Lecture 11 Flashcards
what are some options to correct dental crowding?
expand to make space, extract to make space, or interproximal reduction to make space
what are some expansion options for correcting dental crowding?
skeletal expansion and dental expansion
when planning to extract to make space as a correction for dental crowding, depending on the patients ___ and ___, orthodontists may extract a single tooth or multiple teeth
cephalometric analysis and orthodontic records
___ are the teeth most often extracted for orthodontic treatment, but any tooth (or combination of teeth) could be considered
premolars
many orthodontists under the guidance of edward angle were arguing that extraction is almost a crime. what word was used to describe this?
odontocide
what happened at the 1902 symposium on extraction at the 2nd district dental society of new york when calvin case (chief challenger of the angle’s new school) presented?
- many dentists decided never to attempt orthodontics again, but instead to refer their patients to a specialist
- this one meeting was very influential in establishing orthodontics as a separate specialty
in 1902, angle set forth his line of reasoning toward the development of his treatment philosophy. in his article, he recounts his conversations with artist edmund wuerpel, whose help led to ___
angle’s concept of facial beauty and harmony
according to angle, “my belief is that if we would confer the greatest benefits upon our patients from an aesthetic standpoint, we must work hand in hand with ___ and assist her to establish the ___ as the creator intended they should be, and not resort to mutilation”
- nature
- relations of the teeth
in angle’s “new school”, his group believed that ___ could be induced by mechanical means to grow beyond its inherent size
bone
describe the extraction debate of 1911
- calvin case presented an article entitled “the question of extraction in orthodontia”
- case claims that the causes of malocclusion partly, at least, arise from the law of heredity
- “but why enter such a field of doubt, of anger, and of possible failure, merely to satisfy a sentiment that god dose not make the mistake of placing in the mouth of the human individual more teeth than is necessary for perfect harmony in all physical and aesthetic relations?”
- why ignore the possibility and the frequent undoubted fact that inherited in-harmonies in continguous structures make it impossible for us to place all of the teeth in the arch without fulfilling the designs of an inherited deformity?
- the controversy was extensive, bitter, and irreconcilable
- angle’s contention was that there is no place for extractions in orthodontics
- case countered with what he called the “rational school” = new bone cannot be induced to grow beyond its inherent size and that, therefore, there are indications for extractions in certain forms of malocclusion
charles tweed trained under edward angle, but was familiar with case’s article “the question of extraction in orthodontia”. after 5 years of orthodontic practice, tweed became disheartened with his work for what 2 reasons?
- the protrusive faces that he was creating
- the unstable dentitions
- tweed became so disappointed that he almost left orthodontics, but resolved to study his many failures and few successes, and came to realize that patients who had pleasing facial balance and harmony also had mandibular incisors that were upright over basal bone
what was tweed’s philosophy, and how did he reach it?
- carefully planned extractions can improve appearance as well as stability
- he selected some of his treatment failures, extracted first premolars, then retreated them
- the outcomes reinforced his commitment to the necessity of extractions in certain cases
- although it was a tremendous exhibit, he was severely criticized by many orthodontists of the era
whenever there is not enough arch length in the mandibular or maxillary bases, to accommodate the size of the adult dentition, the decision must be made whether to ___ or ___
extract or expand
when adult teeth erupt, they tend to erupt with a ___ migration
mesial
if a tooth is extracted or missing, it is possible for the teeth that are located ___ to erupt ___ into the extraction/missing tooth space. this understanding popularized the concept of ___ extraction
- distally
- mesially
- serial
in 1929, kjellgren coined the term serial extraction to describe a procedure where ___
some deciduous teeth were extracted and followed by extraction of permanent teeth to guide the rest of the teeth into normal occlusion
describe what is typically completed in serial extraction cases
- first primary molar is extracted (and primary canine if necessary)
- which then encourages early eruption of the first premolar
- then the first premolar is extracted which creates space for the remaining dentition to erupt properly
during the 1940s, nance popularized the serial extraction technique in the USA and termed it ___
planned and progressive extraction
in the 1970s, holtz called the serial extraction procedure ___
active supervision of teeth by extraction
under angle, in the 1930s-1940s, when dental crowding was present, ___ was the treatment of choice
- expansion of the dental arches
- however, clinicians later found that such expansion procedures did not provide for stable results and resulted in relapse
under tweed, during the early 1940s, the wave of expansionism died out, and ___ became the treatment of choice for crowding
tooth extraction
today, trained orthodontists do a careful analysis of each problem presented by their patient and make treatment decisions based on what 5 things?
- scientific training
- clinical training
- clinical experience
- familiarity with the literature
- if necessary, consultation with peers
what are 3 things to consider with dental crowding?
- esthetics (lip support)
- stability (bony support, equilibrium of forces of soft tissues)
- gingival, bone, and tooth health
what are the contemporary extraction guidelines when the arch discrepancy is less than 4mm?
extraction is rarely indicated
what are the contemporary extraction guidelines when the arch discrepancy is 5-9mm?
extraction or non-extraction treatment is a possibility
what are the contemporary extraction guidelines when the arch discrepancy is 10mm+?
extraction is almost always requried
___ refers to a protrusive dento-alveolar position of the maxillary and mandibular dental arches that produces a convex facial profile
bi-maxillary protrusion
T or F:
some people believe that non-extraction treatment is always better than extraction treatment
true
T or F:
non-extraction treatment is thought to improve the facial profile and appearance of orthodontic patients by providing fuller lips and a broader smile
true