Diagnosis and Treatment Planning


Diagnosis and Treatment Planning

The treatment records for one patient are used here as an example of the advanced diagnostic facilities provided by systems such as Onyx Ceph (Image Instruments Ltd., Chemnitz, Germany). The treatment of most of the cases presented in subsequent chapters was planned using the methodology described below.

An 18-year-old patient presented for an orthodontic evaluation. She had undergone previous orthodontic treatment involving removal of two upper first premolars to align the upper canines. Post-treatment records following the first orthodontic treatment showed a left-sided unilateral crossbite as an initial sign of maxillary deficiency. In addition, she had a reduced overjet and overbite, which was at risk for worsening with further growth given the patient’s class III tendency. The current records showed a bilateral crossbite and anterior edge-to-edge relationship as a result of the previous treatment and additional craniofacial growth.

The patient’s chief complaint was a protruding chin, which was accentuated by a maxillary deficiency. After initial decompensation, it became clear that the underlying class III malocclusion should ideally be treated with an orthognathic approach ( Fig. 4.5 : 21, 22).

After superimposition of the cephalogram and the clinical photograph, a prediction tracing was obtained with a “visualized treatment objective” (VTO). Analysis of the three-dimensional models allowed further planning in this case.

Case Study 4.1 (Fig. 4.5)

Patient: F. K., female, age 18.

Diagnostic records: models, panoramic radiograph, lateral cephalometric radiograph, intraoral/extraoral photographs.

Main findings: class III malocclusion due to mandibular excess and relapse after previous orthodontic treatment, combined with residual craniofacial growth.

Treatment aims: combined orthodontic surgical treatment to improve the profile and the stability of the treatment result.

Appliances: self-ligating brackets, Hybrid RPE (see p. 135).

Archwire sequence: 0.012 round wire, superelastic; 0.016 round wire, superelastic, 0.016 × 0.022 superelastic, 0.018 × 0.025 superelastic and 0.019 × 0.025 stainless-steel archwires.

Alternative treatment strategy: opening of spaces in the upper jaw for later replacement of the previously extracted upper first pre-molar teeth (14 and 24), or alternatively extraction of two corresponding premolars in the lower jaw for further dental compensation.

Active treatment time: 11 months.

Retention: three-dimensional retention.

Fig. 4.5 1–5 Condition after orthodontic treatment of several years’ duration. The treatment involved removal of 14 and 24. 6, 7 Both the profile picture and cephalo-metrics show a hypoplastic and retruded maxilla, combined with mandibular prognathism. 8 The panoramic radiograph shows shortened and pipette-shaped roots on the incisors and premolars in particular; all wisdom teeth are present. 9 Cephalometric analysis reveals a class III malocclusion and a low maxillary-mandibular plane angle. Digital cephalometry allows easy use of a number of analyses and comparison between them. Cephalometric landmarks for further analysis can be easily added. 10 Space analysis using a digital three-dimensional computer-aided analysis of the study models. The plaster models were scanned and measured digitally. The software helps to assess the space requirements for alignment. 11–15 Skeletally supported rapid palatal expansion (see also Chapter 8). Self-ligating brackets are used to align the teeth. 16–20 21, 22 Lateral cephalometric view of the patient after presurgical decompensation. The underlying class III skeletal base is now fully revealed. 23–26 Surgical prediction tracing by means of computer-aided superimposition of the lateral photograph and lateral cephalometric view. This can sometimes be helpful to establish whether single-jaw or bimaxillary osteotomy is indicated, and it also helps establish the best esthetic parameters for the surgical outcome. It is an extremely helpful tool for communication between the multidisciplinary team (orthodontist and maxillofacial surgeon) and the patient. 27 Digital analysis of the preoperative diagnostic models. The arch coordination is usually difficult to determine clinically; digitized three-dimensional analysis of the study models can facilitate this task and is therefore helpful in assessing the outcome of presurgi-cal orthodontics. 28–31 Postoperative situation images. 32–40 Intraoral views before treatment (top row), preoperatively (middle row), and 1 year in retention (lower row). 41–46 Profile view and lateral cephalometric views before treatment (left), preoperatively (middle), and postoperatively (right).

Errors and risks:

It might be prudent to consider a non-extraction approach for the upper jaw when planning treatment for growing patients with a class III malocclusion on a class III skeletal base. Particularly when undertaken in the upper jaw, extractions only often lead to poor treatment outcomes. Maxillary extractions alone are generally not indicated for class III cases.

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Jul 7, 2020 | Posted by in Orthodontics | Comments Off on Diagnosis and Treatment Planning
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