Soft tissue cephalometric analysis: diagnosis and treatment planning of dentofacial deformity.

This article will present a new soft tissue cephalometric analysis tool. This analysis may be used by the orthodontist and surgeon as an aid in diagnosis and treatment planning. The analysis is a radiographic instrument that was developed directly from the philosophy expressed in Arnett and Bergman "Facial keys to orthodontic diagnosis and treatment planning, Parts I and II" (Am J Orthop Dentofacial Orthod 1993; 103:299-312 and 395-411). The novelty of this approach, as with the "Facial Keys" articles, is an emphasis on soft tissue facial measurement.

PKC role in mechanically induced Ca2+ waves and ATP-induced Ca2+ oscillations in airway epithelial cells.

Mechanical stimulation of airway epithelial cells generates the Ca2+ mobilization messenger inositol 1,4,5-trisphosphate and the protein kinase (PK) C activator diacylglycerol. Inositol 1,4,5-trisphosphate diffuses through gap junctions to mediate intercellular communication of the mechanical stimulus (a "Ca2+ wave"); the role that diacylglycerol-activated PKC might play in the response is unknown. Using primary cultures of rabbit tracheal cells, we show that 12-O-tetradecanoylphorbol 13-acetate- or 1, 2-dioctanyl-sn-glycerol-induced activation of PKC slows the Ca2+ wave, decreases the amplitude of induced intracellular free Ca2+ concentration ([Ca2+]i) increases, and decreases the number of affected cells. The PKC inhibitors bisindolylmaleimide and Gö 6976 slowed the spread of the wave but did not change the number of affected cells. We show that ATP-induced [Ca2+]i increases and oscillations, responses independent of intercellular communication, were inhibited by PKC activators. Bisindolylmaleimide decreased the amplitude of ATP-induced [Ca2+]i increases and blocked oscillations, suggesting that PKC has an initial positive effect on Ca2+ mobilization and then mediates feedback inhibition. PKC activators also reduced the [Ca2+]i increase that followed thapsigargin treatment, indicating a PKC effect associated with the Ca2+ release mechanism.

The Treatment Motivation Survey: defining patient motivation for treatment.

The Treatment Motivation Survey questionnaire is presented as a treatment planning tool designed to assist the patient and doctor in defining treatment expectations. With the Treatment Motivation Survey, motivation and expectations are mutually understood, and the treatment plan is successfully designed. Responses to the Treatment Motivation Survey questionnaire can also reveal patients whose expectations are unrealistic.

Acute and repeated exposure to caffeine: effects on reinstatement of extinguished cocaine-taking behavior in rats.

Previously, we demonstrated that caffeine dose-dependently reinstated extinguished cocaine-taking behavior in rats. In the present study, we determined whether this effect of caffeine would extinguish with repeated exposures. Rats were first trained to self-administered cocaine intravenously. Once reliable self-administration was obtained, the pumps that delivered cocaine were turned off and the lever-pressing behavior was extinguished. Every 4 days the rats were given an injection of caffeine (20.0 mg/kg) and its ability to reinstate responding was measured. Some rats received each of four exposures to caffeine in the previously cocaine-associated environment. Other rats received the first three exposures to caffeine in the home cage and the last exposure to caffeine in the previously cocaine-associated environment. The results indicated that although caffeine was an effective cue for reinstatement of extinguished cocaine taking, the effect was reduced when repeated exposures occurred in the test environment. In addition, when 4 drug-free days were interspersed between self-administration and reinstatement testing, the caffeine effect was greater than when testing was conducted 1 day following the last self-administration session. Thus, extended withdrawal increases the priming effects of caffeine. The results are discussed in terms of the effectiveness of cue exposure as an adjunct to current therapies for cocaine abuse.

Central cementoossifying fibroma of the maxillary sinus: a review of six cases.

We present the radiographic findings of six patients with central cementoossifying fibromas of the maxilla. CT typically demonstrated large, spherical tumors in the maxillary alveolar ridge, filling and expanding the maxillary sinus and extending to involve the ipsilateral hard palate. The central tumors ranged from having soft-tissue density with scattered foci of high density to being heavily calcified.

Augmentation of the anterior temporal fossa after temporalis muscle transfer.

Pedicled transfer of the temporalis muscle has proven to be a reliable and versatile procedure in reconstructive craniomaxillofacial surgery. Excluding those complications related to the coronal incision, little specific attention has been given in the literature to the prevention or treatment of the esthetic defect that remains after muscle transfer. This article describes a case in which block porous high-density polyethylene was used to eliminate the residual defect of the anterior temporal fossa after transmaxillary pedicled transfer for closure of a large oral-antral communication. The implant provided an esthetically pleasing augmentation of the defect. A discussion and analysis of the implant materials available for reconstruction of this region is also presented.

Reinstatement of extinguished cocaine-taking behavior by cocaine and caffeine.

Interactions between caffeine and cocaine have been demonstrated in a number of behavioral paradigms. The present study was undertaken in an attempt to determine whether caffeine could reinstate extinguished cocaine-taking behavior in rats. Experienced self-administering rats were first put through extinction training. The rats were then given an injection of either saline, cocaine (5.0, 10.0, or 20.0 mg/kg), or caffeine (5.0, 10.0, 20.0, 40.0 mg/kg). Both cocaine and caffeine induced a dose-dependent increase in the number of responses made on the previously cocaine-associated lever. These results confirm findings that the originally self-administered drug can serve as a prime to reinstate drug-taking behavior, and that nondopaminergic agonists can also provide an effective prime to reinstate responding. Potential mechanisms for these effects are discussed.

Blockade of the acquisition of cocaine self-administration by the NMDA antagonist MK-801 (dizocilpine).

In an attempt to assess the contribution of the NMDA receptor system to the development of cocaine self-administration, acquisition of intravenous self-administration (0.25mg/kg/infusion) was assessed in rats that received pretreatment with MK-801 (0.0, 0.1 or 0.25mg/kg). For control rats, reliable self-administration was obtained in 3-8 days of testing. These rats rapidly discriminated between depression of a lever that resulted in the delivery of cocaine and an inactive lever. Within the initial 10 day test period, most of the rats pretreated with MK-801 failed to acquire a preference for an active lever which, when depressed, resulted in a cocaine infusion: responding was generally high on both the cocaine reinforced and inactive lever. For six rats, MK-801 treatment was discontinued after 10 days. Although some of these rats had received substantial exposure to cocaine during the initial 10 days, self-administration subsequent to the termination of treatment progressed either with a time course comparable to cocaine-naive rats, or not at all. For rats that continued to receive MK-801 treatment, most failed to acquire reliable self-administration within the 18 day test period. These data suggest that the glutamatergic NMDA receptor system plays an important role in the establishment of cocaine as an effective reinforcer.

Bone formation over partially exposed implants using guided tissue generation.

This pilot study tested whether a semipermeable expanded polytetrafluoroethylene (e-PTFE) membrane could be used to induce new bone to cover the partially exposed surface of titanium and hydroxylapatite (HA)-coated endosseous implants. Twenty threaded titanium and 10 HA-coated implants were placed in the tibia of five mongrel dogs. The implants were placed in a manner that left the cervical 2 to 3 mm exposed. Fifteen implants were used as controls and the rest were covered with an e-PTFE membrane. Animals were killed at 6, 8, and 12 weeks. Those implants covered by the membrane showed a progressive formation of bone on the exposed portion. The threaded titanium control implants showed reactive periosteal bone formation in the adjacent area, but no new bone formation on the exposed threads. The HA-coated controls, however, showed progressive bone formation on the exposed portion. Membrane position appeared to have an effect on the quantity of bone that formed, as those test sites in which there was a collapse of the membrane against the implant showed less new bone than those in which a protected space was created. This study showed that guided tissue generation may be used to induce new bone to form over the exposed portion of an implant, that the amount of new bone is influenced by the width of the space between membrane and implant, and that new bone forms on an exposed HA-coated implant even in the absence of a guiding membrane.