Elimination of permanent injuries to the inferior alveolar nerve following surgical intervention of the "high risk" third molar.

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.

Safety and efficacy of levobupivacaine for postoperative pain relief after the surgical removal of impacted third molars: a comparison with lignocaine and adrenaline.

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.

External neurolysis of the lingual nerve.

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.

Adverse reaction to dental local anaesthetic injection--'allergy' is not the cause.

OBJECTIVE: To investigate patients considered to have experienced allergic reactions to local anaesthetics administered for dental treatment. SETTING: Dental facility within a general hospital. PROCEDURE: Skin and intra-oral challenge tests. RESULTS: No patients were found to be allergic to lignocaine or prilocaine. The most likely causes of the adverse reactions were found to be psychogenic. CONCLUSION: Although allergy to lignocaine (and the other amide anaesthetic agents used in dentistry) is known to be extremely rare, it continues to be suggested as a cause when adverse reactions to dental injections occur. Psychogenic reactions are the main causes of untoward events, and some can be alarming. A smaller proportion of adverse responses can be attributed to (avoidable) intravascular injections. Adverse reactions can be reduced if injections are administered carefully.

Pain control after routine dento-alveolar day surgery: a patient satisfaction survey.

OBJECTIVE: An audit study which examines patient's opinions on the efficiency of two analgesic regimes prescribed to them following dento-alveolar surgery in our Day Unit. DESIGN: Single centre prospective study. SETTING: Oral Surgery Day Case Unit SUBJECTS: One-hundred-and-seventy-four adults undergoing routine dento-alveolar surgery under general anaesthetic were asked to assess their pain control (on a five point scale) 1 hour after surgery, at discharge from hospital and at 24 and 48 hours post-operatively. Post-operatively, patients received ibuprofen 400 mg three times daily for five days or two tablets of paracetamol 500 mg with codeine 30 mg six hourly for 5 days if they were allergic to aspirin or were asthmatics sensitive to aspirin. Patients were not given local anaesthesia intra or post-operatively. RESULTS: Completed records were obtained for 161 (93%) patients. Ibuprofen was apparently adequate in controlling pain for 147 out of 161 patients but on further questioning 42 of these patients took supplemental analgesics and self-prescribed paracetamol or a paracetamol combination. Thirteen patients who were prescribed paracetamol with codeine had adequate pain control and did not take supplemental analgesics. One patient did not require any analgesics post-operatively CONCLUSION: Telephone contact with patients 24 and 48 hours post-surgery provides a valuable assessment of pain control following discharge from a day surgery unit. Ibuprofen offered satisfactory control of pain for 65% (95) of patients who underwent routine dento-alveolar surgery. Discharge prescriptions must be given with verbal and written instructions to ensure that patients take the correct dose and self-prescription is within safe doses.

Direct access day case oral surgery.

OBJECTIVE: To compare the effectiveness of direct access referrals with standard letter referrals, and also assess the impact of the direct access system on the primary care provider, secondary sector and from the patients perspective. DESIGN: Surgical and anaesthetic guidelines were agreed and 12 general dental practitioners were recruited to participate in the study. Each practitioner was given 100 envelopes which contained randomly allocated 50 direct and 50 standard referrals. For direct referrals, GDPs completed a pre-operative assessment and obtained an operation date by telephone from the day case unit while the patient was in the surgery. The clinical history sheet was faxed to the day unit and the radiographs posted. The only contact the patient had with the hospital was on the day of surgery. Standard referral patients were referred in the traditional way with a referral letter being sent to an out-patient clinic. Evaluation of the effectiveness of the direct referral system versus standard letter method were made via completion of questionnaires by the patients, dental practitioners, hospital clinicians, day case anaesthetist and co-ordinator. SETTING: The study was carried out over 2 years commencing in 1997 at the Oral Surgery Day Case Unit at Manchester Royal Infirmary. RESULTS: A greater number of direct access referrals (409; 90%) were treated in comparison with (312; 75%) standard referrals (P < 0.001). Eighty nine per cent of direct access records were adequate pre-operatively. More than 70% of dentists and hospital clinicians preferred the direct access referral method. Sixty-three per cent of standard letter patients were satisfied with their mode of referral compared with 87% of direct access patients. CONCLUSIONS: Given appropriate guidelines dental practitioners are able to refer directly to oral surgery day case operation lists. This has proved to be the favoured method of referral for dental practitioners, the secondary sector and patients.

Progress in local anaesthesia.

Research into improving local anaesthetic agents and methods of delivering them in dental practice has been very slow. This article describes some of the progress that is being made in these areas.

Adverse effects of dental local anaesthesia.

This paper considers the adverse effects that a patient may suffer as a result of anticipating an injection of dental local anaesthetic. Although most of these are extremely rare (a testimony to good technique), the dental practitioner should be aware of the possibility of their occurrence and of ways to deal with them.

The effects of vasoconstrictor on transmission of impulses in the peripheral nerve.

The effects of extraneural and intramuscular applications of l-adrenaline on peripheral nerve function were examined. Change in the compound action potential was monitored until a complete conduction block was obtained if it occurred within 100 min. Extraneural application of 0.5 ml l-adrenaline to an isolated segment of the sciatic nerve of the rat in three concentrations of 1:100,000; 1:10,000, and 1:2,000 resulted in complete conduction block within 8 min. However, intramuscular injections of similar concentrations resulted in concentration dependent neural blockades with the highest concentration causing conduction blockade in 27.1 +/- 8.0 min.

A double-blind placebo-controlled study to assess the efficacy of a compound analgesic to prevent postoperative pain following oral surgery.

It has been suggested that small doses of opioid drugs given prior to surgery can reduce postoperative pain. This study was designed to compare the effectiveness of a paracetamol/codeine combination and paracetamol alone in preventing the pain following surgical removal of impacted third molar teeth under general anaesthesia. Analysis of the results showed no statistical differences between treatment groups when compared with placebo. We suggest that the opioids may not be the best drugs available to prevent the moderate to severe pain present following some oral surgery procedures.

Mental nerve dysfunction: a symptom of diverse mandibular disease.

Paraesthesia and anaesthesia of the mental nerve may result from a variety of pathological conditions, and in persistent cases of orofacial sensory disturbance thorough clinical assessment, including CT scanning, is vital to exclude underlying systemic or neoplastic disease. This paper presents three patients with right mental nerve dysfunction, and reviews the aetiology of mental nerve paraesthesia and anaesthesia.

A comparison of broad and narrow retractors for lingual nerve protection during lower third molar surgery.

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.

Ketorolac and diclofenac for postoperative pain relief following oral surgery.

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.

Midazolam and somatosensory evoked potentials.

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.