Oral and maxillofacial surgery; trauma Incidence of oral and maxillofacial skiing injuries due to different injury mechanisms

Gassner R, Ulmer H et al. J Oral Maxillofac Surg 1999; 57: 1068–1073

Dento-alveolar injuries were commonly caused by lift-track accidents and blows from personal skiing equipment, whereas facial fractures were commoner in collisions with people or stationary objects.

Over a 6 year period, 579 patients (mean age 28 years, 90% aged 10–51) with 882 oral and maxillofacial skiing injuries were seen in an Innsbruck clinic. Highest rates of injury were in children aged 7–12, and young adults aged 17–33. Two-thirds of injuries were in males in all age groups; 1/3 of injured people were Austrian. The whole group accounted for 10% of all trauma injuries, and 1/3 of all sports-related injuries.

Facial fractures affected 310 patients, dentoalveolar trauma, 236, and soft-tissue injuries, 336. There were 5 principal distinguishable mechanisms of injury: falls (45%), collision with people (23%), collision with objects (8%), blows from personal skiing equipment (12%) and ski-lift accidents (6%). In 5 cases, injuries were caused by a stroke or heart attack during skiing, and 4 people died because of other severe injuries.

The authors relate mechanisms to types of injury and discuss possible factors in prevention, including speed control, physical fitness, preparatory training, level of experience and avoidance of bad weather and overcrowded slopes.

Endodontics Influence of several factors on the success or failure of removal of fractured instruments from the root canal

Hülsmann M, Schinkel I Endod Dent Traumatol 1999; 15: 252–258

About 2/3 of fragments were removed or bypassed, and success depended on local anatomical and access factors.

A fractured root canal instrument is one of the more irritating complications of dental treatment. Whilst less than 1% of endodontic failures may result from broken instruments, prognosis is more favourable where a vital pulp has been extirpated. Success in removal or bypass of fragments varies from 50–70% and is often time-consuming.

In this study, several ultrasonic and hand instrument techniques were used in an attempt to remove or circumvent 113 fragments in 105 teeth in 105 patients. Complete removal was performed for 55 fragments and a further 22 were fully bypassed and embedded in gutta-percha. In 13 out of 36 failures, root perforation occurred.

Fractures were most frequent in molars, and the lowest success rates (50%) were in premolars, whilst the highest were in anteriors; the 5 fragments in the coronal canal third were all removed, but only 60–70% of fragments in the middle or apical thirds. Straight canals had higher success (82%) than those where fragments were in or beyond a curve (55%). A higher degree of curvature also meant a lower success rate, and longer fragments had higher success rates.

Oral surgery Lingual access for third molar surgery: a 20-year retrospective audit

Moss CE, Wake MJC Br J Oral Maxillofac Surg 1999; 37: 255–258

A lingual approach does not appear associated with higher post-operative morbidity, provided an appropriate technique is used.

Lingual nerve morbidity is low when buccal access is used for lower third molar removal, and some have concluded that lingual flap retraction should be avoided. However, if a broad Hovell's retractor is used instead of a Howarth's elevator, morbidity is lower. The present study was a 20-year audit of one surgeon's removal of 2088 teeth under general anaesthesia with this technique, and 818 by other methods. Chisels were the preferred instruments for bone removal.

Lingual nerve morbidity, in all cases temporary, was present after 16 of the 2088 lingual retraction procedures (0.8%), and 2 of the other 818 operations (0.2%). An accompanying editorial by 2 other oral surgeons adds the additional point that even lower rates of temporary injury occur with buccal approach in the USA, albeit with a very small number of permanent injuries. There, most of these operations are by specialist surgeons, rather than surgeons in training as in the UK. They conclude that the present lingual approach should be used only by specialists and should be audited, and other operators should use only a buccal approach.

Endodontics; trauma Inflammatory and replacement resorption in reimplanted permanent incisor teeth: a study of the characteristics of 84 teeth

Kinirons MJ, Boyd DH et al. Endod Dent Traumatol 1999; 15: 269–272

Where endodontic treatment is required, pulp extirpation should be undertaken within 20 days of reimplantation, and ankylosis may be minimized by limiting splinting to 10 days or less.

Over a 7 year period, 71 children attended a Belfast clinic after avulsion of 84 teeth, of which 73 were upper central incisors, and were followed up for a minimum of 2 years. In 22 teeth, inflammatory root resorption was diagnosed; where pulps were extirpated in the first 19 days, only 25% of teeth were affected, but extirpation after this time was associated with inflammatory root resorption in 39% of teeth. Teeth with this type of resorption had been dry before reimplantation for significantly longer (mean 20 v. 10 min; P < 0.05)

Replacement resorption was diagnosed in about half of the teeth. A splinting period of 4–10 days was associated with replacement resorption in only 1/6 cases, but the rate was 3.5 times greater where splinting was present longer (P < 0.05). The authors discuss the role of early pulpal extirpation and splinting for avulsed incisors, and consider that extirpation within 20 days is not critical, but splinting should be limited.