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Dive into the research topics where John McWilliam is active.

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Featured researches published by John McWilliam.


The Cleft Palate-Craniofacial Journal | 1992

A six-center international study of treatment outcome in patients with clefts of the lip and palate: Part 4. Assessment of nasolabial appearance

Catherine Asher-McDade; Viveca Brattström; Erik Dahl; John McWilliam; Kirsten Mølsted; Dennis A. Plint; Birte Prahl-Andersen; Gunvor Semb; William C. Shaw

One hundred and fifteen frontal and profile photographs of the nasolabial area of subjects with complete unilateral clefts of the lip and palate from six European centers were assessed. Four components of the nasolabial area were rated separately by a panel of judges using a five-point scale of attractiveness. The Tukey multiple comparison test showed significant differences between the centers. The relative position of the six centers in this study followed a similar pattern to their respective positions in the cephalometric and dental cast studies.


The Cleft Palate-Craniofacial Journal | 1992

A six-center international study of treatment outcome in patients with clefts of the lip and palate: Part 5. General discussion and conclusions

William C. Shaw; Erik Dahl; Catherine Asher-McDade; Viveca Brattström; Mike Mars; John McWilliam; Kirsten Mølsted; Dennis A. Plint; Birte Prahl-Andersen; Chris Roberts; Gunvor Semb

Part 5 is the final part of a series of five articles reporting on an international, multicenter clinical audit of treatment outcome for complete UCLP. A number of recommendations for the methodology of future studies is made especially with respect to entry criteria, sample size, assumptions of homogeneity, and the reproducibility and validity of outcome measures. The findings of the present study regarding clinical procedures are presented tentatively, and improvement and extension of the methodology are required. It appears, however, that acceptable results can be achieved by different programs and ultimately clinical choices may be based on factors such as complexity, costs, and demands of treatment. Standardization, centralization, and the participation of high volume operators were associated with good outcomes, and nonstandardization and the participation of low volume operators with poor outcomes. Therapeutic factors associated with good outcomes were the employment of a vomer flap to close the anterior palate, and poor outcomes with primary bone grafting and with active presurgical orthopedics.


The Cleft Palate-Craniofacial Journal | 1992

A six-center international study of treatment outcome in patients with clefts of the lip and palate: Part 3. Dental Arch Relationships

Michael Mars; Catherine Asher-McDade; Viveca Brattström; Erik Dahl; John McWilliam; Kirsten Mølsted; Dennis A. Plint; Birte Prahl-Andersen; Gunvor Semb; William C. Shaw

One hundred and forty-nine dental casts of subjects with complete unilateral clefts of the lip and palate from six European cleft palate centers were assessed by means of the Goslon Yardstick. The Yardstick proved capable of discriminating between the quality of the dental arch relationships between the six centers. Two centers showed especially poor results. Three centers obtained satisfactory results although differing surgical techniques were used in these centers. One of the centers showing satisfactory dental arch relationships employed a more complex and expensive treatment program than the other two centers, which both used simpler centralized treatment regimens.


American Journal of Orthodontics and Dentofacial Orthopedics | 1991

Mandibular and maxillary growth after changed mode of breathing

Donald G. Woodside; Sten Linder-Aronson; Anders Lundström; John McWilliam

The amount of maxillary and mandibular growth and the direction of maxillary growth were studied in 38 children during the 5 years after adenoidectomy for correction of severe nasopharyngeal obstruction. The amount of mandibular growth measured between successive gnathion points on superimposed radiographs was significantly greater in the group who had an adenoidectomy than in the matched controls. In the boys the difference was 3.8 mm (p less than 0.001), and in the girls the difference was 2.5 mm (p less than 0.01). The boys also showed a tendency toward greater growth in the maxilla as measured between successive subnasal points (1.2 mm, p less than 0.05). We detected no difference in the direction of maxillary growth between who had undergone adenoidectomy and the controls.


The Cleft Palate-Craniofacial Journal | 1992

A six-center international study of treatment outcome in patients with clefts of the lip and palate: Part 1. Principles and study design

William C. Shaw; Catherine Asher-McDade; Viveca Brattström; Erik Dahl; John McWilliam; Kirsten Mølsted; Dennis A. Plint; Birte Prahl-Andersen; Gunvor Semb

This article describes the design of an intercenter comparative study of treatment outcome in the treatment of children with a unilateral complete cleft of the lip and palate. The rationale and aims of this study are defined and treatment schemes of the participating centers are described. The findings are presented in a series of three papers (Parts 2, 3, and 4) dealing with the comparison of craniofacial form, dental arch relationships, and nasolabial appearance. In Part 5, conclusions and general recommendations regarding future research are discussed.


The Cleft Palate-Craniofacial Journal | 1992

A six-center international study of treatment outcome in patients with clefts of the lip and palate: Part 2. Craniofacial form and soft tissue profile.

Kirsten Mølsted; Catherine Asher-McDade; Viveca Brattström; Erik Dahl; Michael Mars; John McWilliam; Dennis A. Plint; Birte Prahl-Andersen; Gunvor Semb; William C. Shaw

The craniofacial morphology and the soft tissue profile were evaluated in this part of the intercenter study of the European Cleft Lip and Palate Research Group. The sample was comprised of cephalometric x-rays of the full cohort of 151 cases from the six European cleft palate centers. The facial morphology in complete unilateral cleft lip and palate patients was evaluated by means of roentgen cephalometry. Approximately 25 consecutive cases from each of six European cleft palate centers were compared. Only one center showed notable and consistent differences from the others. A contributing factor for these differences may be an inconsistent treatment regimen with many surgeons involved. Analysis of the soft tissue profile between the centers showed more pronounced differences than analysis of the skeletal profile. The treatment outcome in centers with more complex or expensive programs was no better than those centers using simpler management approaches.


Angle Orthodontist | 1992

A proportional analysis of the soft tissue facial profile in young adults with normal occlusion

Anders Lundström; Carl-Magnus Forsberg; Sheldon Peck; John McWilliam

A proportional soft tissue profile analysis is presented, based on natural head position (NHP) and an extracranial vertical reference line through Porion. Twelve linear soft tissue variables and norms for 11 indices expressing vertical and horizontal soft tissue proportions of the face were obtained from lateral skull radiographs of 40 Swedish adults (20 males, and 20 females) with good occlusion. Sexual dimorphism, with larger dimensions in men than in women, was most pronounced in the vertical plane. With regard to facial soft tissue proportions, significant differences between men and women were found only for those indices which involved measurements of lower jaw prominence and facial height. The means and standard deviations for six indices in the female group were compared with corresponding data obtained from the Peck and Peck sample, which had been selected on esthetic grounds. The results showed a close match between the groups. The proportional soft tissue analysis is recommended for the treatment planning of patients scheduled for orthognathic surgery.


Scandinavian Journal of Plastic and Reconstructive Surgery and Hand Surgery | 1991

Craniofacial development in children with unilateral clefts of the lip, alveolus, and palate treated according to four different regimes. I. Maxillary development.

Viveca Brattström; John McWilliam; Ola Larson; Gunvor Semb

Lateral skull radiographs of 85 patients with unilateral clefts of the lip, alveolus, and palate treated according to four different regimes were compared at three different ages regarding maxillary development. Regimes that included primary bone grafting to the alveolus at six months of age resulted in inhibited anterior maxillary growth and reduced maxillary inclination. Regimes that included secondary bone grafting after eruption of the incisors but before the eruption of the canines, resulted in better maxillary development, but were not as good as regimes that omitted bone grafting altogether.


Angle Orthodontist | 2009

The Effect of Image Quality on the Identification of Cephalometric Landmarks

John McWilliam; Ulf Welander

The effect of rare-earth phosphor intensifying screens on diagnostic image quality was examined. Five observers were asked to identify ten landmarks on each of fifteen cephalometric images having varying screen-film-kvp combinations. The most sensitive screens were found to significantly affect diagnostic image quality and thereby the reliability of landmarks identification. This finding was, however, only established for those landmarks having the lowest standard deviations and the clinical significance is thus questionable. There would appear to be other more important factors than physical image quality involved in the reliability of landmark identification. High intensifying screens are, therefore, recommended for use in cephalometric analyses since they help to reduce patient dose and do not appear to sacrifice diagnostic image quality to the extent that the reliability of cephalometric measurements is significantly affected.


The Cleft Palate-Craniofacial Journal | 1993

A six-center international study of treatment outcome in patients with clefts of the lip and palate: evaluation of maxillary asymmetry.

Kirsten Mølsted; Erik Dahl; Viveca Brattström; John McWilliam; Gunvor Semb

This investigation was carried out by the European Cleft Lip and Palate Research Group. The purpose of this part of the investigation was to compare and evaluate maxillary asymmetry in children born with complete unilateral cleft lip and palate treated at cleft palate centers with different surgical management. Posteroanterior radiographs from three of the six participating centers were included in the investigation. Statistically significant differences were found in the symmetry of the anterior part of the maxillary complex. Children with a primary bonegrafting procedure involved in their primary treatment procedure had a more symmetric dentoalveolar development. Children from centers with primary surgical procedures including a vomer plasty and no involvement of the alveolar process had a more asymmetric development with a tilted premaxilla and a deviating inclination of the central incisors.

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Gunvor Semb

University of Manchester

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Birte Prahl-Andersen

Academic Center for Dentistry Amsterdam

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Ola Larson

Karolinska University Hospital

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Michael Mars

Great Ormond Street Hospital

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