IADR Abstract Archives
Skeletal and Soft Tissue Changes in Normal Occlusion Throughout Lifetime
Objectives: Age-related skeletal and soft tissue changes in human normal occlusion are important for orthodontic treatment planning and retention, especially due to the increase of adult patients seeking orthodontic intervention. The objective of this systematic review was to assess the available evidence in the literature on age-related skeletal and soft tissue changes in untreated normal occlusion.
Methods: An electronic search was performed until August 2020 using the terms ‘Maxilla’, ‘Mandible’, ‘Lips’, ‘Ageing’, ‘Age groups’. Articles studying skeletal and soft tissue changes in orthodontically untreated subjects with neutro occlusion and comparing them between various age groups were included. Studies focusing on a single age group or written in languages other than English were excluded. The risk of bias of the studies was assessed with both the MINORS and ROBINS-I tools.
Results: From the initial 5539 studies, 52 were included. A high methodological heterogeneity was found. Mandibular plane inclination reduces from 7 years until 20 years. Facial height increases both anteriorly and posteriorly until 28 years of age. Anterior cranial base length increases until 20 years and follows a slow increase until 46 years. Nasal width increases from 10 to 14 years, Nasolabial angle shows reduction from 8.8 to 17.8 years. Upper lip and lower lip length increase from 6 to 18 years along with protrusion of upper lip from 8 to 12 years and retrusion of the lower lip from 5 to 45 years.
Conclusions: Greater emphasis should be placed on the age-related soft tissue, skeletal and dental changes during diagnosis and orthodontic treatment planning to ascertain the available limits soft tissue adaptation to balance the given skeletal and dental changes made by the orthodontist. Well-designed prospective cohort studies with all the three dimensions of skeletal and soft tissues are necessary for confirmatory evidence. (PROSPERO: CRD42020203206)
Methods: An electronic search was performed until August 2020 using the terms ‘Maxilla’, ‘Mandible’, ‘Lips’, ‘Ageing’, ‘Age groups’. Articles studying skeletal and soft tissue changes in orthodontically untreated subjects with neutro occlusion and comparing them between various age groups were included. Studies focusing on a single age group or written in languages other than English were excluded. The risk of bias of the studies was assessed with both the MINORS and ROBINS-I tools.
Results: From the initial 5539 studies, 52 were included. A high methodological heterogeneity was found. Mandibular plane inclination reduces from 7 years until 20 years. Facial height increases both anteriorly and posteriorly until 28 years of age. Anterior cranial base length increases until 20 years and follows a slow increase until 46 years. Nasal width increases from 10 to 14 years, Nasolabial angle shows reduction from 8.8 to 17.8 years. Upper lip and lower lip length increase from 6 to 18 years along with protrusion of upper lip from 8 to 12 years and retrusion of the lower lip from 5 to 45 years.
Conclusions: Greater emphasis should be placed on the age-related soft tissue, skeletal and dental changes during diagnosis and orthodontic treatment planning to ascertain the available limits soft tissue adaptation to balance the given skeletal and dental changes made by the orthodontist. Well-designed prospective cohort studies with all the three dimensions of skeletal and soft tissues are necessary for confirmatory evidence. (PROSPERO: CRD42020203206)