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Biomedical subjects

Derek Mahony

Publications and source records attributed to Derek Mahony.

11 recordsLinked to original sources
PubMed2006

How we got from there to here and back.

Edward H. Angle dominated orthodontic armamentarium, diagnosis and treatment planning for almost a half century until Charles Tweed successfully challenged his mentor's nonextraction mantra. The ensuing diagnostic regimen used by Tweed, however, proved to have serious limnitations and clearly resulted in the extraction of too many teeth. This caused a subsequent deterioration of soft tissue appearances of patients that neither they nor their doctors liked. This article will describe and illustrate how new expansion techniques differ qualitatively from those of Angle, and how these techniques offer patients and doctors less invasive and more comfortable therapies which do not jeopardize facial appearances.

History, 19th Century↗
PubMed2005

Refining occlusion with muscle balance to enhance long-term orthodontic stability.

The primary objective of orthodontic treatment is the movement of teeth into a more ideal relationship, not only for aesthetic, but also for functional considerations. Another very important objective, often not given enough consideration, is the need to finish the case with the muscles of mastication in equilibrium. If muscle balance is not achieved, an endless procession of retainers is required for retention. In simple terms, if the occlusal forces in maximum intercuspation are unevenly distributed around the arch, tooth movement will most likely occur. Today, however, it is possible to simultaneously and precisely measure the relative force of each occlusal contact, the timing of the occlusal contacts and the specific muscle contraction levels. This technological breakthrough represents a paradigm shift in thinking and may improve orthodontic stability.

Bite Force↗
PubMed2004

Effects of adenoidectomy and changed mode of breathing on incisor and molar dentoalveolar heights and anterior face heights.

BACKGROUND: Mouth breathing may affect facial form and the positions of the teeth. OBJECTIVES: To determine whether the increased dentoalveolar and facial heights found in mouth breathing children with enlarged adenoids are maintained following adenoidectomy and changed mode of breathing from mouth to nose. METHODS: The subjects were Swedish children, either mouth breathers with nasal obstruction caused by large adenoids, or nose breathers. The children in the mouth breathing group were adenoidectomized at seven years of age and changed from mouth breathing to nose breathing. The unoperated subjects were age and sex matched to the operated subjects, and both groups were followed up again at 12 years of age. The incisor and molar dentoalveolar heights and anterior face heights, measured on lateral cephalometric radiographs, were compared prior to adenoidectomy and at 12 years of age. RESULTS: Significant intra-group increases were found for all dentoalveolar heights and 5 out of 6 facial heights. Only the ratio of upper anterior to lower anterior face height in the controls was not different statistically. Upper posterior dentoalveolar height was significantly larger (p < 0.05) in the adenoidectomized group compared with the controls at follow up, but not before adenoidectomy. Lower face height was significantly longer (p < 0.001) in the adenoidectomized group compared with the control group initially, and at follow up (p < 0.01). Initially, the ratio of upper face height to lower face height was significantly larger (p < 0.001) in the control group than the adenoidectomized group, but the groups were similar at follow up. Small, but statistically significant, correlations were found between the changes in upper molar dental height and the mode of breathing (p < 0.05) in the adenoidectomized group, and between the change in the ratio of upper to lower face heights and the mode of breathing (p < 0.01). CONCLUSION: The changes in the dentoalveolar heights of the maxillary molars, and the ratio of the upper and lower anterior face heights seem to be associated with the change in mode of breathing from mouth to nose breathing after adenoidectomy.

Adenoidectomy↗
PubMed2002

Combining functional appliances in the straightwire system.

The Trainer for Braces (T4B) helps speed up fixed appliance therapy, by derotating teeth and pushing them into the line of the arch. It also aids treatment stability by reducing the influence of undesirable myo-functional habits and retraining the oral musculature. I issue a T4B to all my patients on the day of bracket placement. I have noticed a 30% reduction in treatment times for those patients who wear the T4B as directed.

Bruxism↗
PubMedDate not supplied

Refining occlusion with muscle balance to enhance long-term orthodontic stability.

The primary objective of orthodontic treatment is the movement of teeth into a more ideal esthetic and functional relationship. Finishing a case with the muscles of mastication in equilibrium is another very important objective that often does not receive enough consideration. If the occlusal forces in maximum intercuspation are distributed unevenly around the arch, tooth movement most likely will occur and an endless procession of retainers will be necessary for retention. Today, it is possible to make simultaneous and precise measurements of the relative force of each occlusal contact, the timing of the occlusal contacts, and the specific muscle contraction levels. This technological breakthrough represents a paradigm shift in thinking and may improve orthodontic stability.

Bite Force↗
PubMedDate not supplied

How we got from there to here and back.

Edward H. Angle dominated orthodontic armamentarium, diagnosis and treatment planning for almost a half century until Charles Tweed successfully challenged his mentor's nonextraction mantra. The ensuing diagnostic regimen used by Tweed, however, proved to have serious limitations and clearly resulted in the extraction of too many teeth. This caused a subsequent deterioration of soft tissue appearances of patients that neither they nor their doctors liked. This article will describe and illustrate how new expansion techniques differ qualitatively from those of Angle, and how these techniques offer patients and doctors less invasive and more comfortable therapies which do not jeopardize facial appearances.

Biomechanical Phenomena↗