Jan B. Rosenquist

Intermediate Bone Grafting of Alveolar Clefts

During the five year period 1980 to 1985 bone grafting was performed in 37 cleft patients before the eruption of the canine tooth (group IBG) and in 30 patients after the eruption of the canine tooth (group SGB). The initial healing was more favourable in the IBG group. In 72.5% of the clefts oro-nasal fistulae were present preoperatively. In all cases the fistulae were successfully closed. In the IBG group with orthodontic closure of the gap in the dental arch the interdental bone height in the grafted area was more than 75% of normal bone height in all clefts. In group SBG this situation was found in only 66% of the bone-grafted areas. There seems to be a clear relation between the age or the developmental stage of the canine tooth on the one hand and the possibility of orthodontic closure of the gap in the dental arch and good interdental bone height on the other hand. This also leads to the suggestion that if bone grafting to the alveolar cleft is required the operation should be performed before the eruption of the canine tooth on the cleft side.

Effects of bradykinin and thrombin on prostaglandin formation, cell proliferation and collagen biosynthesis in human dental-pulp fibroblasts

Bradykinin and thrombin caused a time- and dose-dependent stimulation of prostanoid biosynthesis in human dental-pulp fibroblasts, as assessed by the release of prostaglandin E2 (PGE2) and 6-keto-prostaglandin F1 alpha (the stable breakdown product of prostacyclin). The stimulatory effect of bradykinin and thrombin on PGE2 biosynthesis was maximal within 5-10 min. The concentration of bradykinin producing half-maximal stimulation (EC50) of PGE2 and prostacyclin formation was 10 nM. EC50 for thrombin-induced formation of PGE2 and prostacyclin were 0.05 and 0.2 U/ml, respectively. Bradykinin analogues with affinity to the bradykinin B2 receptor, but not those with affinity to the B1 receptor, caused a burst of PGE2 formation. The stimulatory action of bradykinin and thrombin on PGE2 biosynthesis was abolished by two structurally different cyclo-oxygenase inhibitors and significantly reduced by two corticosteroids. Thrombin dose-dependently enhanced the incorporation of [3H]-thymidine into DNA in pulpal fibroblasts by a mechanism that was unrelated to the effect on prostanoid biosynthesis. Bradykinin did not affect thymidine incorporation. Thrombin, but not bradykinin, stimulated the biosynthesis of type 1 collagen in the pulpal fibroblasts. The stimulatory effect of thrombin on collagen biosynthesis was not affected by cyclo-oxygenase inhibitors. These data show that human dental-pulp fibroblasts are equipped with receptors for bradykinin and thrombin linked to enhanced prostanoid biosynthesis. Occupancy of the thrombin receptors also leads to a prostaglandin-independent stimulation of cell proliferation and collagen biosynthesis.

Occlusion of the incisal canal with bone chips. A procedure to facilitate insertion of implants in the anterior maxilla

In 4 patients, who had lost one or both central maxillary incisors due to trauma, the incisal canals were filled with autogenous cancellous bone harvested from the chin. After a healing period of 4-5 months implants were inserted. At the time of implant surgery in all cases the canal appeared to be replaced by cancellous bone and the implants were placed partially into the grafted area. After another 6 months abutments were connected and crowns made. After follow-up of between 12 and 15 months no fixture has been lost.

Effects of bone grafting on maxillary bone healing in the growing pig

The healing of defects of the lateral wall of the maxilla was studied in the growing pig. In Series I the effect on bone healing of AAA-bone and Kiel bone was compared with that of autografts, and in Series II a comparison was made between autografts and AAA-bone implants. It was found that both autografts and AAA-bone implants improved the rate of healing, but the Kiel bone had no effect. Comparison between autografts and AAA-bone implants in Series II did not show any significant differences. Therefore. it was concluded that AAA-bone can be a useful substitute for autografts in grafting procedures in the maxilla.

Comparison of sedation, amnesia, and patient comfort produced by intravenous and rectal diazepam☆

In a cross-over study, intravenous diazepam was compared with rectal diazepam for sedation in outpatient oral surgery. Fifty-four operations were performed on 27 patients. Recovery from sedation, experience during the postoperative course, amnesia, estimation of the sedative effect, and patient preference of method of sedation were studied. The recovery times of the sedation methods did not differ. Sedative effects after the first operation were estimated as good by 87% of patients given intravenous sedation and by 75% of those given rectal sedation. However, there was a significant relationship between the subjective experience of stronger sedative effect and preference of sedation method that favored the intravenous technique. The degree of amnesia was significantly higher during intravenous sedation, but a high degree of amnesia was not related to patients preference for a sedation method. Neither sedation method produced any local side effects.

Intravenous or rectal diazepam for outpatient sedation in minor oral surgery

In a randomized cross-over study on sedation in outpatient oral surgery, intravenous and rectal administration of diazepam were compared. The mean dose for intravenous diazepam was 0.22 mg X kg-1 (range 0.15-0.38) and for rectal diazepam 0.58 mg X kg-1 (range 0.50-0.71). The determining factors for the patients preference for sedation method, apprehension, effect produced by the sedative, recovery from sedation and the postoperative course were studied. The patients preferred the session in which they experienced stronger effect, regardless of the route of administration. Patient preference for sedation method did not differ when optimal dose regimens were used, and a preset dose of 10 mg rectal diazepam did not produce the desired effect. Apprehension was significantly higher prior to and during the first operation than the second operation, and all patients recovered from sedation within 2 1/2 hours after the administration.