Primarily Research

Abstract: Composite materials have become an integral part of the wide range of filling materials currently available. Conditioning is necessary to achieve adequate bonding of the composite material to enamel and dentin. Normally, this is done by applying acid preparations to the dental surfaces. These acids have an etching effect that causes surface roughening. The increasing application of lasers in dentistry has introduced another possibility. Laser irradiation can cause roughening of enamel and dentin surfaces. Another interesting alternative is the so-called kinetic cavity preparation technique. This method also results in distinct surface roughening. The purpose of the present study, was to compare the described methods. Tensile bond strength tests and shear bond tests were carried out to examine the adhesion of a composite material to surfaces treated with these methods. Laser irradiation with certain devices and the air-abrasive technique yielded results similar to those with acid etching.     

Temporalis myofascial flap in maxillofacial reconstruction: clinical and histological studies of the oral healing process

Objectives—To report our experience with temporalis myofascial flaps (TMF), describe the healing process of uncovered flaps in the mouth, and the histology of the repaired mucosa in the long term. Design—Prospective clinical and histological study. Subjects—36 patients who received a TMF over a 6.5 year period for serial assessment of the oral healing, 24 patients whose scars over the reconstructed area were assessed clinically, and 11 whose repaired mucosa was assessed histologically. Main outcome measures—To follow the clinical process of oral healing of the TMF and describe the repaired mucosa healed over the flap. Results—The uncovered TMF in the mouth healed gradually starting with an acute inflammatory phase, going through chronic inflammatory and proliferative phases with eventual epithelialisation of the oral mucosa. There were no major complications. The healed mucosa showed mild scarring in 70% of cases and the repaired mucosa had characteristic histological features that were distinct from the normal mucosa. Conclusion—The TMF is an extremely reliable and versatile flap for maxillofacial reconstruction which heals gradually with eventual coverage by mildly scarred repaired mucosa.     

Anticipating the Future and Change

As in all of medicine, there are basic assumptions underlying the present system of dental education and delivery. These basic assumptions are facing challenges due in part to the marked reduction in the incidence of caries and the development of more effective therapies. This current period of time is described as an era of true change, rather than the mere modification of existing technology. Changes are going to occur in a number of areas. The move will be from government to private, from small to large, from generalist to specialist. Since change is inevitable, one can learn about and prepare for the stress of change, the changes happening now, and how to adapt to change. Although many changes are beyond the individual's control, their occurrence may be beneficial.     

Radionuclide skeletal imaging and single photon emission computed tomography in suspected internal derangements of the temporomandibular joint

Fifty one subjects who had pain involving the temporomandibular joint were evaluated using multidirectional tomography, arthrography, conventional nuclear scanning, and single photon emission computed tomography (SPECT) to assess the association of arthritis of the temporomandibular joint with internal derangements related to meniscal dysfunction. Five (56%) of the nine subjects who had normal arthrograms and normal multidirectional tomograms had SPECT scans that were positive for osseous changes. Twenty-two subjects (27 temporomandibular joints) were diagnosed by arthrography to have meniscal displacement with reduction. Multidirectional tomograms of the 27 joints were positive for osseous changes in five (18%) joints, whereas SPECT scans were positive in nine (70%) joints. Twenty subjects (20 temporomandibular joints) had an arthrographic diagnosis of meniscal displacement without reduction. Multidirectional tomograms of the 20 joints were positive for osseous changes in 14 (70%) joints, and SPECT scans were positive in 16 (80%) joints (P less than 0.001 vs control group). Initial observations with SPECT indicate it is a promising imaging method for detecting and staging osseous disease of the TMJ related to meniscal dysfunction.     

Primary Hodgkin''s disease of the mandible: A case report and review of the literature

Extranodal presentation in Hodgkin's disease is uncommon and bone involvement is rare at diagnosis. However, late in the course of this disease, bone involvement may occur in 9% to 35% of the cases. The mandible is very rarely involved even in advanced stages with only seven such cases reported in the literature. Of these only one had primary Hodgkin's disease of the mandible. A second case is described in this report.     

Evaluation of condylar translation by sonography versus axiography in orthognathic surgery patients

PURPOSE: This study compares measurement of the condylar translation by sonography or axiography in preoperative assessment and follow-up of orthognathic surgery patients. PATIENTS AND METHODS: Forty-seven moderately dysgnathic patients had consecutive examinations by axiography and sonography in a blind fashion at a single time point by 2 observers. Thirty-nine different dysgnathic patients, scheduled for isolated Le Fort I osteotomy, had preoperative condylar translation and 24-month follow-up measured randomized by either axiography (25 patients as control group) or sonography (14 patients as study group). RESULTS: The examination time for axiography was 20 minutes average versus 2 minutes for sonography. The mean differences were 1.7 mm in opening, 2.1 mm in protrusion, and 3.3 mm for mediotrusion. Pearson's proportionality quotient was r = 0.75, analysis of variance (P <.95, F = 3.9, alpha =.05 significance level) was not significant. The 24-month longitudinal follow-up showed a Pearson's proportionality quotient of r = 0.7 between study and control group, and no significant difference in analysis of variance (P <.075, F = 2.81, alpha =.05 significance level). CONCLUSION: Sonography proved adequate for assessment and follow-up of condylar translation compared with axiography in orthognathic surgery patients. Temporomandibular joint sonography was faster and more comfortable, allowed 1-week postoperative examination and reexaminations, and was equally exact. Anatomic details like joint degeneration and disc displacement could be assessed. However, sonography did not measure the inclination of the condylar track.     

Conventional radiographic and computed tomographic findings in cases of fracture of the mandibular condylar process

A total of 40 patients with 46 fractures of the mandibular condylar process were examined an average of 47 months after the injury. The conventional radiologic examination consisted of panoramic radiography and lateral transcranial view of the fracture in the mouth-open and mouth-closed positions. Sixteen patients with 21 fractures of the condylar process were examined additionally by computed tomography (CT) because of temporomandibular joint problems in the sagittal and coronal projection. Computed tomography revealed bony changes in the fractured mandibular condyle and its position in the mandibular fossa more exactly than conventional radiographic examinations. Furthermore, the results showed that disturbances in the position and function of the articular disc may be more common than was earlier anticipated, suggesting the more frequent use of CT examinations to evaluate temporomandibular joint changes after condylar process fractures.     

Fatal subarachnoid haemorrhage associated with dental local anaesthesia

A case is described of sudden death occurring after the use of a noradrenaline-containing local anaesthetic. Autopsy revealed a massive subarachnoid haemorrhage following a ruptured cerebral aneurysm. The noradrenaline in the local anaesthetic is thought to be an important factor in the cause of the rupture. It is recommended that preparations containing 1:25,000 noradrenaline not be used.     

Restoration of irradiated patients using osseointegrated implants: Current perspectives

Statement of problem. The success rates of osseointegrated implants used to restore patients who were irradiated for head and neck tumors are influenced by radiation-induced changes in the hard and soft tissues.Purpose. This article examined, by review of the literature, current perspectives on the restoration of irradiated patients using osseointegrated implants.Results. In published reports that investigated both intraoral and extraoral applications, irradiation decreased implant success rates and the amount of reduction was dependent on the location within the craniofacial skeleton. The limited number of implants and patients in these studies precludes definitive conclusions regarding the efficacy of placing implants into irradiated tissues. The implants placed into the irradiated anterior mandible have demonstrated an acceptable implant success rate of 94% to 100% with a minimal risk of osteoradionecrosis. The efficacy of implants in the posterior mandible has not been examined. Implant success rates ranged from 69% to 95% in the irradiated maxilla for intraoral applications. Extraoral applications demonstrated excellent implant success rates in the temporal bone (91% to 100%). The rates in the anterior nasal floor have varied from 50% to 100%. The implant success rates in the frontal bone decreased as the length of the studies increased (96% to 33%). The long-term efficacy of implants in the irradiated frontal bone is poor. (J Prosthet Dent 1998;79:641-7.)