3 3, delayed root development of 5 and dentigerous cyst of 3, is described. In family history, the parents were consanguinity and the younger brother died of unknown etiology at one year old. Systemic roentogenological examination revealed characteristic findings e.g., sclerosis of the base of skull, “sandwich” appearance of the spine, “bone within a bone” appearance of the epiphises of long bones. By clinical examinations, anemia and cerebral nerve palsy were not observed. The serum calcium, phosphorus, alkaline phosphatase, thyrocalcitonin and parathormone levels were within normal limits. Impacted E3 B and 3 associated with dentigerous cyst were surgically removed under local anesthesia and intravenous dripping infusion of piperacillin. The wounds healed uneventfully. Microscopically, hyperplastic cementum of the root of 3 showed ankylosis with bone. Sclerosed cancellous bone of the mandible was composed of thickened lamellar bone exhibiting mosaic pattern with cement lines.