The reliability of high resolution ultrasound in the identification of pus collections in head and neck swellings.

Head and neck swellings often present to oral and maxillofacial surgeons. It is often unclear whether a collection of pus is present. This information is essential for decisions regarding surgical intervention. Although ultrasound scanning (USS) is widely used to investigate the presence of a collection, the reliability and validity of this investigation in this context is uncertain. A retrospective review of 4000 consecutive head and neck USS reports over a 4 year period in the Cardiff University Health Board produced 43 cases in which ultrasound had been used to look for evidence of pus collection. The management and treatment outcome of these patients were reviewed and the data analysed. 36 of 43 patients had their swelling incised in theatre, and in 92% of these cases USS and clinical findings corresponded. Of the seven not taken to theatre, four were USS negative and three USS positive; in all seven cases the swelling resolved with antimicrobial therapy. Sensitivity and specificity of USS imaging to identify pus collection were very high, 96% and 82%, respectively. The evidence in this study indicates that USS is a very reliable diagnostic tool in the diagnosis of a collection as well as providing evidence that small collections of pus can resolve without surgical drainage.

Facial templates: a new perspective in three dimensions.

PURPOSE: This paper describes the use of adult facial template in gender-specific facial analysis. SUBJECTS AND METHODS: Eighty adults, mean age 24.5, were selected for the study. Laser-scanned images of the subjects were obtained under a reproducible and controlled environment with two Minolta Vivid 900 (Osaka, Japan) optical laser-scanning devices assembled as a stereo-pair. A set of left and right scanned images was taken for each subject and each scan took an average of 2.5 s. These scanned images were processed and merged to form a composite three-dimensional soft tissue reproduction of the subjects using commercially available reverse modelling software. The differences in facial morphology were measured using shell deviation colour maps. The facial template was used to compare differences between males vs. females groups and two subjects with facial disproportions. RESULTS: The difference between the male and female facial templates was 1.28 +/- 1.02 mm. The areas of greatest deviation were at the nasal, zygomatic area and lower jaw line. The results of the surface deviation maps between the templates and subjects with facial disproportion showed that the results could be applied for orthodontic diagnosis. CONCLUSIONS: The construction of the adult facial templates provides an interesting perspective into measuring changes in groups of patients and also acts as a useful template for the comparison of skeletal disproportion.