White-spot lesions and gingivitis microbiotas in orthodontic patients.

White-spot lesions (WSL) associated with orthodontic appliances are a cosmetic problem and increase risk for cavities. We characterized the microbiota of WSL, accounting for confounding due to gingivitis. Participants were 60 children with fixed appliances, aged between 10 and 19 yrs, half with WSL. Plaque samples were assayed by a 16S rRNA-based microarray (HOMIM) and by PCR. Mean gingival index was positively associated with WSL (p = 0.018). Taxa associated with WSL by microarray included Granulicatella elegans (p = 0.01), Veillonellaceae sp. HOT 155 (p < 0.01), and Bifidobacterium Cluster 1 (p = 0.11), and by qPCR, Streptococcus mutans (p = 0.008) and Scardovia wiggsiae (p = 0.04) Taxa associated with gingivitis by microarray included: Gemella sanguinis (p = 0.002), Actinomyces sp. HOT 448 (p = 0.003), Prevotella cluster IV (p = 0.021), and Streptococcus sp. HOT 071/070 (p = 0.023); and levels of S. mutans (p = 0.02) and Bifidobacteriaceae (p = 0.012) by qPCR. Species' associations with WSL were minimally changed with adjustment for gingivitis level. Partial least-squares discriminant analysis yielded good discrimination between children with and those without WSL. Granulicatella, Veillonellaceae and Bifidobacteriaceae, in addition to S. mutans and S. wiggsiae, were associated with the presence of WSL in adolescents undergoing orthodontic treatment. Many taxa showed a stronger association with gingivitis than with WSL.

Air abrasion of failed bonded metal brackets: a study of shear bond strength and surface characteristics as determined by scanning electron microscopy.

Failed bonded orthodontic brackets generally require their replacement with a new bracket. The introduction of air abrasion (microetching) technology to orthodontics may allow for immediate use of these failed brackets. This study compared the in vitro shear bond strengths of previously failed bonded metal brackets (experimental group) subjected to air abrasion with new untreated brackets (control group). All bonding used a light-cured orthodontic bonding system. In addition, representative samples from each group were examined by scanning electron microscopy. The results of this study found no significant differences in shear bond strengths between the two groups. Scanning electron microscopy examination of the air abraded brackets revealed a roughened mesh surface with residual bonded material in the bracket base. This simple technique should allow for the immediate reuse of previously failed bonded metal brackets.

The oral health of long-term survivors of acute lymphoblastic leukaemia: a comparison of three treatment modalities.

Sixty-eight children who were diagnosed with acute lymphoblastic leukaemia (ALL) prior to age 5 years and treated with chemotherapy alone, chemotherapy plus 1800 cGy cranial irradiation (RT), or chemotherapy plus 2400 cGy RT were assessed clinically for overall dental health. All patients were at least 60 months in continuous remission. Dental caries were assessed by NIDR diagnostic criteria, oral hygiene was assessed by the modified Oral Hygiene Index, and gingival health was assessed by the modified gingival index of Loe and Silness. There was no significant difference in caries experience between the three groups nor with the normal population. Those patients that received 2400 cGy RT had significantly higher plaque and periodontal index scores than patients in the other treatment groups. The results of this study suggest that: (1) children with ALL treated with any of the described modalities are at no greater risk of developing dental caries than the normal population; and (2) patients receiving 2400 cGy prior to age 5 years are at greater risk of developing periodontal disease than patients treated with other central nervous system prophylaxis regimens examined in this study.

A longitudinal study of oral ulcerative mucositis in bone marrow transplant recipients.

BACKGROUND: Few longitudinal studies have investigated the onset, duration, and resolution of ulcerative mucositis in bone marrow transplant recipients. This study prospectively followed a group of such patients on a daily basis to obtain data on the incidence of ulcerative mucositis, location and duration of lesions, severity with different conditioning regimens, and the relationship of such mucositis to the absolute neutrophil count. METHODS: Fifty-nine bone marrow transplant recipients on prophylactic acyclovir were examined daily for 26 days after marrow infusion, and all oral ulcerative lesions were recorded. RESULTS: Oral ulcers occurred in 76.3% of patients, began at a mean of 5 days after marrow infusion (day + 5), and lasted for a median of 6 days. More than 90% of patients showed complete resolution of ulcers on or before day + 15, and all showed resolution when the absolute neutrophil count was > 500 cells/ml. Persistence of ulcers was noticed in patients who had oral graft-versus-host disease and in some patients who initially developed more severe ulcerations. Ninety-six percent of ulcers were located on nonkeratinized mucosa. CONCLUSIONS: Ulcerative mucositis occurs in about 75% of bone marrow transplant recipients in the absence of herpes simplex virus infection. Most lesions occur on nonkeratinized mucosae which are vulnerable to trauma, especially if such mucosae are rendered atrophic by conditioning regimens. Oral ulcers may persist beyond day + 15 and after recovery of the neutrophil count in patients who initially develop more severe ulcerations or in patients who develop graft-versus-host disease.

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.

The role of herpes simplex virus in the development of oral mucositis in bone marrow transplant recipients.

Herpes simplex virus (HSV) has been implicated as a major etiologic factor in the development of ulcerative mucositis in bone marrow transplant (BMT) recipients. In this study, 60 patients who received BMTs were evaluated for at least 30 days post-transplant for ulcerative mucositis and the presence of culturable HSV. Fifty-nine patients received prophylactic acyclovir. Forty-six patients developed ulcerative lesions and 45 of these were culture negative for HSV. Neither the source of transplant (autologous versus allogenic) nor the HSV antibody status of the patient affected the frequency of mucositis. The conditioning regimen appeared to be the most significant factor contributing to the severity of ulcerative mucositis. While the majority of ulcers occurred on movable nonkeratinized mucosa in BMT recipients, the usual sites of reactivation of intraoral HSV are nonmovable, keratinized mucosa. We conclude that HSV is probably not a major etiologic agent of mucositis in BMT recipients and that acyclovir is an effective agent in preventing HSV reactivation.

An evaluation of a fluoride-releasing, visible light-activated bonding system for orthodontic bracket placement.

In spite of improved preventive measures, decalcification around bonded orthodontic appliances continues to be a problem for the clinician. Various fluoride-containing mediums have been proposed as aiding in the elimination of this problem; however, almost all are dependent on patient cooperation for their success. An ideal preventive system would be one that would operate independently of patient cooperation. The purpose of the present study was to compare a visible light-activated, fluoride-releasing bonding system with a visible light-activated conventional bonding system relative to bracket retention and prevalence of decalcification. Twenty-two patients were entered into the study, representing 206 experimental brackets and 206 control brackets. The average treatment period was 25 months. No significant differences in bracket retention rates were found between the two systems. Significantly, 26 teeth in the control group demonstrated decalcification (12.6%), whereas none of the teeth in the experimental group did. The results of this study suggest that a visible light-activated, fluoride-releasing bonding system is capable of adequately retaining brackets while aiding in the prevention of decalcification around bonded appliances.

A comparison of elastomeric auxiliaries versus elastic thread on premolar extraction site closure: an in vivo study.

Twenty-five patients requiring symmetric premolar extractions (representing eighty quadrants requiring canine retraction) were entered into the study. Standard 0.022 X 0.028-inch Siamese edgewise appliances with 0.016 X 0.022-inch arch wires were used during canine retraction. In 30 of the quadrants, canine retraction was accomplished with Unitek Alastik chain; 10 quadrants were treated with Rocky Mountain energy chain (medium). In the remaining 40 groups, canine retraction was accomplished via Unitek nylon-covered latex thread. The forces initially applied to the system were between 350-400 grams. Patients were seen at 3-week intervals to measure the amount of space closure and to change the elastic modules. A comparison among the three groups revealed no significant differences in rates of canine retraction (P less than 0.05). Empirically, the elastomeric auxiliaries were found to be more hygienic and required less chair time to apply than did the elastic thread.

Oral bleeding in classic hemophilia.

Charts of 132 patients with proved classic hemophilia were reviewed. The diagnosis of hemophilia was most often made after 6 months of age but before 2 years. Persistent oral bleeding led to the diagnosis in 13.6 percent of the cases. The oral site most often involved was the frenum of the lip. In the patient with proven hemophilia, oral bleeding accounted for 9 percent of those bleeding episodes requiring infusion therapy.