Radiographic examination of ectopically erupting maxillary canines

This study analyzes the need for and possibility of obtaining further information from different radiographic procedures in 125 children with potential ectopic eruption of the maxillary canines. After clinical examination of 3,000 10 to 15-year-old children, it was found that 7% needed radiographic examinations for determination of the canine position. Eighty-four children (2.8%), with a total of 125 potential ectopically erupting maxillary canines diagnosed clinically and by means of periapical radiographs, were selected and a stepwise extended radiographic diagnostic procedure was used. Most canines in ectopic eruption were positioned palatally; the positions could be assessed with sufficient accuracy from conventional periapical films in 92% of the cases. Only in 37% of the cases, however, could the lateral incisor be projected free from the ectopic canine by the intraoral technique. The lamina dura of the lateral incisor facing the canine was often found to be interrupted. For 29% of the ectopic canines, the lateral incisors could neither be projected free nor judged free from resorptions and a supplementary polytomographic investigation was believed to be necessary. The number of resorbed teeth was doubled by polytomography and altogether 12.5% of the ectopic canines caused resorptions. A stepwise radiographic procedure including polytomography is described and recommended in cases of ectopic eruption of maxillary canines for determining the correct position and ruling out or confirming resorptions on incisors, thereby optimizing the orthodontic treatment planning.

Resorption of maxillary lateral incisors caused by ectopic eruption of the canines. A clinical and radiographic analysis of predisposing factors

Factors predisposing to resorption of adjacent permanent lateral incisors caused by ectopic eruption of maxillary canines were evaluated. The subjects consisted of two groups: one with 40 lateral incisors with resorption caused by ectopic eruption and a control group of 118 ectopic eruption cases with no lateral incisor resorption. The mean age of the children in the two groups differed by only 0.7 of a year and ranged from 10.0 to 15.0 years, covering the normal eruption period of the maxillary canine. Resorption of lateral incisors was three times as common in girls as in boys. The resorption cases showed a more advanced dental development, a more medial canine position in the dental arch, and a slightly more mesial horizontal path of eruption (an average of 10 degrees) than that of the control cases. Factors such as the width of the dental follicle and proclination or distal tilting of the lateral incisor showed no correlation to the resorption. Potential resorption cases are always those in which the canine cusp in periapical and panoramic films is positioned medially to the midline of the lateral incisor. Such situations should be carefully investigated with polytomography if necessary. The risk of resorption also will increase with a more mesial horizontal path of eruption. From 10 years of age or younger, annual clinical examination by palpation of the canine eruption path is recommended. This clinical examination should be supplemented with a stepwise extended radiographic procedure in cases in which ectopic eruption of the maxillary canines is suspected.

Longitudinal study and analysis of clinical supervision of maxillary canine eruption

In 505 Swedish schoolchildren, the need to supervise the eruption of the maxillary canines was assessed by digital palpation and related to occlusal development and somatic maturity. The aim was to judge the extent to which clinical methods should be supplemented with radiographic methods. The 505 children, aged 8-12 yr, were clinically investigated and the eruption was followed over a 3-yr period. The age of the child was found not to be a valid criterion for radiographic investigation of the canine position. The investigation showed that 29% of 10-yr-old children had non-palpable canines bilaterally. In 11-yr-old children, the corresponding figure was 5%. A palpable buccal bulge in the primary canine apical area was found to signify a favorable eruption position. The prevalence of non-palpable or unerupted canines was 3% in the age group 11-15 yr. Indications for radiographic examination of canine position were present in altogether 7% of the children over 10 yr of age according to the clinical diagnostic criteria used.

Periodontal healing after impacted lower third molar surgery. A retrospective study

The effect on periodontal tissues of lower third molar surgery, due to impaction or semi-impaction, has been investigated in a retrospective study comprising 215 cases. The post-operative examination took place 2 years after the surgical treatment and included both clinical and radiographic variables. Clinical registrations included the amount of plaque, and presence of gingivitis and periodontal pockets. The results showed a higher incidence of plaque, gingivitis and pockets on the distal surface of the second molar than on other surfaces of the first and second molars. The alveolar bone level distal to the second molar was registered by radiographic examination with a periodontal probe as indicator. 2 years post-operatively, 43.3% of the cases exhibited pocket depths exceeding 7 mm and 32.1% showed intrabony defects exceeding 4 mm. Some factors affecting the periodontal healing after lower third molar surgery are discussed.

Periodontal healing after impacted lower third molar surgery in adolescents and adults. A prospective study

The effects of impacted lower 3rd molar surgery on periodontal tissues in the adjacent 2nd molar area have been investigated in a prospective study comprising 176 cases from 2 age groups: less than or equal to 20 years (n = 93) and greater than or equal to 30 years (n = 83), respectively. The preoperative and 1-year postoperative examinations included both clinical and radiographic variables. All patients were subjected to a standardized surgical procedure and optimal plaque control pre-, intra- and postoperatively. Early removal of impacted lower 3rd molars with large angulation and close positional relationship to the adjacent 2nd molar proved to have a beneficial effect on periodontal health.

Fluconazole vs low-dose amphotericin B for the prevention of fungal infections in patients undergoing bone marrow transplantation: a study of the North American Marrow Transplant Group

Systemic fungal infections are a major problem in bone marrow transplant recipients who have prolonged neutropenia or who receive high-dose corticosteroids. Prophylaxis with Fluconazole or low-dose amphotericin B reduces, but does not eliminate these infections. To determine which prophylactic agent is better, we performed a prospective randomized study. Patients undergoing allogeneic (related or unrelated) or autologous marrow or peripheral stem cell transplantation were randomized to receive Fluconazole (400 mg/day p. o. or i.v.) or amphotericin B (0.2 mg/kg/day i.v.) beginning 1 day prior to stem cell transplantation and continuing until recovery of neutrophils to >500/microl. Patients were removed from their study drug for drug-associated toxicity, invasive fungal infection or suspected fungal infection (defined as the presence of fever >38 degrees C without positive culture while on broad-spectrum anti-bacterial antibiotics). Proven or suspected fungal infections were treated with high-dose amphotericin B (0.5-0.7 mg/kg/day). Patients were randomized at each institution and stratified for the type of transplant. The primary end-point of the study was prevention of documented fungal infection; secondary endpoints included fungal colonization, drug toxicity, duration of hospitalization, duration of fever, duration of neutropenia, duration and total dose of high-dose amphotericin B and overall survival to hospital discharge. From July 1992 to October 1994, a total of 355 patients entered into the trial with 159 patients randomized to amphotericin B and 196 to Fluconazole. Patient groups were comparable for diagnosis, age, sex, prior antibiotic or antifungal therapy, use of corticosteroids prior to transplantation and total duration of neutropenia. Amphotericin B was significantly more toxic than Fluconazole especially in related allogeneic transplantation where 19% of patients developed toxicity vs 0% of Fluconazole recipients (p < 0.05). Approximately 44% of all patients were removed from prophylaxis for presumed fungal infection. Proven fungal infections occurred in 4.1% and 7.5% of Fluconazole and amphotericin-treated patients, respectively. Proven fungal infections occurred in 9.1% and 14.3% of related allogeneic marrow recipients receiving Fluconazole or amphotericin B, respectively, and 2.1% and 5.6% of autologous marrow recipients receiving Fluconazole or amphotericin B, respectively (P > 0.05). In this prospective trial, low-dose amphotericin B prophylaxis was as effective as Fluconazole prophylaxis, but Fluconazole was significantly better tolerated.

Recurrent parotitis and sialectasis in childhood. Clinical, radiologic, immunologic, bacteriologic, and histologic study

Twenty children with juvenile recurrent parotitis, between 3 months and 16 years of age at onset, were followed up over a period of 7 to 22 years. Radiologic, histopathologic, cytologic, immunologic, and bacteriologic studies were performed to investigate the cause of sialectasis, commonly found in juvenile recurrent parotitis, and the pathogenesis of the disease. It was considered that a combination of a congenital malformation of portions of the salivary ducts and infections ascending from the mouth following dehydration of the children are contributory to the pathogenesis of the disease. The results of the investigations into the cause of the disease appear to exclude an auto-immunologic response or an allergic condition, an immature immune response, mumps, a sensitivity to upper respiratory tract infection, and familial factors.

The influence of anatomical, pathophysiological and other factors on periodontal healing after impacted lower third molar surgery. A multiple regression analysis

A multifactorial approach has been used to identify some predictors of postoperative intrabony defects (IBD) on the distal surface of the adjacent second molar (M2) after impacted lower third molar (M3) surgery. The material consisted of 215 lower third molar removals, performed on 144 persons (age range 16-53 years; mean 27.2 years). The postoperative examination took place 2 years after impaction surgery and included both clinical and radiographic variables. Statistically significant (5% significance level) predictors of IBD found in stepwise multiple regression analyses were: (1) preoperative intrabony defect M2 distal; (2) age at the time of surgery; (3) size of contact-area M3/M2; (4) root resorption M2 distal; (5) probing dept distal surface of adjacent first molar postoperatively; (6) pathological follicle M3. The regression model with IBD as regressand produced a total R2 of 0.45. When the regressand was the difference between IBD and the preoperative intrabony defect, the regression analysis explained 62% of the variance (R2 = 0.62). These regression models explained the variance in terms of the size of the remaining postoperative intrabony defect as well as in terms of periodontal healing after impacted lower third molar surgery.

The clinical impact of antibacterial prophylaxis and cycling antibiotics for febrile neutropenia in a hematological malignancy and transplantation unit

Febrile neutropenia is an expected complication during treatment of aggressive hematological malignancies and hematopoietic cell transplantation. We conducted a prospective cohort trial to determine the effects and safety of prophylactic fluoroquinolone administration, and rotation of empiric antibiotics for neutropenic fever in this patient population. From March 2002 through 2004, patients were treated with prophylactic levofloxacin during prolonged neutropenia, and a cycling schedule of empiric antibiotic therapy for neutropenic fever was initiated. The rates of bacteremia, resistance and complications were compared to a retrospective cohort of previously treated patients. The rate of gram-negative bacteremia decreased after the initiation of prophylactic levofloxacin (4.7 vs 1.8 episodes/1000 patient days, P<0.05). Gram-positive bacteremia rates remained unchanged, but more isolates of Enterococcus faecium were resistant to vancomycin after the intervention began. Resistance to the antibiotic agents used in the rotation did not emerge. There was no change in mortality during the intervention period. A prophylactic and cycling antibiotic schedule was successfully implemented on a hematological malignancy and hematopoietic cell transplant unit. gram-negative bacteremia was significantly decreased, without emergence of resistance. Concerns with Gram-positive resistance will require further observation.

Resorption of incisors after ectopic eruption of maxillary canines: a CT study

The purpose of the study was to analyze the extent and prevalence of resorption of maxillary incisors after ectopic eruption of the maxillary canines in a sample of subjects referred to an orthodontic specialist clinic for consultation. The subjects consisted of 107 children, 39 boys and 68 girls, between 9 and 15 years of age (mean 12.5 years), with 156 ectopically and 58 normally erupting maxillary canines. All children were subjected to a basic clinical and intraoral radiographic investigation. These radiographs were supplemented with computerized tomography (CT) of the upper alveolar bones in order to get more precise information on the positions and relationships between the maxillary canines and adjacent incisors and to evaluate resorptions on the roots of the incisors. The results showed that, relative to the roots of the adjacent incisors, the crowns of 21% the ectopically positioned canines were located to the buccal, 18% to the distobuccal, 27% to the lingual, 23% to the distolingual, 5% apically and 6% between the central and lateral incisors. Ninety-three percent of the ectopically positioned canines were in contact with the roots of the adjacent lateral incisor and 19% were in contact with the central incisor. The corresponding figures for the normally erupting canines were 49%. Resorptions on the roots of the incisors adjacent to the ectopically positioned canine occurred in 38% of the laterals and in 9% of the centrals. The resorptions were graded and tended to be extensive. Among the 58 resorbed lateral incisors, resorptions were slight in 31%, moderate in 9%, and severe with pulpal involvement in 60%. The corresponding figures for the 14 resorbed centrals were 36%, 21%, and 43%, respectively. About 60% of the resorptions involved the middle and apical thirds, the tip of the apex not included. On the sides with normally erupting canines, 3 lateral maxillary incisors were slightly or moderately resorbed distally. In all, 51 of the 107 subjects with ectopically erupting maxillary canines (48%) had resorbed maxillary incisors during the eruption of the maxillary canines. There were statistically significant correlations between ectopic eruption of the maxillary canine, contacts between the teeth and resorptions on the adjacent incisors. It was concluded that resorption on maxillary incisors after ectopic eruption of the maxillary canines is a more common phenomenon than previously reported and has to be considered in all cases with seriously diverging eruption of maxillary canines. It was also concluded that the resorptions of the roots of the incisors were caused by pressure during the eruption of the adjacent, aberrant canine. Finally, it was shown that CT scanning substantially increased the detection of root resorptions on incisors adjacent to ectopically erupting maxillary canines (about 50%). The sensitivity of intraoral films was low when diagnosing the resorptions, being calculated to 0.68.

Mature polymorphonuclear leukocytes express high-affinity receptors for IgG (Fc gamma RI) after stimulation with granulocyte colony-stimulating factor (G-CSF)

The high-affinity receptor for the constant region of immunoglobulin G IgG (Fc gamma RI; CD64) is virtually undetectable on mature polymorphonuclear neutrophils (PMNs) in healthy individuals but is expressed on PMNs in patients with certain infections and in patients treated with recombinant human granulocyte colony-stimulating factor (rhG-CSF). The induction of Fc gamma RI by rhG-CSF has previously been reported to result from effects on immature granulocyte progenitors. To evaluate the G-CSF effect on mature PMNs, we studied the correlation between G-CSF plasma concentration and expression of Fc gamma RI on PMNs in vivo as well as the effect of G-CSF on Fc gamma RI expression on mature PMNs in vitro. Fc gamma RI expression on PMNs correlated (R = 0.79; p < .001) with plasma concentrations of endogenous or recombinant G-CSF in healthy volunteers and in patients undergoing high-dose chemotherapy and autologous bone marrow transplantation. PMNs exhibited a unimodal distribution for elevated Fc gamma RI expression, suggesting that G-CSF induced increased expression of Fc gamma RI on mature as well as on immature PMNs. In vitro, incubation of mature PMNs with G-CSF induced mRNA for Fc gamma RI. Significant Fc gamma RI surface expression was induced in a time- and dose-dependent manner. Thus, G-CSF can act on mature PMNs to increase Fc gamma RI expression and may be useful for stimulating antibody mediated immune functions of PMNs in vivo.

Monoclonal antibody 197 (anti-Fc gamma RI) infusion in a patient with immune thrombocytopenia purpura (ITP) results in down-modulation of Fc gamma RI on circulating monocytes

A 44-year old woman with refractory immune thrombocytopenia purpura was treated with the murine monoclonal antibody 197 in a phase 1 trial. It vitro studies have demonstrated that the monoclonal antibody 197 (subclass IgG2a) binds to two distinct epitopes of Fc gamma RI, with the constant domain binding to the Fc-binding portion of the Fc gamma RI and the variable domain binding to a different epitope, resulting in crosslinking and modulation of this receptor. The monoclonal antibody 197 was administered on days 1, 3 and 5 at doses of 0.25 mg/kg, 0.35 mg/kg and 0.45 mg/kg, respectively. The fusions were well tolerated with transient facial flushing, and wheal-and-flare rash during the first infusion, which resolved with a slower infusion rate and the administration of diphenhydramine and acetaminophen. Although a marked clinical improvement did occur with resolution of oral ecchymoses and epistaxis after the first mAb infusion, the initial platelet count of 6 x 10(9)/I did not change appreciable over the 5 d course of monoclonal antibody treatment. Binding of fluorescein-labelled monoclonal antibody 197 to peripheral monocytes showed a rapid and persistently decreased mean fluorescein intensity, indicated binding of administered 197 to the monocytes in vivo. Indirect staining for FcgammaRI using fluorescein-labelled goat anti-mouse immunoglobulin was also decreased, suggesting modulation of the receptor. The patient experienced monocytopenia which persisted throughout the 5 d of monoclonal antibody 197 therapy, but reversed following institution of intravenous IgG. These data indicate that intravenous monoclonal antibody 197 induces specific down-modulation of Fc gamma RI expression on monocytes.

Regulation of BAX and BCL-2 expression in breast cancer cells by chemotherapy

Optimizing chemotherapeutic drug delivery strategies relies, in part, on identification of the most clinically effective sequence, dose, and duration of drug exposure. The combination of dose intensive etoposide (VP-16) followed by cyclophosphamide has clinical efficacy in the treatment of advanced breast cancer. However, molecular mechanisms that underlie the effectiveness of this combination of chemotherapeutic agents have not been investigated. In this study we investigated regulation of BAX and BCL-2 expression by VP-16 and cyclophosphamide as a potential mechanism for the induction of breast cancer cell death induced by this regimen. There was a dose and time dependent increase in BAX expression in the breast cancer cell lines MCF-7, MDA-MB-435S, and MDA-MB-A231 following in vitro treatment with 50-100 microM VP-16. Elevation of BAX protein expression in the presence of VP-16 alone did not correlate with reduced viability or induction of apoptosis in MCF-7, MDA-MB-435S, or MDA-MB-A231. VP-16 did effectively block the breast cancer cell lines evaluated (MCF-7 and MDA-MB-435S) at G2/M phase of the cell cycle, confirming activity of the drug in vitro. MCF-7 and MDA-MB-435S cells that were pre-treated with VP-16 and subsequently exposed to 1.0-12.0 microg/ml 4-hydroperoxycyclophosphamide (4HC), an active metabolite of cyclophosphamide, had markedly reduced viability when compared to matched controls treated with either VP-16 or 4HC individually. Consistent with this loss of viability, exposure of all three cell lines to the combination of VP-16 and 4HC resulted in higher BAX protein levels than those observed following treatment with either single agent. This combination of chemotherapeutic agents also resulted in reduced BCL-2 expression. These observations suggest that combination chemotherapy may derive its efficacy, in part, through coordinated regulation of specific gene products associated with apoptosis. Characterization of molecular events that underlie susceptibility of specific tumor cells to combination chemotherapeutic regimens may lead to additional improvements in treatment strategies for this disease.

Incisor root resorptions due to ectopic maxillary canines imaged by computerized tomography: a comparative study in extracted teeth

The purpose of the study was to analyze the ability of computerized tomography (CT) scanning to discriminate maxillary incisor root resorptions caused by ectopically erupting canines. Seventeen maxillary incisors were radiographed in vivo by CT scanning. Contiguous transverse CT scans with a slice thickness of 2 mm were exposed perpendicular to the long axis of the lateral incisors and through the crown of the adjacent, ectopically positioned maxillary canine. Each scan was analyzed and the resorptions on the roots of the laterals were graded according to the maximum depth of the cavity. After the lateral incisors were extracted they were clinically inspected, photographed in different light settings and views, and probed at the contact area between the laterals and the canines. The assessment of the extent of resorption in 4 stages on the CT images compared with the in vitro observations of the extracted roots showed a high degree of agreement for the extent of loss of root substance for all teeth. We conclude that CT scanning performed with good technique accurately reveals tooth root resorption. The presence and influence of the inherent artifacts of tooth root resorption on CT scans are discussed.

The effects of periodontal treatment on mucous membrane thickening in the maxillary sinus

This study was performed to elucidate the effect of periodontal treatment on the sinus mucosa. 21 patients with periodontal lesions of the upper molars and/or premolars and chronic mucous membrane thickening in the maxillary sinus diagnosed radiographically participated in the study. No teeth in the regions studied showed pulpal or periapical changes. Altogether, the patients exhibited 36 maxillary sinuses with mucous membrane thickening. 15-20 months after the final periodontal treatment, a marked reduction of the plaque index, gingival index and probing depth was recorded. Radiographic examination of the sinus mucosa before and after periodontal treatment showed that successful periodontal treatment in all quadrants resulted in normalisation of the sinus mucosa. Periodontal treatment was not successful in 2 quadrants. In one of these cases the thickness of the mucosa was unchanged and in the other case, further thickening of the mucosa seemed to have occurred. The study shows that severe periodontitis of the upper molars and/or premolars may initiate mucous membrane thickening in the maxillary sinus, and that successful periodontal treatment results in normalisation of the sinus mucosa.