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Trends ORTHO TRIBUNE | MARcH SUpplEMENT4 In many cases, the objectives of dentoalveolar treatment measures — the achievement of the func- tional and esthetic optimum for the patient — can be achieved using modern treatment methods. While minor dysgnathias can be treated using dentoalveolar mea- sures only, successful treatment of prominent sagittal discrepancies, such as Class II dysgnathias, is far more difficult. Correction can be achieved through dental movement if the jaw proportion is correct and if the dysgnathia is purely dentoalveolar. However, dental movements are possible only up to a certain degree and are thus limited. A correction or stable dental compensation of a skeletal dys- gnathia (for example, the correc- tion of a frontal cross-bite in a Class III or the correction of an extremely enlarged sagittal overjet in a Class II) is doubtful in some cases and, in general, shows a compromise in esthetics and/or function. In order to determine the options available for the therapy of a Class II dysgnathia, the remain- ing growth of the patient must be determined.35 Functional orthodon- tic treatment is a therapy form that can influence growth and is con- sidered a causal therapy in adoles- cents.8,51,57,67,70,71,79 If there is no growth therapeu- tically, orthognathic surgery to correct the position discrepancy between both jaws is a causal ther- apy form (Fig. 1). A premise for the successful real- ization of a combined therapy is that less invasive treatment options (for example, growth influence, as mentioned above) can no longer be used or do not achieve the treat- ment objectives or even worsen the situation (for example, extraction in a shallow mouth profile or distaliza- tion in a narrow overbite).33,34,77 The second option for the caus- al therapy of a skeletal dysgnathia (Class II) using combined orthodon- tic and orthognathic surgical cor- rection is discussed in this article, with a special focus on Class II dys- gnathias with skeletal deep occlu- sion. case report: diagnosis A 21-year-old female patient pre- sented at our practice complaining of temporomandibular joint pain when chewing and poor esthetics, due to the malpositioning of her maxillary incisors. The lateral image shows a frontal face oblique to the back, a deepened supramentale and, in comparison to the mid-face, a short lower face — 54:46 instead of 50:50 (Table I; Figs. 2a, b). Owing to the enlarged overjet (13 mm), there was a malfunctioning of the lower lips in occlusion, owing to which lip closure was not possible without habitual, ventral position- ing of the mandible. Furthermore, the frontal image shows a Class II/1-dysgnathia angle, mesial deviation to the left, a deep occlusion (6 mm) with abra- sion in the palatal mucous mem- brane and corresponding periodon- tal destruction palatinal of the teeth Nos. 11 and 21, as well as anterior maxilla labial tilt. In addition, there was clear crowding in the mandibular arch and slight crowding in the maxil- lary arch. The maxilla was lowered while the mandible was raised, which was expressed by a difference in the level of the distinctive Spee’s curva- ture (Figs. 3a–c). The FRS analysis (Tables I, II) clearly shows sagittal and vertical dysgnathia in the soft-tissue profile and the skeletal region. The parameters indicated a skel- etal deep occlusion with the typical extra-oral symptoms of the short- face syndrome: disto-basal jaw relation, small gonion angle, small interbase angle due to the anterior rotation of the mandible, large ratio between anterior and posterior facial height, and a growth pattern with an anterior course. The vertical arrangement of the soft-tissue profile showed a dishar- mony between the mid-face and the lower face (G’-Sn:Sn-Me’; 54:46), which was expressed in the bony structures (N-Sna:Sna-Me; 50:50). Disharmony in the region of the lower face was also evident (Sn- Stm:Stm-Me’; 37:63). These discrepancies in the ratio are the result of the deficient lower face, rather than the length of the upper lip. An additional assessment of the lower face indicated that the ratio between the subnasal-labral inferi- us (Sn-Li) and the soft-tissue men- ton (Li-Me’), which should have been 1:0.9, was shifted in the favor of Sn-Li (1:0.7). This larger ratio was primarily caused by the short mandible (Figs. 4a, b). Therapeutic objectives and treatment planning An improvement of the facial esthet- ics, not only in the sagittal but also in the vertical axis, was a specific treatment objective. This was to be achieved through the elongation of the lower face without amplifying the prominence of the chin. Elongation of the lower face as causal therapy and the subse- quent effect on the facial esthetics could be achieved in the case of this patient using combined orth- odontic and orthognathic surgical treatment. It would not have been possible to achieve the treatment objectives with respect to esthetics using orthodontic procedures alone. The decisive step for the desired functional and esthetic results was taken during surgery. The surgi- cal enlargement of the mandibular angle (gonion angle) was decisive for the improvement of the extra- oral appearance through a posterior rotation of the dentigerous segment. The three-point support on the incisors and molars was a prereq- uisite for a stable enlargement of AD f OT page 1 Table I: Proportions of soft-tissue structures before and after treatment. Table II: Mean values or proportions of skeletal structures before and after treatment. Fig. 3a Fig. 3b Fig. 3c Fig. 2: Lateral view, left, of the 21-year-old patient, showing a posteriorly inclined upper face, short lower face and a deepened supramentale. Right, frontal view, showing the poor lip closure due to the anterior maxilla labial tilt and the enlarged sagittal overjet. Figs. 3a–c: Clinical situation before the start of treatment.