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Biomedical subjects

J P Moss

Publications and source records attributed to J P Moss.

At least 19 recordsLinked to original sources
PubMed2006

The use of three-dimensional imaging in orthodontics.

The article illustrates the value of three-dimensional imaging of the face and jaws in the diagnosis and treatment of patients. The applications of programs that have been written for the analysis of facial form are also described, including registration and prediction. The use of the Procrustes analysis is demonstrated in groups of children and adults to differentiate between male and female facial morphology. The use of scanning in forensic science is also described. The application of surface shape analysis to groups of monozygotic and dizygotic twins and to family studies to detect those areas that are genetically determined from those areas, which are not, is illustrated.

Adolescent↗
PubMed2003

Three-dimensional assessment of treatment outcomes on the face.

OBJECTIVES: To investigate the effect on the face of treatment involving extractions. DESIGN: A prospective study of the effects of extraction and non-extraction treatment on two groups of patients was undertaken. SETTING AND SAMPLE POPULATION: Initially there were 16 non-extraction and 18 extraction patients but at the end of treatment there were only 12 in each group. EXPERIMENTAL VARIABLE: Each of the patients was scanned using a three-dimensional (3-D) MGI scanner and the 3-D scans were analysed using registration and surface shape analysis programs. The registration program registers the scans over the forehead and then shows the differences in colour between the two scans. The surface shape analysis mathematically differentiates the surface into nine different surface shapes. RESULTS: The results indicated that there was a difference between the two groups at the start of treatment but there were no differences in the effect on the face of treatment in the two groups. The surface morphology was similar at the end of treatment in both groups. CONCLUSION: It was concluded that in this preliminary study that whether treatment is undertaken with or without extractions, in this group of patients the facial morphology was not significantly different.

Adolescent↗
PubMed2002

The three-dimensional effects of orthodontic treatment on the facial soft tissues--a preliminary study.

OBJECTIVE: To examine the three-dimensional effects of extraction and non-extraction orthodontic treatment on the facial soft tissues. SETTING: Department of Orthodontics, Royal London Hospital. DESIGN: Longitudinal study of two prospective cohorts of patients who were attending for orthodontic treatment. METHOD 12 patients were included in each group, in accordance with the selection criteria. Three-dimensional optical surface scans of these patients were obtained in the one month prior to having fixed appliances placed and this was repeated at the end of treatment. RESULTS: The average face of the non-extraction patients was of greater general dimensions than the extraction average, both at the start and the end of treatment. During the fixed appliance treatment, the vermilion of the upper lip became more protrusive to a similar extent in both groups in relation to the reference plane. The lower lip vermilion and the philtrum showed no change for either group over the treatment time. The labiomental fold area showed a slightly greater forward movement in the extraction group with treatment. CONCLUSION: Three-dimensional optical surface scanning allows data from the whole of the face to be assessed, as opposed to the lateral profile view used in the majority of the studies to date. The effects of the two types of treatment on the facial soft tissues were very similar, indicating that orthodontic treatment involving the extraction of teeth does not have a detrimental effect on the face.

Adolescent↗
PubMed2002

Three-dimensional assessment of the effects of extraction and nonextraction orthodontic treatment on the face.

The purpose of this prospective study was to compare the 3-dimensional (3-D) effects on the face of extraction and nonextraction orthodontic treatment in patients with skeletal Class I patterns. The sample of 24 patients included 12 whose treatment included extractions and 12 who were treated without extractions. Pretreatment study casts were assessed to evaluate dental differences between the 2 groups. Pretreatment and posttreatment lateral cephalograms and optical surface scans were also compared. In the lateral cephalometric assessment, the only significant (P <.05) pretreatment difference was lower lip length. Posttreatment, the nasolabial angle and lower lip thickness were significantly different (P <.05). Registration of the average 3-D optical surface scans indicated that, before treatment, the nonextraction group had longer and broader faces by 5 to 7 mm, and the upper lip and labiomental fold were 3 to 5 mm farther forward than in the extraction group. Posttreatment, the nonextraction group still had larger faces, but the difference was smaller. Faces in the extraction group became relatively more protrusive with treatment. The surface shape analysis technique showed that the cheeks were flatter in the nonextraction group at the start of treatment, but this reversed with time. In the extraction group, the concavity of the labiomental fold increased, while the nonextraction group showed no change in this area. The study demonstrates that 3-D optical surface scans offer more data for analysis compared with lateral cephalograms alone. It also highlights the changes that can be detected with surface shape analysis.

Adolescent↗
PubMed2002

[Lasers in dentistry 7. The use of 3D imaging in dentistry].

Optical surface scanning accurately records the 3D nature of the face non-invasively and quantitatively. Programmes to analyse the data now enable the clinician to compare the changes in the face as the result of growth or of treatment and also to average groups of patients to provide an assessment of treatment. An average face has been obtained from groups of patients each year from 5 to 18 years. Growth of an individual can be compared with the norm for that age to determine which areas of the face show abnormal growth. Prediction of facial form for forensic and surgical purposes is possible. Programmes have been developed that analyse shape and curvature of areas of the facial surface. Such an analysis can be used to determine the changes in the facial surface as the result of growth, treatment, or drug therapy and to study genetic effects.

Adolescent↗
PubMed2001

A prospective optical surface scanning and cephalometric assessment of the effect of functional appliances on the soft tissues.

The aim of this study was to evaluate the effect of different functional appliances on the soft tissues as assessed by cephalometry and optical surface scanning. Forty-two patients were randomly allocated to Bass, Twin Block (TB), and Twin Block + Headgear (TB + Hg) groups. Lateral cephalograms and optical surface scans were recorded before and after the 10-month study period. ANOVA was used to test the cephalometric variables for differences at the 5 per cent level. The optical surface scanning and cephalometric results were consistent in the sagittal dimension. In the vertical dimension, however, the optical surface scans consistently recorded a greater increase compared with cephalometric values. No differences were detected with regard to cephalometric values at the 5 per cent level. However, the Bass appliance produced greater forward positioning of soft tissue pogonion as assessed by optical surface scanning.

Analysis of Variance↗
PubMed2001

Facial growth: separating shape from size.

Optical surface scanning technologies produce dense three-dimensional (3D) data sets, which allow detailed analysis of surface morphology. This paper describes a method of analysing change in facial shape independently of change in size. The 3D data from three male subjects from the age of 6-21 years were recorded using an optical surface scanner. A series of 22 conventional landmarks were located with the aid of horizontal and vertical profiles across the face, and were analysed using geometric morphometrics. The 3D landmark co-ordinates were scaled and aligned using Generalized Procrustes Analysis (GPA) and analysed by Principal Component Analysis (PCA) to determine the shape change over the growth period for each individual. The results show that the centroid size reaches a steady value at different times for each of the subjects. When analysing shape versus age, highly significant correlations were found with principal component 1 (PC-1), but not with other principal components. PC-1 encompassed 40 per cent of the total variance for each subject. The movement of facial landmarks with time that is represented by PC-1 in each of the individuals is described. The use of these techniques has enabled the individual characteristics of facial growth to be identified and also has revealed the subtle changes in shape that continue after change in size has ceased.

Adolescent↗
PubMed2000

Three-dimensional facial growth studied by optical surface scanning.

The objective of the investigation was to study the three-dimensional growth of the face, and to examine the hypothesis that there are three-dimensional differences between the faces of boys and girls. The subjects comprised 132 British Caucasians aged 5-10 years measured by optical surface scanning in this cross-sectional study. Average scans for each age and sex subgroup were superimposed to assess the differences with age and sex. Males were generally larger than females. The greatest difference was between the facial heights and the least in the mid-facial dimensions. The face height of both sexes increased by an average of 3-4 mm annually. Mid-face prominence and width altered little. Mandibular width increased by 1-3 mm a year, rising to 3-5 mm in some years at the inferior areas of the mandibular region. Mandibular prominence also increased. Nose height and prominence and alar base width increased by 2 mm per year on average. Dorsum width changed little. Boys were generally larger than girls. Growth in facial height was greatest. Mid-face prominence and width changed little with age, whilst the prominence and width of the lower face increased more. Nasal prominence and alar base width increased at most ages. Dimensions changed more than reported by cephalometric studies, possibly as this study included the soft tissues. Refereed Scientific Paper

Age Factors↗
PubMed2000

[The state of dentistry education in Europe].

In order to find out what branches of Dentistry are recognized in Europe as Dental specialties a questionnaire was designed and sent to various Associations and groups across Europe. It contained eight main questions covering the various specialties that were recognised or were to be recognised. Responses were obtained from 28 countries, 15 EU member states and 13 non member states. The results from the questionnaire indicated that there was a broad agreement on many of the questions but a considerable variety of opinions. There seems to be a desire to harmonize standards across Europe for the benefit of the profession and the public.

Education, Dental↗
PubMed1999

Specialisation in dentistry in Europe--a review.

In order to find out what branches of Dentistry are recognized across Europe as Dental specialties, a questionnaire was designed and sent to various Associations and groups across Europe. It contained 8 main questions covering the various specialties that were recognised or were to be recognised. Responses were obtained from 27 countries, 15 EU member states and 12 non member states. The results from the questionnaire indicated that there was a broad agreement on many of the questions, but a considerable variety of opinions. There seems to be a desire to harmonize standards across Europe for the benefit of the profession and the public.

Education, Dental↗
PubMed1998

Orthodontics in the National Health Service.

In order to, understand the development of the National Health Service, we need to look at the state of orthodontics in the country prior to its introduction in 1948. This article considers the various factors which contributed to orthodontics' development in the NHS. The progress of this specialty is described together with comments on its future in the NHS.

Certification↗
PubMed1997

Three-dimensional analysis techniques--Part 1: Three-dimensional soft-tissue analysis of 24 adult cleft palate patients following Le Fort I maxillary advancement: a preliminary report.

The three-dimensional, facial soft-tissue changes of 24 patients with various cleft types following transpalatal Le Fort I osteotomy were measured using laser scanning techniques, radial measurements, and a color millimetric scale. There was a varying degree of midface retrusion in the different cleft groups, and a very similar pattern of retrusion over the nasal complex. Each group of patients showed a varying degree of relapse postsurgically, but there was a failure in all the cleft groups to correct the lack of nasal projection.

Adolescent↗
PubMed1997

Three-dimensional analysis techniques--Part 2: Laser scanning: a quantitative three-dimensional soft-tissue analysis using a color-coding system.

New methods for measuring and averaging three-dimensional soft-tissue morphology and change from laser scans using a color millimetric scale are described. The techniques were employed to measure facial differences between a group of Class I skeletal males and females. The surgical change in one patient following bimaxillary surgery is also illustrated. The combination of the laser scanning technique and the new color coding system probed to be a simple, noninvasive, effective, and easily interpreted method for measuring three-dimensional soft-tissue differences and change across the facial complex.

Adolescent↗
PubMed1997

Three-dimensional analysis techniques--Part 3: Color-coded system for three-dimensional measurement of bone and ratio of soft tissue to bone: the analysis.

A new color-coded method of illustrating three-dimensional changes in the bone and the ratio of soft tissue to bone movement is described. The technique is illustrated by superimposing preoperative and 1-year postoperative CT scans of three patients following bimaxillary surgery. The method has proved to be a very simple, effective, and readily interpreted method of quantifying both bone and the ratio of movement of the overlying soft tissues across the face following surgery.

Adult↗
PubMed1997

Three-dimensional analysis techniques--Part 4: Three-dimensional analysis of bone and soft tissue to bone ratio of movements in 24 cleft palate patients following Le Fort I osteotomy: a preliminary report.

The three-dimensional changes in the bone and the ratio of soft tissue to bone movement were investigated in a group of 24 cleft palate patients following Le Fort I osteotomy. CT scans were taken for each patient preoperatively and 1 year postoperatively. The scans were superimposed, radial measurements calculated, and the changes illustrated by two separate color scales. In all of the groups, there was a fairly consistent pattern of movement over the mandible. The soft tissues moved in a 1.25:1 ratio over the chin and canine regions, and reduced to 1:1 over the body. In the maxilla, there was a 1:1 movement in the midline increasing to 1.25:1 bilaterally over the alar bases for both the bilateral clefts and clefts of the secondary palate groups. In the unilateral cleft group, however, there was a greater degree of movement over the cleft than over the noncleft side.

Adolescent↗
PubMed1996

Three-dimensional nasal changes following maxillary advancement in cleft patients.

Three-dimensional laser surface scanning of the face was performed before and after Le Fort I maxillary advancement in 24 patients with replaced clefts of the lip and palate. The surgery resulted in advancement of the upper lip and para-alar tissues and an increase in the relative prominence of the nose within the face. These changes were produced at the expense of an increase in nasal width and a reduction in nasal tip protrusion. The changes in nasal morphology showed significant variation among patients.

Adult↗