Three-dimensional computed tomography analysis of mandibular morphology in patients with facial asymmetry and mandibular retrognathism

You, Kug-Ho; Kim, Kyung Ho; Lee, Kee‐Joon; Baik, Hyoung-Seon

doi:10.1016/j.ajodo.2017.08.024

Cited by 16 publications

(30 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Therefore, in this study, we used two reference planes to distinguish between the mandibular asymmetry itself and mandibular misalignment problems. AMP was used as the mandibular internal median plane to evaluate the structural asymmetry of the mandible 12,13 ; MSP was used as the clinically applied sagittal reference plane for the evaluation of mandibular asymmetry relative to the face, which is caused by rotation or misalignment, as well as structural asymmetry of the mandible 14 . AMP used in this study is landmark-based, simple to establish, and can be useful for quantitatively comparing bilateral measurement values, such as surface area and volume.…”

Section: Discussionmentioning

confidence: 99%

“…Using the medical studio of Invivo 6 (Anatomage, San Jose, CA, USA), fourteen 3D Landmarks were selected in accordance with the procedure used in a previous study (Table 5) 12,13 . The images were reoriented using 2 reference planes: the Frankfort horizontal plane (FHP), passing through the bilateral Po and left Or, and the MSP, passing through the N and S (perpendicular to the FHP).…”

Section: Methodsmentioning

confidence: 99%

“…The ramal length was defined as the distance between Con sup and Go mid , and the body length was defined as the distance between Go mid and Me 12,13 . The mandible was divided into two hemi-mandibles by the plane connecting Me, B, and G, which was defined as the AMP (Fig.…”

Section: Methodsmentioning

confidence: 99%

See 2 more Smart Citations

Similarity index for intuitive assessment of three-dimensional facial asymmetry

Kwon

Hwang

Jung

et al. 2019

Sci Rep

Self Cite

View full text Add to dashboard Cite

Evaluation of facial asymmetry generally involves landmark-based analyses that cannot intuitively assess differences in three-dimensional (3D) stereoscopic structures between deviation and non-deviation sides. This study tested a newly developed similarity index that uses a mirroring technique to intuitively evaluate 3D mandibular asymmetry, and characterised the resulting lower facial soft tissue asymmetry. The similarity index was used to evaluate asymmetry before and after surgery in 46 adult patients (27 men, 19 women; age, 22 ± 4.8 years) with skeletal Class III malocclusion and facial asymmetry who underwent conventional bimaxillary orthognathic surgery. Relative to the midsagittal plane used as the reference plane, the non-overlapping volume of the mandible significantly decreased, and the similarity index significantly increased after surgery. Similarity indexes of the mandible and lower facial soft tissue were strongly negatively correlated with non-overlapping volumes of each measurement. Differences in bilateral hemi-mandibular and hemi-lower facial soft tissue surface and volume measurements before surgery were significantly negatively correlated with similarity indexes of the mandible before and after surgery. This newly developed similarity index and non-overlapping volume using a mirroring technique can easily and intuitively evaluate overall 3D morphological discrepancies, especially 3D mandibular asymmetry, before and after surgery in skeletal Class III patients with facial asymmetry.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Similarity index for intuitive assessment of three-dimensional facial asymmetry

Kwon

Hwang

Jung

et al. 2019

Sci Rep

Self Cite

View full text Add to dashboard Cite

show abstract

“…There has been growing demand for the correction of facial asymmetry as patient expectations have increased [ 1 ]. Disharmony of lower facial width is a type of facial asymmetry whose mainstay corrective surgical procedures include orthognathic surgery, resection of the corresponding portion of the mandible, and resection of the masseter muscle [ 1 , 2 ]. Meanwhile, patients tend to prefer less invasive options, such as botulinum neurotoxin (BoNT) injection into masseter muscle to reduce its volume [ 3 ].…”

Section: Introductionmentioning

confidence: 99%

“…As precisely predicting the post-treatment outcome in facial asymmetry remains challenging, given the diverse patterns of asymmetry and the involvement of both skeletal and soft tissue changes, the asymmetry can remain after the corrective surgery [ 1 , 2 , 9 ]. BoNT can be utilized as an adjunct procedure in such cases.…”

Section: Introductionmentioning

confidence: 99%

Effect of Botulinum Toxin Injection on Asymmetric Lower Face with Chin Deviation

Kim

Park

Favero

et al. 2020

Toxins

View full text Add to dashboard Cite

The purpose of this study was to compare the efficacy of botulinum toxin (BoNT) in masseter muscle reduction depending on the amount of chin deviation. Exploring distinctive effects of BoNT relative to the characteristics of facial asymmetry will aid in planning and predicting treatment outcomes. Sixteen adult volunteers were classified into two groups according to the degree of menton deviation observed in posteroanterior cephalograms. Eight had a menton deviation of 3 mm or more and the other eight had less than 3 mm. A total of 25 Units of BoNT was injected into the unilateral masseter muscle of the prominent side for each participant. Changes in the volume and bulkiest height of the lower face on each side were measured with a 3D laser scan at four time points: before and 4, 8, and 12 weeks after the injection. Two-way mixed ANOVA was employed for analyses. The volume and bulkiest height of the injected side decreased over time in both types of asymmetry, with significant differences at each time point. The reductions in the volume and bulkiest height were significantly greater in subjects without chin deviation. The reductions in the volume and bulkiest height of the lower face using BoNT are more effective for subjects without chin deviation.

show abstract

Dreidimensionale Charakteristika der Mandibula bei skelettalen Malokklusionen

Olbrisch

Santander²,

Moser³

et al. 2022

J Orofac Orthop

View full text Add to dashboard Cite

Purpose We aimed to comprehensively analyse a possible correlation between skeletal malocclusions, gender and mandibular characteristics in all three dimensions in adults and to identify mandibular characteristics that are typical for extreme skeletal patterns. Methods A 3D model of the skull was calculated in 111 adult patients (mean age = 27.0 ± 10.2 years; 49 women, 62 men) from available computed tomography or cone beam computed tomography scans of their heads. Based on the 3D models, the skeletal patterns were examined in (a) the transversal dimension regarding asymmetry according to menton deviation, (b) the sagittal dimension according to the Wits appraisal and (c) the vertical dimension according to the maxillomandibular plane angle. The mandibular characteristics assessed were linear (ramus height and width, body length), angular (ramus, gonial and body angle) and volumetric (ramus/mandibular volume, body/mandibular volume) parameters. Results No correlation between transversal skeletal asymmetry and mandibular characteristics were found, while sagittal (F(16, 174) = 3.32, p < 0.001, η2 = 0.23) and vertical (F(16, 174) = 3.18, p < 0.001, η2 = 0.23) skeletal patterns were shown to have a significant effect on the mandible. Gender correlated with mandibular characteristics independently from the skeletal pattern. Discriminant analysis revealed that class II and III patients differed in ramus and body angle with class II patients showing higher angles (ramus angle: class II = 89.8 ± 3.9° vs. class III = 84.4 ± 4.8°; body angle: class II = 87.7 ± 4.8° vs. class III = 82.1 ± 5.2°). Hypo- and hyperdivergent patients were discriminated by gonial angle, body angle and body/mandibular volume with hyperdivergent patients having a greater gonial and body angle and body/mandibular volume (gonial angle: hypodivergent = 114 ± 9.3° vs. hyperdivergent = 126.4 ± 8.6°; body angle: hypodivergent = 82.9 ± 4.4° vs. hyperdivergent = 87.7 ± 6.5°; body/mandibular volume: hypodivergent = 72.4 ± 2.7% vs. hyperdivergent = 76.2 ± 2.6%). Conclusion When analysing 3D data for treatment planning of adult patients, the orthodontist should pay attention to angular and volumetric characteristics of the mandible to identify extreme skeletal sagittal or vertical malocclusions.

show abstract

Three-dimensional computed tomography analysis of mandibular morphology in patients with facial asymmetry and mandibular retrognathism

Abstract: Condylar, body, and coronoid units contribute to mandibular asymmetry in patients with facial asymmetry and mandibular retrognathism.

Cited by 16 publications

References 16 publications

Similarity index for intuitive assessment of three-dimensional facial asymmetry

Similarity index for intuitive assessment of three-dimensional facial asymmetry

Effect of Botulinum Toxin Injection on Asymmetric Lower Face with Chin Deviation

Dreidimensionale Charakteristika der Mandibula bei skelettalen Malokklusionen

Contact Info

Product

Resources

About