# An Orthodontic Treatment Case of a TMD Patient with Maximly Posterior Intrusion Using TsADs
## 2 Materials and Methods
### Case Report
\begin{table}
\begin{tabular}{c c c c c} \hline
**Measurement** & **Korean Norm** & **Pretreatment** & **Post-stabilization** & **Posttreatment** \\ \hline SNA (\({}^{\circ}\)) & 81.5 & 83.0 & 83.0 & 81.5 \\ SNB (\({}^{\circ}\)) & 79.0 & 71.5 & 70.5 & 72.0 \\ ANB (\({}^{\circ}\)) & 2.5 & 11.5 & 12.5 & 8.5 \\ Saddle Angle (\({}^{\circ}\)) & 123.0 & 122.0 & 120.5 & 121.0 \\ Articular Angle (\({}^{\circ}\)) & 149.0 & 167.0 & 169.0 & 168.5 \\ Gonial Angle (\({}^{\circ}\)) & 121.0 & 119.0 & 119.0 & 119.0 \\ SUM (\({}^{\circ}\)) & 393.0 & 408.0 & 408.5 & 408.5 \\ Anterior Cranial Base Length (mm) & 71.0 & 65.3 & 65.3 & 65.3 \\ Posterior Cranial Base Length (mm) & 33.0 & 36.0 & 35.0 & 35.0 \\ Mandibular Body Length (mm) & 71.0 & 72.0 & 72.0 & 72.0 \\ Ramus Height (mm) & 44.0 & 39.6 & 40.5 & 40.5 \\ ACB: MBL & 1:1 & 1:1.1 & 1:1.1 & 1:1.1 \\ PCB: Ramus Height & 3:4 & 33.3 & 3:3.5 & 3:3.5 \\ Post.FH/Ant.FH (\%) & 66.8 & 58.0 & 57.3 & 57.3 \\ SN-MP (\({}^{\circ}\)) & 33.5 & 48.0 & 50.0 & 49.0 \\ TVL to MoD (\({}^{\circ}\)) & 100.0 & 95.0 & 95.0 & 101.5 \\ UI-FH (\({}^{\circ}\)) & 116.6 & 115.0 & 115.0 & 100.0 \\ IMPA (\({}^{\circ}\)) & 90.0 & 90.0 & 90.0 & 92.0 \\ U1 to Stms (mm) & 3.0 & 3.9 & 3.9 & 3.0 \\ U1/L1 (\({}^{\circ}\)) & 124.0 & 99.0 & 95.0 & 119.0 \\ Overjet (mm) & 2.8 & 11.5 & 11.5 & 3.0 \\ Overbite (mm) & 3.0 & 0.5 & 0.0 & 2.8 \\ Upper lip (mm) & 0.0 & 4.3 & 3.8 & 0.0 \\ Lower lip (mm) & 0.0 & 5.9 & 5.0 & 0.0 \\ \hline \end{tabular} \(SNA\), sella-nasion–A point angle; \(SNB\), sella-nasion–B point angle; \(ANB\), A point–nasion–B point angle; \(ACB\), Anterior craiel base; \(MBL\), mandibular body length; \(PCB\), posterior cranial base; \(FH\), facial height; \(SN\), sella-nasion line; \(MP\), mandibular plane; \(TVL\), true vertical line; \(M\)\(\alpha\)\(OP\), maxillary occlusal plane; \(IMPA\), incisor and mandibular plane angle; \(Stms\), stomion superior.  
\end{table} 
Table 1: Cephalometric measurements. With the re-diagnosed data, two treatment options were suggested to the patient. The first option included orthognathic surgery accompanying maxillary posterior impaction and mandibular advancement after presurgical orthodontic treatment with the extraction of the four first premolars. This treatment option effectively improved her open bite and facial esthetics. The other option was an orthodontic camouflage treatment with the extraction  
Figure 2: **(a) Pretreatment dental models mounted in CRO and the MPI data. The MPI data presented MIP–CRO discrepancies at the joint level; (b) intraoral photographs during splint treatment; (c) post-stabilization intraoral photographs, dental models mounted in CRO, and changes of MPI data during the application of the stabilization splint. The MPI data discovered upward seating of the condyles in the articular fossa compared to their initial positions; (d) post-stabilization lateral cephalogram and panoramic radiograph. **  
of two maxillary first premolars and a left mandibular first premolar. This treatment alternative included the intrusion of her maxillary posterior teeth with the use of multiple TSADs to induce counterclockwise rotation of the mandible. These treatment mechanics were thought to eventually resolve the severe vertical and anteroposterior problems. The patient's maxillary anterior teeth had a normal inclination, while her overjet was 11.5 mm, which indicated that bodily movement of her maxillary anterior teeth would be needed during the retraction of the anterior segments, with her maxillary molars retaining absolute anchorage value. The left mandibular first premolar needed to be extracted to resolve the 7 mm arch length discrepancy and the denture midline discrepancy in her mandibular arch. After discussion, our patient rejected the invasive orthognathic surgery and chose the option of camouflage treatment using TSADs. Before orthodontic treatment, both maxillary and left mandibular first premolars were extracted.