BASIS OF CRANIOMETRY & CEPHALOMETRY the branch of physical anthropology dealing with the study and measurement of dry skull after removal of its soft part Craniometry Cephalometry - Is a measurement of the head and facial structures - Is used in dentistry, and especially in orthodontics, to gauge the size and special relationships of the teeth, jaws, and cranium. - This analysis informs about treatment planning, quantifies changes during treatment, and provides data for clinical research The way of measurement using antropometric instruments (sliding gauge, cephalometr) Craniometric / cephalometric Points The most important craniometric points Unpaired – in the middle line nasion glabella bregma lambda opisthocranion basion akanthion gnathion orale staphylion Paired pteryon porion euryon zygion gonion endomolare Points marked with Greek or Latin names glabella nasion akanthion gnathion bregma opistocranion lambda UNPAIRED UNPAIRED orale staphylion basion PAIRED porion pteryon zygion euryon gonion PAIRED PAIRED endomolare Frankfurt horizontal plane A prerequisite for correct measurement is the position of the head in the basic orientation plane linea horizontalis auriculoorbitalis The Size Of The Human Skull FROM TO Length glabella opisthocrani on Width euryon euryon Height bregma basion Facial length nasion gnathion Facial width zygion zygion Palatal width endomolare endomolare Palatal length orale staphylion Peripheral measurement circumferentia horizontalis frontooccipitalis Variability in the skull size We distinguish several specific views on the measured skull – side view (norma lateralis) front view ( norma frontalis) view from above (norma verticalis) to be able to compare objectively Norma lateralis Side view direction basion bregma Height Length glabella opisthocranion Norma frontalis – front view Facial length Facial width zygion zygion gnathion nasion Norma verticalis – view from above Width Lengthglabella opisthocranion euryon euryon On the basis of measured parameters we can calculate indexes: Cephalic index (CI) the ratio of the maximum width of the head multiplied by 100 and divided by its maximum length Facial index (FI) the ratio of the length of the face multiplied by 100 divided by width Palatomaxillary index (PMI) the ratio of the length of the hard palate to its breadth (width) multiplied by 100 CI Dolichocephalic x - 74,9 (long-headed) Mesocephalic 75,0 - 79,9 (medium-headed) Brachycephalic 80,0 - x (short-headed) FI Leptoprosopic 90,9 - x (long narrow face) Mesoprosopic 85,0 - 89,9 (average width face) Euryprosopic x - 84,9 (short broad face) PMI Leptostaphylic x - 79,9 (narrow palatum) Mesostaphylic 80,0 - 84,9 (average width) Eurystaphylic 85,0 - x (broad palatum) Clinical Diagnosis of Orofacial Anomalies Use of craniometry in dentistry ▪ Anamnesis (patient´s medical history) ▪ Examination of orofacial region: - Intraoral, extraoral - Functional - Others: photographs (en face, profile), analysis of models, X-rays: 1.orthopantomogram (OPG) 2.teleradiography – basis for cephalometric analysis 2. Cephalometry ▪ A standardized and reproducible form of skull radiography used extensively in orthodontics to assess the relationships of the teeth to the jaws and the jaws to the rest of the facial skeleton ▪ Main indications - monitoring treatment progress, preoperative evaluation of skeletal and soft tissue patterns, postoperative appraisal of the results of surgery and long-term follow-up studies ▪ The pacient is positioned within the cephalostat in the Frankfort plane horizontal, teeth should be in maximum intercuspation ▪ The head is immobilized within the apparatus with the plastic ear rods being inserted into the external auditory meati ▪ The X-ray beam is horizontal and centred on the ear rods ▪ Soft x-rays Cephalometric Analysis S Sella mid point of sella turcica N Nasion most anterior point on fronto-nasal suture Or Orbitale most inferior anterior point on margin of orbit Po Porion upper most point on bony external auditory meatus ANS anterior Nasal Spine PNS posterior Nasal Spine Go Gonion most posterior inferior point on angle of mandible Me Menton lowest point on the mandibular symphysis A point deepest concavity on anterior profile of maxilla B point deepest concavity on anterior profile of mandibular symphysis Pog Pogonion the most ventr point of the bony chin in the med plane Ar Articulare intersection of the shadow of ramus mandib. and the lower edge of the base of the skull Nasion Sela Gonion Menton Gnathion Pogonion Orbitale Sp.nas.ant. Sp.nas.post. Condylion A B Articulare Frankfort Plane Po - Or Equivalent to the true horizontal when patient is standing upright Maxillary Plane PNS - ANS Gives inclination of maxilla relative to other lines/planes Mandibular Plane Go - Me Gives inclination of mandible relative to other lines/planes S - N Line indicates orientation of anterior cranial base N - A indicates relative position of maxilla to the cranial base N - B indicates relative position of mandib. to the cranial base The angles SNA; SNB; ANB indicate relative position of maxilla or mandible to each other and to the cranial base