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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
PubMed1992

A three dimensional analysis of soft and hard tissue changes following bimaxillary orthognathic surgery in skeletal III patients.

The three dimensional changes in the bone and the ratio of soft tissue to bone movement were investigated in a group of 16 Skeletal III patients following orthognathic surgery. Computerised tomogram scans were taken for each patient pre-operatively and 1 year postoperatively. The scans were superimposed, radial measurements calculated, and the changes illustrated by two separate colour scales. There was no constant pattern of movement in the maxilla or mandible in these patients. However, following a Le Fort 1 osteotomy there was commonly a 1:1 ratio in the midline which increased to 1.25:1 at the alar bases and over the canine regions bilaterally. There was also a 1.25:1 ratio or greater over the chin and mentalis regions following mandibular set back.

Adult↗
PubMed1992

Le Fort I maxillary osteotomy: is it possible to accurately produce planned pre-operative movements?

The planned preoperative maxillary movements for five groups of patients requiring orthognathic surgery were prospectively compared to the actual surgical movements achieved in the operating theatre. There was a very poor success rate in achieving predicted movements in all the patient groups. There is a need to test and implement a reliable method of assisting the surgeon in spatially orientating the jaws on the operating table.

Cephalometry↗
PubMed1992

A three-dimensional soft tissue analysis of 16 skeletal class III patients following bimaxillary surgery.

A three-dimensional soft tissue study of the results of surgery in a group of 16 skeletal Class III adult patients following orthognathic surgery was carried out using laser scans (Arridge et al., 1985). The patient group was compared to a control group of the same population. Laser scans were taken prior to surgery, 3 months post-surgery, and at least 1 year after retention. Preoperative comparison to the control groups revealed that the facial disproportion related to both the maxilla and the mandible. Le Fort I advancements resulted in broadening of the lateral aspects of the nose, advancement of the dorsum, and overcorrection of the alar bases. There was a degree of change over the cheeks bilaterally, because of alterations in the general drape of the soft tissues. There was a degree of overcorrection in the female group following mandibular set back but the male group were still more prognathic, when compared to the control group. There was a marked degree of relapse in the mandible from 3 months to 1 year postoperatively, with a resultant anterior movement of the maxillary arch. Laser scanning has proved to be a simple non-invasive method of measuring three-dimensionally, and is a very useful tool in auditing surgical outcome and measuring surgical relapse.

Adult↗
PubMed1992

Stability of surgical correction of patients with Skeletal III and Skeletal II anterior open bite, with increased maxillary mandibular planes angle.

The surgical correction of eleven Class III patients and 10 Class II patients with a long face, increased maxillary mandibular planes angle and anterior open bite was undertaken using bimaxillary surgical procedures. Lateral skull radiographs were examined pre-operatively, 48 hours, and 1 year post-operatively, to quantify the amount and direction of surgical change achieved and the subsequent stability. There was no consistent pattern in the actual movements achieved in either group of patients in the maxillae or the mandibles. Some of the cases being impacted and continuing to impact, others impacting then relapsing. In the Class III patients some of the mandibular set backs remained stable others relapsing and some continuing to move posteriorly. However, despite these inconsistent patterns, there was a 7-degree reduction in the maxillary mandibular planes angle which relapsed by 1.7 degrees over the first year. The overbite was increased from -6 mm to +3.1 mm post-operatively and this relapsed at the 1 year stage to +2.4 mm. The overjet reduced from -4 to 1.7 mm and continued to improve to -0.9 mm at the 1-year stage. In the Class II patients some of the mandibular advancements remained stable others relapsing and some continuing to advance. However, despite these inconsistent patterns there was a 9-degree reduction in the maxillary mandibular planes angle which reduced by a further degree at the 1 year stage. The overbite was increased from -4.6 to -1.6 mm post-operatively and this remained stable at the 1 year stage.(ABSTRACT TRUNCATED AT 250 WORDS)

Cephalometry↗
PubMed1992

The analysis of profiles using curvature analysis.

The difficulties of localizing landmarks using standardized lateral skull radiographs has been acknowledged. A method is described for producing an objective way of identifying landmarks on the facial profile leading to a useful segmentation and quantitative description of the contours and features of the face. The method uses scale space filtering techniques and curvature analysis, first employed in pattern recognition. The method has been used on two groups: a random sample of twelve-year-old females and a sample of 10 patients with a normal facial morphology who had cephalometric X-rays taken at 5, 9, 13, 16, and 20 years. It demonstrated that the shape of each of the curves is similar in the first group except in the mouth region. The growth study produced meaningful data on the growth of the face.

Adolescent↗
PubMed1992

Detection of polymorphic loci in Arachis germplasm using random amplified polymorphic DNAs.

The development of easily scoreable genetic markers in Arachis will facilitate the introgression of desirable traits from wild species into adapted germplasm. We have used random amplified polymorphic DNAs (RAPDs) to identify polymorphic molecular markers in a range of wild and cultivated Arachis species. From a total of sixty 10-mer oligonucleotide primers, 49 polymorphic loci were identified between cultivated A. hypogaea type (TMV-2) and a synthetic amphidiploid (B x C)2 created from a A. batizocoi and A. chacoense cross. The inheritance of polymorphic markers, both in the amphidiploid and in the F1 progeny in a TMV-2 x (B x C)2 cross, has also been demonstrated. The potential exploitation of RAPD markers in groundnut improvement programs is discussed.

Arachis↗
PubMed1991

A mathematical method for the comparison of three-dimensional changes in the facial surface.

Many attempts have been made to measure and compare the changes in the facial surface brought about by facial reconstructive surgery. Three-dimensional (3-D) analyses have largely consisted of qualitative descriptions rather than a quantitative treatment of these changes. Until recently, the lack of availability of 3-D data for the face and head has limited the advancement of these techniques. However, with 3-D information readily available from a laser scanning system which we have constructed, a technique has been applied which describes mathematically the facial shape and changes occurring in the face in terms of fundamental surface types. The method is described and used to compare the faces of two patients (one a cleft palate patient and the other a long-face, Class II malocclusion patient) before and after surgery along with the clinical description of the surgery, the resulting facial changes, the actual surgery performed, and the predicted surgical expectation. A strong relationship is found between the surface type description and the clinical observations. The implications of the method for surgery, facial aesthetics, and other disciplines are discussed.

Cleft Lip↗
PubMed1991

Methods of three dimensional analysis of patients with asymmetry of the face.

One of the problems of patients with facial asymmetry is that two dimensional analysis of such patients does not give a satisfactory picture of the underlying problem. Various methods have been suggested to overcome this problem, such as stereophotogrammetry (Burke et al. 1983) and Moire fringes (Takasaki 1970, Xenofos and Jones 1979). These methods are time consuming and are not fully automated. At present no 3D method is available which provides a readily analysable, global description of change in the face due to the limitations of the techniques which have been used. The 3D changes in shape of the face which occur during growth and with surgical intervention remain undetermined, either qualitatively or quantitatively. Although the importance of such a development has been pointed out, no method of 3D analysis has been developed. (Cutting et al. 1986). Attempts at three dimensional (3D) measurement of the face for monitoring the growth of children with facial deformities usually use hazardous and invasive techniques of ionizing radiation and metallic implants to assess the growth of the skull. Over the past 10 years the Departments of Orthodontics and Medical Physics and Bio-Engineering at University College London have collaborated in the development of a computer graphics based 3D system for the simulation, planning and prediction of maxillo-facial surgery. The laser scanning system developed measures over 20,000 points over the surface of the face in 10 seconds using a non-invasive and completely non-hazardous technique (Arridge et al. 1985, Moss et al. 1987, Moss et al. 1988). The data acquired is accurate to approximately 0.5 mm. Analytical programmes have been developed to handle the enormous quantity of data produced. These programs form the basis of a practical, user-friendly, clinical system whose performance has been evaluated and is now in routine use (Moss et al. 1989).

Cephalometry↗
PubMed1979

Consistent, effective technique for muscle and nerve biopsy.

Muscle and nerve biopsy provides information of increasing importance in the management of neuromuscular disorders. A simplified technique is presented that yields a specimen which equals and often surpasses in quality specimens obtained by more complex methods that require specially designed clamps and forceps.

Biopsy↗
PubMed1979

Bilary tract exploration via T-tube tract: improved technique.

A total of 40 cases referred for postoperative reexploration of the biliary tract via the T-tube trace was reviewed. In selected cases, a modified technique of dilatation of the T-tube tract or bile ducts and endoscopy via the T-tube tract was used. Dilatation of the T-tube tract is a relatively simple procedure that was necessary in over one-half of our cases, since the retained stone was larger than the T-tube inserted during surgery. A new T-tube with a larger external limb was developed in order to reduce the necessity for dilatation of the biliary-cutaneous fistulous tract. Fiberoptic endoscopy of the biliary system via the T-tube tract offers another means for removing large or impacted stones and for investigating mucosal defects. This modified technique has reduced the number of patients requiring surgical reexploration.

Biliary Tract Diseases↗
PubMed1978

Unsuccessful postoperative extraction of retained common duct stones: an analysis.

An analysis of unsuccessful extractions of retained biliary calculi using basket catheters reveals more than half the failures are related to the selection, placement, and size of the T tube. A new T tube has been developed which will improve postoperative access to the common duct and facilitate removal of retained calculi.

Adult↗
PubMed1978

Strongyloides stercoralis colitis: findings in four cases.

The 4 cases of Strongyloides stercoralis colitis presented show various radiological manifestations of colonic reaction. Mild involvement may be associated with minimal radiographic changes. Invasion of the bowel wall by the larvae results in ulceration and edema with loss of haustral markings; stricture may develop. Barium-enema examinations can help in evaluating the nature and clinical progress of the disease.

Colitis, Ulcerative↗