The frontal clinical assessment showed a symmetric long face, with a harmonious and flat facial profile, a well-defined nasolabial angle, a pronounced labiomental fold, and a chin aligned with the facial midline. Vertically, the patient exhibited a normodivergent facial pattern (Figure 1Figures 1(a)-(c)).

Figure 1. (a)-(c): Initial extraoral photographs: frontal, profile, and smiling views.

At intraoral examination, the patient presented with a Class I canine and molar relationship on the right side, and a Class II canine with a Class I molar relationship on the left side, associated with a dentallyoriginated midline deviation and a moderately increased overjet.

In the maxillary arch, anterior crowding was noted, along with constriction of the lateral segments, distorotation of teeth 13 and 23, and buccal flaring of teeth 11 and 21.

In the mandibular arch, anterior crowding of 4 mm was observed, in addition to moderate left lateral crowding of approximately 4 mm related to the buccal displacement of tooth 35 (Figure 2Figures 2(a)-(c), Figure 3Figures 3(a)-(b)).

Figure 2. (a)-(c): Right, frontal, and left intraoral buccal views at the beginning of treatment.

Figure 3. (a) & (b) Initial maxillary and mandibular occlusal views.

The analysis of the dental casts confirmed all clinically observed findings, particularly the accentuated mandibular Curve of Spee (Figure 4Figure 4).

Figure 4. Pre-treatment study cast photographs.

The functional examination revealed a mixed oral-nasal breathing pattern and an atypical swallowing pattern characterized by lower lip interposition, associated with a lower-lip sucking habit. No signs of temporomandibular joint disorder were reported.

The initial panoramic radiograph showed a complete permanent dentition, including the four third molars, with no evidence of osseous pathology (Figure 5Figure 5).

Figure 5. Pre-treatment panoramic radiograph.

The initial lateral cephalometric radiograph showed signs of moderate anterior rotation, with both mandibular and maxillary incisors positioned labially (Figure 6Figure 6).

Figure 6. Pre-treatment lateral cephalometric radiograph.

Steiner and Tweed analyses were performed (Table 1 and Table 2). Cephalometric evaluation confirmed a skeletal Class II maxillomandibular sagittal relationship (ANB = 4˚; AoBo = −2 mm) with a normodivergent vertical pattern (GoGn = 30˚; FMA = 25˚). The upper incisors were proclined (U1 − NA = 24˚/6 mm), as were the lower incisors (L1 − NB = 30˚/6 mm; IMPA = 97˚).

Steiner’s analysis also revealed a total mandibular arch crowding of 17 mm, mainly associated with dental crowding and a pronounced curve of Spee (Figure 7Figure 7).

Facial examination revealed a normodivergent pattern with an accentuated labiomental fold. Skeletally, the patient presented a normodivergent skeletal Class II relationship. Dentally, she exhibited an increased overbite in the vertical dimension, a left canine Class II relationship with deviation of both maxillary and mandibular midlines, and a bimaxillary protrusion. The severe dental crowding was suggestive of relative macrodontia.

Table 1.Pre-treatment Steiner analysis.

Table 2.Pre-treatment Tweed analysis.

Figure 7. Chevron diagrams and the Steiner BoxTreatment objectives.

They were established as follows:

Correct the dental crowding Achieve a Class I canine relationship on the left side Restore normal overbite and overjet Ensure long-term stability of the treatment outcomes

To achieve these objectives, two treatment options were considered:

The first therapeutic option consisted of extracting the maxillary and mandibular second premolars, as confirmed by Steiner’s analysis, which revealed a total mandibular arch discrepancy of 17 mm indicating the need for premolar extractions. This approach would allow correction of the left canine Class II relationship and resolution of dental crowding, while improving the axial inclinations of both maxillary and mandibular incisors.

The second therapeutic option involved a non-extraction treatment approach. In this case, correction of the left canine Class II relationship and both maxillary and mandibular crowding would be achieved through arch expansion and further proclination of the lower incisors, combined with Class II mechanics. This option would preserve the facial profile harmony, and since the patient presents a normodivergent pattern, a certain degree of lower incisor proclination can be tolerated.

Therefore, this second option was selected, although it requires strict control of the anterior torque to achieve optimal occlusal results and ensure long-term stability.

A standard Edgewise appliance with a 0.022 × 0.028-inch slot was used. Alignment and leveling were initiated using 0.016-inch NiTi archwires in both arches, with slight expansion and an accentuated curve of Spee in the maxilla and an inverse curve of Spee in the mandible, with bends placed behind the molar tubes. Leveling was continued using 0.019 × 0.025-inch NiTi archwires while maintaining the same curve of Spee principles. At the end of this phase, significant proclination of the mandibular incisors and absence of overbite were observed (Figure 8Figures 8(a)-(c)).

The consolidation phase was carried out using 0.019 × 0.025-inch stainless steel archwires in both arches (Figure 9Figures 9(a)-(c)). The mandibular archwire included an inverse curve of Spee and a lingual-crown torque, which increased the overjet and enabled correction of the Class II using intermaxillary elastics (3/16 in, 3.5 oz, ORMCO) (Figure 10Figures 10(a)-(c)).

The total treatment duration was 15 months. After debonding, fixed retainers were placed from teeth 12 to 22 in the maxillary arch and from 33 to 43 in the mandibular arch.

Figure 8. (a)-(c) Right, frontal, and left intraoral buccal views during treatment.

Figure 9. (a)-(c) Right, frontal, and left intraoral buccal views during the finishing phase.

Figure 10. (a)-(c) Right, frontal, and left intraoral buccal views during the finishing phase.

The treatment objectives were successfully achieved. From a facial and profile standpoint, there was a notable improvement in the nose-lips-chin relationship, along with a significantly enhanced smile esthetics (Figure 11Figures 11(a)-(c)). A Class I canine relationship on the left side was obtained, with coincident dental midlines and ideal overbite and overjet (Figure 12Figures 12(a)-(c), Figure 13Figures 13(a)-(b), and Figure 14Figure 14).

The panoramic radiograph demonstrated parallelism of the dental roots (Figure 15Figure 15).

Cephalometric analysis and superimpositions showed no skeletal changes; however, they revealed significant dentoalveolar improvements, including substantial reduction of the overjet and overbite, primarily achieved through intrusion of both maxillary and mandibular incisors, as well as a marked proclination of the mandibular incisors (Figure 16Figures 16-18; Table 3 and Table 4).

Figure 11. (a) & (c) Frontal, profile, and smiling extraoral photographs at the end of treatment.

Figure 12. (a) & (c) Right, frontal, and left intraoral buccal views at the end of treatment.

Figure 13. (a) & (b) Maxillary and mandibular occlusal views at the end of treatment.

Figure 14. Post-treatment cast photographs.

A 6-month post-treatment follow-up was conducted. Clinical examination showed stable overjet and overbite with no relapse of midline deviation. Fixed retainers remained intact, and no periodontal changes were observed. These early findings support short-term stability of the treatment outcome.

Figure 15. Post-treatment panoramic radiograph.

Figure 16. Post-treatment lateral cephalometric radiograph.

Figure 17. Tweed general superimpositions.

Figure 18. Tweed local superimpositions.

Table 3. Post-treatment Steiner analysis.

Table 4. Post-treatment Tweed analysis.