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Biomedical subjects

S J Cunningham

Publications and source records attributed to S J Cunningham.

At least 37 records · Page 2Linked to original sources
PubMed1999

An investigation into the effects of polishing on surface hardness and corrosion of orthodontic archwires.

The purpose of this study was to investigate the effect of surface roughness on the relative corrosion rates of wires of four alloys-stainless steel, nickel titanium, cobalt chromium, and beta titanium. Batches of wire were divided into two groups. Wires in one group were industrially polished to provide a uniform surface finish; wires in the other group were left for comparison "as received." Wire diameter, hardness, and relative corrosion rates were compared within groups before and after polishing. Comparisons were also made across the four groups of alloys. The samples of as-received wires showed variations in surface finish, with beta titanium having the roughest appearance and cobalt chromium the smoothest. Nickel titanium and stainless steel surfaces were similar. Polishing provided a more uniform finish, but significantly reduced the diameter of the wires. Microhardness testing of wire surfaces of each alloy indicated that no significant work-hardening occurred as a result of polishing. The relative corrosion rates (expressed in terms of corrosion current density) in a 0.9% sodium chloride solution were estimated using the electrochemical technique of polarization resistance. Nickel titanium wires exhibited the greatest corrosion current density in the as-received state. Polishing significantly reduced the corrosion rate of nickel titanium, such that comparison between the four alloys in the polished state revealed no significant difference in their relative corrosion rate/corrosion current density.

Chromium Alloys↗
PubMed1999

The psychology of facial appearance.

Facial attractiveness is now recognized as being important in situations as diverse as education, relationships and employment. An individual's facial appearance is one of their most obvious characteristics and facial disfigurements are judged to be among the least desirable 'handicaps'. A face which deviates from the norm becomes a stigma. This paper looks at the complex area of facial appearance and its importance in the field of dentistry. The relationship between facial attractiveness and varying forms of dental and surgical intervention are discussed, as well as some of the problems which may be encountered during treatment.

Craniofacial Abnormalities↗
PubMed1999

Providing immunizations in a pediatric emergency department: underimmunization rates and parental acceptance.

OBJECTIVES: To assess the vaccination status and vaccinate eligible children with age-appropriate antigens. DESIGN: Intervention. SETTING: Pediatric emergency department in an urban, public hospital. PATIENTS: Convenience sample of children, aged birth through 72 months. INTERVENTIONS: Immunization of eligible children. MAIN OUTCOME MEASURES: 1) Immunization coverage rates in the sample population, 2) Acceptance rates of immunization. RESULTS: A total of 9321 children were enrolled over a 2-year period. Fifty-nine percent were documented to be underimmunized. Overall, 2514 children received a total of 6482 immunizations. Parents who carried portable immunization cards documenting that their child was underimmunized were almost five times more likely to accept immunization for their child than parents who lacked documentation (71% vs 15%, P < 0.0001). The estimated cost of providing immunizations in the emergency department was $47.15 per child immunized, or $18.56 per immunization given. CONCLUSIONS: The majority of children with documentation of immunization status were underimmunized. When documentation of underimmunization was available, parents were significantly more likely to accept vaccination. These data suggest that vaccinating children in nontraditional settings is feasible and support the creation of an accessible vaccine registry.

Child↗
PubMed1999

Soft tissue changes associated with incisor decompensation prior to orthognathic surgery.

A retrospective cephalometric study employing angular and linear measurements was undertaken to examine soft tissue changes associated with incisor decompensation prior to orthognathic surgery. Subjects were divided into 3 groups based on the presenting malocclusion, and radiographs for each subject were traced and subsequently digitized. The results showed that incisor decompensation was achieved more markedly in Class II division 2 and Class III patients. In Class II division 1 subjects, changes in the mandibular incisor inclination were contrary to what was anticipated. The soft tissue change/dental change ratio following incisor decompensation showed that the soft tissues were least affected in the Class II division 2 group. This may be due to the increased tone of the soft tissues in this group, which resisted the effects of the incisor change. Alternatively, it may indicate that the soft tissue "drape" is not in close approximation to the dentition and therefore dental changes are not transmitted to the soft tissues.

Cephalometry↗
PubMed1999

A comparison of the perception of facial profile by the general public and 3 groups of clinicians.

Orthodontists and maxillofacial surgeons frequently plan orthognathic treatment to produce an "ideal" Class I occlusion and skeletal relationship. The aim of this study was to investigate whether the preferred facial profile chosen by orthodontists, maxillofacial surgeons, dental students, and members of the general public conformed to a Class I profile. Photographs were taken of 2 male and 2 female adult subjects with Class I profiles, and by means of a computer program the images were manipulated to produce Class II, Class III, and long face profiles. The orthodontists, surgeons, dental students, and members of the general public ranked each group of 4 photos in order of their attractiveness. Orthodontists and maxillofacial surgeons were found to be significantly more likely to choose a Class I skeletal relationship as the most attractive profile. A significant difference was found between orthodontists and dental students (P < 0.01) and between orthodontists and the general public (P < 0.001) with regard to the assessment of the Class I profile as the most attractive, when all 4 subjects were considered. Similar results were noted for maxillofacial surgeons. Whether the assessor was an orthodontist, maxillofacial surgeon, or a member of the general public was found to be significant when examining subjects 1 (female) and 3 (male). The sex of the assessor was also a significant factor for subject 3 (male), where female assessors were more likely to rank the Class I profile as most attractive (P < 0.05).

Adult↗
PubMed1998

The use of kinesiography to assess mandibular rest positions following corrective orthognathic surgery.

This study utilized the kinesiograph to assess the effect of orthognathic surgery on mandibular rest positions in a group of 27 patients exhibiting vertical facial deformities (14 long faced and 13 short faced patients). Two distinct rest positions were confirmed--clinical and physiological. Following surgery to alter the vertical dimensions, the clinical freeway space was found to adapt immediately whereas the physiological rest position partially adapted in the immediate postoperative period and continued to do so over the following year.

Adaptation, Physiological↗
PubMed1998

The effect of two alternative methods of canine exposure upon subsequent duration of orthodontic treatment.

OBJECTIVES: The aim of this study was to compare the effectiveness, in terms of orthodontic treatment duration, of two methods of canine exposure. DESIGN: This was a retrospective study using patients' records and lateral cephalometric radiographs. SAMPLE AND METHODS: 50 patients were selected, 25 in each group. In all subjects the impaction was categorized as being 'intermediate'. The methods of canine exposure were: (i) simple surgical exposure; (ii) surgical exposure and placement of an orthodontic attachment, followed by flap replacement. RESULTS: The treatment duration until the canine was in the line of the arch was 17.7 months in the simple exposure group and 19.3 months in the bonded attachment group. The mean treatment duration (from exposure to debond) was 28.8 months for both groups. CONCLUSIONS: In terms of treatment duration, no significant difference could be demonstrated between the two methods of surgical exposure to palatally impacted canines.

Adolescent↗
PubMed1998

Psychological assessment of patients requesting orthognathic surgery and the relevance of body dysmorphic disorder.

The psychological assessment of patients requesting orthognathic treatment is a vital and integral part of the overall assessment procedure. It allows identification of potential problems at an early stage before irreversible decisions have been made. This paper aims to highlight some of the aspects of psychological assessment which are particularly important. It also discusses current concepts in the diagnosis and treatment of those patients suffering from body dysmorphic disorder (BDD). This is the term applied to those individuals with a normal appearance who present requesting treatment because they believe that they have a 'defect'.

Humans↗
PubMed1998

Parental perceptions of access to care and quality of care for inner-city children with asthma.

The objective of this study was to describe perceptions of asthma care, morbidity, and health service utilization by parents of children with asthma presenting to an inner-city emergency department (ED). A cross-sectional survey was conducted in an urban pediatric ED, with a convenience sample of 466 parents of children receiving asthma treatment during a consecutive 6-week period in late fall 1995. Parents completed a 30-item survey including sociodemographic data, source of primary medical care and asthma care for their child, selected measures of access to care, and medications used by their child in the week prior to the ED visit. Perceived quality of asthma care was measured by six items (summary score = 0-6) reported to have been performed by the child's asthma doctor: discussion of home peak flow monitoring, child-specific triggers, dogs/cats, smoke, postexacerbation calling instructions, and provision of a written asthma management plan. Functional morbidity was measured by nights of poor sleep, days of cough, and school days missed due to asthma in the previous month. Among 325 patients with previously diagnosed asthma, 308 (97%) were reported to have a source of primary medical care. Of these, 126 respondents identified their primary care provider as the child's usual source of asthma care, while 158 identified the ED as the usual source. The groups did not differ by insurance status, ethnicity, or mean age of the child. Thirty-nine percent of children with the same provider for primary and asthma care compared with 15% of children reported to receive their asthma care predominantly in the ED had used inhaled steroids or cromolyn in the week prior to the ED visit (p < .0001). Children with the same provider for primary and asthma care had a higher mean quality score than children receiving asthma care in the ED (3.7 vs. 2.8, p < 0.0001), but there was no relationship between source of asthma care and functional morbidity. The ED remains the usual source of asthma care for many inner-city children. Among parents surveyed in the ED, there was a significant relationship between source of usual asthma care and quality of care, but a relationship between usual source of asthma care and functional morbidity could not be identified.

Adult↗
PubMed1998

Stability of mandibular incisor decompensation in orthognathic patients.

This retrospective cephalometric study examined the stability of mandibular incisor decompensation following orthognathic treatment. It also studied the relationship between the mandibular incisor-mandibular plane angle (LIMnp) and the maxillary-mandibular planes angle (MMA). Two groups of 22 subjects each underwent either mandibular advancement only or bimaxillary surgery with mandibular setback. Serial radiographs of each subject were digitized. Twenty-seven Class I subjects who were part of the Leighton Growth Study served as the control. The control group showed a significant association between LIMnp and MMA. For the surgical groups, the only significant relationship between LIMnp and MMA was seen in the mandibular advancement group at debond. No definite indicator was found to suggest that the final MMA dictates the amount of mandibular incisor relapse following debond. Only the bimaxillary group showed an association between changes in LIMnp and changes in MMA during the review period.

Adult↗
PubMed1997

The influence of orthognathic surgery on occlusal force in patients with vertical facial deformities.

This study utilized bite-force measurements to determine the effect of various orthognathic surgery procedures on occlusal force generation in 42 patients with vertical facial deformities. The results showed that orthognathic surgery produced marked alterations in occlusal force levels which continued to occur up to a year after surgery. Measurements indicated that advancement of the mandible may result in weaker force levels, while bimaxillary surgery for the treatment of a "long face" brings the previously weaker bite force to a more "normal" level.

Adult↗
PubMed1996

Dysmorphophobia: recent developments of interest to the maxillofacial surgeon.

Recent changes in the classification of psychiatric illnesses have resulted in the term dysmorphophobia being replaced by that of body dysmorphic disorder (BDD). This paper attempts to alert the clinician to the presenting features of the condition and discusses its management, with particular emphasis on the role of surgery and current concepts of pharmacological treatment. A number of case reports are included to illustrate the diversity of this interesting disorder and the difficulties involved in treatment.

Adolescent↗
PubMed1996

Perceptions of outcome following orthognathic surgery.

The definition, evaluation and assurance of quality of health care are becoming increasingly important with health care moving into purchaser/provider mode. This questionnaire based study investigated patient satisfaction and changes in their quality of life following joint orthodontic/surgical treatment for the correction of facial deformity. Questionnaires were distributed to 83 pre-operative and a separate group of 100 postoperative patients with data analysis involving comparison of pre- and postoperative mood states and opinions about various aspects of appearance and personality. The results indicated that the majority of respondents were happy with the outcome of treatment. There was significant improvement in appearance, as well as in self-confidence, overall mood states and the ability to mix socially. The majority of respondents felt that the technical aspects of the operation had been well explained but almost a quarter felt that the effects following surgery were badly explained. Pre-operative counselling, therefore, needs to be improved.

Affect↗
PubMed1996

Thyrotropin (TSH) receptor antibodies (TSHrAb) can inhibit TSH-mediated cyclic adenosine 3',5'- monophosphate production in thyroid cells by either blocking TSH binding or affecting a step subsequent to TSH binding.

In the present study, rabbit antibodies that possess thyroid stimulation-blocking activity were used to investigate potential mechanisms by which TSH receptor antibodies can inhibit thyroid cell function. The antibodies were produced against two synthetic peptides corresponding to amino acids 357-372 (p357) and 367-386 (p367) of the human TSHr (hTSHr). By enzyme-linked immunosorbent assay, both antisera (alpha 357 and alpha 367) had high titers ( > 1:100,000) of IgG against their respective peptides and recombinant extracellular TSHr protein (ETSHr); alpha 357 had a low IgG titer to p367 (1:800), and alpha 367 had a low IgG titer to p357 ( < 1:200). Based on competitive inhibition studies, alpha 357 and alpha 367 displayed similar relative binding affinities for their respective peptides and for recombinant ETSHr. When tested by commercial RRA, alpha 357 did not block (TSH binding inhibition index, -3.7%), whereas alpha 367 blocked TSH binding to TSHr (TSH binding inhibition index, 53.9%). The blocking effect of alpha 367 could be reversed by incubating the antiserum with p367 before assay. When applied alone to FRTL-5 cells, IgG from alpha 357 inhibited [compared to normal rabbit IgG (NRI); P < 0.01] based cAMP production by the cells, whereas IgG from alpha 367 did not. IgG from both alpha 357 and alpha 367, however, were able to inhibit (P < 0.001) TSH-mediated cAMP production by FRTL-5 cells [bovine (b) TSH, 2.5 x 10(-10) M; cAMP (mean +/- SD; picomoles per ml): NRI, 62.5 +/- 6.1; alpha 357, 12.2 +/- 2.4; alpha 367, 36.2 +/- 3.5]. Alpha 357 continued to inhibit (P < 0.05) cAMP production by FRTL-5 cells in 10(-8) M bTSH, whereas alpha 367 no longer inhibited cAMP production at bTSH concentrations above 5 x 10(-10) M. Compared to NRI, both alpha 357 and alpha 367 were also able to inhibit (P < 0.001) Graves' IgG-mediated cAMP production by FRTL-5 cells. When IgG were tested on FRTL-5 cells in the presence of 10(-7) M forskolin, only alpha 357 inhibited (P < 0.001) cAMP production (NRI, 75.1 +/- 4.8; alpha 357, 52.3 +/- 4.5; alpha 367, 77.2 +/- 1.4). To determine whether the inhibitory effect of alpha 357 on forskolin-mediated stimulation was thyroid cell dependent, IgG were tested on Chinese hamster ovary (CHO) cells transfected with the complementary DNA of the hTSHr (CHO-R). Again, alpha 357 inhibited (P < 0.005) cAMP production mediated by forskolin (at 10(-7) M; NRI, 68.7 +/- 4.4; alpha 357, 36.8 +/- 5.7; alpha 367, 64.6 +/- 8.5). alpha 357 did not inhibit forskolin-mediated cAMP production by untransfected CHO cells (CHO-N), indicating that the inhibitory effect of alpha 357 on forskolin stimulation was TSHr dependent. In addition, alpha 357 inhibited (P < 0.01) basal cAMP production by CHO-R cells, but not by CHO-N cells. alpha 367 had no effect on the basal cAMP production in either CHO-R or CHO-N cells. Neither alpha 357 nor alpha 367 inhibited cholera toxin-mediated cAMP production in FRTL-5 cells. In all relevant bioassays, the inhibitory effects of alpha 357 and alpha 367 could be reversed by preincubating the IgG with the respective peptides. From these data, we conclude that 1) alpha 367 binds to the ETSHr and blocks TSH-mediated cAMP production by inhibiting TSH from binding to its receptor; 2) alpha 357 binds to the TSHr and, without blocking TSH binding, inhibits TSH-mediated cAMP production at a step(s) subsequent to ligand binding that affects adenylate cyclase activity; and 3) forskolin-mediated cAMP production by thyroid cells can be inhibited by IgG that bind directly to the TSHr.

Animals↗