Frans Vinckier

Dental caries, gingival health, and oral hygiene of long term survivors of paediatric malignant diseases.

Fifty two children who had had cancer and been treated with chemotherapy, and who were long term event free, were examined for caries prevalence, gingival health, and oral hygiene and compared with a control group. A higher dental caries prevalence for the 14-17 year age group was noted. The restorative index was significantly lower in the age group 10-13. There were no significant differences in gingival index, plaque index, or toothbrushing frequency. It is concluded that these patients should be considered as at high risk for caries after cancer treatment. Professional dental follow up should be integrated in the medical follow up.

Accuracy and surgical feasibility of a CBCT-based stereolithographic surgical guide aiding autotransplantation of teeth: in vitro validation

The aims of this study were to determine the accuracy of a 3D computer model and stereolithographic (STL) replica when compared to the real tooth and to develop a cone beam computed tomography (CBCT)-based planning technique including surgical guide fabrication. A STL surgical guide and a tooth replica were fabricated using SimPlant Pro 12.1. To validate this process, tooth segmentation and replica design were prepared for comparison to an optical scan of the corresponding tooth. For surgical intervention, a dry dentate mandible was scanned using a Scanora CBCT and the donor tooth was segmented. The donor tooth was repositioned, and two guides were designed. These tooth replica and guides were used in socket preparation of the dry mandible. The 3D computer model of the segmented teeth and related STL models showed satisfactory results with an acceptable accuracy. The surfaces were within 0·25mm distance, but in some areas up to 2·5mm deviation were seen. The results showed that 79% of the points was between 0·25 and -0·25mm, 3% was overestimated (>0·25mm) and 18% was underestimated (<-0·25mm). The computer-based repositioning of the donor tooth and construction of tooth replica and guide allowed socket preparation before donor tooth extraction and optimization of the STL procedure for in vivo planning of CBCT-based autotransplantation.

Influence of Anticoagulation on Blood Loss Following Dental Extractions

The coagulation activity level at which oral surgical procedures can be performed in anticoagulated patients without triggering bleeding complications and without enhancing the risk of developing thrombo-embolic events remains controversial. The objective of the present study was to evaluate blood loss following dental extractions at different levels of anticoagulation and to determine its effect on wound closure rates. Blood loss was measured following the removal of four front teeth in warfarinized rabbits. Immediate blood loss was evaluated by determining the tooth socket bleeding times and by using a technique based on hemoglobin determinations. Long-term blood loss was assessed by comparison of labeled red-blood-cell disappearance curves. The results showed that blood loss following dental extractions was significantly greater in animals anticoagulated at a therapeutic level than in non-anticoagulated control animals. Determination of blood loss at different levels of anticoagulation clearly demonstrated that complete correction of the coagulation activity was unnecessary. Partial correction (INR values of 1.6-1.8) allowed extractions to be performed without extensive blood loss. With this technique of partial correction, the period of interruption of the anticoagulation could be kept very short, and the risk of postoperative bleeding complications was minimal. Wound closure rates were negatively influenced in anticoagulated animals.

Caries-related salivary microorganisms and salivary flow rate in bone marrow recipients

Cancer treatments often induce oral complications. In this study we investigate longitudinally the salivary gland function, the salivary caries-related microorganisms, and buffer capacity in bone marrow recipients. Stimulated saliva samples were taken midmorning. The salivary factors were studied in 42 patients from before transplant until 4 months after transplant. A dramatic reduction (66%) of salivary flow rate is noticed in all patients at 1 month after transplant, and only a partial recovery (42% reduction) is seen after 4 months. A clear shift toward a lower buffer capacity and a higher amount of cariogenic microorganisms is seen posttransplant. This shift is more pronounced when total body irradiation was included in the pretransplant conditioning therapy. These findings indicate that the studied parameters in transplant recipients can contribute to a higher caries risk and oral complications during the early posttransplant period.

Validation of the cone beam computed tomography–based stereolithographic surgical guide aiding autotransplantation of teeth: clinical case–control study

OBJECTIVE To compare the outcome of cone beam computed tomography (CBCT)-based surgical planning and transfer technique for tooth autotransplantation versus conventional autotransplantation. STUDY DESIGN The study material comprised 40 pediatric subjects in whom 48 teeth were transplanted following a case-control design. While the study group (mean age 11 years) underwent CBCT imaging for surgical planning and transfer via stereolithographic tooth replica fabrication, the historical control group (mean age 12 years) was subjected to conventional autotransplantation. RESULTS The CBCT-based preoperative planning and the use of a tooth replica decreased the extra-alveolar time and reduced the number of positioning trials with the donor tooth. In the control group, 6 patients showed 1 or more complications, while this was noticed for only 2 study patients. CONCLUSION CBCT-based surgical planning of tooth autotransplantation may benefit from a shorter surgical time, while being a less invasive technique, causing fewer failures than a conventional approach.

Bisphosphonate-Related Osteonecrosis of the Jaw Bone: Radiological Pattern and the Potential Role of CBCT in Early Diagnosis

OBJECTIVES To systematize the clinico-radiological symptoms and course of bisphosphonate-related osteonecrosis of jaw bone and toevaluate the diagnostic potential of various radiological techniques to detect mild osteonecrosis in each stage of the disease. MATERIAL AND METHODS The sample consisted of 22 patients previously diagnosed with extraoral malignant disease. Diagnosis was based on a clinical examination in conjunction to digital panoramic radiography and cone beam computed tomography (CBCT). Two dentomaxillofacial radiologists reviewed all images. RESULTS Twenty patients showed mandibular involvement clinically, while two others had a maxillary involvement. Four stages of the disease were proposed based on the clinico-radiological findings. Subclinical cortical and lamina dura thickening was detected with only three-dimensional CBCT and periapical images, while ulceration and cortical bone thickening was detected only by three-dimensional CBCT. Mixed sclerotic, lytic bone destruction involving alveolar and basal bone with or without encroachment on the mandibular canal, pathological mandibular fractures were detected by two-dimensional panoramic and three-dimensional CBCT images. Other findings are non healing extraction sockets, periapical radiolucencies, osteolysis, sequestra, oroantral fistula, and periosteal new bone formation. CONCLUSIONS The present study showed that bisphosphonate-related osteonecrosis of jaw bone occurs in four distinct clinico-radiological stages. For mild cases, panoramic image diagnosis was much less obvious, whereas cone beam computed tomography was able to fully characterise the bony lesions and describe their extent and involvement of neighbouring structures in all cases. Thus cone beam computed tomography might better contribute to the prevention of bisphosphonate-related osteonecrosis of jaw bone as well to the disease management.

Importance of root development in autotransplantations: a retrospective study of 137 teeth with a follow-up period varying from 1 week to 14 years

The aim of the present study was to perform a retrospective study of autotransplanted teeth with a variable but individually maximized follow-up period in order to provide information on the long-term clinical outcome. The sample was obtained from patients who were treated at the University Hospitals KU-Leuven, Belgium, during the period 1996-2010. Of the total of 109 subjects (137 teeth), 98 patients were invited for recall, of whom 68 patients (87 teeth) responded positively. Eleven out of the 109 patients were excluded due to loss of the transplanted tooth. Although 41 patients had no re-examination visit, clinical and radiological data from all 109 subjects were included in the sample. The follow-up period varied from 1 week of 14.8 years, with a mean of 4.9 years. Transplanted teeth receiving orthodontic treatment had a lower risk of ankylosis and were less likely to fail. The risk of root resorption was lower for teeth with stages one-half to three-quarters of root length at the time of transplantation. Molars were more susceptible to ankylosis. Almost all teeth showed partial or full obliteration of the pulp. Absence of further root development was higher in donor teeth with root length stage less than one-half. Trans-alveolar transplantation was less successful. Autotransplantation can be a valid alternative method in young adolescents for replacing missing teeth because of agenesis or trauma. The optimal time to transplant is when the root has reached two-thirds to three-quarters of the final root length.

Oral health status in Belgian 3- to 5-year-old children

Abstract The aim of this study was to determine the need for oral health care in young Belgian children in the municipality of Leuven, Belgium. The sample consisted of 750 boys and girls (3 years=200, 4 years=200 and 5 years=350). Clinical examination was carried out by one examiner and duplicate recordings were made on 10% of the sample. The clinical examination included recording of: (1) plaque index; (2) gingival index; (3) caries index; and (4) fluorosis index. Plaque and gingival indices were recorded at six sites of smooth surfaces on selected teeth. Occlusal plaque was also registered. Before the clinical examination for caries and fluorosis, the children had their teeth professionally cleaned with toothbrushes and dental floss and dried by means of gauze bandages. In all age groups, the percentage of plaque-free sites was of the order of 60% and sound gingiva was identified at 83% of the recorded sites. The percentages of caries-free children were 69% (3 years), 57% (4 years) and 52% (5 years). The mean deft scores (standard error) were 1.37 (±0.21), 1.76 (±0.21) and 2.03 (±0.17). The corresponding mean defs scores were 2.04 (±0.44), 2.46 (±0.35) and 3.75 (±0.42). Non-cavitated active lesions, included in the defs scores, represented about 50% of all caries lesions. Early signs of dental fluorosis were identified in 19% (3 years), 17% (4 years) and 9% (5 years) of children. The need for oral health care in the population studied is mainly related to non-operative treatment procedures aimed at controlling the progression of disease.