Search

We aimed to find out whether improved preoperative assessment and surgical planning with cone beam computed tomography (CT) could reduce damage to the inferior alveolar nerve when high risk impacted mandibular third molars are extracted. We recorded the presence or absence of postoperative neuropathy after extraction of 200 lower third molars in 185 patients (where cone beam CT had shown contact between the nerve and root) after treatment in the oral surgery department of King's College Hospital. All patients had had cone beam CT of the teeth after panoramic radiography had indicated increased risk of injury to the nerve during extraction. Experienced oral surgeons did all the operations and postoperative reviews. Patients reported temporary alteration of sensation after operation in 12% of teeth but it resolved in all cases and no patient reported permanent loss of sensation. Permanent sensory disturbance in the distribution of the inferior alveolar nerve after third molars have been removed can be eliminated in high risk cases if operations are planned carefully (including cone beam CT), and the procedure is done by a skilled surgeon who has an appreciation of the anatomy of the nerve and roots, and an insight into the mechanical effect of their surgical manipulation. The incidence of permanent neurosensory dysfunction in this study was zero even though all teeth were intimately related to the inferior alveolar canal., (Copyright © 2012 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.)

In a randomised, double-blind placebo-controlled single-centre study we compared the efficacy and safety of 0.75% levobupivacaine (without vasoconstrictor) with 2% lignocaine (with adrenaline 1:80,000) and with placebo for postoperative pain relief in 93 patients having day surgery under general anaesthesia for the removal of impacted mandibular third molars. Premedication and preoperative analgesics were not prescribed, although a short-acting opioid analgesic agent was allowed if required during the anaesthetic procedure. Patients were asked to keep a diary card for 2 days after discharge from hospital. The primary endpoint was the number of patients who requested analgesia within 2 h of completion of the operation. In total, 16 (53%) of patients given levobupivacaine requested analgesia compared with 22 (71%) given lignocaine and 23 (72%) given placebo. Patients given levobupivacaine had lower maximum visual analogue pain scores (VAS) and took longer to request rescue medication (P=0.045 compared with lignocaine). Fewer patients after levobupivacaine n=20 (7%) than after lignocaine n=7 (23%) or placebo n=5 (16%) experienced adverse events. Levobupivacaine seems to be a suitable alternative local anaesthetic to lignocaine with adrenaline for pain control after oral operations.

The lingual nerve is sometimes injured during the surgical removal of an impacted mandibular third molar. The level of sensory recovery was studied in 10 patients who underwent external neurolysis of the lingual nerve. The mean time from third molar surgery to neurolysis was 13.5 months (range 9-24 months). Seven of the 10 patients showed significant improvement, three patients regaining normal sensation. Three patients showed no improvement. These results show that external neurolysis should be considered for patients with altered sensation in the distribution of the lingual nerve.

The incidence of altered lingual nerve sensation following lower third molar removal was examined in 150 cases where a broad retractor was used to retract the lingual flap and compared with 150 cases where a more conventional Howarth's periosteal elevator was employed. This study supports the view that a broad retractor employed to protect the lingual nerve during lower third molar surgery produces significantly less altered lingual nerve sensation at 1 month than a Howarth's periosteal elevator used for the same purpose.

A double-blind clinical study was designed to compare the efficacy and safety of intramuscular and oral ketorolac, a new non-steroidal anti-inflammatory analgesic with that of diclofenac and placebo for patients undergoing removal of impacted mandibular third molar teeth. Results showed that both analgesic preparations were more effective than placebo (p = 0.0029) and that ketorolac provided a similar degree of pain relief to that of diclofenac. It is concluded that ketorolac is important new addition to the available intra-muscular NSAID preparations.

The effect of intravenous midazolam on the somatosensory evoked potentials (SEP's) elicited from median nerve stimulation was investigated in a study on 20 volunteers. SEP's were recorded from contralateral scalp before and at 5, 30, and 60 min after drug administration. Relative amplitudes of the early components (N18-N20) were essentially stable, while relative amplitudes of the late components (N50-P90, P90-N160, N160-P250 and P250-N380) were reduced significantly after midazolam administration and had not returned to baseline 60 min after administration. Given the correlation between late SEP amplitude and subjective reports of experimental pain, the data support the possibility that administration of midazolam in conscious sedation doses may have some effect on pain in addition to its better documented sedative and amnesic properties.

In a randomised, double-blind, cross-over study on 20 healthy human volunteers, the effect of intravenous midazolam on pain tolerance using the 'submaximum effort tourniquet technique' is described. Intravenous midazolam administered in conscious sedation doses was found to significantly reduce the affective and motivational component of the pain experience.

The concentration of cephradine in serum and mandibular bone was assayed in 28 patients undergoing 3rd molar surgery following a single 1 g intravenous injection. Serum and cortical bone samples taken simultaneously, contained mean cephradine concentrations of 42.11 micrograms/ml and 2.61 micrograms/g respectively. These results, when compared with those reported for other bony sites including the femoral head and knee, show a reduced bone penetration with a bone-to-serum ratio of approximately 0.06:1.

The surgical removal of an impacted mandibular third molar may result in damage to the inferior alveolar nerve and may cause disabling anaesthesia of the lip; anaesthesia of the lower gingivae and anterior teeth may also result. Assessing the likelihood of injury depends to a great extent on preoperative radiographic examination. Seven radiological diagnostic signs have been mentioned in the literature; the reliability of these signs as predictors of likely nerve injury have been evaluated through retrospective and prospective surveys. Three signs were found to be significantly related to nerve injury and a further two were probably important clinically.

Oro-facial sensory impairment is a common event following third molar extractions, osteotomies and maxillo-facial trauma. Trigeminal somatosensory-evoked potentials (TSEPs) may offer an objective means of assessing neuronal function in such cases. TSEPs may be recorded non-invasively in man following peripheral stimulation of the trigeminal nerve, the principal nerve of oro-facial sensation. TSEP recording has gained popularity over the last decade and it is thus timely to review experimental methods and proven clinical applications in the light of recent interest in this technique within oral and maxillo-facial surgery.

13 patients who sustained mandibular trauma were investigated with radiographs and scintiscans. The scintiscans showed abnormal uptake of radiopharmaceutical in the temporomandibular joint (TMJ). In patients with a long history of traumatic arthrosis, there was more positive correlation between the scintiscans, and clinical symptoms and histology than between radiographs, and symptoms and histology. In patients with mandibular body fractures and no TMJ symptoms, the scans showed abnormal uptake in the TMJ in 7/8 joints, in the absence of radiographic abnormality. The significance of the abnormal uptake and the value of scintigraphy is discussed.

It is a well recognised phenomenon that acute inflammation often interferes with the success of local analgesia. It has been suggested recently that this apparent reduction in the efficiency of the local anaesthetic is due to an increase in peripheral nerve activity. This investigation was undertaken to identify possible alternations in the impulses evoked in sensory nerves in the presence of inflammation. The saphenous nerve was exposed in the thigh of an anaesthetised rat. Stimulating and recording electrodes were applied under paraffin oil and an area of skin supplied by the nerve was identified. An electronically driven mechanical probe was used to apply a repeatable tap of short duration to the skin, and the force was adjusted so that a submaximal evoked potential was produced. A number of these potentials were averaged electronically. Inflammatory changes were induced in he skin by electrical antidromic stimulation and the mechanical stimulation schedule was repeated. The evoked action potential was shown to have increased substantially. These results are considered in conjunction with findings of other investigators who have shown a similar sensitisation using multifibre preparations.

Prophylactic metronidazole was found to be an effective means of preventing 'dry socket' after routine dental extractions. The oral anaerobic bacterial may be implicated therefore in the development of the disorder. It has been confirmed in this study that 'dry socket' occurs following three per cent of routine dental extractions and almost exclusively in the mandible. The causes of the condition are probably numerous and may even vary from patient to patient, but the control of infection by anerobic organisms may be important in its prevention or early resolution. The prophylactic administration of metronidazole (Flagyl) has been shown to be a simple and effective method of prevention which would suggest the implication of anaerobic organisms in 'dry socket'. The drug appears to be free from side effects when a dosage of 200 mgs eight hourly for three days is given.