Class I malocclusions—The development and etiology of mandibular malalignments  Peter H. Buschang, PhD  Seminars in Orthodontics  Volume 20, Issue 1, Pages 3-15 (March 2014) DOI: 10.1053/j.sodo.2013.12.002 Copyright © 2014 Elsevier Inc. Terms and Conditions

Figure 1 Prevalence of maxillary and mandibular crowding among the US population. (Adapted from Proffit et al.5) Seminars in Orthodontics 2014 20, 3-15DOI: (10.1053/j.sodo.2013.12.002) Copyright © 2014 Elsevier Inc. Terms and Conditions

Figure 2 Changes in anterior mandibular TSALD and arch length between 14 and 46 years of age. (Adapted from Bishara et al.9,10) Seminars in Orthodontics 2014 20, 3-15DOI: (10.1053/j.sodo.2013.12.002) Copyright © 2014 Elsevier Inc. Terms and Conditions

Figure 3 Annualized changes in malalignment of untreated patients between 12 and 42 years of age. Seminars in Orthodontics 2014 20, 3-15DOI: (10.1053/j.sodo.2013.12.002) Copyright © 2014 Elsevier Inc. Terms and Conditions

Figure 4 Maxillary (Mx) and mandibular (Md) discrepancies (mm) between interproximal contacts (e.g., right canine and right lateral incisor or rC-rI2 and left lateral incisor and left central incisor or lI1–lI2) of (A) a large cross-sectional sample of adults from the NHANES III and (B) similar untreated and treated longitudinal patients. Seminars in Orthodontics 2014 20, 3-15DOI: (10.1053/j.sodo.2013.12.002) Copyright © 2014 Elsevier Inc. Terms and Conditions

Figure 5 Adolescents (ages 10–15 years) changes in first molar eruption and migration. Yearly increases in malalignment of untreated subjects who were followed up longitudinally. Seminars in Orthodontics 2014 20, 3-15DOI: (10.1053/j.sodo.2013.12.002) Copyright © 2014 Elsevier Inc. Terms and Conditions

Figure 6 The dentition of native Americans showing extensive interproximal and occlusal wear and supraeruption of the teeth. Seminars in Orthodontics 2014 20, 3-15DOI: (10.1053/j.sodo.2013.12.002) Copyright © 2014 Elsevier Inc. Terms and Conditions

Figure 7 Normal changes in maxillary and mandibular arch perimeters between 6 and 16 years of age. (Adapted with permission from Moyers et al.25) Seminars in Orthodontics 2014 20, 3-15DOI: (10.1053/j.sodo.2013.12.002) Copyright © 2014 Elsevier Inc. Terms and Conditions

Figure 8 Decreases (mm) in incisor irregularity associated with lip bumper therapy only. Seminars in Orthodontics 2014 20, 3-15DOI: (10.1053/j.sodo.2013.12.002) Copyright © 2014 Elsevier Inc. Terms and Conditions

Figure 9 Lack of relationship between patients' pretreatment incisor irregularity and post-treatment changes in irregularity. Seminars in Orthodontics 2014 20, 3-15DOI: (10.1053/j.sodo.2013.12.002) Copyright © 2014 Elsevier Inc. Terms and Conditions

Figure 10 Post-retention incisor irregularity increases of patients treated with (A) nonextraction and (B) with extractions. Seminars in Orthodontics 2014 20, 3-15DOI: (10.1053/j.sodo.2013.12.002) Copyright © 2014 Elsevier Inc. Terms and Conditions

Figure 11 Reference chart showing various factors thought to move teeth, disrupt contacts, and lead to malalignment of the anterior dentition. Seminars in Orthodontics 2014 20, 3-15DOI: (10.1053/j.sodo.2013.12.002) Copyright © 2014 Elsevier Inc. Terms and Conditions

Figure 12 Relationship between the contact angles of the six anterior teeth (blue line) and the amount of discrepancy between contacts (green line). (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.) Seminars in Orthodontics 2014 20, 3-15DOI: (10.1053/j.sodo.2013.12.002) Copyright © 2014 Elsevier Inc. Terms and Conditions

Figure 13 Changes in (A) D + E space and (B) lower molar mesial migration associated with severe caries and premature loss of deciduous molars. (Adapted with permission from Northway et al.23) Seminars in Orthodontics 2014 20, 3-15DOI: (10.1053/j.sodo.2013.12.002) Copyright © 2014 Elsevier Inc. Terms and Conditions

Figure 14 Adult changes in upper anterior face height (UAFH), lower anterior facial height (LAFH), and posterior face height (PFH). Seminars in Orthodontics 2014 20, 3-15DOI: (10.1053/j.sodo.2013.12.002) Copyright © 2014 Elsevier Inc. Terms and Conditions