Jaw fractures in Stockholm 1988-90. Changing trends in injury dynamics over a 10 year interval

This paper presents a review of injury dynamics of jaw fractures sustained by 1374 patients in the county of Stockholm during 1978-1980 = M1 (795 patients) and 1988-1990 = M2 (579 patients). The material comprised 1620 mandibular (M1 = 904, M2 = 716) and 439 maxillary (M1 = 249, M2 = 190) fractures. Forty-three per cent of the mandibular fractures and 40% of the maxillary fractures were single fractures in M1. The corresponding figures for M2 were 35% and 43%. During both periods the anatomical region most frequently fractured was the mandibular condyle (M1 = 35%, M2 = 29%). Violence was the cause in 39% of all fractures and 42% of the mandibular fractures (M2). This compared to M1 confirms other reports of altered trends in jaw fractures related to violence during the 1980's. The proportion of jaw fractures caused by traffic increased slightly between the periods.

Analgesic efficacy of acetaminophen sustained release

The analgesic efficacy of acetaminophen sustained release (SR) and acetaminophen immediate plus sustained release (IR + SR) was evaluated in 200 outpatients with pain after oral surgery. Under double-blind conditions SR high dose (2000 mg) or low dose (1000 mg), IR + SR high dose (500 + 1500 mg) or low dose (250 + 750 mg), or acetaminophen standard tablet high dose (1000 mg) or low dose (500 mg) were randomly administered after removal of a lower third molar. The hourly pain intensity was rated on a visual analog scale during 12 hours. The efficacy was based on peak effect (maximum pain intensity difference in percent), pain reduction (mean percentage pain intensity difference), duration of effect (time to remedication) and pain reduction index (pain reduction multiplied by duration of effect). Pain reduction was 37% with the 500-mg tablet and 54% with SR 2000 mg. The peak effect increased from 53% after 1.9 hours for the 500-mg tablet to 67% after 2.6 hours for SR 2000 mg. The SR formulation significantly increased the duration of effect without reduction in peak effect.

Integrating knowledge-based technology into computer aided ventilation systems

A knowledge-based decision support system for respirator treatment, the KUSIVAR system, has been designed in cooperation between hospital, university and industry. Changes in patient data from respirator and monitoring equipment trigger a computer program that generates advice to the staff concerning e.g. therapy modes and respirator settings using expert systems and process control technology. A prototype has been built on an advanced development workstation, the Unisys Explorer, using the software Knowledge Engineering Environment (KEE). The clinical version is implemented on an Intel 80396-based microcomputer connected on-line via a data-acquisition processor to the respirator. The decision support software is implemented as a module under the Microsoft Windows multitasking environment and communicates with modules for data acquisition, database handling and data presentation by means of message passing using the Windows Dynamic Data Exchange protocol. The modules present coherent user interfaces by conforming to Microsoft Windows standards. The knowledge base is being extensively validated by an expert group in the ICU and the system will be evaluated through animal experiments and clinical studies.

An unusual case of lingual mandibular depression

The literature concerning lingual mandibular depressions is briefly presented, and a case of an anterior depression containing salivary gland tissue is described. Since this is a rare condition, the presentation of an additional case is of interest.

CT of the edentulous maxilla intended for osseo-integrated implants

CT has been used as a diagnostic tool in presurgical planning for osseo-integrated implants in the edentulous maxilla. No other technique provides more information. The examination-procedures are easy.

Adrenoceptor modulated flow through the rabbit ampulloisthmic region studied in vivo and in vitro

In adult rabbit does ovulation was induced by human choriongonadotropin (hCG) 48 hours before experiments. At laparotomy the oviducts were cannulated from the ovarian and uterine ends. In vivo as well as in vitro the patency of the isthmus was studied with low viscous fluid perfusion of the ampulloisthmic region in antegrade direction. Intraluminally applied norepinephrine (NE) or phenylephrine (PhE) caused dual changes in transisthmic flow; administration of a low dose increased the flow, while high doses decreased the flow in vivo. In vitro, application of PhE only induced a dose-dependent reduction of flow. The PhE-induced reduction of flow was prevented by pretreatment with phenoxybenzamine in vivo and in vitro, suggesting activation of an alpha-adrenoceptor mechanism. Intraluminal application of terbutaline (T) caused a dose-dependent increase of flow, which was most prominent in vivo. Such an increase of flow was prevented by blockade of beta-adrenoceptors with propranolol or by selective blockade of beta 2-adrenoceptors with IPS 399 both in vivo and in vitro, indicating activation of a beta 2-adrenoceptor mechanism. The biochemical and hormonal changes 48 hours after ovulation imply a role for the sympathetic transmitter NE in causing a contractile state of the ampulloisthmic region ("tube locking") for retention of ova prior to nidation in the uterine cavity. The isthmus would then hypothetically act as a sympathetically innervated smooth muscle sphincter. The present results demonstrate a constrictory response of this region to high-dose stimulation of alpha-adrenoceptors in support of such a hypothesis. However, it must be noted that this region also possesses a population of beta-adrenoceptors at this time interval, which may interfere with a constrictor mechanism via circulating epinephrine.

Two-year assessment of anterior resin restorations inserted with two acid-etch restorative procedures

Fifty-two pairs of Class III restorations in a microfilled resin Silar were inserted in acid-etched cavities. A bevel preparation was performed along the margin of one cavity (A) whereas the other cavity was treated with the surface-active comonomer NPG-GMA before filling (B). After finishing of the restorations, the surface of the type B filling was re-etched and covered with a layer of non-composite, low-viscous resin. Following a 2-yr observation period 65 restorations were classified as "good", 33 were "adequate" and 4 were "unsatisfactory" or were replaced during the study period. The only significant difference between type A and type B restorations was marginal discolorations which most frequently were observed along the beveled type A restorations. The occurrence of such failures was increased by marginal deficiencies and occlusion/articulation on the restorations.

Multiple doses of paracetamol plus codeine taken immediately after oral surgery

A double-blind randomized analgesic trial was carried out in 180 patients undergoing surgical removal of an impacted lower wisdom tooth. The patients received the first dose of either paracetamol 1000 mg plus codeine 60 mg, paracetamol 500 mg plus codeine 30 mg or placebo immediately after surgery during the effect of the local anaesthetic. The mean pain intensity, the duration of effect and the number of patients needing additional analgesics were all significantly dose related. In the evaluation procedure a pain intensity index was defined which took into account both the efficacy and the duration of effect. In addition, the analgesic efficacy was calculated over a 12 hour period after first medication and thereby including the efficacy of a second dose, if taken. Paracetamol 1000 mg plus codeine 60 mg followed by paracetamol 500 mg plus codeine 30 mg after around 5 hours was a very effective treatment and over 40% of these patients did not need any further pain relief during the evaluation period. In conclusion, an effective analgesic taken immediately after oral surgery reduces the total pain and diminishes the need of analgesics.

Effects of intraluminal administration of adrenoceptor agonists on transisthmic flow in the rabbit oviduct

By perfusing the isthmic segment of the rabbit oviduct in vivo at low hydrostatic pressures with Ringer's solution (+38 degrees C), the resistance of the isthmic segment could be measured quantitatively using a drop-recording system. Transisthmic flow, from mid-tube to the uterine end, was thus studied in 45 animals, 48 h after human chorionic gonadotropin (hCG) injection. Stimulation of alpha-adrenoceptors by administration of norepinephrine or phenylephrine to the perfusate resulted in an immediate reduction or cessation of the basal flow. The duration of this effect varied dose-dependently. The administration of beta-adrenoceptor agonists (isoprenaline, prenalterol or terbutaline) markedly increased transisthmic flow. The beta 2-adrenoceptor agonist terbutaline was considerably more potent than the other beta-agonists. Thus, it seems that the isthmic contraction caused by adrenergic luminal stimulation is mediated via alpha-adrenoceptors, while the isthmic dilation is mediated via beta-adrenoceptors, mainly of the beta 2-type.

In vivo studies of the motility of the isthmic segment in the perfused rabbit oviduct

The motility of the isthmic segment of the rabbit oviduct was studied in vivo using a perfusion model. The transisthmic flow of saline (38 degrees) was recorded at constant inflow pressures uni- or bilaterally. In untreated control animals there was a high resistance to flow within the isthmic segment. 12, 24, 48 and 72 h after induced ovulation by i.v. injection of human choriongonadotropin (HCG; 50 IU) the resistance gradually declined. No synchronous spontaneous motility pattern was recorded from the oviducts of any animal. When adrenergic agonists were administered 48 h after HCG, either intraluminally or intravenously, flow ceased after the alpha-adrenoceptor agonists noradrenaline (2-50 micrometers) or phenylephrine (2-10 micrograms), while an increased flow was recorded after the beta-adrenoceptor agonist isoprenaline (5-100 micrograms). The duration of the motor effects varied dose-dependently. Therefore it seems as if the motility of the isthmic segment is under adrenergic control, at least 48 h after HCG, with contractions caused by alpha-adrenoceptor stimulation and dilations caused by beta-adrenoceptor stimulation. The perfusion model used appears to be suitable for studying the adrenergic control of the isthmic segment after appropriate pretreatment with HCG.