Class 3 Correctors Flashcards
What is a pseudo class 3 malocclusion?
Pts present with anterior crossbite that are caused by a premature tooth contact or improper inclinations of the maxillary and mandibular incisors. Elimination of the MI/CR discrepancy may avoid abnormal wear and traumatic occlusal forces to the affected teeth, avoid potential adverse growth influences in the maxilla and mandible, and improve maxillary lip posture and facial appearance.
True or false.. an expansion appliance or maxillary lingual arch in conjunction with partial field appliance can be used to correct anterior crossbite in young class 3 patients
True
When is facemask therapy indicated?
It is most effective in the treatment of mild-moderate skeletal class 3 malocclusions with a retrusive maxilla and a hypodivergent growth pattern. Pts presenting with some degree of anterior mandibular shift on closure and a moderate overbite have a more favorable prognosis.
Why is an expansion device important for protraction in facemask treatment?
The expansion device breaks up other sutures that can help in “disarticulating” the maxilla and initiate cellular response in the circumaxillary sutures, allowing a more positive reaction to protraction forces
Several circumaxillary sutures play an important role in the development of the nasomaxillary complex. Name 8 of them
Frontomaxilary
Nasomaxillary
Zygomaticotemporal
Zygomaticomaxillary
Pterygopalatine
Intermaxillary
Ehmomaxillary
Lacrimomaxillary
The circumaxillary sutures are patent until __ year of age in which they start becoming increasingly tortuous
8
What is the optimal time to intervene in a patient with early class 3 malocclusion?
At the time of initial eruption of the maxillary central incisors
Studies have shown that better skeletal and dental response can be obtained in the primary and early mixed dentin rather than in the late mixed dentition
A positive overjet and overbite at the end of facemask treatment appear to maintain the anterior occlusion after treatment
The erupted ___ provide the best anchorage for maxillary protraction. Maxillary protraction is effective through ___, with diminishing skeletal response as the sutures mature
Maxillary first molars
Puberty
In a prospective clinical trial, in facemask treatment, overjet correction was found to be the result of forward maxillary movement (___%), backward movement of the mandible (__%), labial movement of the maxillary incisors (___%), and lingual movement of the mandibular incisors (__%).
31%
21%
28%
20%
In facemask treatment, how is face height increased?
Inferior movement of the maxilla and downward and backward rotation of the mandible
Are these treatment results stable long term?
The effects on the maxilla remain stable for 2 years after facemask treatment.
Long-term studies have shown that treatment is successful in 67% - 75% of the patients.
An overcorrection of the maxilla ___mm anterior overjet is recommended for patients who are diagnosed with excessive mandibular growth
3-4mm
Which retention device is useful after facemask treatment?
Frankel 3 regulator
It helps in maintaining the Sagittal and transverse correction by facemask and allows muscle adaptation to the new position of the maxilla
In older patients where growth is completed, treatment is limited by camouflaging the underlying jaw differences with ___ of the maxillary incisors and ___ of the mandibular incisors.
Proclination
Retraction
In camouflage treatment, fixed appliances with class 3 elastics that run from the maxillary ___ to the mandibular ___ are used to achieve the desired tooth movements. In patients with crowded dentitions or dentoalveolar protrusion, extraction of the ___ and ___ may be necessary to camouflage the malocclusion
Molars
Canines
Mandibular first premolars
Maxillary second premolars
