scholarly journals Displacement in root apex and changes in incisor inclination affect alveolar bone remodeling in adult bimaxillary protrusion patients: a retrospective study

2019 ◽  
Author(s):  
Huimin Mao ◽  
Andi Yang ◽  
Yue Pan ◽  
Houxuan Li ◽  
lang lei

Abstract Background Periodontal risk is of great concern for periodontists and orthodontists in the inter-disciplinary management of patients with bimaxillary protrusion. The aim of present study is to investigate changes in the alveolar bone in the maxillary incisor region and to explore its relationship with displacement of root apex as well as changes in the inclination of maxillary incisors during incisor retraction.Methods Samples in this retrospective study consisted of 38 patients with bimaxillary protrusion. Cone-beam computed tomography (CBCT) images was taken before(T0) and after (T1) treatment. Alveolar bone thickness (ABT), height (ABH) and area (ABA) were utilized to evaluate changes in the alveolar bone, while incisor inclination and apex displacement were used to assess changes in the position of maxillary central and lateral incisors. Correlations between alveolar bone remodeling and apex displacement as well as changes in the inclination were investigated.Results The labial ABT of central and lateral incisors at the mid-root third was increased. In contrast, the palatal ABT at crestal, mid-root and apical third level were consistently decreased. ABH was not altered on the labial side, while significantly decreased on the palatal side. ABA was not significantly increased on the labial side, but significantly decreased on the palatal side, leading to a significantly reduced total ABA. Orthodontic treatment significantly reduced inclination of upper incisors. Changes in the amount (T1-T0) of ABA was remarkably correlated with apex displacement and changes of inclination (T1-T0); in addition, using the multivariate linear regression analysis, changes of ABA on the palatal side (T1-T0) can be described by following equation: Changes of palatal ABA (T1-T0) = -3.258- 0.139× changes of inclination (T1-T0) + 2.533×apex displacement (T1-T0).Conclusions Retraction of incisors in bimaxillary protrusion patients may compromise periodontal bone support on the palatal side. An equation that incorporated the displacement of root apex and change in the incisor inclination may enable periodontist-orthodontist interdisciplinary coordination in assessing treatment risks and developing an individualized treatment plan for adult patients with bimaxillary protrusion.

2020 ◽  
Author(s):  
Huimin Mao ◽  
Andi Yang ◽  
Yue Pan ◽  
Houxuan Li ◽  
Lang LEI

Abstract Background: Periodontal health is of great concern for periodontists and orthodontists in the inter-disciplinary management of patients with bimaxillary protrusion. The aim of present study is to investigate changes in the alveolar bone in the maxillary incisor region and to explore its relationship with displacement of root apex as well as changes in the inclination of maxillary incisors during incisor retraction. Methods: Samples in this retrospective study consisted of 38 patients with bimaxillary protrusion. Cone-beam computed tomography (CBCT) images was taken before(T0) and after (T1) treatment. Alveolar bone thickness (ABT), height (ABH) and area (ABA) were utilized to evaluate changes in the alveolar bone, while incisor inclination and apex displacement were used to assess changes in the position of maxillary central and lateral incisors. Correlations between alveolar bone remodeling and apex displacement as well as changes in the inclination were investigated. Results: The labial ABT of central and lateral incisors at the mid-root third was increased. In contrast, the palatal ABT at crestal, mid-root and apical third level were consistently decreased. ABH was not altered on the labial side, while significantly decreased on the palatal side. ABA was not significantly increased on the labial side, but significantly decreased on the palatal side, leading to a significantly reduced total ABA. Orthodontic treatment significantly reduced inclination of upper incisors. Changes in the amount (T1-T0) of ABA was remarkably correlated with apex displacement and changes of inclination (T1-T0); in addition, using the multivariate linear regression analysis, changes of ABA on the palatal side (T1-T0) can be described by following equation: Changes of palatal ABA (T1-T0) = -3.258- 0.139× changes of inclination (T1-T0) + 2.533×apex displacement (T1-T0). Conclusions: Retraction of incisors in bimaxillary protrusion patients may compromise periodontal bone support on the palatal side. An equation that incorporated the displacement of root apex and change in the incisor inclination may enable periodontist-orthodontist interdisciplinary coordination in assessing treatment risks and developing an individualized treatment plan for adult patients with bimaxillary protrusion.


2020 ◽  
Author(s):  
Huimin Mao ◽  
Andi Yang ◽  
Yue Pan ◽  
Houxuan Li ◽  
Lang LEI

Abstract Background: Periodontal health is of great concern for periodontists and orthodontists in the inter-disciplinary management of patients with bimaxillary protrusion. The aim of present study is to investigate changes in the alveolar bone in the maxillary incisor region and to explore its relationship with displacement of root apex as well as changes in the inclination of maxillary incisors during incisor retraction.Methods: Samples in this retrospective study consisted of 38 patients with bimaxillary protrusion. Cone-beam computed tomography (CBCT) images was taken before(T0) and after (T1) treatment. Alveolar bone thickness (ABT), height (ABH) and area (ABA) were utilized to evaluate changes in the alveolar bone, while incisor inclination and apex displacement were used to assess changes in the position of maxillary central and lateral incisors. Correlations between alveolar bone remodeling and apex displacement as well as changes in the inclination were investigated.Results: The labial ABT of central and lateral incisors at the mid-root third was increased. In contrast, the palatal ABT at crestal, mid-root and apical third level were consistently decreased. ABH was not altered on the labial side, while significantly decreased on the palatal side. ABA was not significantly increased on the labial side, but significantly decreased on the palatal side, leading to a significantly reduced total ABA. Orthodontic treatment significantly reduced inclination of upper incisors. Changes in the amount (T1-T0) of ABA was remarkably correlated with apex displacement and changes of inclination (T1-T0); in addition, using the multivariate linear regression analysis, changes of ABA on the palatal side (T1-T0) can be described by following equation: Changes of palatal ABA (T1-T0) = -3.258- 0.139× changes of inclination (T1-T0) + 2.533×apex displacement (T1-T0).Conclusions: Retraction of incisors in bimaxillary protrusion patients may compromise periodontal bone support on the palatal side. An equation that incorporated the displacement of root apex and change in the incisor inclination may enable periodontist-orthodontist interdisciplinary coordination in assessing treatment risks and developing an individualized treatment plan for adult patients with bimaxillary protrusion. Moreover, the equation in predicating area of alveolar bone may reduce the risks of placing the teeth out of the bone boundary during 3D digital setups.


2020 ◽  
Vol 16 (1) ◽  
Author(s):  
Huimin Mao ◽  
Andi Yang ◽  
Yue Pan ◽  
Houxuan Li ◽  
Lang Lei

Abstract Background Periodontal health is of great concern for periodontists and orthodontists in the inter-disciplinary management of patients with bimaxillary protrusion. The aim of present study is to investigate changes in the alveolar bone in the maxillary incisor region and to explore its relationship with displacement of root apex as well as changes in the inclination of maxillary incisors during incisor retraction. Methods Samples in this retrospective study consisted of 38 patients with bimaxillary protrusion. Cone-beam computed tomography (CBCT) images was taken before(T0) and after (T1) treatment. Alveolar bone thickness (ABT), height (ABH) and area (ABA) were utilized to evaluate changes in the alveolar bone, while incisor inclination and apex displacement were used to assess changes in the position of maxillary central and lateral incisors. Correlations between alveolar bone remodeling and apex displacement as well as changes in the inclination were investigated. Results The labial ABT of central and lateral incisors at the mid-root third was increased. In contrast, the palatal ABT at crestal, mid-root and apical third level were consistently decreased. ABH was not altered on the labial side, while significantly decreased on the palatal side. ABA was not significantly increased on the labial side, but significantly decreased on the palatal side, leading to a significantly reduced total ABA. Orthodontic treatment significantly reduced inclination of upper incisors. Changes in the amount (T1-T0) of ABA was remarkably correlated with apex displacement and changes of inclination (T1-T0); in addition, using the multivariate linear regression analysis, changes of ABA on the palatal side (T1-T0) can be described by following equation: Changes of palatal ABA (T1-T0) = − 3.258- 0.139× changes of inclination (T1-T0) + 2.533 × apex displacement (T1-T0). Conclusions Retraction of incisors in bimaxillary protrusion patients may compromise periodontal bone support on the palatal side. An equation that incorporated the displacement of root apex and change in the incisor inclination may enable periodontist-orthodontist interdisciplinary coordination in assessing treatment risks and developing an individualized treatment plan for adult patients with bimaxillary protrusion. Moreover, the equation in predicating area of alveolar bone may reduce the risks of placing the teeth out of the bone boundary during 3D digital setups.


2020 ◽  
Author(s):  
Huimin Mao ◽  
Andi Yang ◽  
Yue Pan ◽  
Houxuan Li ◽  
lang lei

Abstract Background: Periodontal health is of great concern for periodontists and orthodontists in the inter-disciplinary management of patients with bimaxillary protrusion. The aim of present study is to investigate changes in the alveolar bone in the maxillary incisor region and to explore its relationship with displacement of root apex as well as changes in the inclination of maxillary incisors during incisor retraction. Methods: Samples in this retrospective study consisted of 38 patients with bimaxillary protrusion. Cone-beam computed tomography (CBCT) images was taken before(T0) and after (T1) treatment. Alveolar bone thickness (ABT), height (ABH) and area (ABA) were utilized to evaluate changes in the alveolar bone, while incisor inclination and apex displacement were used to assess changes in the position of maxillary central and lateral incisors. Correlations between alveolar bone remodeling and apex displacement as well as changes in the inclination were investigated. Results: The labial ABT of central and lateral incisors at the mid-root third was increased. In contrast, the palatal ABT at crestal, mid-root and apical third level were consistently decreased. ABH was not altered on the labial side, while significantly decreased on the palatal side. ABA was not significantly increased on the labial side, but significantly decreased on the palatal side, leading to a significantly reduced total ABA. Orthodontic treatment significantly reduced inclination of upper incisors. Changes in the amount (T1-T0) of ABA was remarkably correlated with apex displacement and changes of inclination (T1-T0); in addition, using the multivariate linear regression analysis, changes of ABA on the palatal side (T1-T0) can be described by following equation: Changes of palatal ABA (T1-T0) = -3.258- 0.139× changes of inclination (T1-T0) + 2.533×apex displacement (T1-T0). Conclusions: Retraction of incisors with palatal apex displacement reduced periodontal bone support on the palatal side. An equation that incorporated the displacement of root apex and change in the incisor inclination may enable periodontist-orthodontist interdisciplinary coordination in assessing treatment risks and developing an individualized treatment plan for adult patients with bimaxillary protrusion.


2021 ◽  
Author(s):  
Ya Zheng ◽  
Chenjing Zhu ◽  
Meng Zhu ◽  
Lang Lei

Abstract Background: The purpose of this study was to compare the difference of alveolar bone remodeling between the adolescents and adults in the maxillary incisor area during retraction. Methods: This retrospective study included 72 female patients who needed moderate anchorage to correct the bimaxillary protrusion. Subjects were further divided into the minor group (n=36, 11-16 years old) and adult group (n=36, 18-35 years old). Digital lateral cephalography and cone beam CT scanning were taken in each patient before (T0) and after treatment (T1). Cephalometry was conducted to assess incisor retraction, while alveolar bone thickness (ABT), alveolar bone distance (ABD, and alveolar bone area (ABA) were detected to assess changes in the alveolar bone. Results: No difference in the inclination of upper incisors was observed at both T0 and T1. Changes in the alveolar bone showed a similar tendency with bone apposition on the labial side and resorption on the palatal side. Less increase in the labial ABT (T1-T0) and more decrease in the palatal ABT (T1-T0) was found in the adult group, leading to less total ABT in the adult group. Higher reduction inn ABD (T1-T0) was found in the adult group. Moreover, more decrease in the ABA (T1-T0) was found in the adult group. Conclusion: When compared adolescents, adult patients have less alveolar bone support after orthodontic treatment, showing a through-the-bone remodeling pattern. Orthodontic should take the age into consideration to reduce the potential periodontal risks during treatment planning.


Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4225
Author(s):  
Cinzia Maspero ◽  
Francesca Gaffuri ◽  
Iury O. Castro ◽  
Valentina Lanteri ◽  
Alessandro Ugolini ◽  
...  

The aim of this study was to evaluate the correlation between dental vestibular–palatal inclination changes and the cortical bone remodeling after fixed orthodontic treatment using cone beam computed tomography (CBCT). Twenty-two patients with Angle Class I malocclusion, permanent dentition, and mild to moderate dental crowding were included in the present three-dimensional (3D) analysis. Bone dimensions were evaluated by CBCT scans obtained before and after orthodontic treatment, whereas the torque values were calculated by means of digital models using the 3D VistaDent software. A paired t-test was used to compare the changes between the pretreatment and post-treatment measurements. The correlations between variables were analyzed with linear regression analysis. A significant correlation between torque variations and bone thickness changes was observed for the apical buccal level of the anterior side (P < 0.05). Limited and not significant alveolar bone resorption for the apical thickness of anterior teeth occurred at ± 5 degrees of torque variation, while for tooth inclination exceeding +5 or −5 degrees, the bone remodeling was more evident. The present study demonstrated that anterior region was the most affected area by bone remodeling and that torque variation was highly related to apical bone thickness adaptation for maxillary and mandibular incisors and maxillary canines.


2021 ◽  
pp. 002203452110199
Author(s):  
Y. Xie ◽  
Q. Tang ◽  
S. Yu ◽  
W. Zheng ◽  
G. Chen ◽  
...  

Orthodontic tooth movement (OTM) depends on periodontal ligament cells (PDLCs) sensing biomechanical stimuli and subsequently releasing signals to initiate alveolar bone remodeling. However, the mechanisms by which PDLCs sense biomechanical stimuli and affect osteoclastic activities are still unclear. This study demonstrates that the core circadian protein aryl hydrocarbon receptor nuclear translocator–like protein 1 (BMAL1) in PDLCs is highly involved in sensing and delivering biomechanical signals. Orthodontic force upregulates BMAL1 expression in periodontal tissues and cultured PDLCs in manners dependent on ERK (extracellular signal–regulated kinase) and AP1 (activator protein 1). Increased BMAL1 expression can enhance secretion of CCL2 (C-C motif chemokine 2) and RANKL (receptor activator of nuclear factor–κB ligand) in PDLCs, which subsequently promotes the recruitment of monocytes that differentiate into osteoclasts. The mechanistic delineation clarifies that AP1 induced by orthodontic force can directly interact with the BMAL1 promoter and activate gene transcription in PDLCs. Localized administration of the ERK phosphorylation inhibitor U0126 or the BMAL1 inhibitor GSK4112 suppressed ERK/AP1/BMAL1 signaling. These treatments dramatically reduced osteoclastic activity in the compression side of a rat orthodontic model, and the OTM rate was almost nonexistent. In summary, our results suggest that force-induced expression of BMAL1 in PDLCs is closely involved in controlling osteoclastic activities during OTM and plays a vital role in alveolar bone remodeling. It could be a useful therapeutic target for accelerating the OTM rate and controlling pathologic bone-remodeling activities.


1994 ◽  
Vol 266 (5) ◽  
pp. E731-E738 ◽  
Author(s):  
C. Dolce ◽  
J. Anguita ◽  
L. Brinkley ◽  
P. Karnam ◽  
M. Humphreys-Beher ◽  
...  

Effects on bone remodeling have been attributed to epidermal growth factor (EGF). Sialoadenectomy (SX) removes the major source of EGF in rodents and decreases both salivary and serum EGF levels. EGF effects on rat alveolar bone remodeling manifested by molar drift (MD) and orthodontic tooth movement (OTM) were examined using the following two approaches: 1) EGF depletion by SX and replacement by orally administered EGF (50 micrograms.animal-1.day-1); 2) sham rats supplemented with matching amounts of EGF. MD and OTM were measured using cephalometric radiographs; bone formation was measured histomorphometrically using tetracycline labeling. Normal MD was not detected after SX, and alveolar bone formation was significantly reduced both around the tooth and in nondental sites. Replacement EGF given to SX rats and supplemental EGF administered to sham rats changed the direction and enhanced the rate of MD. A mesially directed orthodontic force applied to the molars of SX animals increased bone formation on the distal aspect of the tooth roots. Supplemental EGF did not significantly affect OTM. EGF affects alveolar bone remodeling, as manifested clinically by alterations in normal maxillary MD.


2019 ◽  
Vol 90 (3) ◽  
pp. 321-329
Author(s):  
Adilson Luiz Ramos ◽  
Monique Cimão dos Santos ◽  
Márcio Rodrigues de Almeida ◽  
Carlos Flores Mir

ABSTRACT Objectives To test the null hypothesis that there is no difference in bone dehiscence formation before and after orthodontic tooth movement through an atrophic alveolar ridge. Material and Methods This longitudinal retrospective study evaluated pretreatment and posttreatment cone-beam computed tomography imaging of 15 adult patients. Twenty-five teeth were moved through the atrophic alveolar bone, whereas 25 teeth not subjected to translational movement were considered controls. The distances between the cementoenamel junction and the alveolar bone crest were assessed at the mesial, distal, buccal, and lingual surfaces of all of these teeth. Data were compared using the Wilcoxon test. The Spearman correlation test and multivariate linear regression analysis were also performed. Results In general, crestal bone height was reduced around 0.5 mm in all groups in every direction. Median buccal dehiscence increased significantly (+2.25 mm) (P &lt; .05) in teeth moved through the atrophic ridge. Control teeth also had buccal crest loss (+0.83 mm), but this was not statistically different from that of the experimental teeth. Lingual dehiscence increased significantly for the experimental (+0.17 mm) and control (+0.65 mm) groups. Mesial bone height decreased more in the control group (–0.44mm) than in the experimental group (–0.14mm). There was moderate correlation between amount of tooth movement and alveolar bone loss. Conclusions The null hypothesis was rejected as dehiscence increased after tooth movement through an atrophic alveolar ridge, mainly in the buccal plate.


Bone ◽  
2019 ◽  
Vol 128 ◽  
pp. 115041 ◽  
Author(s):  
Celso Martins Queiroz-Junior ◽  
Anna Clara Paiva Menezes Santos ◽  
Izabela Galvão ◽  
Giovanna Ribeiro Souto ◽  
Ricardo Alves Mesquita ◽  
...  

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