Biomedical subjects
Publications and source records attributed to D G Woodside.
Posterior occlusal bite blocks of varying thicknesses inserted in seven juvenile and six adolescent monkeys resulted in changes in maxillary position and dental intrusion.
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It has been recognized for many years that muscle function influences bone formation and morphology. It is hypothesized here that the movement of bone into new positions within a muscle system results in rearrangement of the stress distribution and reorganization of shape and internal structure. To test the above hypothesis, clinical and animal experiments involving the use of posterior occlusal bite blocks, Herbst appliances, and temporal and masseter muscle stimulation were undertaken. Chronic or continuous alteration in mandibular position within the neuromuscular environment with the posterior occlusal bite block and the Herbst appliance in a sample of monkeys produced extensive condylar remodeling and change in mandibular size. Short periods of induced hyperactivity in the masseter and temporal muscles were associated with the production of malocclusion symptoms. Excess induced temporal muscle activity of specific frequency and intensity may interfere with the remodeling of bone grafts placed under the temporal muscle, while a lesser level of activity was associated with bone remodeling.
A custom fiberglass facemask was designed for cynomolgus monkeys to protect an orthodontic appliance. The mask was constructed from impressions and models made of the animal's head. It prevented the fingers from entering the mouth to dislodge the intra-oral appliances. The facemask permitted normal physical activity, eating, and drinking.
This study will report on some of the conditions necessary for the presence of short or diminishing lower anterior face height and test the relationship between it and selected facial and occlusal variables. The sample consisted of 120 males with complete longitudinal orthodontic records at the ages of 6, 9, 12, 14, 16, 18 and 20 years obtained from the serial experimental sample of the Burlington Growth Centre, Toronto, Canada. In addition, a sample of 162 Swedish children between the ages of 6 and 12 years with a mean age of 8 years was used to calculate correlations between airflow through the nose, mode of breathing and selected skeletal variables. The following results were observed: 1. The prevalence of small or diminishing lower anterior face height compared to the upper anterior face height was 26% in the total sample of 120 males. This represents an estimate of the prevalence of overclosure in a population of Canadian males. 2. The association between respiratory pattern and small lower anterior face height relative to upper anterior face height showed that the percentage of individuals with a clear nasal airway was 90% while 100% of the sample showed an unobstructed pharyngeal airway. Thus a clear airway may be a necessary prerequisite for the establishment of overclosure. 3. Correlation analyses showed significant negative correlations between the lower anterior face height, the overbite and the airflow through the nose. 4. Three case reports may illustrate the interrelations between mandibular growth direction expressed at the chin and environmental factors such as oral respiration. 5. The association between small or diminishing lower anterior face height and selected facial variables showed the midface normally positioned in the majority of individuals. 6. The mandibular growth direction expressed at the chin was more horizontal in overclosed cases. 7. The gonial angle was more acute in overclosed individuals in relation to population standards.
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Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.