Posteroanterior /certified fixed orthodontic courses by Indian dental academy

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The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and offering a wide range of dental certified courses in different formats.

Indian dental academy provides dental crown & Bridge,rotary endodontics,fixed orthodontics,
Dental implants courses.for details pls visit www.indiandentalacademy.com ,or call
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  • 1. POSTEROANTERIO R CEPHALOMETRY INDIAN DENTAL ACADEMY Leader in continuing dental education www.indiandentalacademy.com www.indiandentalacademy.com
  • 2. Introduction  In orthodontics , the primary indication for obtaining a posteroanterior cephalometric film is the presence of facial asymmetry, it is also important in cases of dentoalveolar asymmetries, dental and skeletal crossbites, and functional mandibular displacements. (transverse discrepancies)  The posteroanterior cephalometric projection, also called as the Caldwell projection. www.indiandentalacademy.com
  • 3.  1. 2. 3. Importance of posteroanterior cephalometry is in Orthodontic surgery planning Differential tooth eruption with segmental TMJ therapy Functional jaw orthopaedics including three dimensional improvements in facial or dental proportion or symmetry. www.indiandentalacademy.com
  • 4.  Tracing suggestion 1) One must ensure that the head position and intermaxillary occlusal relationships that appear in the X-ray do not differ significantly from those identified during the clinical or photographic evaluation of the patient or those found in the analysis of dental cast. 2) Examine the cephalogram in order to exclude the possibility of pathology of the hard and soft tissues involved. 3) During tracing of the posteroanterior cephalogram, it is essential to bear in mind where the structures have been identified in lateral cephalogram www.indiandentalacademy.com
  • 5. . 4) Tracing of posteroanterior cephalogram may begin with the midline structures seen in the lateral cephalogram and should include the occipital, parital, frontal, nasal bones, the maxilla, the sphenoid bone, and the symphysis of the mandible. 5) The fan of x-ray beam expands as it passes through the head, causing a divergence between the images of all bilateral structures except those along the central beam. Structures whose images are doubled and exhibit an apparent asymmetry are conventionally averaged and traced as a single image. www.indiandentalacademy.com
  • 6. Landmarks www.indiandentalacademy.com
  • 7.       LANDMARKS ag- antegonion – the highest point in the antegonial notch ans- anterior nasal spine cd- condylar- the most superior point of the condylar head cor –coronoid – the most superior point of the coronoid process iif- incision inferior frontale – the midpoint between the mandibular central incisiors at the level of the incisal edges www.indiandentalacademy.com
  • 8.     isf- incision superior frontale – the midpoint between the maxillary central incisors at the level of incisal edges. lpa – latereal pyriform aperature – the most lateral aspect of the pyriform aperature. lo – larero – orbitale – the intersection of the lateral orbital contour with the innominate (oblique) line m – mandibular midpoint – located by projecting the mental spine on the lower mandibular border , perpendicular to the line ag – ag. www.indiandentalacademy.com
  • 9.     lm- mandibular molar – the most prominent lateral point on the buccal side of the second deciduous or first permanent mandibular molar ma – mastoid – the lowest point of the mastoid process mx – maxillare – the intersection of the lateral contour of the maxillary alveolar process and the lower contour of the maxillozygomatic process of the maxilla um – maxillary molar – the most prominent lateral point on the buccal surface of the second deciduous or first maxillary molar www.indiandentalacademy.com
  • 10.     mo- medio-orbitale – the point on the medial orbital margin that is closest to the median plane mf- mental foramen – the center of the mental foramen om- orbital midpoint – the projection on the line lo-lo of the top of the nasal septum at the base of crista galli za- point zygomatic arch – point at the most lateral border of the center of the zygomatic arch www.indiandentalacademy.com
  • 11.    tns- top nasal septumthe highest point on the superior aspect of the nasal septum mzmf- zygomaticofrontal medial suture point-in -point at the medial margin of the zygomaticofrontal suture lzmf- zygomaticofrontal lateral suture point-out – point at the lateral margin of the zygomaticofrontal suture www.indiandentalacademy.com
  • 12.  1. 2. 3. 4. 5. Most of the posteroanterior cephalometric analysis described in the literature are quantitative , and they evaluate the craniofacial skeleton by means of linear absolute measurements of Width or height ( Grummons and Kappeyne 1987, Athanasiou et al 1992, Ricketts et al 1972, Solow and Ingerslev 1975) Angles (Grummons and Kappeyne 1987, Athanasiou et al 1992, Ricketts et al 1972, Solow and Ingerslev 1975) Ratios (Costaras et al 1982, Grummons and Kappeyne 1987, Athanasiou et al 1992) Volumetric comparison (Grummons and Kappeyne 1987) Using qualitative methods (Graysons et al 1983) www.indiandentalacademy.com
  • 13.  Landmarks and variables that can be identified on coronal planes of different depths in the same posteroanterior cephalogram can provide useful information concerning the vertical, transverse, and saggital dimensions of the craniofacial dimension.  The multiplane analysis developed by grayson et al (1983) is the best and most complete method in this category. www.indiandentalacademy.com
  • 14. Method of Analysis 1.   Multiplane cephalometric analysis (Grayson Analysis 1983) Introduction Landmarks are identified in different frontal planes at selected depths of the craniofacial complex and subsequent skeletal midlines are constructed in saggital plane. The midpoints and midlines may be combined and a ‘warped midsaggital plane’ can be the outcome of the analysis. www.indiandentalacademy.com
  • 15.  Method  Analysis is performed on three different acetate papers using the same posteroanterior cephalogram. Structures are traced within or near the three different planes indicated on the lateral view.  www.indiandentalacademy.com
  • 16. Tracing of landmarks for various planes   In the first acetate sheet, for plane A, orbital rims (A) along with pyriform aperature (B), maxillary and mandibular incisors (C), and the midpoint of the symphysis (D) are outlined. This first tracing, represents the anatomy of the most superficial aspect of the craniofacial complex, as indicated by plane A, is present www.indiandentalacademy.com
  • 17.   On the Second sheet, for plane B, the greater and lesser wings of sphenoid (A), the most lateral cross-section of the zygomatic arch (B), the coronoid process (c), the maxillary and mandibular first permanent molars (D), the body of the mandible (E), and the mental foramina (F) are traced. These structures are located on or near the deeper coronal plane B. www.indiandentalacademy.com
  • 18.   Third tracing, for plane C, includes the upper surface of the petrous portion of the temporal bone (A), the mandibular condyles with the outer border of the ramus down to the gonial angle (B), and the mastoid processes (C) with the arch of temporal and parietal bones connecting them. This tracing corresponds to the plane C. www.indiandentalacademy.com
  • 19. When these three tracings are viewed separately, they reveal cross section of the craniofacial complex.  For each tracing , midsaggital midlines are constructed as follows.  www.indiandentalacademy.com
  • 20.      For plane A, it Passes through orbits, Pyriform aperature, incisors Mce- the centrum of each orbit is identified and the midpoint Mce is constructed, Mp- the most lateral point on the perimeter of each pyriform aperature is located, and the midpoint Mp is marked, Mi- the midpoint Mi is constructed between the maxillary and mandibular incisors, Mg- point Mg is identified at the gnathion area www.indiandentalacademy.com
  • 21.    All these midpoints are close to the midline in some sense. The midline in plane A can be constructed by connecting these midpoints. The result is a segmented construction of these midlines , whose angles express the degree of asymmetry of the structures in this specific plane. The same principle are applied to the planes B and C. www.indiandentalacademy.com
  • 22.       For plane B (for sphenoid and zygomatic arch region) the midpoint that are used are point Msi, which is the bisector between points Si, (point of intersection of the shadow of the greater and lesser wing of sphenoid) Point Mz, between the center of the zygomatic arches, Point Mc, between the tips of the coronoid processes, Point Mx, between left and right maxillare, Point Mf, between left and right mental foramina. www.indiandentalacademy.com
  • 23.     For plane C , the midpoints used are Point Md – between heads of condyles, Point Mm – between the innermost inferior points of the mastoid processes, Point Mgo – between the two gonions. www.indiandentalacademy.com
  • 24.    If the three tracings are superimposed , the phenomenon of wraping within the craniofacial skeleton can be observed. The midline constructs deviate progressively laterally as one passes from plane C, through plane B, to the plane A. This multiple analysis gives the possibility to view the saggital plane in posteroanterior cephalometry. www.indiandentalacademy.com
  • 25. Grummons analysis    Introduction The analysis is presented in two forms: the comprehensive frontal asymmetry analysis and the summary frontal asymmetry analysis. The analysis consist of different components, including horizontal planes, mandibular morphology, volumetric comparison, maxillomandibular comparison of asymmetry, linear asymmetry assessment, maxillomandibular relation, and frontal vertical proportions www.indiandentalacademy.com
  • 26. •Landmarks used in Grummons analysis Ag -antegonial notch ANS Anterior nasal spine Cg crista galli Cd condylion (most superior aspect) Fr foramen Rotundum J jugal process Me menton MSR Mid-saggital reference line www.indiandentalacademy.com at crista galli
  • 27. •Landmarks used in Grummons analysis Nc nasal cavity at widest point Z Zygomatic frontal suture, medial aspect ZA zygomatic arch A1 upper incisor edge B1 lower incisor edge www.indiandentalacademy.com
  • 28. The practical procedure includes the following 1.      . Construction of four horizontal planes One connecting the medial aspect of the zygomaticofrontal suture (Z); One connecting the centers of the zygomatic arches (ZA); . One connecting the medial aspect of the jugal process (J) and ; One parallel to Z- plane through menton. These planes are drawn to show the degree of parallelism and symmetry of facial structures. www.indiandentalacademy.com
  • 29. 2. A midsaggital reference line (MSR)  Is constructed from crista galli (Cg) through the anterior nasal spine (ANS) to the chin area .  If anatomical variation in upper and middle facial region exist, an alternative way of making MSR is, draw a line from midpoint of Z- plane either through ANS or midpoint of both foramina rotundum (Fr - Fr line). www.indiandentalacademy.com
  • 30. 3. Mandibular morphology analysis  Left sided and right sided triangles are formed between the head of the condyle (Co) to the antegonial notch (Ag) and menton (Me).  A vertical line from ANS to Me visualizes the midsaggital plane in the lower face. www.indiandentalacademy.com
  • 31. 4. Volumetric comparison –  Four connected points determine an area, and here a connection is made between the points;  Condylion (Co);  Antegonial notch (Ag);  Menton (Me) and ;  The intersection with a perpendicular from Co to MSR.  Two polygons (left and right) are defined by these points can be superimposed with the aid of a computer program, and a percentile value of symmetry can be obtained. www.indiandentalacademy.com
  • 32. 5. Maxillomandibular comparison of asymmetry –  Four lines are constructed, perpendicular to MSR, from Ag and from J,  And lines from Cg to Ag, are also drawn.  Two pairs of triangles are formed in this way, and each pair is bisected by MSR.  If symmetry is present , the four triangles becomes two triangles, namely J-Cg-J and Ag-Cg-Ag.  This assess symmetries in both jaws. www.indiandentalacademy.com
  • 33. 6. Linear asymmetry assessment;  The linear distance to MSR and the difference in the vertical dimension of the perpendicular projections of bilateral landmarks to MSR are calculated for the landmarks Co, NC, j, Ag, and Me. www.indiandentalacademy.com
  • 34. 7. Maxillomandibular relation –  The distances from the buccal cusps of the maxillary first molar to the J - perpendiculars are measured.  Lines connecting Ag-Ag and ANS-Me, and the MSR line, are also drawn to reveal dental compensations for any skeletal asymmetry, the so-called maxillomandibular imbalance in horizontal or vertical planes.  This shows midline asymmetry of the upper and lower incisors and asymmetry in occlusal plane. www.indiandentalacademy.com
  • 35. 8. Frontal vertical proportion analysis  Ratios of skeletal and dental measurements, made along the Cg-Me line, are calculated with division at ANS, A1 and B1. (A1: upper central incisor edge, B1: lower central incisor edge):  The following ratios are taken into consideration  Upper facial ratio - Cg-ANS : Cg-Me;  Lower facial ratio - ANSMe : Cg-Me; www.indiandentalacademy.com
  • 36.      Maxillary ratio - ANS-A1 : ANS-Me; Total maxillary ratio - ANSA1 : Cg-Me; Mandibular ratio – B1-Me : ANS-Me; Total mandibular ratio – B1Me : Cg-Me; Maxillomandibular ratio – ANS-A1 : B1-Me. www.indiandentalacademy.com
  • 37.  These ratios can be compared with common facial aesthetic ratios and measurements. www.indiandentalacademy.com
  • 38. The summary facial asymmetry analysis includes only the construction of the horizontal planes, the mandibular morphology analysis, and the maxillomandibular comparison of facial asymmetry.  This provides a practical summary of the patient’s frontal asymmetry , emphasizing key dentoalveolar and skeletal factors that influence treatment decision.  www.indiandentalacademy.com
  • 39. Ricketts analysis   In 1972 Ricketts proposed a posteroanterior analysis. The measurements used in this analysis are given in the diagram. www.indiandentalacademy.com
  • 40.   1. 2. 3. 4. 5. This analysis includes clinical norms of measurements used. Measurements , in this includes 15 factors , that are grouped into 5 fields. Dental frontal problem Maxillomandibular relationship Dentoskeletal relationship Craniofacial relationship Inner structural problems www.indiandentalacademy.com
  • 41. Field I Dental-frontal problems  1. Molar relationship (left and right):  Molar relationship involves the distance between the buccal surfaces of the maxillary and mandibular first molars, measured at the level of the occlusal plane.  Normal value: maxillary molar 1.5 mm buccaly.  Standard deviation : ±1.5mm www.indiandentalacademy.com
  • 42.  Interpretation: This measurement describes the molar relationship on the transverse plane. Lower or negative values indicate a cusp-tocusp molar or lingual cross bite, respectively. Values higher than +3 mm correspond to buccal cross bites. www.indiandentalacademy.com
  • 43. 2. Inter molar width:  The distance between the buccal surfaces of the mandibular first molars measured at the level of the occlusal plane.  Normal value : 55mm. For boys and 54mm. For girls.  Standard deviation : ±2mm.  Interpretation : measures the arch width in milimeters at level of first molars. www.indiandentalacademy.com
  • 44. 3. Intercuspid width :  Distance between the cusps of both mandibular cuspids measured at the occlusal plane.  Normal value:22.7 mm at age 7 (non erupted teeth). The distance widens 0.8 mm per year until age 13 when it reaches the adult value of 27.5 mm.  Standard deviation : ±1.5mm.  Interpretation : describes the coincidence or lack of coincidence of the denture midlines. www.indiandentalacademy.com
  • 45. 4.Denture midline :  Distance between the maxillary and mandibular dental midlines.  Normal value: 0 mm.  Standard deviation: ±1.5mm.  Interpretation: Describes the coincidence or lack of coincidence of the denture midlines. www.indiandentalacademy.com
  • 46. Field II Maxillomandibular relationship : 5. Left and right maxillomandibular width:  The distance between the maxilla (point J) and the frontal facial plane (Z - AG).  Normal value : 10mm. For an patient aged 8½ years.  Standard deviation : ±1.5mm  Interpretation : indicates the transverse development of the maxilla, useful for the differential diagnosis of crossbite.  www.indiandentalacademy.com Z J AG
  • 47. 6. Maxillomandibular midline :  The angle formed between the midsagittal plane and the ANS-Me plane.  Normal value: 0°.  Standard deviation: 2°.  Interpretation: Determines the mandibular midline deviation with respect to the midsagittal plane. This asymmetry might be the consequence of functional or skeletal problems. www.indiandentalacademy.com Z Z
  • 48. Field III : Dentoskeletal relationship 7. Molar to both jaws (left and right)  Distance between the buccal surface of the mandibular first molar and the frontal maxillomandibular plane (JAG).  Normal value : 6.3mm. For an average boy at age 8½.  Standard deviation : ±1.7mm.  Interpretation: An increased measure indicates the likelihood of a buccal mandibular expansion.  www.indiandentalacademy.com J AG
  • 49. 8. Dental midline to maxillomandibular midline :  The distance between the mandibular incisors midline and the maxillomandibular midline (ANS-Me).  Normal value: 0 mm.  Standard deviation: ±1.5 mm  Interpretation: Relates the mandibular midline to the maxillomandibular midline. An increased value indicates deviation of the mandibular midline of dental origin www.indiandentalacademy.com
  • 50. 9. Inclination of the occlusal plane :  Difference between the measurements from the Z-Z line to the occlusal plane at the level of the left and right molars.  Normal value : 0mm.  Standard deviation : ± 2mm.  Interpretation: A value out of the norm is due to an inclination of the occlusal plane. It should be taken into account because it might be the result of skeletal asymmetry and possible TMJ disorders www.indiandentalacademy.com Z Z
  • 51. Field IV : Craniofacial relationship 10. Postural symmetry :  Difference between angles ZAG-ZA on left and Z-AG-ZA on right side.  Normal value: 0°.    Standard deviation : ± 2°. Interpretation: Used for the diagnosis of asymmetry. It can easily be distorted due to an incorrect position of the head when taking the radiograph (lateral rotation). www.indiandentalacademy.com Z
  • 52. Field V : Inner structural problems 11. Nasal width :  The maximum width of the nasal cavity.  Normal value: 25 mm at age 8½. It increases 0.7 mm per year.  Standard deviation: ± 2 mm.  Interpretation: Used for the analysis of the airways. Sometimes mouth breathing might be due to a narrow nasal cavity or to insufficient transverse growth of the www.indiandentalacademy.com maxilla. 
  • 53. 12. Nasal height :  The distance between the anterior nasal spine (ANS) and the Z - Z plane.  Normal value: 44.5 mm at age 9, increases 1 mm per year   Standard deviation : ± 3mm Interpretation: Like nasal width, this measurement describes the nasal cavity. www.indiandentalacademy.com z
  • 54. 13. Maxillary width :  The distance between J points.  Normal value: 62 mm at age 9. It increases 0.6 mm per year.   Standard deviation: ± 3 mm. Interpretation: Indicates transverse maxillary growth and should be taken into account for planning and evaluation of palatal disjunction J www.indiandentalacademy.com
  • 55. 14. Mandibular width :  The distance between points AG and AG.  Normal value: 76 mm at age 9. It increases 1.4 mm per year.   Standard deviation: ± 3 mm. Interpretation: Used for the study of mandibular morphology www.indiandentalacademy.com
  • 56. 15. Facial width :  The distance between points ZA and ZA.  Normal value:116 mm at age 9. It increases 2.4 mm per year.   Standard deviation: ± 3 mm. Interpretation: Used to describe facial morphology. www.indiandentalacademy.com
  • 57. HEWIT ANALYSIS  According to this method (Hewitt, 1975), analysis of craniofacial asymmetry is performed by dividing the craniofacial complex in constructed triangles, the so-called triangulation of the face. www.indiandentalacademy.com
  • 58.             The anatomical points used are shown in figure. 1. Sella 2. Medial extent of orbit 3. Inferior extent of orbit 4. Condylar point 5. Mastoidale 6. Anterior nasal spine 7. Zygomatic arch 8. Upper molar point 9. Incisor point 10. Gonion 11. Menton www.indiandentalacademy.com
  • 59.   The two longitudinal axes representing the midline points of the maxillary and mandibular regions are constructed. Axis X : which represents the middle third of the face is formed by joining: sella, anterior nasal spine and bisectors of lines joining the medial extent of orbits, right and left orbitale, right and left mastoidale, bilateral zygomatic points, and right and left molar points. (X midline axis of maxillary region N midline axis of mandibular region) www.indiandentalacademy.com
  • 60.  Axis N : which represents the lower third of the face is formed by joining : menton and bisectors of lines joining condylar points and bilateral gonial points. www.indiandentalacademy.com
  • 61. The angle of divergence of the axes is proportional to the degree of asymmetry between the middle and lower third of the face.  The angle between the two axes can be bisected to give the arbitrary anatomical axis of the face. (AA Anatomical axis of face)  www.indiandentalacademy.com
  • 62. Method of triangulation   The reference points already described were plotted and the following triangles drawn on both sides of the tracings: A) Cranial base region: Between the extreme upper extent of the head of the condyle, extreme mesial extent of the head of the condyle and sella to represent the cranial base region; www.indiandentalacademy.com
  • 63.  B) Lateral maxillary region: Between sella, mastoidale and the root of the zygoma representing the lateral maxillary region;  C) Upper maxillary region: Joining sella, anterior nasal spine and the root of the zygoma representing the upper maxillary region; www.indiandentalacademy.com
  • 64.   D) Middle maxillary region: Drawn between the root of zygoma, upper molar points and the anterior nasal spine representing the right and left middle maxillary regions; E) Lower maxillary region: Joining anterior nasal spine, upper molar points and the point of intersection of a line drawn between the bilateral upper molar points and the arbitrary anatomical axis representing the right and left lower maxillary regions; www.indiandentalacademy.com
  • 65.   F) Dental region: Drawn between upper molar points, upper incisal point and the point of intersection of a line joining the upper molar points and the anatomical axis representing the right and left dental regions; G) Mandibular region: Drawn between the condylar points, gonion, and menton to represent the mandibular component of the fact www.indiandentalacademy.com
  • 66.  The area of the respective triangles are calculated for the component areas of the face and compared for both the left and right side. www.indiandentalacademy.com
  • 67. Sassouni analysis 1. Upper Face and Cranial Base 2. Mid Face 3. Lower Face www.indiandentalacademy.com
  • 68. Landmarks  Upper face and Cranial Base    Roof of Orbit (RO)- Uppermost point on the roof of the orbit Lateral Orbitale (LO)Intersection point between the external orbital contour laterally and the oblique orbital line. This represents the upper face breadth. www.indiandentalacademy.com RO RO
  • 69.  Mid face   Maxillare (Mx)- Maximum concavity on the contour of the maxilla between Malare (Ma) and maxillary first molar. Zygoma (Zyg)- Most lateral and superior point of the zygomatic arch. www.indiandentalacademy.com
  • 70.  Lower face     Mastoidale(Ms)- lowest point on the contour of mastoid process. Gonion (Go)- Intersection of posterior border of ramus and inferior border of mandible. Menton (Me)- Lowermost point on the contour of the chin. This represents the mandibular breadth. www.indiandentalacademy.com
  • 71.  Construction of planes  Supraorbital plane is constructed by joining points RO to RO  Bizygomatic plane is constructed by joining points Zygoma (Zyg) to Zygoma (Zyg)  Bimastoid plane is constructed by joining points Mastoidale (Ms) to Mastoidale (Ms)  Bigonial plane is constructed by joining points Gonion (Go) to Gonion (Go) www.indiandentalacademy.com
  • 72. Symmetry  Trace the supraorbital line, the lateroorbitale-to-lateroorbitale (LO) line, the bizygomatic line, the bimastoid line, and the bigonial line  In an ideal situation all these lines are parallel. www.indiandentalacademy.com
  • 73. Symmetry  Symmetry of face in transverse direction is assessed by dropping a perpendicular to the mid point of these lines.  When they are not parallel, select the three planes that are the most nearly parallel. From their midpoints drop a perpendicular and assess the transverse symmetry of the face. www.indiandentalacademy.com
  • 74. Position of upper first molars  A line connecting LO (lateroorbitale) and Mx (maxillare) is drawn and prolonged downward.  The buccal contour of the maxillary first permanent molar should be tangent to this line, with a normal variation of 2mm.  This is a guide, especially in crossbite cases. www.indiandentalacademy.com
  • 75. Limitations of posteroanterior cephalometry    The main problems are related to the absence of well-defined, stable (or relatively stable) structures for the superimposition of the subsequent cephalometric tracings. Measurements used are subject to errors that may be related to the X-ray projection, the measuring system, or the identification of landmarks. Difficulty in reproducing head posture, difficult in identifying landmarks because of superimposed structures or poor radiographic technique, these factors also contributes in limiting the use of posteroanterior cephalometry. www.indiandentalacademy.com
  • 76.  Case   analysis Patient name: Vaishali Asole 21 yrs female Grummons analysis www.indiandentalacademy.com
  • 77. Grummons analysis : 1. construction of four horizontal planes  Z-Z plane  ZA-ZA plane  J-J plane  Parallel to Z plane through menton  Not parallel, asymmetry in zygomatic region 2. MSR through Cg-ANS 3. Mandibular morphology analysis – two triangles, CoMe-Ag on right and left side compared Cg Z Co ZA J ANS Ag www.indiandentalacademy.com Me
  • 78. 4. Volumetric comparison  Two polygons formed by Co-Ag-Me-the intersection with a perpendicular from Co-MSR are compared with computer program. Co 5. Maxillomandibular comparison of asymmetry  Four lines from Ag, J bilaterally, and from Cg- J , Cg – Ag Ag  If symmetry is present four triangles become two.  Asymmetry in maxillary region. www.indiandentalacademy.com Cg J Me
  • 79. 6. Linear asymmetry analysis  Linear distance to MSR and vertical difference of perpendicular projection of Co, NC, Ag, Me to MSR .  Vertical discrepancy lies with Co, J, and NC region. 7. Maxillomandibular relation  Distance from buccal cusp of first molar to the J perpendicular, lines Ag-Ag and ANS – Me constructed to reveal dental compensation for any skeletal asymmetry. www.indiandentalacademy.com Co NC J Ag Me
  • 80. Ricketts analysis Field I 1. Molar relationship  Buccal surfaces of first molar at the level of occlusal plane. Patients value- 1mm Normal – 1.5mm ±1.5mm No presence of crossbite 2. Intermolar width  Distance between the buccal surfaces of mandibular first molars at occlusal plane. Patient value – 55mm for boy Normal -55mm ± 2mm for boy Arch width in molar region is normal  www.indiandentalacademy.com
  • 81. 3. Intercuspid width Distance between the cusps of both mandibular cuspid at occlusal plane Patient value 21mm Normal - 27.8mm Lack of coinciding denture midline 4. Denture midline Patient 1.5mm Normal 0mm ±1.5mm Normal, within in range. www.indiandentalacademy.com
  • 82. Field II 5.Left and right maxillomandibular width  Distance between J and ZAG Z-AG plane. Patient value- left-16mm, right-14mm Normal – 10mm for an average patient aged 8½ years. 6. Maxillomandibular midline Angle between midsaggital plane and ANS-Me plane. Patient value- 0° Normal- 0° ± 2 ° Normal Z AG www.indiandentalacademy.com
  • 83. Field III 7. Molar to both jaw  Distance between the buccal surfaces of mandibular first molars and J-AG plane Patient value left- 12mm right – 7mm Normal – 6.3 mm for an averaged boy at age 8½ years. 8. Dental midline to AG maxillomandibular midline  Distance between mandibular incisor midline and ANS-Me plane Patient value 2mm Normal 0mm ±1.5mm www.indiandentalacademy.com Midline is shifted.  J ANS M
  • 84. 9. Inclination of the occlusal plane  Difference betweeen measurement from Z-Z line to occlusal plane at the level of right and left molars Patient value – left- 72mm right – 65mm Normal – 0mm ± 2mm Difference is 7mm , asymmetry present due to skeletal asymmetry.  Field IV 10.Postural symmetry Difference between angles Z- AG-ZA on both sides. Patient value- left - 10° right – 10° Normal - 0° ± 2 ° Asymmetric face. ZA Z AG www.indiandentalacademy.com Z
  • 85. Field V 11. Nasal width NC-NC patient value- 24mm Normal – 33.7mm (for age 21 year) Narrow nasal cavity 12.Nasal height Distance between ANS and Z plane Patient value- 61mm Normal – 56.5mm (for age 21 years ) Nasal height is short  www.indiandentalacademy.com Z Nc
  • 86. 13. Maxillary width Distance between J points Patient value – 65mm Normal – 69.2mm (for age 21years). constricted maxillary region 14. Mandibular width Distance between points AGAG Patient value – 88mm Normal – 92.8mm (for age 21 years). constricted mandibular region J AG www.indiandentalacademy.com
  • 87. 15. Facial width Distance between points ZA-ZA Patient value- 103mm Normal : 142.8mm (for age 21 years). Constricted interzygomatic width ZA www.indiandentalacademy.com
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