CHAPTER 4 139 4.1 Definition of 3-D Cephalometric Hard Tissue Landmarks Lower Molar Cusp: LMcusp r – LMcusp l Definition of the Lower Molar Cusp Landmarks Lower Molar Cusp (LMcusp) is the most superior point of the mesial cusp of the crown of each first lower molar in the profile plane. Virtual Definition of the Lower Molar Cusp Landmarks Step 1: Define Lower Molar Cusp r and Lower Molar Cusp l on the profile views of the 3-D hard tis- sue surface representation (Figs. 4.57, 4.58). Step 2: Verify and correct the position of Lower Mo- lar Cusp r and Lower Molar Cusp l on the virtu- al lateral (Fig. 4.59) cephalogram linked to the 3-D hard tissue surface representation. Fig. 4.55. Lower Molar Cusp r .Profile view right (cadaver skull) Fig. 4.56. Lower Molar Cusp r .Profile view right (3-D CT, cadaver skull) CHAPTER 4 140 3-D Cephalometric Hard Tissue Landmarks Fig. 4.57. Lower Molar Cusp r .Profile view right (3-D CT, patient K.C.) Fig. 4.58. Lower Molar Cusp l .Profile view left (3-D CT, patient K.C.) Fig. 4.59. Lower Molar Cusp r .and Lower Molar Cusp l .Virtual lateral cephalogram linked to the 3-D hard tissue surface representation (3-D CT, patient K.C.) CHAPTER 4 141 4.1 Definition of 3-D Cephalometric Hard Tissue Landmarks Fig. 4.60. Virtual frontal cephalogram linked to the 3-D hard tissue surface representation shows an overview of dental landmarks (3-D CT, patient K.C.) CHAPTER 4 142 3-D Cephalometric Hard Tissue Landmarks Menton: Men Definition of the Menton Landmark Menton is the most inferior midpoint of the chin on the outline of the mandibular symphysis. Fig. 4.61. Menton.Profile view right (cadaver skull) Fig. 4.62. Menton.Profile view right (3-D CT, cadaver skull) Fig. 4.63. Menton.Base view (cadaver skull) Fig. 4.64. Menton.Base view (3-D CT, cadaver skull) CHAPTER 4 143 4.1 Definition of 3-D Cephalometric Hard Tissue Landmarks Virtual Definition of the Menton Landmark Step 1: Define Menton on the virtual lateral cephalo- gram (Figs. 4.65, 4.66). Fig. 4.65. Menton.Virtual lateral cephalogram (patient K.C.) Fig. 4.66. Menton. Virtual lateral cephalogram linked to the 3-D hard tissue surface representation (patient K.C.) CHAPTER 4 144 3-D Cephalometric Hard Tissue Landmarks Step 2: The position of Menton is verified on the right (Fig. 4.67) and left (Fig. 4.68) profile views of the 3-D hard tissue surface representations. Step 3: Verify the midline position of Menton on the base view of the 3-D hard tissue surface rep- resentation (Fig. 4.69). Note that Menton is the skeletal midline point of the chin and can therefore be out of the midplane. Fig. 4.67. Menton.Profile view right (3-D CT, patient K.C.) Fig. 4.68. Menton.Profile view left (3-D CT, patient K.C.) Fig. 4.69. Menton.Base view (3-D CT, patient K.C.) CHAPTER 4 145 4.1 Definition of 3-D Cephalometric Hard Tissue Landmarks Fig. 4.70. Menton.Virtual lateral and frontal cephalograms linked to the 3-D hard tissue sur- face representation (3-D CT, patient K.C.) CHAPTER 4 146 3-D Cephalometric Hard Tissue Landmarks Gonion: Go r – Go l Definition of the Gonion Landmarks Gonion (Go) is the point at each mandibular angle that is defined by dropping a perpendicular from the inter- section point of the tangent lines to the posterior margin of the mandibular vertical ramus and inferior margin of the mandibular body or horizontal ramus. Virtual Definition of the Gonion Landmarks Step 1: Define Gonion r and Gonion l on the right (Fig. 4.73) and left (Fig. 4.74) profile views of the 3-D hard tissue surface representation. Step 2: Verify the correct transversal position of Go- nion r and Gonion l on the base view (Fig. 4.75) of the 3-D hard tissue surface representation. Fig. 4.71. Gonion r .Profile view right (cadaver skull) Fig. 4.72. Gonion r .Profile view right (3-D CT, cadaver skull) CHAPTER 4 147 4.1 Definition of 3-D Cephalometric Hard Tissue Landmarks Fig. 4.73. Gonion r .Profile view right (3-D CT, patient K.C.) Fig. 4.74. Gonion l .Profile view left (3-D CT, patient K.C.) Fig. 4.75. Gonion r and Gonion l .Caudal view (3-D CT, patient K.C.) CHAPTER 4 148 3-D Cephalometric Hard Tissue Landmarks Fig. 4.76. Gonion r and Gonion l .Virtual lateral and frontal cephalograms linked to the 3-D hard tissue surface representation (3-D CT, patient K.C.) [...]... Frontozygomaticl on the virtual lateral cephalogram linked to the 3-D hard tissue surface representation (Fig 4.81) 150 Fig 4.80 Frontozygomaticr and Frontozygomaticl Virtual frontal cephalogram (3-D CT, patient K.C.) 4.1 Definition of 3-D Cephalometric Hard Tissue Landmarks CHAPTER 4 Fig 4.81 Frontozygomaticr and Frontozygomaticl.Virtual lateral and frontal cephalograms linked to the 3-D hard tissue... of 3-D Cephalometric Hard Tissue Landmarks Fig 4.91 Zygionl Close-up zygomatic arch, endocranial skull base view (3-D CT, patient A. G.) CHAPTER 4 Fig 4.92 Zygionl Close-up zygomatic arch, endocranial skull base view (3-D CT, patient A. G.) Fig 4.93 Zygionr and Zygionl Frontal view (3-D CT, patient A. G.) 155 CHAPTER 4 3-D Cephalometric Hard Tissue Landmarks Fig 4.94 Zygionr Profile view right (3-D CT,... 4.100 A- Point Profile view right (3-D CT, patient K.C.) CHAPTER 4 Fig 4.101 A- Point Profile view left (3-D CT, patient K.C.) Fig 4.102 A- Point Frontal view (3-D CT, patient K.C.) 159 CHAPTER 4 3-D Cephalometric Hard Tissue Landmarks Fig 4.103 A- Point.Virtual frontal cephalogram linked to the 3-D hard tissue surface representation (3-D CT, patient K.C.) Fig 4.104 A- Point.Virtual frontal cephalogram (patient... (3-D CT, patient K.C.) Fig 4.122 Pogonion Base view (3-D CT, patient K.C.) 167 CHAPTER 4 3-D Cephalometric Hard Tissue Landmarks Fig 4.123 Pogonion.Virtual lateral and frontal cephalograms linked to the 3-D hard tissue surface representation (3-D CT, patient K.C.) 168 4.1 Definition of 3-D Cephalometric Hard Tissue Landmarks CHAPTER 4 Basion: Ba Definition of the Basion Landmark Basion is the most anterior... patient A. G.) 156 Fig 4. 95 Zygionl Profile view left (3-D CT, patient A. G.) 4.1 Definition of 3-D Cephalometric Hard Tissue Landmarks CHAPTER 4 A- Point: A Definition of the A- Point Landmark A- Point is the point of maximum concavity in the midline of the alveolar process of the maxilla Fig 4.96 A- Point Profile view right (cadaver skull) Fig 4.97 A- Point Profile view right (3-D CT, cadaver skull) 157 ... Condylionr and Condylionl Virtual lateral cephalogram (3-D CT, patient K.C.) 172 4.1 Definition of 3-D Cephalometric Hard Tissue Landmarks CHAPTER 4 Fig 4.134 Condylionr and Condylionl.Virtual frontal cephalogram linked to the 3-D hard tissue surface representation (3-D CT, patient K.C.) allows verification of the transverse position of the Condylion landmarks 173 CHAPTER 4 3-D Cephalometric Hard Tissue Landmarks... Zygionl Exocranial skull base view (3-D CT, cadaver skull) Fig 4. 85 Zygionl Close-up zygomatic arch, endocranial skull base view (3-D CT, cadaver skull) 4.1 Definition of 3-D Cephalometric Hard Tissue Landmarks CHAPTER 4 Virtual Definition of the Zygion Landmarks Fig 4.86 Zygionr and Zygionl Exocranial skull base view (3-D CT, patient K.C.) Fig 4.87 Zygionr and Zygionl Frontal view (3-D CT, patient K.C.)... great foramen (foramen magnum) Fig 4.124 Basion Exocranial skull base view (3D-CT, cadaver skull) Fig 4.1 25 Basion Exocranial skull base view (3-D CT, cadaver skull) Virtual Definition of the Basion Landmark Step 1: Define Basion on the exocranial skull base view (Fig 4.126) of the 3-D hard tissue surface representation Step 2: Verify the vertical position of Basion on the virtual lateral cephalogram... 3-D hard tissue surface representation (Figs 4.127, 4.128) 169 CHAPTER 4 3-D Cephalometric Hard Tissue Landmarks Fig 4.126 Basion Exocranial skull base view (3-D CT, patient K.C.) Fig 4.127 Basion.Virtual lateral cephalogram (3-D CT, patient K.C.) Fig 4.128 Basion.Virtual lateral cephalogram linked to the 3-D hard tissue surface representation (3-D CT, patient K.C.) 170 4.1 Definition of 3-D Cephalometric... 3-D Cephalometric Hard Tissue Landmarks CHAPTER 4 B-Point: B Definition of the B-Point Landmark B-Point is the point of maximum concavity in the midline of the alveolar process of the mandible Fig 4.1 05 B-Point Profile view right (cadaver skull) Fig 4.106 B-Point Profile view right (3-D CT, cadaver skull) 161 CHAPTER 4 3-D Cephalometric Hard Tissue Landmarks Virtual Definition of the B-Point Landmark . Virtual frontal cephalo- gram (3-D CT, patient K.C.) CHAPTER 4 151 4.1 Definition of 3-D Cephalometric Hard Tissue Landmarks Fig. 4.81. Frontozygomatic r and Frontozygo- matic l .Virtual lateral and. amalgam artefacts, definition of Zygion r and Zygion l land- marks is not possible on the exocranial skull base view (3-D CT,patient A. G.) CHAPTER 4 155 4.1 Definition of 3-D Cephalometric Hard. patient A. G.) Fig. 4. 95. Zygion l .Profile view left (3-D CT, patient A. G.) CHAPTER 4 157 4.1 Definition of 3-D Cephalometric Hard Tissue Landmarks A- Point: A Definition of the A- Point Landmark A- Point