The effect of extraction of third molars on late lower incisor crowding: a randomized controlled trial.

The problem of late mandibular incisor crowding is a well established phenomenon, the cause of which has been the substance of considerable debate over the years. A central issue is the possible role of the third molars though no definitive conclusions have been consistently drawn. This prospective study was designed to investigate the effects of randomly assigned early extraction of third molars on late crowding of the mandibular incisors. One-hundred-and-sixty-four patients entered the study from 1984 following completion of retention after orthodontic treatment. Seventy-seven patients (47%) returned for records up to a mean of 66 months later, and their start and finish study casts were digitized on a reflex microscope to determine Little's index of irregularity, intercanine width and arch length. Forty-four of the patients had been randomized to have third molars removed. There was no evidence of responder bias. Where third molars were extracted the mean increase in lower labial segment irregularity was reduced by 1.1 mm from a mean of 2.1 mm for the group where third molars were retained (P = 0.15, not statistically significant). This difference was also not considered to be clinically significant. The principal conclusion drawn from this randomized prospective study is that the removal of third molars to reduce or prevent late incisor crowding cannot be justified.

Management of palatally impacted canines: the findings of a collaborative study.

The impacted palatal canine requires a combination of both surgical and orthodontic management. Two types of approach are commonly used: simple exposure, or exposure with bracketing at the time of surgery. In this study 104 consecutively treated patients with palatally impacted canines were examined at two centres, one at which the ectopic tooth was surgically exposed alone and the other where an orthodontic bracket was bonded to facilitate early traction, and the flap replaced. The aim was to compare the outcome and complication rate for each type of procedure. In 30.7 per cent of all cases exposed and bracketed a second surgical intervention was required, compared with 15.3 per cent in the simple exposure group. Bracketing, though effective, is a more costly and time-consuming procedure, and it is suggested that simple exposure provides an equally efficient and predictable method of managing the palatally impacted canine with obvious clinical and financial benefits. The long-term periodontal status of the teeth which have been exposed in these two ways, however, needs further investigation.

Lesions of the mandibular condyle in juvenile chronic arthritis.

A total of 371 serial dental panoramic radiographs from 71 children with juvenile chronic arthritis (JCA) were examined to determine the presence and extent of radiographically detectable condylar abnormalities. The series included 12 children with so called 'bird face' deformity and 55 in whom facial growth was judged to be normal. By the age of 15 years, 27 patients (38 per cent), showed lesions of the TMJ, of which 14 (55 per cent) were bilateral. Of those cases with unilateral destruction, the left condyle was affected nine times more frequently than the right. All of the children with 'bird face' deformity had condylar abnormality, but these facial characteristics should not be considered pathognomonic of juvenile chronic arthritis. Moderate to severe condylar abnormality was detectable in 10.9 per cent of children with normal facial growth, and where condylar destruction is present it can often be established as early as 8 years. Systemic corticosteroids appear to have little or no effect on the condyle or mandibular growth.

Extrusion of the ectopic maxillary canine using a lower removable appliance.

The ectopic eruption and impaction of maxillary canines is a frequently encountered problem. The prevalence is estimated to be between 0.92% to 2.2%. It is found to be palatal to the dental arch in about 85% of cases and buccal only in about 15% of cases. Ericson and Kurol suggested that removal of the deciduous canine before the age of 11 years will normalize the position of the ectopically erupting permanent canine in 91% of cases if the canine crown is distal to the midline of the lateral incisor. We strongly endorsed this interceptive approach. Early recognition that a canine is erupting ectopically is extremely important. Ericson and Kurol estimate that in 0.71% of children in the 10 to 13 year age group, permanent incisors have resorbed because of the ectopic eruption of maxillary canines. Resorption may be found as early as 10 years but occurs most frequently in the age groups 11 to 12 years. In this article a simple, well-clasped lower removable appliance is shown to be an excellent base for using light elastics to move the impacted canine, first posteriorly away from the incisor roots and then vertically and buccally. A gold chain is bonded to the unerupted canine to provide a simple and flexible means of traction that ensures the canine erupts into a zone of attached mucosa with normal crown length.

Juvenile chronic arthritis: a cephalometric analysis of the facial skeleton.

A retrospective cross-sectional cephalometric investigation was undertaken to examine the facial form of a group of Finnish children with juvenile chronic arthritis (JCA). Following digitization, the radiographs were divided into three age groups, and according to whether or not 'bird-face' deformity was present. From a total of 67 cases (39 females and 28 males) 19 per cent were judged to be 'affected'. Analyses were carried out and the groups compared using t-tests. The mandible was found to be smaller both in ramal height and body length in the affected sample, with reduction in posterior face height being only partly compensated by increase in bony apposition at the angle producing antegonial notching. There was posterior rotation of the mandible with a reduction in angles S-N-B and S-N-Pog, and an increase in the gonial angle, the angle between the mandibular plane and S-N, maxillary, and occlusal planes. The changes in the maxilla were less marked. Although S-N-A was reduced in all three age groups, it was not significantly so. Maxillary length (ANS-PNS) was significantly smaller in the two younger age groups. In the vertical plane maxillary dimensions were reduced in the two younger age groups. A highly significant increase in the occlusal to maxillary planes angle was observed in all groups. There was, however, no difference in S-N to maxillary planes angle, indicating a more steeply inclined occlusal plane due to subnormally erupted maxillary molars. Although the inter-incisal angle was reduced there was no significant difference in the incisor inclinations in relation to the jaws and despite the posterior rotation of the mandible there was no significant increase in size of overjet or in the frequency of anterior open bite.

Management of service personnel with a history of penicillin allergy: discussion paper.

A false label of penicillin allergy may have important consequences for wartime medical evacuation. This article outlines the antibiotic protocol for war wounds, the current status of tests to diagnose true penicillin allergy and suggests a strategy for the management of personnel with a history of such allergy.

Arterial embolisation of a facial haemangioma.

Non-invasive investigations in the diagnosis of highly vascular lesions are without doubt a sound principle. A case is presented however, in which the clinical diagnosis of a haemangioma was confirmed by ultrasound and magnetic resonance imaging (MRI) but required further investigation by angiography to facilitate treatment. Embolisation is a well established technique available in most large radiology departments, but may not be well known by general dental practitioners.

Complications in the use of compression plates in the treatment of mandibular fractures.

The use of internal rigid fixation with plates in the treatment of facial fractures continues to increase in popularity. The principal advantage is in avoiding the use of maxillary mandibular fixation (intermaxillary fixation), thus enabling early return of function. However, there are clear guidelines for their use and technique of placement. A case is reported that demonstrates several avoidable complications in the use of compression plates and outlines the principles for the correct use of bone plates in mandibular fractures.

Pleomorphic adenoma of the parotid gland.

A case of pleomorphic adenoma arising from the deep lobe of the parotid gland is presented. Controversy often surrounds the management of a parotid lump, and many investigations are of little help. The first operation cures most salivary tumours and the patient usually has no residual disability. There is no place for the use of radiotherapy, in the treatment of pleomorphic adenoma.

Pilomatrixoma: a rare condition in the differential diagnosis of a parotid swelling.

Pilomatrixoma is an uncommon tumour arising from hair follicles. It is more common in the hair bearing areas of the upper region of the body, but is relatively rare. A case is presented in which clinical examination, ultrasound and computed tomography suggested the presence of a pleomorphic adenoma arising from the superficial lobe of the parotid gland, but at operation the mass was found to be separate from it and subsequent histological examination revealed a pilomatrixoma.

Importance of histological assessment of dental follicles following extractions.

A case is reported of actinomyces being isolated histologically from an enlarged dental follicle surrounding a partially erupted, impacted third molar. This allowed prophylactic therapy to prevent the possible development of cervicofacial actinomycosis.

Left ventricular mechanical efficiency in coronary artery disease.

The effect of coronary artery disease and prior myocardial infarction on cardiac energetics was determined by measuring left ventricular myocardial blood flow, oxygen consumption (MVO2), efficiency and ejection phase indexes in 36 patients undergoing coronary arteriography. Eight control patients with normal coronary arteriograms and normal left ventricular function, 15 patients with coronary artery disease without prior myocardial infarction and 13 patients with coronary disease and prior myocardial infarction (greater than 6 months) were studied. Left ventricular efficiency was calculated from left ventricular work, myocardial blood flow (measured by clearance of intracoronary xenon-133), and aortic and coronary sinus oxygen content. Left ventricular volumes, mass and ejection phase indexes were measured by quantitative left ventriculography. Left ventricular myocardial blood flow per 100 g/min was reduced in patients with coronary artery disease (49.0 +/- 8; p less than 0.01) and in patients with myocardial infarction (51.6 +/- 10; p less than 0.05) compared with control subjects (62.4 +/- 16), but total left ventricular flow was not reduced because of increased left ventricular mass. As a result, MVO2 did not differ significantly for the three patient groups (control 13.3, coronary artery disease 14.0 and myocardial infarction 14.3 ml/min). In the patients with myocardial infarction, left ventricular work index was reduced (2.4 versus 4.0 kg X m/m2 per min in the control group; p less than 0.001), causing efficiency to be reduced (15.9 versus 28.8% in the control group; p less than 0.001). Decreased efficiency correlated with ejection fraction (r = 0.54), mean velocity of circumferential fiber shortening (MVcf) (r = 0.45) and mean percent chordal shortening (r = 0.43) (all p less than 0.01). These data indicate that in control patients with normal coronary arteriograms, left ventricular myocardial efficiency averages 29%; in patients with coronary disease without myocardial infarction, left ventricular MVO2 and efficiency are in the normal range; in patients with prior myocardial infarction, left ventricular efficiency is significantly reduced as a result of diminished left ventricular work and normal MVO2; and reduced efficiency after myocardial infarction correlates with reduced ejection phase indexes.