## 2 Methods
### Combined Use of SBJA and High-Pull J-Hook Headgear  
After mounting the SBJA in the oral cavity, the SBJA and the high-pull J-hook headgear were used together by attaching the high-pull J-hook to the loop attached to the SBJA, and patients were instructed to wear it for 12 hours a day (Figure 1C). Case 1. Findings from initial examination  
The patient was a Japanese boy of 10 years and 7 months at the time of his initial examination, with a chief complaint of overbite. In terms of family history, the patient's father had a gap between his teeth. There were no items in the history of current illness or medical history that were particularly problematic. He had no notable habits. In terms of facial findings (Figure 2A), the frontal view did not demonstrate any deviation of the mandible. When smiling, the distance between the upper lip to the maxillary left central incisor cervical line was 6.0 mm, and a gummy smile was notable. In the lateral view, a protrusion of the upper lip was observed. Figure 1: Combined use of SBJA and high-pull J-hook headgear. SBJA with loop attached to the labial side of maxillary anterior teeth (**A**); intra-oral photograph while wearing SBJA (**B**); facial photograph while wearing SBJA and high-pull J-hook headgear (**C**). Figure 2: Facial photographs and intra-oral photographs at initial examination for Case 1; facial photograph and enlarged photograph of the mouth at initial examination (**A**); intra-oral photograph at initial examination (**B**). In the intra-oral findings (Figure 2B), the occlusal relationship of the molars was Angle Class II on both the left and right sides, and the overjet was +6.5 mm. In addition, the deep overbite was +5.5 mm. The maxillary and mandibular dentition midlines were coincident with the facial midline. The dental age was stage IIIA, and the width of the dental arches was small in both the upper and lower jaws. However, the length of the dental arch was large in both the upper and lower jaws. As for the dental arch morphology, the lower jaw exhibited a parabolic morphology. In addition, a midline diastema was noted in the maxilla. In the panoramic radiograph (Figure 3), the maxillary bilateral central incisors had slightly short roots, and the tooth germs of the maxillary and mandibular bilateral third molars were observed. No other abnormalities in the number of teeth were observed. In the cephalogram angle measurement (Table 1), the SNA angle was 85.0\({}^{\circ}\), the SNB angle was 78.5\({}^{\circ}\), and the ANB angle was +6.5\({}^{\circ}\) and large, thus exhibiting skeletal class II. The Frankfort-mandibular plane angle (FMA) was 30.5\({}^{\circ}\). U1 to SN was 103.0\({}^{\circ}\) and the maxillary anterior axial inclination was normal. In addition, FMIA was 62.0\({}^{\circ}\). In the cephalogram distance measurement (Table 2), the maxillary anterior tooth height (Is-Is') was 31.5 mm. This indicates that the patient's maxillary anterior teeth were higher than the average measurements obtained by [PERSON] et al. [18], who noted the average measurements of Japanese people. Wits appraisal was 0 mm. \begin{table}
\begin{tabular}{c c c} \hline  & **Pre-Treatment** & **Post SBJA + High-Pull Headgear** \\ \hline  & **(10 y 7 m)** & **(14 y 4 m)** \\ \hline Measurements (\({}^{\circ}\)) & Value & Value \\ \hline SNA & 85.0 & 85.0 \\ SNB & 78.5 & 80.5 \\ ANB & 6.5 & 4.5 \\ FMA & 30.5 & 30.5 \\ U-1 to SN & 103.0 & 103.0 \\ FMIA & 62.0 & 61.0 \\ L-1 to mand.pl. & 87.5 & 88.5 \\ Interincisal Angle & 126.0 & 126.0 \\ SN to Nasal floor & 9.0 & 7.5 \\ Occ.pl.to FH & 19.0 & 11.5 \\ \hline \end{tabular}
\end{table} 
Table 1: Cephalogram angle measurements of Case 1. Figure 3: Panoramic radiograph (**A**) and lateral roentgenographic cephalogram (**B**) of Case 1 at initial examination. Diagnosis  
This case was diagnosed as a case of skeletal class II, accompanied by a gummy smile due to the vertical excessive growth of the upper jaw, and a deep overbite.