The acute effects of smokeless tobacco (snuff) on gingival blood flow in man.

Snuff-induced blood flow responses in the gingiva were evaluated in 22 healthy casual consumers of tobacco. Laser Doppler flowmetry (LDF) was used to measure blood flow simultaneously and continuously on two gingival sites (buccal aspect of the papillae between the upper lateral incisors and canines). In addition, measurements of skin blood flow in the forehead and palmar side of the left thumb were performed. Arterial blood pressure (BP) and heart rate (HR) were also recorded. Unilateral application of commercial snuff (500 mg, 1%) caused a marked and rapid increase in gingival blood flow (GBF) on the exposed side (p < 0.001). Blood flow increased also in the contralateral gingiva and forehead skin (p < 0.05). Skin blood flow in the thumb showed an insignificant decrease. BP and HR increased. Vascular conductance increased significantly in the snuff-exposed gingiva but not in the contralateral gingiva or the forehead. Vascular conductance was largely unaffected in the thumb. It is concluded that acute application of snuff, besides giving rise to typical changes in BP and HR, increases GBF in and around the exposed area, probably through activation of sensory nerves and the subsequent release of vasodilatory peptides from their peripheral endings. Blood flow in unexposed gingival and forehead skin may increase probably due to humoral or nervously mediated mechanisms. However, a passive pressure-induced hyperaemia in the unexposed gingiva and forehead skin can not be excluded.

Reflex responses of the masseter muscle in patients with chronic arthritis or internal derangement of the temporomandibular joint. A comparison with symptomfree subjects.

Averaged reflex responses in the masseter muscle to transverse taps delivered to the upper central incisor were studied in 13 patients with chronic arthritic temporomandibular joint (TMJ) disease (arthritis group) and 28 patients having internal TMJ derangement (derangement group). The diagnostic assessment of TMJ disease was based on a combination of imaging methods. Fourteen symptomfree subjects served as a control for the electromyographic observations. The tapping force was increased in steps from 0.25 to 6 N. The pattern of the reflex response consisted of various inhibitory and excitatory waves, which were found to change with increasing tapping force. The first inhibitory wave (I-1) increased in duration with increasing tapping force in all subjects. At certain tapping forces, I-1 was of significantly lower amplitude and longer duration in the arthritis group than in the control group, but latency and threshold did not differ. The excitatory wave seemed to have longer latency and higher amplitude in the arthritis group than in the control subjects at some tapping forces. In summary we conclude that the pattern of the reflex response seemed to be similar in patients with different TMJ disorders and in symptomfree subjects. Only the level of inhibition, duration of I-1 and higher excitatory response, might separate the patients with arthritic TMJ disease and internal TMJ derangement from symptomfree subjects, but no specific differences between the groups could be found.

Increased human gingival blood flow induced by sodium lauryl sulfate.

Laser Doppler flowmetry was used in 14 subjects to investigate the effect of sodium lauryl sulfate (SLS) on gingival microcirculation. SLS, the most widely used detergent in toothpastes, exhibits a denaturing property, increases oral mucosal permeability and may cause epithelial desquamation of oral soft tissues. Gingival blood flow (GBF) was measured bilaterally 3 mm above the gingival margin, between the central and lateral maxillary incisors, before and after application of 1.5% SLS for 90 s to the gingiva on one side. The contralateral side served as a control with water application only. Relative changes in GBF were measured for 15 min on both sides. SLS increased the median GBF significantly between the 2nd and 10th min with a peak at 8 min, whereafter the flow decreased towards baseline. On the contralateral side, GBF initially declined before returning to baseline. 10 subjects felt a burning pain from the gingiva after SLS application and GBF increased in all of them. SLS increased the relative gingival blood flow presumably due to its penetrating and irritative properties, which resulted in vasodilatation. Laser Doppler flowmetry may be a useful non-invasive method for intraoral testing of different agents meant for oral use.

Instant assessment of pulpal blood flow after orthodontic force application.

The purpose of the present investigation was to measure the effect of tooth intrusion and extrusion on pulpal blood flow in man. The flow changes were measured in 10 lateral incisors (6 subjects) by means of laser Doppler flowmetry (Perimed, Sweden) applied on the buccal surface through metal tubes bonded to the teeth. Brackets were bonded onto teeth 13 and 23, and intrusive and extrusive forces of 2 N were applied in random order to the experimental tooth for 5 min before unloading. The contralateral tooth served as a control. Extrusion of the teeth gave no significant changes in pulpal blood flow during loading or unloading. However, intrusion of the teeth reduced the pulpal blood flow by 20% during the first minute after force application. The pulpal blood flow gradually increased towards the preloading flow values for the next 4 min, and was returned to the prestimulus level 3 min after unloading. In conclusion orthodontic intrusion of teeth with a 2 N force evoked a temporary reduction in the pulpal blood flow, whereas extrusion had no effect on the pulpal blood flow.

Effects of mandibular nerve block on heat- or cold-induced changes in pulpal blood flow in man.

Laser Doppler flowmetry (LDF) was used to study the effect of mandibular nerve block, using 3% mepivacain, on heat- or cold-induced changes in pulpal blood flow (PBF) evoked by application of cold or heat to the lingual surfaces of teeth 33 and 43 in nine young subjects. PBF on average showed a 7% increase in response to heat (48 degrees C) and a 20% decrease when exposed to cold (3 degrees C). Neither response was affected by mandibular block. From this we concluded that the effects on PBF of the presently applied heating and cooling of the tooth were solely due to direct thermal influences on the blood vessels, without involvement of vasomotor or sensory nerves.

Laser Doppler flowmetry in the assessment of tooth vitality after Le Fort I osteotomy.

The aim of the present study was to evaluate pulp vitality in 15 patients, 11 to 29 months after a Le Fort I osteotomy. Assessment of pulpal blood flow was obtained by means of laser Doppler flowmetry, and it was measured bilaterally from the first maxillary premolar to the central incisor. The results were compared with those obtained by electric pulp testing in the same teeth. In addition, periodontal ligament perception was evaluated by applying axial loads to the central incisors. Radiographs were also studied. Fourteen subjects served as a control group. There was no significant difference between the level of pulpal blood flow in the teeth of the operated group compared with the control group. Twenty-one per cent of the teeth in the group operated on were insensitive to electric pulp testing, and in the remaining 79% the mean threshold was significantly higher than in the corresponding teeth in the control subjects. Similarly, the axial load threshold for the incisors for the control subjects was below 5 g, but in the group operated on 66% had a threshold above 5 g. These experiments clearly demonstrate that teeth without normal innervation can have an intact blood supply and be vital.

Physiological regulation of the secretion of histatins and statherins in human parotid saliva.

The small salivary phosphoproteins, histatins and statherins, have important functions in the oral cavity in terms of antimicrobial actions and regulation of calcium phosphate homeostasis. Neither the effects of various physiological stimuli on their secretion nor the nature of the efferent receptor involved in the stimulus-secretion coupling has been determined previously. These aspects are important for improved understanding of the secretory control of salivary proteins and may have implications regarding the effects of specific medications on salivary constituents and oral health. The effects of graded mechanical (chewing on short and long silicone tubings) and gustatory stimulation (0.5, 1.5, and 5.0% citric acid) on the secretion of histatins and statherins were studied in the presence and absence of adrenolytic agents (n = 10). In this model, secretory rates of both proteins increased with increases in flow rate, with 5.0% citric acid representing a particularly potent stimulus. Histatin and statherin secretory rates were significantly reduced by the beta 1-adrenolytic agent (histatins to 58 to 72% and statherins to 11 to 29% of that in corresponding control experiments), but not by the alpha 1-adrenolytic agent. Since the beta 1-adrenergic receptors played an important role in the stimulus-secretion coupling of these proteins, protective salivary functions in the oral cavity may be compromised during beta 1-adrenolytic treatment.

Effects of cooling and heating of the tooth on pulpal blood flow in man.

Laser Doppler flowmetry (LDF) was used to study the changes in pulpal blood flow (PBF) evoked by application of cold or heat to the palatinal surfaces of teeth 11 or 21 in nine young subjects. Switching from a thermode temperature of 33 degrees C to 5 degrees C on average induced a slow decrease of PBF to about 80% of control, and also warming to 39 degrees C evoked a small reduction in most subjects. Interindividual differences were large, however, and both cooling and warming sometimes triggered a rise in PBF. In contrast, skin blood flow, as recorded with LDF in the forearm, invariably rose during warming and fell during local cooling. The results suggested a more complex interaction between local and nervously mediated effects of moderate changes in temperature in the tooth pulp than skin, and that the previously held view of cold and heat decreasing and increasing PBF, respectively, is wrong.

A study of cholinergic and beta-adrenergic components in the regulation of blood flow in the tooth pulp and gingiva in man.

In 10 subjects, laser Doppler flowmetry was used to study whether cholinergic or beta-adrenergic pathways are involved in the control of tooth pulp blood flow (PBF) in response to isometric hand grip and the cold pressor test. We also examined if differences exist between the regulation of blood flow in the tooth pulp and the nearby gingiva (GBF). Isometric hand grip (35% of maximum force, 2 min) and the subsequent ischaemia (2 min) induced a brief rise in PBF and a more long-lasting rise in GBF. Atropine increased heart rate about by 40% and changed the pulpal response to a fall in flow, without altering gingival flow. Propranolol, causing a 20% reduction in heart rate, had no effect on either flow during the actual test, but induced a rise in GBF after the ischaemic period. The cold pressor test (2 min at 0.5 degrees C) resulted in a reduction in PBF and GBF, unaffected by the blocking drugs. With atropine, however, PBF increased immediately after this test. The relative changes in arterial pressure and heart rate were unaffected by the drugs. Our study has demonstrated the existence of cholinergic nervous vasodilation in vessels serving the tooth pulp. Non-adrenergic non-cholinergic mechanisms probably contribute to the evoked rise in GBF during exercise. Beta-adrenoceptors are involved in the control of GBF immediately after isometric exercise. While the two tests under control conditions evoked mostly parallel changes in PBF and GBF, the use of blocking agents showed that blood flow is controlled by different mechanisms in the two adjacent vascular beds.

Effects of autonomic reflexes on tooth pulp blood flow in man.

In 15 subjects, laser-Doppler flowmetry (LDF) was used to investigate whether the nervous control of pulpal blood flow (PBF) is affected by three tests known to excite the sympathetic nervous system. For comparison, skin blood flow was similarly recorded. Dynamic exercise (bicycle ergometer, 5 min, 90-100 W) in eight subjects was accompanied by a rise in PBF. PBF was increased by the cold pressor test (2 min) in eight subjects, while in five the flow decreased or remained unaffected. The isometric hand grip (2 min, 30% MVC) and the subsequent muscle ischaemia (2 min) led to a rise in PBF in two subjects and a fall in four. Following unilateral anesthesia of the mandibular nerve, PBF in five subjects became unresponsive to dynamic exercise or the cold pressor test, indicating pressure autoregulation. All three tests triggered increases in mean arterial pressure (MAP) and heart rate (HR). Skin blood flow usually increased in response to the tests, but could also decrease, and often changed in a direction opposite to that of PBF. It is concluded that the circulation of blood in the human tooth is affected by evoked changes in autonomic nerve activity, involving activation of both vasodilator and vasoconstrictor nerves to vessels serving the tooth.

Parotid secretion of fluid, amylase and kallikrein during reflex stimulation under normal conditions and after acute administration of autonomic blocking agents in man.

The purpose of this work was to study the effect of graded mechanical and gustatory stimulation on the secretion of the acinar products fluid and amylase and the ductal product kallikrein from the human parotid gland (n = 9). The involvement of parasympathetic and sympathetic nerves in the salivary reflexes was subsequently examined using receptor blocking agents (n = 4). Chewing elevated the secretion of all products as compared to rest (P less than 0.013). When increasing the length of the chewing object, secretion of fluid (P less than 0.013), but not enzymes, further increased. The shift from mechanical to gustatory stimulation with 0.5% citric acid enhanced significantly the secretion of amylase and kallikrein (P less than 0.009), while application of 5.0% citric acid increased the secretion of both acinar products (P less than 0.009) more than kallikrein. A differentiated reflex control of salivation both with regard to input and output was thereby indicated. The muscarinic-cholinergic antagonist oxyphencyclimin reduced median fluid secretion between 54 and 76% depending on the stimuli. During citric acid stimulation, but not during chewing, fluid secretion was reduced about 40% by the beta 1-adrenergic antagonist metoprolol, and about 20% by the alpha 1-adrenergic antagonist prazosin. Median amylase secretion was reduced 30% during chewing and 75% during gustatory stimulation by metoprolol. It was concluded that the masticatory-salivary reflex mainly activated parasympathetic pathways producing saliva of low protein content.(ABSTRACT TRUNCATED AT 250 WORDS)

Baroreflex responsiveness during hypobaric hypoxia.

Baroreflex responses to graded neck suction during held expiration were studied in five healthy females at sea level and at a simulated altitude of 4,572 m (15,000 ft), with and without oxygen administration. An apparent resetting of the baroreflex was observed during hypobaric hypoxia, but this effect was abolished by oxygen administration. Held expiration alone induced a pulse prolongation in all experimental conditions, however this bradycardiac response was smaller during hypobaric hypoxia than during the two normoxic conditions. When the bradycardic responses of held expiration were subtracted, the baroreflex responses to neck suction were equal in all experimental situations. Similarly, the baroreflex was unaffected by hypobaric hypoxia when the R-R interval prolongations were expressed in percentage of the R-R intervals immediately prior to the neck suction. These data indicate that reduced ambient pressure per se has no influence on the carotid baroreflex control of heart rate.

Force-related changes in the masseter muscle reflex response to tooth-taps in man.

In 14 subjects with no disorder of the masticatory apparatus, excitatory and inhibitory reflex responses in the masseter muscles were derived by standardized mechanical stimulation of the upper central incisor. A series of eight taps was delivered during isometric contraction at 40% of maximum EMG activity, with tapping forces ranging from 0.25-9 N. The mean post-stimulus masseteric EMG complex (PSEC) consisted of up to three inhibitory (I-1, I-2 and I-3) and three excitatory phases. The first inhibitory wave increased in duration with increasing tapping force, and the second and third inhibitory waves occurred at higher thresholds than the first inhibitory wave.

[Chronic disease and sexuality. An interview study on sexual dysfunction in patients with multiple sclerosis]. / Kronisk sykdom og seksualitet. Intervjuundersøkelse om seksuelle dysfunksjoner hos pasienter med multippel sklerose.

Many patients with a chronic disease experience that this condition in some way influences their sexual life. In this paper we present the results from an interview survey of ten patients with multiple sclerosis. The aim of the survey was to assess sexual dysfunctions in patients with chronic disease, the patients' opinion about these matters, and the role of the health services. We found the extent of the sexual problems of these patients to be comparable with the findings presented in earlier studies. The majority of patients considered it a problem that the topic was never raised by their medical practitioner. The patients clearly indicate that it is important for them that this subject be discussed, and that they receive counselling. This task should predominantly be the responsibility of the general practitioner, since she/he is normally the one who ensures continuity in the care of the patients.

Effect of increased alpha-adrenergic activity on the blood pressure/cardiac output relationship in dogs.

The relationship between mean aortic blood pressure (MAP) and cardiac output (CO) was examined in anaesthesized, open-chest dogs during variations in pre-load with and without alpha-adrenergic stimulation with phenylephrine. When phenylephrine increased MAP to 200 mmHg, CO fell greatly and could not be increased by volume expansion. Left ventricular ultrasonic measurements and pressure recordings showed that the Frank-Starling mechanism was maximally activated. During vena cava obstruction CO and MAP fell proportionally. At a lower infusion rate of phenylephrine, MAP increased to 160 mmHg without a great reduction of CO. As in control experiments without phenylephrine infusion, CO could be increased by dextran/saline infusion and lowered about 20% below control by vena cava obstruction with no significant change in MAP; by further caval obstruction CO and MAP fell in proportion. Phenylephrine did not alter the relationship between aortic baroreceptor activity and MAP. The same MAP/CO relationships were obtained before and after bilateral vagotomy and nephrectomy. Caval obstruction and pacing tachycardia resulted in similar MAP/CO relationships despite different effects on left ventricular end-diastolic pressure. Thus, phenylephrine infusion may raise MAP to 200 mmHg but no cardiac reserve is left. During reduction of CO by caval obstruction, peripheral vascular resistance remains constant despite varying baroreceptor activity. At the lower infusion rate of phenylephrine, raising MAP to 160 mmHg, peripheral vascular resistance is constant at low CO, but at high CO the vasoconstrictive effect of phenylephrine is counteracted by a vasodilatory mechanism which seems to be flow-dependent.

Reflex changes in sympathetic activity affect the tooth tap-digastric reflex in rabbits.

We have previously shown that, in the anaesthetized rabbit, electrical stimulation of the sympathetic trunks inhibits the digastric opening reflex, as elicited by standardized tooth taps and monitored by integrated EMG. The site of action was most likely in the periodontal ligament, since the digastric reflex evoked by electrical stimulation of the inferior alveolar nerve was unaffected. In the present investigation we have studied the effects on the reflex of more naturally occurring changes in sympathetic activity, as induced by the baroreceptor reflex. The sympathetic discharge was increased by withdrawal of blood from the femoral vein, and reduced by electrical stimulation of the aortic baroreceptor nerve. Preliminary results in five rabbits showed that haemorrhage reduced the digastric reflex by more than 10% in 7 out of 13 tests (median 19%), while aortic nerve stimulation increased the reflex in 11 out of 13 tests (median 160%). It is therefore concluded that the tooth tap-digastric reflex may be affected also by more naturally occurring changes in sympathetic discharge.

Sympathetic modulation of the jaw-opening reflex in anaesthetized rabbits.

The influence of sympathetic nerve stimulation (SNS) on the digastric muscle response to tapping on a front tooth was investigated in 14 anaesthetized rabbits. The reflex response to transverse taps was measured as changes in EMG activity of the ipsilateral digastric muscle. With taps of 1.1-2.2 times the threshold, the amplitude of the digastric EMG response was reduced by stimulation of the cervical sympathetic trunks (0.5-10.0 Hz) in 35 out of 40 test series. Maximum effect was observed at 6 Hz, which produced an average inhibition of 82%. The sympathetic effect appeared a few seconds after the start of stimulation, and in the range 0.5-6 Hz increased with the stimulation frequency. It was blocked by phenoxybenzamine. The reflex was triggered by receptors in or around the tooth, since it disappeared after sectioning of the inferior alveolar nerve (IAN) or local anaesthesia of the tooth. Afferent electrical stimulation of the IAN evoked a digastric excitation that was insensitive to SNS. We conclude that the sympathetic inhibition of the reflex was mediated by a local action in the receptor area, probably related to the evoked vasoconstriction.

Acute changes in intra-alveolar tooth position and local clearance of 125I from the periodontal ligament.

Changes in intra-alveolar tooth position and local 125I clearance from the periodontal ligament (PDL) were monitored simultaneously in cats. Axial tooth movements, reflecting periodontal ligament volume changes, were measured with an ultrasonic transit time technique. Local blood flow changes in the PDL were studied indirectly by measuring the local clearance of 125I-. Stimulation of the cervical sympathetic trunk caused an intrusive movement of the tooth with a concomitant reduction of the 125I- clearance. Infusion of noradrenaline induced a similar response. Stimulation of the inferior alveolar nerve during systemic treatment with phentolamine caused an extrusive movement of the tooth with a concomitant increase in the clearance of the tracer from the PDL. Intra-arterial infusion of the vasodilator substance P mimicked that response. Fixation of the tooth to the jaw bone, thus preventing an intrusive movement, did not change the reductions in clearance seen on sympathetic stimulation, indicating that this blood flow reduction was not dependent on tooth movement. A qualitative relation between PDL blood flow (as measured by local 125I clearance) and PDL volume (as measured by tooth position) is shown. The two variables measured are suggested to reflect two aspects of blood flow in the PDL.

Parotid salivary flow in response to mechanical and gustatory stimulation in man.

To examine further the role of the oral receptors in the masticatory-salivary reflex, a study with eight subjects was performed. The influence on mean parotid salivation of combined alterations in frequency and force of chewing and length of the chewing object was evaluated by group comparison. Salivary flow rate was recorded using a sensitive micromanometer, and the frequency (12, 60 and 90 cycles min-1) and force of chewing (10 and 40% of maximum) were controlled by a metronome and masseter muscle EMG, respectively. The maximum instantaneous flow and the latency of the masticatory-salivary reflex were examined in three subjects. For comparison with mean salivation rate during chewing, gustatory stimulation was performed with 0.5 or 5.0% citric acid. The masticatory-salivary reflex was mainly ipsilateral, and depended upon having an object between the teeth. Salivation increased with increases in frequency and force of chewing and with the number of teeth involved, each parameter of chewing having the greatest influence when increased from a low level of action. The salivation response to chewing showed two phases; the first, presumably due to contraction of the myoepithelial cells, had a latency of 0.2-0.4 s, while the second phase occurred about 1 s later. Our results support the hypothesis that the periodontal mechanoreceptors have a major role in the parotid response to chewing. Application of 0.5 and 5.0% citric acid on the back of the tongue induced dose-dependent parotid secretions, significantly higher than those of chewing. A negative correlation was found between the maximum fluid outputs during chewing and 5.0% citric acid stimulation.