Introduction

One of the most common daily challenges for the orthodontist is dealing with the Class II malocclusion. Although standard treatment protocols are well‐known to clinicians, they are generally intended for symmetric malocclusions. But how many symmetric Class II patients are encountered in the daily clinical practice? It has been estimated that subdivision cases account to up to 50% of all Class II malocclusions (Rose et al. 1994).

The Class II subdivision malocclusion is known as a primarily dentoalveolar malocclusion (Alavi et al. 1988; Janson et al. 2001). However, analyses carried out with 3D diagnostic methods have highlighted often the presence of skeletal components (Sanders et al. 2010). Once the asymmetry has been located and quantified, the type of treatment should be proposed. Moderate to severe skeletal asymmetries often require surgical correction, nevertheless when these are ruled out and a mild‐to‐moderate asymmetry is diagnosed, dentoalveolar correction might be the most appropriate treatment.

Malocclusions are often characterized by dental crowding. If a certain amount of crowding exists and/or dental protrusion is present in the Class II subdivision malocclusion, extraction treatment can be the strategy of choice and asymmetric extractions can be beneficial and often successful for a camouflage approach (Janson et al. 2004; Turpin 2005).

The present chapter describes camouflage orthodontic treatment with asymmetric extractions of two patients featuring Class II subdivision malocclusions.

Case 1

A healthy 15‐years‐old boy, concerned about his crooked teeth, presented a Class II subdivision right malocclusion with bimaxillary crowding in the full permanent dentition (Figure 12.4.1a–h). The extra‐oral appearance displayed absence of evident asymmetries (apart from a slightly lower left orbit compared to the right one), good lip competence, and a convex profile with a slight protrusion of the upper lip.

The intra‐oral view was characterized by coinciding upper and lower midlines, although the patient presented a full Class II canine and molar relationships on the right side and Class I relationships on the left side. The degree of maxillary crowding was moderate, while mandibular anterior crowding was minimal. The upper and lower dental midlines were coincident, also with the facial midline. The panoramic radiograph displayed a complete permanent dentition with normal condylar anatomy, absence of periodontal pathology and developing buds of the third molars (Figure 12.4.2).

Lateral cephalometric radiographic assessment revealed a Class II normo‐divergent skeletal pattern with increased inclinations of both the upper and especially the lower incisors (Figure 12.4.3; Table 12.4.1).

Nonextraction treatment was initially considered.

The first option considered was a direct straight‐wire approach. The coinciding upper and lower midlines, with different amount of crowding of the right and left sides of the maxillary dental arch, contraindicated an indiscriminate levelling and alignment phase, which would unmask the asymmetry. Furthermore, incisor proclination to unravel the crowding was contraindicated due to the initial cephalometric parameters.

The second option considered was again nonextraction with a monolateral upper molar distalization on the Class II side. This option required a fixed intra‐oral distalizer and the use of skeletal anchorage. The amount of distalization required and the proclination of the lower incisors during the alignment phase, increasing the initial values, were the main reasons to discard this option.

Camouflage extraction treatment was then considered. A Class II extraction protocol (upper first premolar and lower second premolar) was decided for the right side, while two second bicuspids would be extracted on the left side. This option would allow to alleviate both crowding and dentoalveolar protusion, maintaining midlines symmetry.

This last option became the treatment of choice.

Figures 12.4.4a–c and 12.4.5a–c describe the progress of the treatment, which lasted overall 23 months.

The final result (Figure 12.4.6a–h) displays a symmetric and aligned final occlusion with Class I molar and canine relationships, normal overjet and overbite values and coincident midlines. The extra‐oral photos reveal a balanced face with good proportions, a natural smile, and a slightly convex profile.

The final panoramic radiograph demonstrates acceptable root parallelism and absence of detectable root resorption, with developing buds of the third molars (Figure 12.4.7). The final lateral cephalogram displays normalization of the overjet and overbite values (Figure 12.4.8) (Table 12.4.2).

The 24 months post‐treatment follow‐up displays a stable result (Figure 12.4.9a–f).

Case 2

A highly motivated healthy 32‐years‐old female came to a first orthodontic consultation concerned about the protrusion of her dentition. Her words, describing her chief complaint were “my teeth are too much forward and I cannot close my lips.” She presented a Class II subdivision right malocclusion in the full permanent dentition with increased overjet and overbite without crowding (Figure 12.4.10