Persentase Sisa Tinggi Tulang Alveolar Gigi Molar Mandibula pada Pasien Periodontitis Menyeluruh Usia 26-50 Tahun dari Radiograf Panoramik di RSKGM FKG UI = Percentage of Remaining Alveolar Bone of Mandibular Molar in Generalized Periodontitis Patients Aged 26-50 Years from Panoramic Radiograph at RSKGM FKG UI