Increase in adult orthodontics from 1970 by 800%

50% of adults have some element of periodontal disease

Untreated adult population 51% dehiscence 37% areas of fenestration Evangelista 2010

Dolichocephalic = narrow alveolus and elongated to compensate for vertical growth

Brachycephalic = larger alveolus

Dolichocephalic - Red flag patients

facial tooth movement Wennström 1996

Reduced bucco lingual width

Therefore, reduced free gingiva

Increased risk only if tooth is moved out of the alveolar housing

Tipping (uncontrolled) increase likelihood of recession Condo 2017

Proclination causes recession, but inconclusive 

Thickness more relevant than final inclination Yared 2006

Limit of labial bone – shape is coincident with the mucogingival junction, coincident with centre of resistance

Upper incisors – located anterior 1/3 of alveolus

Mandibular incisors – cantered within the alveolus 

Gingival recession did not increase in treatment orthodontic population with segmental mechanics Melsen 2005

Association between non-extraction clear aligner therapy and alveolar bone deficiency and fenestration

Presence of both fenestration and dehiscence

Monkey – moved teeth outside of bone for 8 months, then reposition within bone with appliances =  repair bony dehiscence and fenestration

Morten  Laursen and Melsen 12 consecutive patients 2020

Teeth moved towards the centre of the cortical plate = improvement in gingival height of depth decrease of 23%, the width with 38%

Use of intrusion arch increases the thickness of the periodontal fibres 0.7 to 2.3 mm  Melsen 1988

Free gingival graft – 6 weeks

Connective tissue graft – 12 weeks