Cephalometric analysis

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computerized cephalometric analysis. The process allows for automatic measurement of landmark relationships. Depending on the software and hardware available, the incorporation of data can be performed by digitizing points on a tracing, by scanning a tracing or a conventional radiograph, or by originally obtaining computerized radiographic images that are already in digital format, instead of conventional radiographs. Computerized cephalometrics offers the advantages of instant analysis; readily available race-, sex- and age-related norms for comparison; as well as ease of soft tissue change and surgical predictions. Computerized cephalometrics has also helped in eliminating any surgeon inadequacies as well as making the process less time-consuming.

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object-to-film interval of 15 cm and a source-to-object span of 5 feet, magnification of anatomical landmarks will be reduced in all three dimensions.When attempting to analyze a patient's anatomy through lateral and frontal cephalograms, the challenge arises due to these images being two-dimensional projections of three-dimensional structures. Magnification and distortion as an outcome of traditional radiography further complicates the process by blurring important details.

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to its growth early in life. Therefore, a posteriorly positioned nasion will increase ANB and more anterior positioned nasion can decrease ANB. In addition, short S–N plane or steeper S–N plane can also lead to greater numbers of SNA, SNB and ANB which may not reflect the true position of the jaws compare to the cranial base. In addition, clockwise rotation of both jaws can increase ANB and counter-clockwise rotation of jaws can decrease ANB.

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of intracranial reference lines. True vertical is an external reference line, commonly provided by the image of a free-hanging metal chain on the cephalostat registering on the film or digital cassette during exposure. The true vertical line offers the advantage of no variation (since it is generated by gravity) and is used with radiographs obtained in natural head position.

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as in superimpositions, to evaluate treatment and growth changes. Historically, tracings of the cephalometric radiographs are done on an 0.003 inch thick matte acetate paper by using a #3 pencil. The process is started by marking three registration crosses on the radiograph which are then transferred to the acetate paper.

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Computer processing of cephalometric radiographs uses a digitizer. Digitization refers to the process of expressing analog information in a digital form. A digitizer is a computer input device which converts analog information into an electronic equivalent in the computer's memory. In this treatise

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A cephalometric tracing is an overlay drawing produced from a cephalometric radiograph by digital means and a computer program or by copying specific outlines from it with a lead pencil onto acetate paper, using an illuminated view-box. Tracings are used to facilitate cephalometric analysis, as well

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Registration of the head in its natural position while obtaining a cephalogram has the advantage that an extracranial line (the true vertical or a line perpendicular to that) can be used as a reference line for cephalometric analysis, thus bypassing the difficulties imposed by the biologic variation

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in 1955, states that in a well proportioned face, the following four planes meet at the point O. The point O is located in the posterior cranial base. This method categorized the vertical and the horizontal relationship and the interaction between the vertical proportions of the face. The planes he

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developed Steiner Analysis in 1953. He used S–N plane as his reference line in comparison to FH plane due to difficulty in identifying the orbitale and porion. Some of the drawbacks of the Steiner analysis includes its reliability on the point nasion. Nasion as a point is known not to be stable due

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SNA and SNB is important to determine what type of intervention (on maxilla, mandible or both) is appropriate. These angles, however are influenced also by the vertical height of the face and a possible abnormal positioning of nasion. By using a comparative set of angles and distances, measurements

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Prof. Jean Delaire started developing his analysis along with Dr M. Salagnac back in the 70's. This analysis is still developed and improved by his pupils. This analysis is based on reciprocal proportion and balance and doesn't use standard deviation. It gives the ideal architecture the patient

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is the process of entering cephalometric data in digital format into a computer for cephalometric analysis. Digitization (of radiographs) is the conversion of landmarks on a radiograph or tracing to numerical values on a two- (or three-) dimensional coordinate system, usually for the purpose of

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and can be used to diagnose facial growth abnormalities prior to treatment, in the middle of treatment to evaluate progress, or at the conclusion of treatment to ascertain that the goals of treatment have been met. A Cephalometric radiograph is a radiograph of the head taken in a Cephalometer

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To carry out cephalometry, the X-ray source is placed a steady five feet away from the mid sagittal plane, with film situated just 15 cm from there. This allows for accurate measurements to be taken and recorded. Distance has a direct impact on cephalometric image magnification. With an

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Cephalometric radiographs can be superimposed on each other to see the amount of growth that has taken place in an individual or to visualize the amount of movement of teeth that has happened in the orthodontic treatment. It is important to superimpose the radiograph on a stable anatomical

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Therefore, it measured the AP positions of the jaw to each other. This analysis calls for 1. Drawing an Occlusal Plane through the overlapping cusps of Molars and Premolars. 2. Draw perpendicular lines connecting A point and B Point to the Occlusal Plane 3. Label the points as AO and BO.

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when it was presented in 1978 in an issue of AJODO. This was followed by Soft Tissue Cephalometric Analysis for Orthognathic Surgery in 1980 by Arnette et al. In this analysis, Burstone et al. used a plane called horizontal plane, which was a constructed of Frankfurt Horizontal Plane.

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In a patient who has a clockwise growth pattern, the sum of 3 angles will be higher than 396 degrees. The ratio of posterior height (S-Go) to Anterior Height (N-Me) is 56% to 44%. Therefore, a tendency to open bite will occur and a downward, backward growth of mandible will be observed.

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A radiograph of the head taken with the x-ray beam perpendicular to the patient's coronal plane with the x-ray source behind the head and the film cassette in front of the patient's face. PA ceph can be evaluated by following analyses that have been developed through the years:

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The basic elements of analysis are angles and distances. Measurements (in degrees or millimetres) may be treated as absolute or relative, or they may be related to each other to express proportional correlations. The various analyses may be grouped into the following:

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in 1974. This analysis developed standards for the unit length of the maxilla and mandible. The difference between the unit length describes the disharmony between the jaws. It is important to know that location of teeth is not taken into account in this analysis.

1761:. They together make a Polygon on a face when connected with lines. These points are used to study the anterior/posterior facial height relationships and predict the growth pattern in the lower half of the face. Three important angles used in his analysis are: 161:

Anatomical structures are traced first and some structures are bilateral and have tendency to show up as two separate lines, should have an "average" line drawn which is represented as a broken line. These landmarks could include inferior border of mandible.

2863:. This method divides superimposition in three categories: Cranial base superimposition, maxillary superimposition and mandibular superimposition. Some of the important landmarks in each category is listed below as per the structural method. 1632:

was developed in 1947 based on 322 Swedish boys and 281 conscripts. He introduced a facial polygon which was based on 5 angles and is listed below. Bjork also developed the 7 structural signs which indicates the mandibular rotator type.

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developed his analysis in the year 1966. In this analysis, he tried describing the lower incisor position in relation to the basal bone and the face. This is described by 3 planes. He used Frankfurt Horizontal plane as a reference line.

213:(N) are points that together form the sella-nasion line (SN or S-N), which can be projected into the SN plane. A prime symbol (′) usually indicates the point on the skin's surface that corresponds to a given bony landmark (for example, 2830:

and its application to computerized cephalometrics, digitization refers to the resolving of headfilm landmarks into two numeric or digital entities – the X and Y coordinate. 3D analysis would have third quantity – Z coordinate.

1403:. Its clinical significance is that in a Class 2 skeletal patient, AO is located ahead of BO. In skeletal Class 3 patient, BO is located ahead of AO. Therefore, the greater the wits reading, the greater the jaw discrepancy. 1102:, B point) indicates whether the skeletal relationship between the maxilla and mandible is a normal skeletal class I (+2 degrees), a skeletal Class II (+4 degrees or more), or skeletal class III (0 or negative) relationship. 4111:

Arnett, G. W.; Jelic, J. S.; Kim, J.; Cummings, D. R.; Beress, A.; Worley, C. M.; Chung, B.; Bergman, R. (September 1999). "Soft tissue cephalometric analysis: diagnosis and treatment planning of dentofacial deformity".

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is a standardized orientation of the head that is reproducible for each individual and is used as a means of standardization during analysis of dentofacial morphology both for photos and radiographs. The concept of

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The more parallel the planes, the greater the tendency for deep bite and the more non-parallel they are the greater the tendency for open bite. Using the O as the centre, Sassouni created the following arcs

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structures. Traditionally, this process has been done by tracing and superimposing on cranial landmarks. One of the most common used methods of superimposing is called the Structural Method.

3100: 5040: 1324:. It states that chin prominence should be as far away as the farthest point of the lower incisor should be. An ideal distance is 2mm from Pogonion to NB line and L1 to NB line. 4508: 3173:

Grayson, Barry; Cutting, Court; Bookstein, Fred L.; Kim, Hiechun; McCarthy, Joseph G. (1988). "The three-dimensional cephalogram: Theory, techniques, and clinical application".

1378:". This analysis was created as a diagnostic aid to measure the disharmony between the AP degree. The ANB angle can be affected by multitude of environmental factors such as: 4176:

Björk, A.; Skieller, V. (February 1983). "Normal and abnormal growth of the mandible. A synthesis of longitudinal cephalometric implant studies over a period of 25 years".

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Most posterior inferior point on angle of mandible. Can also be constructed by bisecting the angle formed by intersection of mandibular plane and ramus of mandible

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is measured from posterior border of mandibular condyle (Co) to Pogonion. This analysis also looks at the lower facial height which is from upper ANS to Menton.

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Moorrees, Coenraad F. A.; Kean, Martin R. (1958-06-01). "Natural head position, a basic consideration in the interpretation of cephalometric radiographs".

2799: 5045: 5050: 4744: 4463: 3064: 4468: 2206: 3633:"Cephalometric analyses for cleft patients: a statistical approach to compare the variables of Delaire's craniofacial analysis to Bergen analysis" 4990: 1757:

in 1972. The analysis interprets how the craniofacial growth may affect the pre and post treatment dentition. The analysis is based on 5 points:

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This plane is formed by connecting the Bolton point to nasion. This plane includes the registration point and is part of the Bolton triangle.

1073:: averages serve as the norms for these and may be arithmetical (average figures) or geometrical (average tracings), e.g. Bolton Standards 4688: 119:

was introduced by Coenraad Moorrees and M. R Kean in 1958 and now is a common method of head orientation for cephalometric radiography.

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as a treatment planning tool. Two of the more popular methods of analysis used in orthodontology are the Steiner analysis (named after

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Björk, A.; Skieller, V. (April 1977). "Growth of the maxilla in three dimensions as revealed radiographically by the implant method".

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Lateral cephalometric radiograph is a radiograph of the head taken with the x-ray beam perpendicular to the patient's sagittal plane.

5096: 5091: 4579: 1085:: used to assess individual variations of facial structure to establish their mutual relationships, e.g. the Sassouni arcial analysis 3967:

Phillips, J. G. (August 1978). "Photo-cephalometric analysis in treatment planning for surgical correction of facial disharmonies".

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Juvvadi, ShubhakerRao; Gandikota, ChandraSekhar; Rayapudi, Naveen; Challa, PadmaLatha; Yudhister, PV; Rao, GuttiHariprasad (2012).

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Burstone, C. J.; James, R. B.; Legan, H.; Murphy, G. A.; Norton, L. A. (April 1978). "Cephalometrics for orthognathic surgery".

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Point at the intersection of the occipital condyle and Foramen Magnum at the highest notch posterior to the occipital condyle

5376: 5356: 5081: 5066: 3873:"Björk-Jarabak cephalometric analysis on CBCT synthesized cephalograms with different dentofacial sagittal skeletal patterns" 3464: 5453: 2235:– Arc of a circle between the anterior cranial base and the mandibular plane, with O as the center and O-ANS as the radius. 5172: 4060: 3855: 314:

Junction between inferior surface of the cranial base and the posterior border of the ascending rami of the mandible

4270:"The cranial base: The postnatal development of the cranial base studied histologically on human autopsy material". 85:. in USA. The Cephalometer is used to obtain standardized and comparable craniofacial images on radiographic films. 5381: 5366: 5207: 5202: 3542: 3085:

Predoctoral Orthodontic Laboratory Manual 2008, Department of Undergraduate Orthodontics, New Jersey Dental School

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This plane is formed by bisecting the anterior incisors and the distal cusps of the most posterior in occlusion.

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can be related to one another and to normative values to determine variations in a patient's facial structure.

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This plane represents the anterior cranial base and is formed by projecting a plane from the sella-nasion line

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Point at base of fissure where anterior and posterior wall meet. Anterior wall represents posterior surface of

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Point on the occlusal plane located perpendicular to the distal surface of the crown of the lower first molar

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Point on the occlusal plane located perpendicular to the distal surface of the crown of the upper first molar

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Notch above the tragus of the ear where the upper edge of the cartilage disappears into the skin of the face

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The first medically certified automated cephalometric analysis of 2D lateral cephalometric radiographs by

5371: 5139: 5076: 3072: 1079:: for these a whole series of norms are used, with age and sex taken into account, e.g. Bolton Standards 1066:

These in turn may be grouped according to the following concepts on which normal values have been based:

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This plane is formed by connecting the point gonion to gnathion at the inferior border of the mandible.

5361: 5086: 4880: 4347: 2241:– Arc of a circle between anterior cranial base and mandibular base with O as centre and OSp as radius. 3095: 5478: 5391: 4584: 2994:

Tenti, F. V. (1981-01-01). "Cephalometric analysis as a tool for treatment planning and evaluation".

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Line formed by connecting Soft Tissue Pogonion and middle of an S formed by lower border of the nose

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Below is a list of cephalometric planes that are commonly used in different cephalometric analyses.

3116:"A comparative study of linear measurements on facial skeleton with frontal and lateral cephalogram" 1017:

This vertical plane is formed by connecting nasion to pogonion as described in the Schudy analysis.

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This plane is formed by connecting ANS to PNS and is used to measure the vertical tilt of maxilla

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The most inferior anterior point on the maxillary alveolar process between the central incisors

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This plane passes is formed by drawing a line that touches the posterior premolars and molars.

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Björk, A. (September 1966). "Sutural growth of the upper face studied by the implant method".

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The following are important cephalometric landmarks, which are points of reference serving as

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Rodriguez-Cardenas, Yalil Augusto; Arriola-Guillen, Luis Ernesto; Flores-Mir, Carlos (2014).

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Point on the anterior curve of the soft tissue chin tangent to the esthetic plane or E line

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The point of intersection of the pterygoid root vertical to the Frankfort horizontal plane

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In the midline, the junction where base of the columella of the nose meets the upper lip

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Bansal, Naveen; Singla, Jeetinder; Gera, Gurmeet; Gupta, Monika; Kaur, Gurpreet (2012).

1116:, B point) indicates whether or not the mandible is normal, prognathic, or retrognathic. 5463: 5300: 5272: 5262: 5242: 5158: 5035: 4975: 4970: 4604: 4392: 4252: 3905: 3888: 3872: 3670: 3657: 3632: 3631:

Doberschütz, Philine Henriette; Schwahn, Christian; Krey, Karl-Friedrich (2021-05-29).

3608: 3573: 3391: 3356: 3150: 3115: 2263: 1374:, which is a University in South Africa. Jacobsen in 1975 published an article called " 1109:, A point) indicates whether or not the maxilla is normal, prognathic, or retrognathic. 502: 434:

Point located perpendicular on mandibular symphysis midway between pogonion and menton

4314: 4283: 4125: 3980: 3814: 3771: 3744: 3357:"Reliability of natural head position in orthodontic diagnosis: A cephalometric study" 3278: 5290: 5025: 4960: 4945: 4940: 4915: 4870: 4795: 4780: 4693: 4554: 4318: 4244: 4236: 4201: 4193: 4137: 4129: 4093: 4085: 4056: 4031: 4027: 3992: 3984: 3949: 3945: 3910: 3892: 3851: 3826: 3818: 3783: 3775: 3713: 3705: 3674: 3662: 3613: 3595: 3554: 3523: 3515: 3511: 3460: 3431: 3423: 3414:

Bergman, R. (March 1988). "Practical applications of the PA cephalometric headfilm".

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If curve of spee is deep then it may be difficult to create a straight occlusal plane

23: 2253:– From Te and should pass tangent to the mesial surface of the maxillary first molar 5490: 5305: 5015: 5005: 4865: 4845: 4840: 4770: 4765: 4739: 4639: 4614: 4574: 4310: 4279: 4256: 4228: 4185: 4121: 4023: 3976: 3941: 3900: 3884: 3810: 3767: 3740: 3697: 3652: 3644: 3603: 3585: 3507: 3386: 3368: 3321: 3274: 3235: 3190: 3182: 3145: 3127: 3003: 2927: 2888: 1674: 1134: 696: 487: 472: 198: 190: 178: 51: 47: 423:

Most prominent point in the median sagittal plane between the supraorbital ridges

5468: 5330: 5325: 5010: 4985: 4965: 4955: 4805: 4719: 4714: 4503: 4422: 4377: 4050: 3930:"A roentgenographic cephalometric analysis of cephalo-facio-dental relationships" 3845: 3452: 582: 182: 171: 3325: 3065:"Evaluating Ricketts' Cephalometric Analysis as Diagnostic Aid in Black Females" 5340: 5320: 5315: 5282: 5247: 5232: 4935: 4895: 4890: 4885: 4830: 4815: 4589: 4524: 3648: 1754: 1502:

Angle between Frankfort horizontal line and the line intersecting Gonion-Menton

755: 596: 568: 458: 286: 77: 70: 3701: 1401:-1mm in Males (AO is behind BO by 1mm) and 0mm in Females (AO and BO coincide) 5510: 5295: 5267: 5020: 4925: 4910: 4875: 4860: 4785: 4709: 4539: 4483: 4427: 4322: 4240: 4197: 4133: 4089: 4035: 3988: 3953: 3896: 3822: 3779: 3709: 3599: 3590: 3519: 3427: 3382: 3333: 3286: 3247: 3204: 3141: 3015: 2873: 1665:– Formed by line connecting Infradentale to Pogonion to the Mandibular Plane. 759: 739: 729: 206: 4790: 3480: 3373: 3239: 3132: 5495: 5227: 5217: 5030: 4920: 4855: 4835: 4775: 4760: 4564: 4544: 4498: 4412: 4407: 4387: 4363: 4141: 3914: 3870: 3666: 3617: 3400: 3341: 3159: 2860: 2856: 2062:

This line extends from the tip of soft tissue nose to soft tissue Pogonion

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A point on the condyle head in contact with and tangent to the ramus plane

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Angle between line through long axis of Lower incisor and Mandibular Plane

763: 102: 62: 39: 27: 4205: 3830: 3787: 3717: 3558: 3527: 3435: 3294: 3212: 3050: 3023: 3007: 2484: 1926:

Point at which shape of symphysis mentalis changes from convex to concave

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is measured from posterior border of mandibular condyle (Co) to ANS. The

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Angle between line through long axis of Lower Incisor and occlusal Plane

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Cross, J. J. (December 1996). "The Tweed philosophy: the Tweed years".

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Occlusal plane through molars and premolars contact (functional plane)

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A line connecting the incisal edge and root apex of the most prominent

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Clinical application of cephalometry (measurement of parts of the head)

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Projection on the line FH of the distance between the markers PT/Ms-d

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This plane can be used as an alternate to Frankfort horizontal plane.

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Jacobson, A. (1975-02-01). "The "Wits" appraisal of jaw disharmony".

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Point of intersection of the basion-nasion plane and the facial axis

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Point of junction of maxillary bone, lacrimal bone, and frontal bone

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This line is drawn through PTM and is perpendicular to the FH plane

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Nasion (Na), Sella (S), Menton (Me), Go (Gonion) and Articulare (Ar)

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Posterior vertical portion and inferior curvature of left and right

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Point of intersection between the line between pogonion and menton

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Angle between long axis of lower incisor and mandibular plane angle

1062:– involving the construction of arcs to perform relational analyses 415: 395:

Point at which outer ends of upper and lower eyelids meet (lateral

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relationships of a human skull. It is frequently used by dentists,

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Oria, A; Schellino, E; Massaglia, M; Fornengo, B (June 1991). "".

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In his study, Jacobsen mentioned that average jaw relationship is

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This plane represents the habitual postural position of the head.

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Point at which inner ends of upper and lower eyelids meet (medial

81:(Cephalostat) that is a head-holding device introduced in 1931 by 4734: 4729: 4448: 3801:

Vaden, J. L. (December 1996). "The Tweed-Merrifield philosophy".

898: 506: 396: 381: 361: 241: 126: 3308:

Weber, Diana W.; Fallis, Drew W.; Packer, Mark D. (2013-05-01).

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Point of intersection between ramus plane and mandibular plane

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Junction of Pterygomaxillary fissure and the foramen rotundum.

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should have, based on his skull shape, posture and functions.

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The Rickett analysis also consists of following measurements

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Point in the center of the condyle neck along the Ba–N plane

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