Grummons analysis

Fronto facial analysis- Grummons analysis
Dr Farisha Mohammed
Yenepoya Dental College, Mangalore

1. GRUMMONS ANALYSIS ( Grummons and Kappeyne van de Coppello,JCO , 1987) Farisha Mohammed

2. Introduction The PA cephalogram offers an effective tool in evaluating the craniofacial structures in transverse and vertical dimensions. It allows us to look at the facial skeleton in relative view of the right-left face and upper-lower face .

3. Frontal and asymmetry information is vitally important in: Orthodontic surgery planning (lateral and frontal VTOs); Differential tooth eruption with segmental TMJ splint therapy; and Functional jaw orthopedics including three dimensional improvements in facial or dental proportions or symmetry.

4. Cephalometric set-up A headholder or a cephalostat that can be rotated 90° is used, so that the central X-ray beam penetrates the skull of the patient in a posteroanterior direction and bisects the transmeatal axis perpendicularly. The standard distance from X-ray source to patient is 5 feet (152.4 cm) The tip of the nose and forehead should lightly touch the cassette and the FHP should be parallel to the floor

5. PA Ceph Analysis Most of the posteroanterior cephalomctric analyses described in the literature are quantitative , and they evaluate the craniofacial skeleton by means of linear absolute measurements of: Width or height (Solow, 1966; Ricketts et al, 1972; Ingerslev and Solow, 1975; Movers et al, 1988; Nakasima and Ichinose, 1984; Grummons and Kappeyne van de Coppello , 1987; Athanasiou et al, 1992);

6. Angles (Ricketts et al, 1972; Svanholt and Solow, 1977; Droschl , 1984; Grummons and Kappeyne vande Coppello , 1987; Athanasiou et al, 1992); Ratios ( Costaras et al, 1982; Grummons and Kappeyne van de Coppello , 1987; Athanasiou et al, 1992); and Volumetric comparison ( Grummons and Kappeyne van de Coppello , 1987).

7. The different structures of the craniofacial complex can also be analysed using qualitative methods ( Sollar , 1947; Grayson et al, 1983; Proffit , 1991). The analysis proposed by Grummons and Kappeyne van de Coppello (1987) contains quantitative assessment of vertical dimensions and proportions.

8. DR. DUANE GRUMMONS DDS MSD “Top Orthodontist” by Orthopedic Products Magazine  – 2012 American Board Certified in Facial Orthopedics and Orthodontics

9. Born- Sept 14, 1944 DDS – Marquette Univ School of Dentistry, Milwaukee,Wisconsin (1970) MSD – Fairleigh Dickinson Dept of Speciality Orthodontics (1974) Faculty – Loma Linda Dept of Facial Orthopedics and Orthodontics (25 years) Military – US Air Force Captain Innovator of orthodontic and facial orthodontic therapies

10. Grummons Analysis This is a comparative and quantitative posteroanterior cephalometric analysis. It is not related to normative data. The analysis is presented in two forms: The C omprehensive frontal asymmetry analysis The Summary frontal asymmetry analysis.

11. LANDMARKS

12. Crista Galli (Cg) : located on the midpart of the ethmoid bone. Constricted part is marked Cg. Upper part of crista galli is superimposed by frontal crest. Lower part leads to perpendicular plate of ethmoid bone Anterior Nasal Spine (ANS) : located in the central part of piriform aperture Nasal cavity(NC)- Nasal cavity at widest point J point : Intersection of lower border of zygomatic process and outer surface of maxillary tuberosity

13. Menton is the most inferior midpoint of the chin on the outline of the mandibular symphysis Frontozygomatic Suture(Z) is the most medial and anterior point of each frontozygomatic suture at the level of the lateral orbital rim Zygomatic Arch (ZA) : Cross section of zygomatic arch A1-Upper Central Incisor Edge B1- Lower Central Incisor Edge

14. Condylion (Co) is the most postero -superior point of each mandibular condyle in the sagittal plane . Antegonial notch (Ag)-The highest point of the notch or concavity of the lower border of the vertical mandibular ramus where it joins the body of the mandible

15. Tracing Suggestion Before tracing the various skeletal and dental structures of a posteroanterior cephalogram , the examiner must ensure that the head position and the 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 casts.

16. To ensure correct head tilt Check the patient from side to see the Frankfort Horizontal Plane ( from infraorbital margin to external auditory canal) is close to horizontal Another technique- Plumb Line Suspend a plumb line, made from thin wire and a weight, from the X-ray cassette. This Line will then appear as a true vertical reference line on radiographs

17. Midsagittal Reference Line A midsagittal reference line (MSR) is constructed from crista galli (Cg) through the anterior nasal spine (ANS) to the chin area An alternative way of constructing the MSR line, if anatomical variations in the upper and middle facial regions exist, is to draw a line from the midpoint of Z-plane either through ANS or through the midpoint of both foramina rotundum ( Fr-Fr line )

18. MSR LINE Midsagittal reference line permits the clinician to compare right and left sides for transverse and vertical variations, disproportional relationships, and assymetry Look down the tracing (MSR) at the midline If the horizontal lines donot match or intersect at MSR, one side is different than the other by millimeter difference Locate the chin and measure its deviation from MSR

19. COMPONENTS

20. Horizontal Planes Four planes are drawn to show the degree of parallelism and symmetry of facial structures

21. One connecting the medial aspects of the zygomaticofrontal sutures (Z ) ; One connecting the centres of the zygomatic arches (ZA); One connecting the medial aspects of the jugal processes (J) ; and One parallel to the Z-plane through menton . Construction of Horizontal Planes

22. Mandibular M orphology Analysis L eftsided and rightsided 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.

23. PARAMETERS RIGHT SIDE LEFT SIDE Difference Co-Ag linear 69mm 70mm 1 Ag-Me linear 54mm 41mm 13 Co-Me linear 119mm 100mm 19 <Co-Ag-Me 123 o 130

24. Volumetric Comparison Four connected points determine an area, and here a connection is made between the points: condylion (Co ); antegonial notch (Ag ); menton ( Me) the intersection with a perpendicular from Co to MSR The two polygons ( leftsided and rightsided ) that are defined by these points can be superimposed with the aid of a computer program, and a percentile value of symmetry can be obtained

25. Maxillomandibular Comparison of Asymmetry Four lines are constructed, perpendicular to MSR, from Ag and from J , bilaterally. Lines connecting Cg and 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 constructed lines also form the two triangles, namely J-Cg-J and Ag-Cg-Ag .

26. Linear Asymmetry A ssessment 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 . With the use of a computer, left and right values and the vertical discrepancies between bilateral landmarks can be listed

27. 54 52 18 12 34 29 43 37

28. Parameter Right side Left side Difference Co-MSR 54 52 2 Nc -MSR 18 12 6 J-MSR 34 29 5 Ag-MSR 43 37 6

29. Maxillomandibular relation During the X-ray exposure, an 0.014-inch (0.356-cm) Australian wire is placed across the mesioocclusal areas of the maxillary first molars, indicating the functional posterior occlusal plane . The distances from the buccal cusps of the maxillary first molar to the J-perpendiculars are measured .

30. 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.

31. 15 15 6

32. Frontal V ertical P roportion A nalysis The following ratios are taken into consideration (Al: upper central incisor edge, Bl : lower central incisor edge): upper facial ratio - Cg- ANS:Cg -Me lower facial ratio - ANS- Me:Cg -Me maxillary ratio - ANS-A1:ANS-Me

33. total maxillary ratio – ANS- Al:Cg -Me mandibular ratio – Bl - Me:ANS -Me total mandibular ratio – Bl - Me:Cg -Me maxillomandibular ratio – ANS- Al:Bl:Me These values can be compared with common facial esthetic ratios and measurements

34. upper facial ratio - Cg- ANS:Cg -Me = 55/124 =44.35% lower facial ratio - ANS- Me:Cg -Me = 69/124=55.6% maxillary ratio - ANS-A1:ANS-Me =27/69=39.1% total maxillary ratio - ANS- Al:Cg -Me = 27/124=21.77% mandibular ratio - Bl - Me:ANS -Me =33/69=47.8% total mandibular ratio - Bl - Me:Cg -Me = 33/124=26.6% maxillomandibular ratio - ANS- Al:Bl:Me = 27/33=81.8%

35. upper facial ratio – Cg- ANS:Cg -Me 44.35% lower facial ratio – ANS- Me:Cg -Me 55.6% maxillary ratio – ANS-A1:ANS-Me 39.1% total maxillary ratio- ANS- Al:Cg -Me 21.77% mandibular ratio – Bl - Me:ANS -Me 47.8% total mandibular ratio - Bl - Me:Cg -Me 26.6% maxillomandibular ratio- ANS- Al:Bl:Me 81.8%

36. Rocky Mountain Data Systems (Los Angeles, CA, USA). Shown are Grummons frontal/partial (2), and Grummons frontal/complete.

37. Dolphin Imaging

38. FACIAL ASYMMETRY:: FIVE IMPORTANT QUESTIIONS 1.Is the maxillary width equally wide ? 2. Is the occlusal plane level ? 3. Is the maxillary dentition centered with the facial skeletal midline ? 4. Are the maxillary and mandibular midlines aligned ? 5. Is the chin location centered, or nearly so?

39. The Comprehensive Frontal Assymetry Analysis consists of all the data described and three tracings The horizontal planes, mandibular morphology, and maxillo-mandibular comparisons have been combined to produce the Summary Facial Asymmetry Analysis , which by intention displays less data. This provides a practical summary of the patient's frontal asymmetry, emphasizing key dentoalveolar and skeletal factors that influence treatment decisions

40. Frontal Tracing and Surgical o rthodontic VTO planning steps

41. (b) locate lateral maxillary and lateral mandibular anatomic points/planes, occlusal plane; mandibular midline ( menton ) (a) locate midsagittal reference Line (MSR)

42. (c) overlay tracing with leveled occlusal plane reveals extent of osteotomy required to create symmetric maxillary component ; (d) locate incisors to treatment objective and center on facial midline (MSR); (e) trace key landmarks and lines on overlay tracing

43. (f) position mandibular overlay optimally to level horizontally Ag- gA plane with chin at midline (decision about possible separate chin osteotomy may be needed to reach best-fit occlusion and a centered chin in the final result); ( e) trace key landmarks and lines on overlay tracing;

44. (g) when occlusal plane is set level, mandibular Ag- gA plane and chin are still asymmetric ; (h) symmetry of lower facial two-thirds exists, as does molars best-fit occlusion ;

45. ( i ) if mandible is positioned to best symmetry, then molars are not reaching on the short side (these can be erupted and leveled postoperatively (j) if chin is more than 3 mm off facial midline (MSR), then consider chin relocation for centering and lower facial third proportionality (side overlay tracing so Me region is on MSR and the contour of chin border is balanced);

46. (k) measure/record chin reference point changes to predict millimeters of movement laterally, rotationally, and vertically ; (l) symmetric outcome predicted and summary of treatment changes and extent/location of surgical moves are known and calculated

47. Conclusion The Simplified Grummons Frontal Analysis provides a practical method to determine conditions, locations, and extent of facial assymetry using hard tissue analysis It is of greatest clinical value when integrated with data from lateral and submental vertex radiographs Head rotation and improper construction of MSR can reduce the effectiveness of this analysis . In addition , measurements are subject to distortion

48. References A Frontal Asymmetry Analysis- Duane C. Grummons, DDS, MSD ; Martin A. Kappeyene Van De Coppello ; JCO Volume 1987 Jul(448 - 465 ) Frontal Cephalometrics:Practical Applications, Part 1 ; World J Orthod 2003;4:297-316 Frontal Cephalometrics:Practical Applications, Part 2 ; World J Orthod 2004;5:99-119 Orthodontic Cephalometry by Athanasios E Athanasiou Contemporary Cephalometric Radiography - Kunihiko Miyashita