British Journal of Oral Surgery (x973), IO, 3oo-3o4

AN U N U S U A L COMPLICATION OF LOWER THIRD MOLAR REMOVAL

RUSSELL HOPKINS, M.R.C.S., L.R.C.P., B.D.S., F.D.S, R.C.S. University Hospital of Wales, Cardiff

A 25-YEAR-OLD female teacher was referred to the Dental Hospital, Cardiff, by her general dental practitioner, complaining of pain arising from the lower left wisdom tooth. Clinical and radiographic examination revealed gross caries in the/8 which, like the 8/, was mesio-angularly impacted. A root in the 7/area was also noted. The patient was admitted for the removal of both lower wisdom teeth and the root under general anaesthesia. The haemoglobin was 14.5 gm per cent and urinalysis normal.

On admission the patient stated that she had been hoping tO conceive during the three weeks since her last menstrual period.

Surgery, anaesthesia and post-operative recovery were uneventful. The 8/ was removed using the lingual split technique. Eight days post-operatively when the sutures were removed healing and progress were normal. The patient was discharged with advice to return should this not continue.

Her condition continued to improve and she went on vacation. Approximately two weeks post-operatively, she developed a sudden attack of trismus, which cleared after a week following treatment with co-trimoxazole (Septrin) prescribed by a physician. The patient remained well for a further 17 days when she again developed limitation of opening.

When seen in the Dental Hospital by a member of the junior staff she also complained of ear-ache and mild malaise, which had been present for the previous two days. She was not obviously unwell and her discomfort was not severe. Jaw opening was only 3 mm approximately and she had bilateral submandibular lymphadenopathy. The intra-oral examination confirmed healthy buccal areas without swelling. The patient was given a screw-gag, advised to continue with hot mouthwashes, and to return if the progress was not maintained.

Two days later the patient was seen as an acute emergency. She was com- plaining of severe ear-ache, sore throat with dysphagia, considerable malaise, vomiting and diarrhoea.

Examination revealed an obviously unwell patient in severe pain. The axillary temperature was 37°C but the pulse rate was 124. Bilateral tender sub- mandibular lymphadenopathy was confirmed, the right side being larger than the left. Complete trismus was evident, the teeth being in contact, and a marked foetor oris was noted. There was no external swelling; the masseter muscles were not tender or in spasm and there was no evidence of infection in the retromolar areas.

The white blood count was 14,7oo with 85 per cent polymorphs. Tomography demonstrated marked enlargement of the soft palate. The air-

way was seen to be reasonable and there was no distension of the posterior pharyn- geal wall (Fig. I).

300

AN UNUSUAL COMPLICATION OF LOWER THIRD MOLAR REMOVAL 301

A diagnosis of a lateral pharyngeal abscess involving the soft palate was made, and the patient was admitted as an emergency for tracheostomy and drainage of the abscess.

It was decided to perform a tracheostomy for the following reasons:

(a) Spontaneous rupture of the abscess in the presence of such severe trismus would have constituted an acute hazard to life, even in hospital.

(b) General anaesthesia would have been a dangerous procedure (Thompson, I966): instrumentation might easily have ruptured the abscess. Even with suction available this manoeuvre would still have been unsafe, especially if the anaesthetic had failed to relax the jaw. Passage of an endotracheal

FIG. I

Tomograph demonstrating the markedly enlarged soft palate encroaching on the nasopharynx. The posterior margin of the

tongue is shown.

tube following rupture of this abscess would have carried organisms down into the trachea causing possible post-operative chest infection.

(c) With tracheostomy the airway was ensured and the patient's life no longer at risk.

A second opinion from a consultant otolaryngologist confirmed the above views and the planned treatment was approved.

Intramuscular cloxacillin 5oo mg and ampicillin 5oo mg were given and the patient taken to theatre. Premedication which might have dried out the oro- pharynx was thought inadvisable, but a total of2o mg of intravenous diazepam was injected in divided doses before and during the operation.

Approximately 2o ml of one per cent lignocaine were infiltrated above the suprasternal notch deep into the neck. A tracheostomy was performed after blunt dissection had demonstrated the trachea. 1.5 ml of lignocaine were injected into the trachea itself before the window was cut. A cuffed tracheostomy tube was

302 BRITISH JOURNAL OF ORAL SURGERY

inserted and general anaesthesia induced. The jaws were opened by using a Mason's gag, and visual confirmation of a grossly enlarged right side of the soft palate, uvula and lateral pharyngeal wall was possible.

A vertical incision was made in the anterior pillar of the fauces and curved Hilton's forceps were passed upwards into the soft palate and downwards to the retromolar area. Copious thick pus was evacuated and the abscess cavity explored by the little finger. A drain was not inserted, but a nasogastric tube was passed.

Post-operatively the patient remained on ampicillin and cloxacillin with intravenous fluids, and her post-operative pyrexia of 38.5°C cleared by the second day. A rapid improvement of the trismus allowed the removal of her tracheostomy tube on the third post-operative day. The patient was discharged on the sixth post-operative day with a normal white blood count and almost normal opening of the jaw. She had no recollection of the tracheostomy operation, and, in fact, this wound closed IO days after removal of the tube when continued improvement was noted.

D I S C U S S I O N

The patient's original operation had been covered by the prophylactic use of one vial of intramuscular Triplopen. Investigation of pus from the second opera- tion showed that the reported bacteria, all normal inhabitants of the oral cavity, were resistant to penicillin (Fig. 2).

Culture--Aerobic and Anaerobic S. albus (Coag-ve) _+ D. pneumoniae ÷ H. influenzae +

Gram film (I) Scanty Gram-negative bacilli. (2) Moderate nur~bers Gram-negative bacilli

and Gram-positive bacilli. Scanty Gram-positive cocci.

(3) Scanty Gram-positive cocci.

Culture Same on all three swabs.

Sensitivities Penicillin - Streptomycin - Erythromycin + Tetracycline - Novobiocin - Chloramphenicol + Sulphafurazole - Ampicillin +

FIG. 2 The bacteriological report on three separate

swabs taken at operation.

Subsequent questioning of the patient revealed that she had ready access to penicillin and had been taking it with some frequency for sore throats. It is likely that penicillin-resistant organisms were implanted into the operation site causing a low-grade infection, which was only partially controlled by the week long course of Septrin. This emphasises both the value of an adequate pre-operative history, and the prescription of an alternative antibiotic in such circumstances.

AN UNUSUAL C O M P L I C A T I O N OF L O W E R T H I R D M O L A R REMOVAL 303

The cone-shaped parapharyngeal space, described by Thoma (I 963) is bounded laterally by the medial pterygoid and medially by the superior constrictor muscles. Posteriorly lie the parotid gland, prevertebral muscles, structures arising from the styloid process and a midline fibrous septum. The roof is formed by the base of skull, and the apex by the carotid sheath. Anteriorly, lies the pterygomandibular raphe into which are inserted the buccinator and superior contrictor muscles; the integrity of this raphe is destroyed by surgery for the removal of a wisdom tooth.

Thoma (1963) described the parapharyngeal abscess, of which this case is a classical example. The source of infection is said to be from a wisdom tooth or following its surgical removal. Occasionally a mandibular block injection or peri- tonsillar infection may be the cause (Scott-Brown et al., 1965). Once in the para-

PAROTID

GLAND

~SSErEa

UPERIOR

,NSTRICTOR

ERYGOID

FIG. 3 A diagrammatic representation of a parapharyngeal abscess,

the abscess cavity being the dark stippled area.

pharyngeal space, infection may spread upwards through the cranial foramina or downwards along the carotid sheath. In this patient, pus spread medially to the superior constrictor to lie between the palatopharyngeus and palatoglossus muscles in the soft palate (Fig 3). Tomography of the area proved invaluable in the investigation of this case, when visual examination was not possible.

Thoma (I963) recommended either forcibly opening the jaw under general anaesthesia with subsequent internal drainage, or carrying out external drainage through the submaxillary space. In this patient the involvment of the soft palate was a contraindication to either procedure. The knowledge of two fatal cases of quinsy where pus was inhaled caused the author to take an extremely serious view of this patient. The dangers of inducing general anaesthesia in patients with large oropharyngeal abscesses are still not as widely appreciated as they might be. The tracheostomy removed this immediate risk to the patient's life.

304 B R I T I S H JOURNAL OF ORAL SURGERY

A parapharyngeal abscess is drained either through the pharynx or neck depending on the direction of spread (Scott-Brown et al., 1965). The decision as to the advisability of either approach and the placing of the incision will be related to the: amount of trismus and the limits of the abscess. I f the latter has extended to below the level of the mandible it must be drained extra-orally. If, however, it has localised in the superior aspect it may be drained intra-orally. I f the soft palate is involved, as in this present case, the incision should allow access to both soft palate and parapharyngeal space.

This patient reminds us again that even apparently simple operations can be the cause not only of morbidity but even mortality.

P O S T S C R I P T

It was subsequently found that this patient had become pregnant three weeks before her tracheostomy. Having previously taught subnormal children she was naturally worried about possible foetal damage. Medical advice against termination was confirmed by the delivery of a full-term normal male infant.

ACKNOWLEDGEMENTS

1 wish to thank Mrs D. Twamley for her secretarial assistance, Mr B. A. Jones of Oral Photography and Mrs P. Ware of Dental Illustration.

REFERENCES

SCOTT-BROWN, W. G., BALLANTYNE, J. & GROVES, J. (I965). Diseases of the Ear, Nose and Throat, 2, znd Ed. London: Butterworths.

THOiVlA, K. H. (1963). Oral Surgery, 4th Ed., Vol. II, 5, PP- 743, 745. St Louis: Mosby. THOMPSON, P. W. (I966). Proceedings of the Royal Society of Medicine, 59, 738.