BASIS OF CRANIOMETRY & CEPHALOMETRY MUDr. Anna Rábová the branch of physical anthropology dealing with the study and measurement of dry skull after removal of its soft part Craniometry technique used to measure the skull and determine human characteristics Ø ØCephalometry Ø Ø- Is a measurement of the head and facial structures Ø- In humans it´s a subset of anthropometry, (measurement of the human body) Ø- Is used in dentistry, and especially in orthodontics, to Ø gauge the size and special relationships of the teeth, jaws, and cranium. Ø- This analysis informs about treatment planning, quantifies changes during treatment, and provides data for clinical research Ø The way of measurement using antropometric instruments (sliding gauge, cephalometr) Craniometric / cephalometric Points - a landmarks on the skull from which craniometric measurements can be taken - -PAIRED / UNPAIRED (in the central plane) - - 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 Nasion – uprostřed kořene nosu v místě sutura nasofrontalis – kožní i kostní Glabella – nejvypouklejdší bod uprostřed čela nad kořenem nosu – kožní i kostní Bregma – průsečík sutura coronalis a sutura sagittalis Lambda – průsečík sutura lambdoidea a sutura sagittalis Opisthocranion – nejdorsálněji čndějící bod lebky ve střední rovině Basion – střed předního okraje foramen magnum Akanthion – hrot spina nasalis ant. Orale – zadní okraj alv. výběžku mezi oběma horními středními řezáky staphylion – střed zadního okraje tvrdého patra Gnathion – nejníže ležící bod dolního okraje mandibuly ve střední rovině Pteryon - místo styku sutura coronalis, sphenofrontalis, sphenoparietalis Porion – leží na horním okraji kostního porus acusticus ext. - kostní Euryon – nejlaterálněji ležící bod neurokrania zygion – nejlaterálněji ležící bod na arcus zygomaticus Gonion – leží na úhlu mandibuly – kožní i kostní Endomolare - vnitřní okraj alveolů ve výši M2 glabella nasion akanthion gnathion bregma opistocranion lambda UNPAIRED UNPAIRED orale staphylion basion PAIRED porion pteryon zygion euryon gonion PAIRED PAIRED endomolare Frankfurt horizontal plane Øa horizontal plane Ørepresented in profile Øby a line between the Ølowest point on the Ømargin of the orbit (orbitale) to the Øhighest point on the Ømargin of the auditory ØMeatus (porion) Ø linea horizontalis auriculoorbitalis The Size Of The Human Skull FROM TO Length glabella opisthocranion 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 measured through glabella and opisthocranion C:\WINDOWS\Plocha\lebky\img_0693.jpg Variability in the skull size Makrocephaly Mikrocephaly We distinguish several specific views on the measured skull – side view front view view from above to be able to compare objectively C:\WINDOWS\Plocha\lebky\img_0636.jpg Norma lateralis - Side view směr basion bregma Height Length glabella opisthocranion C:\WINDOWS\Plocha\lebky\img_0637.jpg Norma frontalis – front view Facial length Facial width zygion zygion gnathion nasion C:\WINDOWS\Plocha\lebky\img_0638.jpg Norma verticalis – view from above Width Length glabella opisthocranion euryon euryon On the basis of measured parametrs 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) Brachystaphylic 85,0 - x (broad palatum) Clinical Diagnosis of Orofacial Anomalies Use of craniometry in dentistry §Anamnesis (patient´s medical history) §Examination of orofacial region: Ø - Intraoral, extraoral Ø - Functional Ø - Others: photographs (en face, profile), analysis of models, X-rays: 1.orthopantomogram (OPG) 2.teleroentgenogram – basis for cephalometric analysis 1. Orthopantomography (OPG) § Used to examine both jaws, TMJ, maxillary sinuses and the teeth together on one image § § Convenient and inexpensive method with low radiation exposure § Panoramatic extraoral technique § Patient is positioned with the Franfort plane horizontal, bite peg between the anterior teeth and the chin positioned on the chin support § § The film and the tubehead (X-ray source) rotate around the patient and produce a series of individual images on a single film 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 rtg rtg Cephalometric Analysis ØS Sella mid point of sella turcica ØN Nasion most anterior point on fronto-nasal suture ØOr Orbitale most inferior anterior point on margin of orbit ØPo Porion upper most point on bony external auditory meatus ØANS anterior Nasal Spine ØPNS posterior Nasal Spine ØGo Gonion most posterior inferior point on angle of mandible ØMe Menton lowest point on the mandibular symphysis ØA point deepest concavity on anterior profile of maxilla ØB point deepest concavity on anterior profile of mandibular symphysis Nasion Sela Gonion Menton Gnathion Pogonion Orbitale Sp.nas.ant. Sp.nas.post. Condylion A B Articulare ØFrankfort Plane Po - Or Equivalent to the true horizontal when patient is standing upright ØMaxillary Plane PNS - ANS Gives inclination of maxilla relative to other lines/planes ØMandibular Plane Go - Me Gives inclination of mandible relative to other lines/planes ØS - N Line indicates orientation of anterior cranial base ØN - A indicates relative position of maxilla to the cranial base ØN - B indicates relative position of mandib. to the cranial base ØThe angles SNA; SNB; ANB indicate relative position of maxilla or Ø mandible to each other and to the cranial base ØReferences: •Čihák, R.: Anatomie 1,2,3, Praha, Grada, 2001 •Netter, F.: Atlas of HumanAnatomy, 4th ed., Elseviesr, USA, 2006 •Naňka, Elišková: Přehled anatomie. Galén, Praha 2009 •Seidl et al.: Radiologie pro studium i praxi, Grada publishing, 2013 •Mrázková, Doskočil: Klinická anatomie pro stomatology, Alberta, Praha, 1994 •Brand, Isselhard: Anatomy of orofacial structures, 8th edition, Elsevier, USA, 2019 •Fehrenbach, Herring: Illustrated anatomy of the head and neck, 5th edition, Elsevier, USA, 2017 •Moore, Dalley: Clinically oriented anatomy, 5th edition, USA, 2006 Ø