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. 2023 Nov 27;23(1):931.
doi: 10.1186/s12903-023-03684-7.

Hard and soft tissue shape variation and changes in Class II division 1 malocclusion during orthodontic treatment: a geometric morphometric analysis

Chin Sin Chu  1 , Murshida Marizan Nor  2 , Alizae Marny Mohamed  1 , Helmi Mohd Hadi Pritam  3
Affiliations

Hard and soft tissue shape variation and changes in Class II division 1 malocclusion during orthodontic treatment: a geometric morphometric analysis

Chin Sin Chu et al. BMC Oral Health. .

Abstract

Background: This study aims to determine the hard and soft tissue shape variation and its changes in Class II division 1 malocclusion before and after orthodontic treatment using Geometric Morphometric Analysis.

Methods: This retrospective study included 141 pre-treatment and near-end treatment lateral cephalometric radiographs of Class II division 1 malocclusion patients aged 16-40 years with a skeletal II pattern (ANB > 4o). 32 landmarks in Cartesian coordinates were created and identified using MorphoJ software to establish a shape analysis.

Results: The vertical dimensions (hypodivergent to hyperdivergent facial profiles) showed the largest variation in the general shape of hard and soft tissue, followed by the anteroposterior dimensions (mild to severe skeletal II patterns). Variations of lip shape (long to short), lip protuberance (everted to inverted), and nasolabial angle (obtuse to acute) were present. Orthodontic treatment affected the shape of the hard and soft tissue significantly (p < 0.0001). T2 showed significant uprighting of upper incisors (17.5o) and lower incisors (3.7o), improved NLA (8o), an increase in upper lip thickness (1.5 mm), and a reduction in lower lip thickness (0.7 mm) (p < 0.05).

Conclusion: Vertical and anteroposterior shape variations were found. Orthodontic treatment had an impact on both hard and soft tissue shapes. Hence, understanding both the hard and soft tissue shape variations and the orthodontic treatment changes is crucial for an accurate diagnosis and treatment plan to achieve a successful outcome and excellent patient satisfaction.

Keywords: Class II division 1; Geometric Morphometric; Soft tissue; Treatment changes.

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Conflict of interest statement

The authors declare no competing interests.

Figures

Fig. 1
Fig. 1
Landmarks for Geometric Morphometric Analysis
Fig. 2
Fig. 2
Angular (o) and linear (mm) measurements used in the study: SNA (∠1), SNB (∠2), ANB (∠3), Maxillary mandibular plane angle (∠4), Gonion angle (∠5), Upper incisor inclination (∠6), Lower incisor inclination (∠7), Interincisal angle (∠8), Nasolabial angle (∠9), Upper lip thickness (d1), and Lower lip thickness (d2)
Fig. 3
Fig. 3
Hard and soft tissue shape variations; black and grey show the mean shape at T1, while blue shows the shape variations associated with PC1 and PC2.
Fig. 4
Fig. 4
Discriminant analysis (DA) of hard and soft tissue; 4(a): Analysis graph and warped outline drawing before (T1) and after orthodontic treatment (T2); 4(b): DA of the maxilla; 4(c): DA of the mandible; and 4(d): DA of the soft tissues
See this image and copyright information in PMC

References

    1. Ismail K, Ghazali-Suhaimi SS, Abu Bakar N, Mokhtar K, Kharuddin AF. Demographics characteristics and analysis of malocclusions of Orthodontic patients seen at IIUM Dental Specialist Clinic, Kuantan, Pahang. Int Med J Malaysia. 2017;16:107–11.
    1. Ardani I, Pratiknjo IS, Djaharu’ddin I. Correlation between Dentoalveolar Heights and Vertical skeletal patterns in Class I Malocclusion in ethnic Javanese. Eur J Dentistry. 2021;15(2):210–5. doi: 10.1055/s-0040-1717156. - DOI - PMC - PubMed
    1. Adams CP, Kerr WJ. Overbite and face height in 44 male subjects with class I, class II/1 and class II/2 occlusion. Eur J Orthod. 1981;3(2):125–9. doi: 10.1093/ejo/3.2.125. - DOI - PubMed
    1. Maetevorakul S, Viteporn S. Factors influencing soft tissue profile changes following orthodontic treatment in patients with Class II Division 1 malocclusion. Prog Orthodont. 2016;17:13. doi: 10.1186/s40510-016-0125-1. - DOI - PMC - PubMed
    1. Su H, Han B, Li S, Na B, Ma W, Xu TM. Factors predisposing to maxillary anchorage loss: a retrospective study of 1403 cases. PLoS ONE. 2014;9(10):e109561. doi: 10.1371/journal.pone.0109561. - DOI - PMC - PubMed

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