Note this is referred to as the late mesial shift of

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Note: This is referred to as "the late mesial shift of a permanent first molar." 1. On occasion, the permanent incisors "spread out" due to spacing. This is referred to as the "ugly Notes duckling stage"of development. With the eruption of the permanent canines, the spaces often will close. As a general guideline, a maxillary central diastema of 2 mm or less will probably close spontaneously, while total closure of a diastema initially greater than 2 mm is unlikely. 2. The permanent dentition stage begins when the last primary tooth is lost. 3. For the maxilla and mandible: Growth in the width is completed first, then growth in length, and finally growth in height. 4. Maxillary and mandibular arch widths increase and this is completed before the adolescent growth spurt 5. The dental arch perimeter (length) decreases a surprising amount during the late adolescent and young adult periods due to the late mesial shift of the permanent molars into the leeway space, the mesial drift tendency of the posterior teeth in general, and the lingual positioning of the incisors. 6. Increases in the vertical height of the jaws and face continue until 17 or 18 in girls and in the early twenties in boys. • tooth # 22 is erupting facially Sometimes the permanent mandibular canines erupt facially relative to the primary canines. However, often they are right in line with the primary canines. If there are problems in erup- tion, these teeth can be displaced either lingually or labially, but usually they are displaced labi- ally if there is not enough room to accommodate them within the arch. 1. The mesial inclined plane of the primary maxillary canine articulates with the Notes distal inclined plane of the primary mandibular canine. This is the normal rela- tionship. 2. In both the maxillary and mandibular arches, the permanent incisor tooth buds lie lingual as well as apical (inferior) to the primary incisors. The result is a ten- dency for the mandibular permanent incisors to erupt somewhat lingually and in a slightly irregular position. This occurs even in children who have normal dental arches and normal spacing within the arches. 3. Permanent teeth normally move occlusally and buccally while erupting. 4. Remember: The maxillary arch is slightly longer (approximately 128 mm) than the mandibular arch (approximately 126 mm).
misc . A 6-year-old patient and her mother present to your office. Her mom's chief complaint is "My kid's overbite makes her look like Bugs Bunny, her front teeth hide her lower lip." What is wrong with the mom's statement? • she is mixing up overbite and overjet • she is mixing up overbite and open bite • she is mixing up overbite and negative overjet • she is mixing up her cartoon characters 61 copyright e 2013-2014- Dental Decks ORTHODONTICS misc .

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