The same sections were again photographed under polarized light and areas of the lesions were digitized quantitatively. Results demonstrated the mean (;pmS.D.) percent change in lesion size (water imbibition) for each material nonexposed and exposed to fluoridated dentifrice to be: Amalgam ;ms64.1 ;pm 22.0, ;ms1.0 ;pm8.5; Glass Ionomer 2.2 ;pm10.6, 14.0 ;pm7.2; Composite;ms28.1 ;pm11.7, 18.2 ;pm6.7. Negative numbers represent demineralization and positive numbers represent remineralization. Duncan's analysis indicated the nonbrushed fluoride-releasing glass ionomer and composite resin to have significantly greater demineralization inhibition compared to the nonbrushed amalgam group and remineralization enhancement effects on adjacent interproximal lesions (p ;lt 0.05) compared to the brushed amalgam group.

Mass, Eliyahu; Gordon, Moshe; Fuks, Anna B.: Assessment of compomer proximal restorations in primary molars: a retrospective study in children. J Dent Child, 66:93-97, March-April 1999.

Based on the clinical performance of the material and on the radiographic findings, the authors conclude that Dyract;rM can be a suitable alternative for restoring primary teeth that need to be retained up to two years. More extensive follow-up is needed to assess longer-term performance.

Mussa, Roxana; Esposito, Salvatore J.; Cowper, Thomas R.: The use of colored elastomeric "Os" as a motivational instrument for patients with anodontia: Report of case. J Dent Child, 66:98-102, March-April 1999.

Some of their suggestions include the placement of diastemas, the use of artificial "baby" teeth and their subsequent replacement with permanent teeth to simulate the primary and mixed dentition stages. They have also recommended deleting primary teeth to mimic the normal exfoliation pattern. The purpose of this article is to report the attitude change and improvement in self-esteem experienced by two young girls from the simple addition of colored elastomeric molded "Os" to the orthodontic appliances placed on their prostheses.

Oral burns in children, whether electrical or thermal, can result in severe local and systemic complications. Use of an oral burn splint following perioral electrical burns in children is a widely accepted treatment. It is felt that these appliances reduce oral scarring and, in some cases, may eliminate the need for future surgical procedures. These appliances, however, can also be beneficial in case of thermal burns in children.

: Dental experiences and parenting practices of native American mothers and caretakers: What we can learn for the prevention of BBTD. J Dent Child, 66:120-126, March-April 1999.

This study, attempts to gather information concerning the dental experiences, beliefs, and parenting practices of Native Americans. Five Native American women were trained to conduct interviews in their own language. After pilot testing, seventeen questions were asked. Sixty- two interviews were tape-recorded and transcribed. Content analysis was performed on the transcriptions. Results indicate maternal and caretaker upset and displeasure with the dental experiences of adults and children. Fear and pain were prominent. Parenting practices indicate children are expected to clean their own teeth at about a year of age and parental awareness of risks associated with sleeping with a bottle. About half of the mothers and caretakers who used a bottle as a pacifier report engaging in one or more protective activities such as removing the bottle when the child falls asleep. Mothers and caretakers with greater parenting experience are likelier to be aware of these protective activities. In conclusion, results of this study highlight the importance of providing positive dental experiences for mothers and caretakers and the need to be aware of actual parenting practices before making recommendations or counseling mothers or caretakers.

The number of people with mental retardation and developmental disabilities (MR/DD) living in small community-based group residences is increasing throughout the United States. Dental services to this population, once provided in large institutional settings, must increasingly be sought at the community level.

The purpose of this study was to determine whether U.S. and Canadian dental schools are adequately training their students to provide quality dental care to this group with complex psychosocial and medical issues.

With a response rate of 78 percent to a mail survey, it was found that 53 percent of the schools provide less than five hours of didactic training in special care dentistry. Clinical training in this area comprised only 0-5 percent of predoctoral students' time in 73 percent of the responding schools.

In 1997, Congress enacted the State Children's Health Insurance Program to extend health insurance coverage to low-income children who are ineligible for other insurance, including Medicaid. The program is reviewed and considered in terms of children's access to health care and their health status.

Invasion of bone and critical neurovascular structures often impedes complete resection of intraosseous skull base neoplasms, and these lesions tend to recur unless all infiltrated bone is removed. Evolving experience with image guidance over the past few years indicates the potential value of neuronavigation in skull base lesions diffusely infiltrating or fixed to bone structures. We report our early experience with the Radionics® Operating Arm System (OAS), specifically emphasizing its utility as an adjunct in the treatment of intraosseous skull base tumors, mainly meningiomas.

In April 1995 the OAS was introduced into clinical use at the neurosurgical university clinic in Münster, Germany. Since then, the system's utility has been explored in 10 patients out of the total neuronavigation series presenting with intraosseous skull base tumors (nine females and one male, mean age 47 years; nine meningiomas, one chordoma). For navigational planning, both 3-mm computed tomography scans and a set of 3-mm fat-suppression magnetic resonance images were chosen. At least four adhesive skin markers were used for system calibration.

The system was technically usable in all cases in this small series. Because of the relative immobility of the bone structures and/or the tumor, no significant deviation from the preoperative registration accuracy was noted at the end of the procedures. The main advantages were easier localization and resection of infiltrated bone, which is often not grossly identifiable, even under the microscope.

Our preliminary experience with the OAS suggests that image guidance is helpful in this type of lesion, providing better anatomical orientation during surgery and delineating tumor margins and their relation to critical neurovascular structures. The problem of a possible intracranial tumor and brain shift can be neglected in these lesions. The system facilitates resection by volumetric contour information, allowing more aggressive and complete resection. Comp Aid Surg 3:312-319 (1998). ©1999 Wiley-Liss, Inc.

ABSTRACT

While deformable object modeling has been studied by computer graphics specialists for more than two decades, only a few applications in the field of surgical simulation have been developed which provide both real-time and physically realistic modeling of complex, nonlinear tissue deformations. Particularly in craniofacial surgery, the prediction of soft-tissue changes–which result from alterations in the underlying bone structure–is critical to the surgical outcome. The prediction of these tissue changes and, therefore, the prognosis of the postoperative appearance of the patient, is still based on empirical studies of the relationship between bone and tissue movements: There exists no physical model which takes into account the individual patient anatomy to simulate the resulting tissue changes during craniofacial surgery. In this article we present two different deformable tissue models which are integrated in an interactive surgical simulation testbed. Both techniques allow precise preoperative simulation of the resulting soft tissue changes during craniofacial surgery and visualization of the patient's postoperative appearance. The different deformable models are described in detail and both are applied to the same craniofacial case study. The simulation results are shown and compared with regard to the speed and accuracy of the prediction of the patient's postoperative appearance. Comp Aid Surg 3:228-238 (1998). ©1999 Wiley-Liss,Inc.

Stefan Hassfeld, M.D., D.M.D., PH.D., and Joachim Mühling, M.D., D.M.D., PH.D.Department of Maxillofacial and Craniofacial Surgery, Ruprecht-Karls-University, Heidelberg, Germany

ABSTRACT