LETTERS TO THE EDITOR Removal of ceramic brackets To the Editor:

Not too long ago, while reading an article in the AJO DO, I experienced the first half of a cold chill down my spine as I encountered someone's first-hand experience with enamel fracturing during ceramic bracket removal. A few weeks later I suffered the remainder of the spine chill as I was removing ceramic brackets from the upper teeth of one of my own patients. I could not imagine that I would ever encounter brackets so firmly bonded to enamel. My patient, a 16-year-old girl, was extremely tolerant during the bracket removal. The initial stages of the procedure had to be fairly painful. There were 10 upper ceramic brackets in place. I normally start bracket removal on the upper left quadrant of a patient, and circle to the right. I struggled through both premolars and the upper left canine and lateral brackets. When I reached the left central, I quit. I felt the possibility of fracturing enamel was great. I do not own a heat-treating bracket aid, but would have purchased one at that moment, had one been available. I then had an idea; I gave the patient some warm water to swish around her teeth. I made it as hot as she could tolerate. After four or five rinses I was able, with minimal difficulty, to remove both the central and the upper right lateral brackets. I stopped and repeated the hot water rinsing again, followed by the fairly easy removal of the remainder of the ceramic brackets. The hot water rinse was a lifesaver, and predictably this procedure, at later debonding sessions, was equally efficacious. I am happy to share this experience with others and hope that it may prove of value. I take note that one ceramic bracket manufacturer has tried to attend to this problem by the addition of a polycarbonate base under the ceramic bracket facade that would flex under the pressures of bracket removal procedures and hence aid adhesive rupture. Even if this idea were found to have a modicum of merit, I suspect that it would be offset by two undesirable side effects. First, if flexing capacity is present beneath a ceramic facade under shear force application, the brackets are likely to fail under routine appliance therapy. And second, I have yet to discover any polycarbonate that does not progressively stain in the oral environment. Arthur L. Wool, DDS Wyomisshlg, PA

Functional appliances--a valuable tool in your a rnamentarium To the Editor:

The rise in functional jaw orthopedic (FJO) appliances has been significant and deserves the attention of every clinician (for the first or second time). This is

despite some disenchantment by clinicians who dropped them after making diagnostic and therapeutic mistakes. Class II malocclusions comprise the majority of the average case load, and in recent years it has become apparent there are morphologically different types of Class II malocclusions. Sassouni, 1Moyers, 2 McNamara, 3 Pfeiffer and Grobety,' among others, have suggested there are many different combinations of Class Ils. It is only logical that these various types of Class IIs should be treated differently as indicated by the individual structure of the patient. In the case of mandibular dental or skeletal retrusion and/or crowding with deep bite, certain functional appliances have proven to be a very effective clinically for me, whereas others have proven to be of limited value. Having used FJO appliances since 1974, I have learned there are at least four areas that functional appliances (and particularly the Fr~.nkel) stand out as being particularly advantageous. These areas are (1) lateral expansion, (2) myofunctional improvement, (3) respiration, and (4) temporomandibular joint (TMJ). 1. EXPANSION is the most beneficial effect of the Fr&nkel appliance, since it directly contributes to reducing the number of extractions. Fr&nkel, s McDougal, McNamara, and Dierkes, 6 and Owen 7 have shown dental arch expansion by using the functional regulator. Owen 8 has also shown the basal bone expands in both the mandible and the maxilla as well. Recently, Hime and Owen 9 showed this expansion to be quite stable several years after treatment. Consistent stability of mandibular arch expansion is still one of the elusive goals of our profession, and the Fr&nkel appliance appears to achieve this desired treatment goal. 2. MYOFUNCTIONAL IMPROVEMENT in response to the functional regulator have been reported by several authors, '°-'2 and apparently it is the myofunctional changes that lead to the stability of the expansion. Also, Owen '3 found that the upper lip was not retracted during Class II correction with the Fr&nkel appliance, even if the incisors were retracted during treatment. This. seemingly contradictory finding would appear to be the result of changes in the muscle tone of the upper lip rather than the upper lip merely following the upper incisor, as is the situation with fixed appliances. I believe I see a more balanced soft tissue profile by using the bionator or Herbst as well, but not the same degree of upper lip protection during Class II treatment as the Fr~inkel. With a fully protrusive construction bite, all of these functional appliances can produce a maxillary retraction similar to a headgear, although with slightly more incisor tipping. 3. RESPIRATION changes are due to the expansion of the nasal cavity, especially during Fr~.nkel treatment. 7.'' The nasal cavity expands significantly more than the average growth increments during Fr&nkel treatment. Although the mechanics are not well understoo.d, it may be the emphasis on lip seal and nasal breathing, as well as the expansion of the maxillary basal bone, combined to provide the answer. Nasal respiration provides a more stable environment for the treated case and may be one more answer why the Fr&nkel expansion appears to hold up well. 31A

Removal of ceramic brackets.

LETTERS TO THE EDITOR Removal of ceramic brackets To the Editor: Not too long ago, while reading an article in the AJO DO, I experienced the first ha...
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