Asymmetric 3-premolar extraction for an adult class II division 2 subdivision with deep bite and midline deviation - A case report

Sep 30, 2026

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Class II subdivision with division-2 features and deep bite creates combined sagittal, transverse, and vertical orthodontic problems that include midline deviation and crowding. An asymmetric 3-premolar extraction strategy was used to correct the dental midline and crowding while supporting incisor decompensation and smile-focused esthetic improvement with limited patient compliance. In this case, an adult woman’s protrusion concerns and mandibular midline deviation were addressed through controlled mechanics and bite leveling, with outcomes showing normalized overjet and overbite and improved lip posture.

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CategoryHealthcare

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Introduction

® Clinical Case Report Asymmetric 3-premolar extraction for an adult class II division 2 subdivision with deep bite and midline deviation A case report Viet Anh Nguyen, DDS MSa ,* , Thi Bao Yen Ngo, DDSb | Abstract
Rationale: Class II subdivision with division-2 features and deep bite presents concurrent sagittal, transverse, and vertical challenges. Asymmetric extraction may correct the midline and crowding while enabling incisor decompensation and esthetic improvement with limited patient compliance.
Patient concerns: A 39-year-old woman sought reduction of “protrusion” and improvement of smile esthetics, along with alignment of crowded maxillary incisors and correction of a rightward mandibular midline deviation.
Diagnoses: Skeletal class II pattern with a right side class II subdivision, division-2 incisor inclination, deep bite, increased overjet, moderate crowding, and mandibular midline deviated 3 mm to the right.
Interventions: An asymmetric 3-premolar extraction protocol (both maxillary first premolars and the mandibular second premolar on the class II side) was combined with controlled incisor mechanics, careful vertical control for bite leveling, space closure, and asymmetric finishing goals.
Outcomes: Treatment achieved full alignment, coincidence of dental and facial midlines, normalization of overjet, overbite, and improvement of smile esthetics and lip posture. The left side finished in class I, and the right side in a deliberate functional class II molar relationship consistent with the asymmetric plan. Radiographic skeletal and dentoalveolar measurements indicated a clinically meaningful reduction in the sagittal discrepancy.
Lessons: For selected adult class II subdivision cases with division-2 features and deep bite, asymmetric 3-premolar extraction offers a predictable, compliance-light alternative to 4-premolar extraction or distalization. Intentional functional class II finishing on the affected side can be compatible with stable occlusion when midlines, overjet, overbite, and incisor torque are properly managed.
Abbreviations: ANB = point A-nasion-point B, NiTi = nickel–titanium, SS = stainless steel, TAD = temporary anchorage device. | | --- | | Keywords: adult orthodontics, camouflage orthodontics, esthetic appliances, lingual orthodontics, torque control | 1. Introduction Class II malocclusion is among the most prevalent sagittal discrepancies, with an estimated global prevalence of about 20% in the permanent dentition; deep overbite is also frequent, and class II division 2, although less common, is typically associated with retroclined maxillary incisors and a deepbite pattern. [1,2] Within this spectrum, class II subdivision – defined by a unilateral class II relationship and midline deviation toward the class II side – is common and often reflects underlying dentoalveolar and skeletal asymmetries. Contemporary cone beam computed tomography-based studies suggest that subdivision patterns may account for up to half of class II cases and have a reported population prevalence of 12% to 37%, underscoring their clinical relevance and the need for 3-dimensional assessment. [3–5] In adults with class II division 2 features and deep bite, diagnosis should integrate facial symmetry and midline analysis, occlusal evaluation, and cephalometric measurements, supplemented by cone beam computed tomography when clarification of the center of asymmetry or transverse discrepancies is required. [4,5] Management options include symmetric extractions (4 premolars), asymmetric extraction protocols (e.g., 2 maxillary first premolars plus a mandibular premolar The authors have no funding and conflicts of interest to disclose. All data generated or analyzed during this study are included in this published article [and its supplementary information files]. Written informed consent was obtained from the patient, and the patient consented to the publishing of all images and clin

FAQs

What orthodontic problems were treated in this case report?

The case involved a skeletal Class II pattern with right-sided subdivision, division-2 incisor inclination, deep bite, increased overjet, moderate crowding, and a 3 mm rightward mandibular midline deviation.

What was the main treatment approach?

Treatment used an asymmetric 3-premolar extraction protocol—both maxillary first premolars and the mandibular second premolar on the Class II side—combined with controlled incisor mechanics and careful vertical control for bite leveling and asymmetric finishing.

What outcomes were reported after treatment?

Full alignment was achieved, dental and facial midlines coincided, overjet and overbite were normalized, and smile esthetics plus lip posture improved. Finishing was Class I on the left side and a deliberate functional Class II molar relationship on the right side.

Sep 30, 2026

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