Significance of the Frankfurt-mandibular plane angle to prosthodontics

1978 ◽  
Vol 6 (1) ◽  
pp. 91
Author(s):  
B.J. Roberts
2018 ◽  
Vol 23 (6) ◽  
pp. 48-55 ◽  
Author(s):  
Waqar Jeelani ◽  
Mubassar Fida ◽  
Attiya Shaikh

ABSTRACT Introduction: Maxillary incisal display is one of the most important attributes of smile esthetics. Objective: The aim of this study was to determine the relationship between maxillary incisal display at rest (MIDR) and various soft tissue, hard tissue and dental components. Methods: A cross-sectional study was conducted on 150 subjects (75 males, 75 females) aged 18-30 years. The MIDR was recorded from the pretreatment orthodontic records. The following parameters were assessed on lateral cephalograms: ANB angle, mandibular plane angle, palatal plane angle, lower anterior and total anterior facial heights, upper incisor inclination, upper anterior dentoalveolar height, and upper lip length, thickness and protrusion. The relationship between MIDR and various skeletal, dental and soft tissue components was assessed using linear regression analyses. Results: The mean MIDR was significantly greater in females than males (p = 0.011). A significant positive correlation was found between MIDR and ANB angle, mandibular plane angle and lower anterior facial height. A significant negative correlation was found between MIDR and upper lip length and thickness. Linear regression analysis showed that upper lip length was the strongest predictor of MIDR, explaining 29.7% of variance in MIDR. A multiple linear regression model based on mandibular plane angle, lower anterior facial height, upper lip length and upper lip thickness explained about 63.4% of variance in MIDR. Conclusions: Incisal display at rest was generally greater in females than males. Multiple factors play a role in determining MIDR, nevertheless upper lip length was found to be the strongest predictor of variations in MIDR.


2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Woei Li Koay ◽  
Yanqi Yang ◽  
Christine Shuk Kwan Tse ◽  
Min Gu

Aims. To assess the effects of two-phase treatment with the Herbst and the preadjusted edgewise appliances on upper airway dimensions and to investigate the correlation between changes in the upper airway dimensions and skeletal morphologies.Methods. A total of 27 Chinese male adolescents aged12.8±1.3years were selected. Lateral cephalograms were collected to assess the skeletal morphology and upper airway dimensions.Results. Following Herbst appliance treatment, the upper airway space was significantly enlarged, with the retropalatal (U-MPW) increasing by1.1±1.6 mm (P<0.001), the retroglossal (PASmin) increasing by1.3±2.9 mm (P<0.05), and the hypopharynx (V-LPW) enlarging by1.6±3.0 mm (P<0.01). PASmin was found to show a negative correlation to the mandibular plane angle (MnPl-SN) byr=-0.413(P<0.05). There was no significant change (P>0.05) in upper airway dimensions during the second-phase treatment.Conclusions. Herbst appliance treatment increased the oropharyngeal and hypopharyngeal airway dimensions among adolescents with Class II malocclusion, and the effects were maintained throughout the second treatment phase with a preadjusted edgewise appliance. There was a negative correlation between the change in the depth of the retroglossal pharynx and the mandibular plane angle.


2021 ◽  
Author(s):  
Ahmed I. Masoud ◽  
T. Peter Tsay

ABSTRACT Amelogenesis imperfecta is a rare hereditary disorder that affects dental enamel and is often associated with an anterior open bite. Orthodontic treatment of a 16-year-old female patient with hypocalcified amelogenesis imperfecta and a 9-mm anterior open bite was presented. Radiographic examination revealed a steep mandibular plane angle, an increased lower face height, a Class II skeletal pattern, and a convex profile. Additionally, the patient had stainless steel crowns on all upper and lower posterior teeth and composite veneers on the upper anterior teeth. The patient was treated nonsurgically using a multiloop edgewise archwire (MEAW). MEAW mechanics allowed for successful correction of the anterior open bite, with significant reduction in the mandibular plane angle and improvement in the patient's profile. No fixed retainers were used, results remained stable 78 months after removal of orthodontic appliances. MEAW mechanics should be considered for patients with large anterior open bites, although this technique requires excellent patient compliance.


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