Two differing terms describe a patient’s facial type: 1) Brachyfacial Type: This facial type is characterized by a short and wide face, usually presentation with a flat mandibular plane angle, and a closed gonial angle. A deep bite is frequently associated with this facial type. 2) Dolichofacial Type: This facial type is characterized by a long and narrow face where the maxilla exhibits excessive vertical growth and the mandibular plane is steeper than normal. This growth pattern results in long and narrow alveolar dental arches, and produce a clockwise rotation of the mandible during growth. This is what opens the mandibular plane angle, and sometimes creates a skeletal open occlusion.
Published in Chapter:
Orthodontic Monitoring and Case Finishing With the T-Scan System
Julia Cohen-Levy, DDS (University of Montréal, Canada)
Copyright: © 2020
|Pages: 68
DOI: 10.4018/978-1-5225-9254-9.ch015
Abstract
This chapter reviews T-Scan use in orthodontics from diagnosis to case finishing, and then in retention, while defining normal T-Scan recording parameters for orthodontically-treated subjects versus untreated subjects. T-Scan use in the case-finishing process is also described, which compensates for changes in the occlusion that occur during “post-orthodontic settling,” as teeth move freely within the periodontium to find an equilibrium position when the orthodontic appliances have been removed. T-Scan implementation is necessary because, often, despite there being a post treatment, visually “perfect” angle's Class I relationship established with the orthodontic treatment, ideal occlusal contacts do not result solely from tooth movement. Creating simultaneous and equal force occlusal contacts following fixed appliance removal can be accomplished using T-Scan data to optimize the end-result occlusal contact pattern. The T-Scan software's force distribution and timing indicators (the two- and three-dimensional force views, force percentage per tooth and arch half, the center of force trajectory and icon, the occlusion time [OT], and the disclusion time [DT]), all aid the Orthodontist in obtaining an ideal occlusal force distribution during case-finishing. Fortunately, most orthodontic cases remain asymptomatic during and after tooth movement. However, an occlusal force imbalance or patient discomfort may occur along with the malocclusion that needs orthodontic treatment. Symptomatic cases require special documentation at the baseline, and careful monitoring throughout the entire orthodontic process. The clinical use of T-Scan in these “fragile” cases of patient muscle in-coordination, mandibular deviation, atypical pain, and/or TMJ idiopathic arthritis, are illustrated by several case reports. The presented clinical examples highlight combining T-Scan data recorded during case diagnosis, tooth movement, and in case finishing, with patients that underwent lingual orthodontics and orthognathic surgery, orthodontic treatment using clear aligners, or conventional fixed treatment with a camouflage treatment plan, which require special occlusal finishing (when premolars are extracted in only one arch).