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Biomedical subjects

Peter Herbison

Publications and source records attributed to Peter Herbison.

41 records · Page 3Linked to original sources

Patterns of emergence of the human mental nerve.

This study investigated the path of emergence of the mental nerve in a number of human population groups. Skeletal material comprised 117 Negro skulls (53 males), 114 caucasoid skulls (62 males) and 100 pre-contact Maori skulls (70 males). In each case, the path of emergence was classified into posterior, anterior, right-angled or multiple. Those cases with severely resorbed alveolar ridges that made classification difficult were excluded from the study. Additionally, 56 cadaveric mandibles were examined, in which an osteotomy of 1cm was made on either side of the mental foramen to expose the nerve. The most common pattern of emergence in caucasoids and Maoris was a posterior direction (86.7% of caucasoid males, 90.2% of caucasoid females; 85.5% of Maori males, 93.1% of Maori females). In Negroes the most common pattern was a right-angled path of emergence (45.8% of males, 45.0% of females), with this difference between population groups being statistically significant (Pearson's chi(2): males=23.4, females=45-97; P<0.01). Multiple foramina were rare, with the highest incidence being in Maori and Negro males. Cadaveric data supported the findings of the skeletal investigation, with the dominant emergence recorded as posteriorly directed (80.7% of males, 86.6% of females). It was concluded that while the traditionally accepted ontogenetic explanation for the inclination of the mental nerve might be applicable to caucasoids and Maoris, it fails to explain the observed right-angled emergence pattern in Negroes. Hence, the nerve's emergence might be genetically, rather than functionally, determined. The study did not show a measurable anterior loop in the emergence of the mental nerve that would have any significant impact on treatment planning for implants in the anterior mandible.

Aged↗

Context rich problems in oral biology teaching.

Problem-based learning (PBL) has now been introduced in at least one of its various taxonomic forms in most dental curricula. We recently developed a novel form of PBL, referred to as Context Rich Problems, which we implemented in the Oral Biology course at the Otago University Dental School. A unique event, the teaching of second and third year students in the same year, allowed us to evaluate CRPs in these two academic years simultaneously. Our findings showed that second year students were not as positive as more mature third year students in accepting the transition from a traditional didactic form of teaching to PBL. Both groups, however, found that CRPs significantly enhanced their learning experience and both groups found that they needed less time spent on preparation than they had expected. In some respects, such as previous exposure to the web and electronic media, non-New Zealanders had had a significantly higher exposure.

Education, Dental↗

Evaluation of explicit prioritisation for elective surgery: a prospective study.

OBJECTIVES: To evaluate whether the Clinical Priority Assessment Criteria (CPAC), used to prioritise access to elective surgery, was associated with: (a) patients' access to surgery in practice; (b) patients' level of need; and (c) patients' ability to benefit from surgery. Patients' perceptions of the 'booking system' for surgery were also explored. METHODS: Prospective cohort study in New Zealand. Consecutive patients assessed for cataract (n = 101), prostate (n = 103) or hip or knee joint replacement (n = 137) surgery were interviewed close to the time of their CPAC prioritisation, and then six and 12 months later. RESULTS: CPAC scores were associated with access to surgery. There were weak-to-moderate correlations between CPAC scores and disease-specific health status before surgery (need) but almost no correlations with improvement in health status following surgery (ability to benefit). Change in health status was highly correlated with pre-surgery health status. Many patients supported prioritisation according to need, although the impersonal nature of the scoring system and the changing thresholds for surgery distressed some. CONCLUSIONS: While prioritisation systems for surgery have potential value the CPAC criteria investigated need modification. Ability to benefit should receive increased weight. The impact of an explicit prioritisation system upon the doctor-patient relationship needs to be explored as there is some evidence that it may impede the discussion of the risks and benefits of surgery, and of the treatment preferences of patients.

Elective Surgical Procedures↗

Skills retention for insertion of the Combitube and laryngeal mask airway.

OBJECTIVE: To determine if the skills to successfully ventilate using the laryngeal mask (The Laryngeal Mask Company Limited, Henley on Thames, United Kingdom) and Combitube (The Kendall Company, Mansfield, USA) can be retained after seven months. METHODS: Nursing, medical and theatre staff from Dunedin Hospital were recruited in a prospective study. Subjects were taught to insert and ventilate an Ambuman manikin using both devices. Subjects were tested on their ability to ventilate the manikin with both devices within one month then following a six-month period. RESULTS: A total of 101 subjects were recruited with 86 subjects retested at least six months later. Initial testing resulted in subjects successfully ventilating the manikin in 90% (laryngeal mask) and 92% (Combitube) of attempts. At retesting, successful ventilation was achieved in 85% (laryngeal mask) and 77% (Combitube) of attempts. The decline in skills level was significant for the Combitube only (95% CI 4% to 26%). CONCLUSION: The ability to successfully ventilate is better maintained with the laryngeal mask than the Combitube after seven months.

Clinical Competence↗

Ultrasound measurements in the management of unstable hips treated with the pavlik harness: reliability and correlation with outcome.

The purposes of this study were to determine the interobserver and intraobserver reliability of ultrasound measurements in unstable neonatal hips treated with the Pavlik harness and to determine whether ultrasound measurements correlate with radiological outcome at 6 months. Sixty-four babies treated from birth with the Pavlik harness for neonatal hip instability were scanned at 2 and 6 weeks. The alpha and beta angles of Graf, the combined (H) angle of Hosny, and the femoral head coverage (FHC) were measured by 3 observers and remeasured by each observer on a minimum of 50 scans. From 248 scans, 792 sets of measurements were made. Hips were categorized as normal, abnormal, or borderline for each parameter; and interobserver and intraobserver repeatability coefficients and Kappa values were calculated. The alpha angle had the smallest interobserver range (17 degrees), the H angle range was 21 degrees, and the beta angle 28 degrees. Kappa values were best for the FHC and beta angle (0.66-0.8). The mean acetabular index (AI) of all hips at 6 months was 26 degrees (SD, 4.9). The AI was 30 degrees or greater in 24 hips (18 babies) despite prolonged splintage in 9 hips (6 babies). A stepwise linear regression analysis showed that the FHC at 6 weeks was predictive of AI at 6 months (regression coefficient -0.27; 95% confidence interval -0.42 to -0.12; P<0.001). We recommend the FHC as being reproducible, useful, and predictive of outcome in neonatal hips treated for instability.

Hip Joint↗