Dataset Information

Clinical implications of age-related change of the mandibular plane angle.

ABSTRACT:

Objective

To identify trajectories of ontogenetic change in the mandibular plane angle (MPA) and to describe the influence of sex and other factors on MPA during growth.

Setting/sample

The data consisted of 7026 MPA measurements from lateral cephalographs representing longitudinal series from ages 6 to 21 for 728 individuals from the Craniofacial Growth Consortium Study (CGCS).

Materials and methods

Facial type was determined from MPA for each assessment, with the assessment closest to age 18 representing the adult facial type. The sample includes 366 males and 362 females, each with between 2 and 15 cephalographs. The mean number of cephalographs per individual is 10. Variation in childhood MPA (earliest assessment between 6 and 9 years of age) and adult MPA (closest assessment to age 18 between 15 and 21 years of age), and change in MPA from childhood to adulthood were compared by sex and adult facial type using ANOVA and post hoc t tests.

Results

Mandibular plane angle decreased from childhood to adulthood in 92% of males and 81% of females, yet increased in 36% of males and 50% of females with the hyper-divergent adult facial type. Childhood MPA and overall change in MPA were significantly different by adult facial type.

Conclusions

Adult facial type is associated with differences in childhood MPA and change in MPA during growth. There are multiple ontogenetic pathways by which an individual can achieve a normo-divergent adult facial type, and an individual's childhood MPA does not necessarily correspond to his or her adult facial type.

SUBMITTER: Hardin AM

PROVIDER: S-EPMC6980205 | biostudies-literature | 2020 Feb

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Clinical implications of age-related change of the mandibular plane angle.

Hardin Anna M AM Valiathan Manish M Oh Heesoo H Knigge Ryan P RP McNulty Kieran P KP Leary Emily V EV Duren Dana L DL Sherwood Richard J RJ

Orthodontics & craniofacial research 20191001 1

<h4>Objective</h4>To identify trajectories of ontogenetic change in the mandibular plane angle (MPA) and to describe the influence of sex and other factors on MPA during growth.<h4>Setting/sample</h4>The data consisted of 7026 MPA measurements from lateral cephalographs representing longitudinal series from ages 6 to 21 for 728 individuals from the Craniofacial Growth Consortium Study (CGCS).<h4>Materials and methods</h4>Facial type was determined from MPA for each assessment, with the assessmen ...[more]

PMID: 31465622

Similar Datasets

Project description:The aim of this study was to investigate the effects of advancement magnitude and changes in mandibular plane angle on the stability of mandibular advancement.This retrospective cohort study evaluated the postoperative stability of mandibular advancement in class II skeletal subjects who underwent bilateral sagittal split osteotomy. Radiographs taken preoperatively, immediately postoperatively and 1 year postoperatively were traced and analyzed using linear and angular measurements. To determine horizontal and vertical relapse, an X-Y coordinate system was established in which the X-axis was constructed by rotating S-N downward by 7° (approximation of the Frankfort horizontal plane) and the Y-axis was defined as a line perpendicular to the X-axis and passing through the point Sella. For certain reference points including point A, point B, pogonion and menton, the perpendicular distance between each point and both axes was determined and cephalometric variables were recorded as X and Y coordinates.Twenty-five subjects were studied. A significant correlation between the amount of mandibular advancement and relapse in the B point (vertical and horizontal) and the pogonion point was observed (vertical and horizontal, P<0.001). Evaluation of data demonstrated a positive correlation between the mandibular plane angle (SN/ML) change and vertical relapse in the B point (P<0.05). A simple regression model demonstrated that 74% of horizontal relapse and 42.3% of vertical relapse in the B point was related to the amount of mandibular advancement. The receiver operating characteristic test showed that 8.5 mm mandibular advancement is related to a relapse rate of 1 mm or more in the pogonion, vertically or horizontally.The magnitude of mandibular advancement is a stronger surgical predictor for horizontal rather than vertical relapse at the B point. Changes in mandibular plane angle (SN/ML) during surgery affect vertical, but not horizontal relapse at the B point.

Project description:Transcriptional profiling of age-related change of callus formation capability in Arabidopsis hypocotyls Organogenesis in vitro consists of many aspects such as phytohormone perception, dedifferentiation of differentiated cell to acquire organogenic competence, and re-entry of quiescent cells into cell cycle. In this study, we established an in vitro experimental system to study the age-dependent callus formation capacity in Arabidopsis. Interestingly, mature (35- to 38-day-old) hypocotyl explants exhibited better callus-forming potential than that of juvenile (7- to 10-day-old), determined by callus growth rates. To explore genome-wide expression changes underlying the phenomenon of age-dependent callus formation, a transcriptome-based analysis was performed. Gene expression profiling indicated that age-dependent callus formation capacity was associated with changes in phytohormone (auxins, cytokinins, abscisic acid, brassinosteroids and gibberellins) homeostasis, epigenetic mechanism and the cell cycle regulation. Besides, we identified two groups of genes involved in age-dependent callus formation capacity: (1) positive regulatory and (2) negative regulatory categories, i.e. genes that were significantly up- or down-regulated during callus formation derived from mature explants, respectively. One gene encoding DNA-binding protein (VARIANT IN METHYLATION 1, VIM1) belonging to the positive regulatory category was selected for functional analysis and assessment of age-dependent callus formation capacity. Indeed, vim1 reduced the efficiency of callus formation in mature explants, but not in juvenile. The result suggests that VIM1 plays an important role in regulating age-dependent callus formation capacity. Taken together, the investigation will help to better understand the molecular regulatory mechanism of age-dependent callus formation. Comparison of young and mature Arabidopsis hypocotyls either with or without auxin treatment for 1 day

Dataset Information

Clinical implications of age-related change of the mandibular plane angle.

Objective

Setting/sample

Materials and methods

Results

Conclusions

Publications

Clinical implications of age-related change of the mandibular plane angle.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets