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Biomedical subjects

C Phillips

Publications and source records attributed to C Phillips.

At least 253 records · Page 14Linked to original sources
PubMed1984

Facial pattern differences in long-faced children and adults.

Vertical facial morphology has traditionally been studied by examining subjects chosen because of open bite/overbite or mandibular plane angle. The underlying skeletal and dental morphology associated with clinical facial appearance of normal and vertically dysplastic children and adults has not been well documented. The purposes of this study were to (1) describe vertical facial morphology in long-, normal-, and short-faced children and long-faced and normal adults, and (2) identify morphologic factors associated with the clinical evaluation of long-faced and normal subjects. Forty-two children, 6 to 12 years old, and forty-two young adults with varied vertical facial types were examined clinically and separated into three vertical classifications: long, normal, or short face. Lateral cephalometric radiographs were obtained in natural head position and seven angular, eighteen linear, and six ratio measurements were made. Descriptive statistics were used to characterize all groups, and intergroup differences were compared using analysis of variance for the three child groups and the t test for the two adult groups. For both long-faced children and adults, anterior total face height, mandibular plane angle, gonial angle, and mandibulopalatal plane angle were significantly greater than normal. Ramus height was not significantly different from normal in the children, but there was a tendency for long-faced adults to have short rami. Excessive dentoalveolar development was evident in long-faced children but not in adults. Factors associated with the clinical identification of vertical dysplastic subjects were identified by a principal component analysis. For each component, a variable highly correlated with that component was selected.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1984

Photocephalometry: errors of projection and landmark location.

A method called photocephalometry was recently described for the possible soft-tissue evaluation of orthognathic surgery patients by the superimposition of coordinated cephalographs and photographs. A grid analysis was performed to determine the accuracy of the superimposition method. In addition, the reliability of landmark identification was analyzed by the method error of Baumrind and Frantz, using three replicates of twelve patients' photographs. Comparison of twenty-one grid intervals showed that the magnification of the photographic image for any given grid plane is not correlated to that of the radiographic image. Accurate comparisons between soft- and hard-tissue anatomy by simply superimposing the images are not feasible because of the difference in the enlargement factors between the photographs and x-ray films. As was noted by Baumrind and Frantz, a wide range exists in the variability of estimating the location of landmarks. Sixty-six percent of the lateral photographic landmarks and 57% of the frontal landmarks had absolute mean errors for all twelve patients that were less than or equal to 2.0 mm. In general, the envelope of error for most landmarks was not circular. Although the photocephalometric apparatus as described by Hohl and colleagues does not yield the desired quantitative correlation between hard and soft tissues, valuable quantitative information on soft tissue can be easily obtained with the standardization and replication possible with the camera setup and enlarged photographs.

Adult↗
PubMed1984

The conserved nucleotide sequences of Bkm, which define Sxr in the mouse, are transcribed.

We have recovered a conserved transcribed component of the snake W chromosome satellite DNA (Bkm) from Drosophila and male mouse libraries. This consists of repeats of the tetranucleotide GATA that are concentrated in the sex-determining region of the Y chromosome of mouse, on the W chromosome of snakes, and in the proximal region of the X chromosome of D. melanogaster, and it appears to be transcribed in a sex-specific and developmentally regulated manner. Sequencing studies show that, unlike most other transcribed repeats, the GATA repeats potentially contain open reading frames. These encode mainly the amino acids leucine, serine, isoleucine, and tyrosine but with occasional variant codons that differ in different clonal isolates. Transcription is exclusive to the GATA strand in different tissues of the same organism and in different unrelated organisms. The complementary strand CTAT contains stop codons in all reading frames. The possible developmental significance of these sequences is discussed.

Amino Acids↗
PubMed1983

A survey of radiographs obtained at the initial dental examination and patient selection criteria for bitewings at recall.

This paper reports the results of a 1980 survey of a 27% simple random sample of all practicing dentists in North Carolina. The objective of the survey was to establish current practice standards regarding panoramic, full-mouth series, and bitewing radiographs. A total of 414 dentists (76.2% of those surveyed) responded. A questionnaire recorded demographic data on the dentists, age-specific prevalence data on the type of radiograph most often done at a patient's initial visit, and prevalence of radiographs based on need as perceived by the dentist and assessed separately for a variety of patient characteristics (age, oral hygiene, caries activity, fluoride treatment, and systemic medical problems). Results of the survey of a subset of 338 dentists in general practice showed the median age to be 40 with a median length of experience of 13 years. At an initial visit, for patients younger than 12, bitewing radiographs only were most commonly taken; for patients older than 12, bitewings plus a panoramic radiograph were taken. Full-mouth series plus bitewings were rarely performed among patients younger than 6 years (2.1% of the time), but were more commonly performed as patients aged (29.0% for patients aged 40 and older). A variety of patient characteristics were considered for their impact on the need for bitewing radiographs on recall. Caries activity was ranked most important by the general dentist, followed by oral hygiene and periodontal activity.

Adolescent↗
PubMed1982

Morphologic alterations in Macaca mulatta following destruction of the motor nucleus of the trigeminal nerve.

In two adolescent male Macaca mulatta monkeys, small unilateral electrolytic lesions were produced in the motor nucleus of the trigeminal nerve. The side contralateral to the muscle paralysis served as the control side. The animals were killed 130 and 300 days postoperatively. One animal (animal A) was prepared as a dry skull preparation. Alterations in craniofacial form were noted clinically in both animals and included paralysis and atrophy of the muscles of mastication on the lesion side and mandibular asymmetry. In animal A (300 days postoperative survival), alterations in form included dental and mandibular asymmetry, the appearance of an anterior open-bite on the affected side, and a decrease in the size of the intratemporal fossa on the affected side. Remodeling changes were evident in the condylar process, the zygomatic arch, the orbit, and the zygomaticotemporal and zygomaticofrontal sutures on the lesion side but were not apparent on the contralateral side.

Animals↗
PubMed1982

A 2-year longitudinal study of overdenture patients. Part II: Assessment of the periodontal health of overdenture abutments.

Eighty-nine patients were examined at 1- and 2-year intervals after treatment with overdentures. The measurements of gingival index, pocket depth, plaque index, and mobility showed little change in the 2-year period. The initial gingival health of some teeth was less than optimal, but the periodontal health did not deteriorate and no teeth were lost during the observation period. The elevated plaque scores of this group of patients clearly shows that periodontal health of the abutments was affected, emphasizes the importance of adequate follow-up care and the need for constant reinforcement of home care instructions. As with any form of dental treatment, proper patient selection is an important step when overdentures are a treatment consideration. Patients should be able to demonstrate that they are motivated and have the ability to clean their teeth. It is doubtful that patients will change their oral hygiene habits after the denture is inserted, and poor hygiene may lead to a loss of abutment teeth from caries and/or periodontal disease.

Adult↗
PubMed1982

Hand involvement in psoriatic arthritis.

From a population of 105 patients with confirmed psoriatic arthritis, 25 patients required hand surgery. These 25 surgical patients were evaluated retrospectively both clinically and radiographically. The patterns of hand and wrist involvement as well as the results of surgery differed from those typically seen in rheumatoid disease. Spontaneous fusion of the wrist in a functional position, severe proximal interphalangeal involvement often with marked flexion contractures, severe erosion of the distal interphalangeal joint with spontaneous fusions, and generalized stiffness characterize these hands. Minimal improvement in motion and a significantly increased incidence of infection following arthroplasty were noted.

Arthritis↗
PubMed1982

Preliminary study of the effects of carbamazepine on congenital orofacial defects in offspring of A/J mice.

Carbamazepine (CBZ; Tegretol) is an effective anticonvulsant drug. We assessed putative CBZ teratogenicity in a sensitive animal model, the A/J mouse. Plasma CBZ levels were determined by gas-liquid chromatography. To achieve the accepted human plasma therapeutic range (TR) of CBZ (8-12 micrograms/ml), up to a 6X human oral dose was given. Test Group A received 300 mg pure crystalline CBZ/kg, suspended in 1.25% carboxymethylcellulose (CMC), at 6 a.m., noon, 6 p.m., and midnight on gestational day 10 (previously determined to be the peak sensitive time for cleft lip and palate induction in the A/J) and at 6 a.m. on day 11. Test Group B received 150 mg/kg of an experimental CBZ elixir (Tegretal Sirup) on the same regimen. Plasma levels rose to above TR within 15 min, then fell steadily, exiting the TR by 5 hr postgavage. Test Group C was given the experimental CBZ elixir at 4-h intervals for 36 hr. The rapid rise and fall of CBZ plasma levels again occurred, but the time within the therapeutic range was greatly increased (through 6 p.m. day 11). Control groups received the appropriate quantity of the CMC vehicle. Fetuses were harvested on day 17. Compared to control animals, none of the CBZ regimens was associated with a major increase in incidence of cleft lip or palate.

Abnormalities, Drug-Induced↗
PubMed1980

Synthetic luteinizing hormone-releasing hormone in impotent male diabetics.

We compared the effect of luteinizing hormone-releasing hormone (LH-RH) 500 micrograms 8-hourly and placebo on sexual function in impotent diabetic males. These patients had no obvious vascular or neurological disease and no major psychological disorders to account for their impotence. Basal serum testosterone concentrations were normal in all. Five patients had elevated basal gonadotropin concentrations and/or exaggerated gonadotropin responses to LH-RH. During the first week of the LH-RH treatment there was a significant rise in LH and follicle-stimulating hormone (FSH) concentrations. The LH levels remained elevated throughout the second week of treatment, whereas the FSH returned to pretreatment values. There was no change in hormone concentration during placebo therapy. Clinical responses to treatment were assessed by a self-evaluating questionnaire relating to (i) sexual function and libido; (ii) erectile potency; and (iii) general well-being. There was no significant change within each category, but taken together a significant improvement was found with both LH-RH and placebo treatment. There was no difference between the two forms of treatment.

Adult↗
PubMed1980

Experimental manipulation of head posture.

Variations in natural head position have been noted by previous workers to be associated with both dentoalveolar and craniofacial skeletal morphologic features. The determinants of cranial posture are as yet not known. Three experiments are described, dealing with the influence of (1) total nasal obstruction, (2) visual feedback deprivation, and (3) a combination of (1) and (2) on the posture of the cranium measured relative to a gravity-defined true vertical reference plane. The results indicate that total nasal obstruction results in all cases in an extended head position. Visual deprivation produces adaptation of a smaller magnitude and unpredictable direction. Combination of both experimentally induced conditions indicates a dominance of the respiratory adaptation in terms of postural response to these stimuli.

Adaptation, Physiological↗
PubMed1979

The effect of splinting on tooth mobility. (2) After osseous surgery.

The purpose of this study was to determine if fixed splinting of teeth with intraoral wire and acrylic splints had advantages with respect to tooth mobility, bone level and attachment level over unsplinted teeth following osseous surgery. Ten patients were chosen who exhibited bilaterally similar chronic destructive periodontitis and mobile teeth. One maxillary sextant was splinted, while the other was unsplinted. Both sextants functioned against an unsplinted mandibular arch. Following initial therapy, osseous surgery was performed in both maxillary sextants on the same day. Tooth mobility data was collected 1 week before and at 3, 6, 12, and 24 weeks following surgery. Levels of gingival attachment and bone were recorded before and 24 weeks after surgery. Splints were removed before measurements, then replaced, and the occlusion refined. Prophylaxes and oral hygiene instruction were repeated every 3 weeks throughout the study. For all categories of teeth and mobility examined, tooth mobility increased initially after surgery and subsequently decreased by 24 weeks to about presurgical values. The splinted and unsplinted segments reacted similarly throughout the study; splinting did not significantly reduce the mobility of individual teeth. Pre- and postsurgical bone and gingival attachment levels were also similar for the splinted and unsplinted segments.

Adult↗
PubMed1979

The effect of splinting on tooth mobility. I. During initial therapy.

The purpose of this study was to assess whether fixed splinting aided in the reduction of posterior tooth mobility during initial therapy. A "split-mouth" approach was used in order to compare splinted segments with similar unsplinted segments. Seven patients were selected, all of whom demonstrated chronic destructive periodontitis and mobile teeth. Initial therapy, consisting of oral hygiene instruction, root curettage and occlusal adjustment, was performed over a 2-week period. At the time of initial therapy, teeth in contralateral segments were splinted with an intracoronal wire-and-acrylic splint. Tooth mobility and gingival inflammation were recorded in all four segments every 3 weeks for a 15-week monitoring period following initial therapy. The splints were removed before each data recording session and then replaced and the occlusion refined. Prophylaxis and oral hygiene instruction were repeated every second week throughout the monitoring period. The reduction in the mobility of teeth splinted during the entire therapy period did not differ from the reduction observed in the unsplinted segments. The reduction in tooth mobility observed in both the splinted and unsplinted segments over the 17-week period can be attributed to the improved occlusal relationships and reduction in inflammation.

Adult↗