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Computer-aided surgical simulation (CASS) is an evolving technology which has significantly affected surgical correction of dentofacial deformities, a key step of which is orientation of the virtual skull model to allow for analysis and treatment planning. Explored in this study is the coplanarity of a 3-dimensional Frankfort horizontal plane (3D FHP).The 122 17.0 cm field-of-view cone-beam computed-tomogram (CBCT) scans were oriented to a 3D FHP using right porion, right orbitale, and left orbitale. The distance between the 3D FHP and left porion was then measured. The 18 CBCT scans were found to have external fiducial markers which were used for orientation into natural head position (NHP). The distance between left porion and a true horizontal plan coincidental with the right porion was measured. Concordance reliability measures were calculated to compare NHP to 3D FHP.The average distance of left porion to 3D FHP was found to be -0.107 mm (SD = 1.148), and the average distance from the coincidental left porion in NHP was found to be 0.846 mm (SD = 2.611). Concordance reliability calculations shows little consistency between the 2 methods of orientation (P = 0.838).The data shows coincidence between left porion and 3D FHP. Orientation of the virtual skull model according to 3D FHP offers a quick and easy method for this important step in CASS. Further study is needed for evaluation of this method in vivo.

Introduction The aim of modern cephalometrics is to evaluate the relationship of skeletal and dental functional units of the face and to implement treatment to establish the position of the units horizontally and vertically. Establishing a correct occlusal vertical dimension is considered one of the most important aspects of facial esthetics for patients in need of orthodontic treatment. Aim The aim of this study is to evaluate the vertical dimension of occlusion in varying dental malocclusions in Solan population. Materials and Methods The sample consisted of pretreatment lateral cephalograms of 100 patients (50 Class I and 50 Class II div 1), aged 15 to 30 years; six angular and one linear parameters were measured to determine the vertical dimension of occlusion. Results All the parameters (Frankfort-mandibular plane angle [FMA], Occl/Frankfort horizontal plane [FHA], angle of Y-axis, Occl/SN, GoGn/SN, and ANS-Me) were found to be decreased in Class I than in Class II div 1 malocclusion except (ANS-Xi-Pm). All the parameters were found to be statistically significant (p < 0.05) when compared between groups. When cephalometric norms of the present study were compared with Moroccan population, all parameters (ANS-Xi-Ptm, FMA, Occl/FH, Occl/SN, GoGn/SN, and ANS-Me) were found to be decreased in Solan population except angle of Y-axis. All the parameters were clinically significant (p < 0.05) except ANS-Xi-Pm and FMA that were found to be clinically nonsignificant (p > 0.05). Conclusion Solan population has distinct cephalometric characteristics, which should be used as the reference in future orthodontic treatments.

The plane formed by the intersection of bilateral porions (PoR and PoL) and left orbitale (OrL) is conventionally defined as the Frankfort horizontal (FH) plane. We aim to test the influence of the FH plane definition on a 3D cephalometric assessment. We selected 38 adult patients (20 males, 18 females, average age: 22.87 &plusmn, 5.17 years) without any gross asymmetry from retrospective records and traced and analyzed their cone-beam computed tomographic images. The findings were categorized into the following four groups: FH1: conventional, FH2: PoR, PoL, right orbitale (OrR), FH3: OrR, OrL, PoL, FH4: OrR, OrL, PoR. The average menton (Me) deviation from the MSP was statistically significant for the FH1 group (0.56 &plusmn, 0.27 mm, p &lt, 0.001), compared to the FH3 (1.37 &plusmn, 1.23 mm) and FH4 (1.33 &plusmn, 1.16 mm) groups. The spatial orientation level (SOL) of the FH plane showed a marked difference (p &lt, 0.05) between the FH2 (0.602&deg, &plusmn, 0.503&deg, ) and FH4 (0.944&deg, 0.778&deg, ) groups. The SOL of the MSP was comparatively small (p &lt, 0.001) for FH2 (0.015&deg, 0.023&deg, ) in comparison to both FH 3 (0.644&deg, 0.546&deg, ) and FH 4 (0.627&deg, 0.516&deg, ). Therefore, the FH plane definition can significantly influence the interpretation of cephalometric findings. Future studies should focus on standardization to improve the reliability and reproducibility of 3D cephalometry.

Introduction: Very little attention has been given in orthodontic diagnosis and treatment planning regarding appropriate facial orientation during photographic recordings. Analysis of facial profile using standardized photographs is a valuable tool for orthodontic diagnosis. Materials and Methods: We have worked on a new way to position the patient's head with Frankfort horizontal parallel to the floor by use of a a specially fabricated device. It consists of a vertically adjustable scale attached to metal framework. The shadow of the scale is projected as a horizontal line onto the face by means of a light source. The patient's head is positioned such that the Frankfort horizontal lies along the projected line. Twenty-five (13 males and 12 females) people aged between 15 and 25 years were photographed using the above method with a digital single-lens reflex camera. The photographs were taken again after a 15-day interval using the same protocol and checked for reliability. Results: Statistical analysis was done using paired student t-test and Kappa test. The results showed that there was no statistically significant difference between the mean angles at the initial (76.92 ± 4.77) and 15-day interval (76.72 ± 4.67) in profile view and between the mean angles at the initial (90.88 ± 2.06) and 15-day interval (90.96 ± 1.96) in the frontal view. Conclusion: This method allows us to take facial photographs by positioning the patient's head such that the FH plane is parallel to the floor. This method also helped us in standardization of facial photographs when photographs are taken in successive visits.

Objetivo: Evaluar las diferencias en la longitud y deflexión de la base craneal anterior en pacientes con diferente patrón esquelético. Materiales y método: El diseño del estudio fue observacional, descriptivo y transversal. La muestra fue distribuida en tres grupos y conformada por radiografías cefalométricas de 310 pacientes, cuyo rango de edad fue de 6 a 12 años. Se obtuvieron las radiografías cefalometricas de cada paciente, las cuales fueron evaluadas a través del trazado cefalométrico. Las variables evaluadas fueron: longitud de la línea sella-nasion y el ángulo formado entre la línea sella-nasion y el plano horizontal de Frankfort. Los datos se analizaron estadísticamente utilizando las pruebas Kruskal-Wallis y U Mann-Whitney (p, Objective: To evaluate the differences in length and deflection of the anterior cranial base in patients with different skeletal patterns, was the objective of the investigation. Materials and method: The study design was observational, descriptive and cross-sectional. The sample was conformed by 310 cephalometric radiographs of 6 to 12 year-old patients divided into three groups. Cephalometric radiographs were evaluated through the cephalometric tracing. The variables evaluated were: length of the sella-nasion line and the angle formed between the sella-nasion line and Frankfort horizontal plane. Data were statistically analyzed using the Kruskal-Wallis and U Mann-Whitney tests (p

Background To assess the reproducibility of landmarks in three dimensions that determine the Frankfort horizontal plane (FH) as well as two new landmarks, and to evaluate the angular differences of newly introduced planes to the FH. Methods Three-dimensional (3D) surface models were created from CBCT scans of 26 dry human skulls. Porion (Po), orbitale (Or), internal acoustic foramen (IAF), and zygomatico-maxillary suture (ZyMS) were indicated in the software by three observers twice with a 4-week interval. Angles between two FHs (FH 1: Or-R, Or-L, mid-Po; FH 2: Po-R, Po-L, mid-Or) and between FHs and new planes (Plane 1-6) were measured. Coordinates were exported to a spreadsheet. A statistical analysis was performed to define the landmark reproducibility and 3D angles. Results Intra- and inter-observer landmark reproducibility showed mean difference more than 1 mm for x-coordinates of all landmarks except IAF. IAF showed significantly better reproducibility than other landmarks (P < 0.0018). The mean angular difference between FH 1 and FH 2 was 0.7 degrees. Plane 3, connecting Or-R, Or-L and mid-IAF, and Plane 4, connecting Po-R, Po-L and mid-ZyMS, both showed an angular difference of less than 1 degree when compared to FHs. Conclusions This study revealed poor reproducibility of the traditional FH landmarks on the x-axis and good reproducibility of a new landmark tested to replace Po, the IAF. Yet, Or showed superior results compared to ZyMS. The potential of using new horizontal planes was demonstrated. Future studies should focus on identification of a valid alternative for Or and ZyMS and on clinical implementation of the findings.

Introduction:Use of cone beam computed tomography (CBCT) in orthodontics is increasing; however, some patients started treatment with conventional images. The objective of this study is to manipulate CBCT panoramic reconstruction to make it comparable to conventional panoramic image and to compare mesiodistal root angulations on both images.Materials and Methods:Concurrent conventional panoramics and CBCT volumes were obtained from 40 subjects. CBCT volumes were manipulated to generate pan-like images that mimic the occlusal plane angle of the corresponding panoramic, allowing comparison of mesiodistal root angulations and determination of the head-tilt required to produce the reconstruction.Results:Clinically meaningful differences (p< .05) in the mesiodistal root angulations between standard panoramics and CBCT reconstructions emerged for 13 out of 24 teeth (54%). Greatest variations were seen in the maxillary and mandibular sextants and in first molar regions. Ideal axial head-tilt for image acquisition was determined to be with Frankfort horizontal plane 3.3onose down.Conclusion:CBCT pan images must be used with caution due to variation between methods in specific areas of arches. The images can be useful for the assessment of mesiodistal root angulations if the volume is properly manipulated to create a pan-like image.

Background The aim of the study is to compare the relationship of the occlusal plane to 3 different ala-tragal lines, namely the superior, middle and inferior lines, in individuals having different head forms and its relation to the Frankfort horizontal plane. Methodology A total of 75 lateral cephalometric radiographs of subjects with natural dentition, having full complement of teeth, between the age group of 18–25 were screened and selected. Lateral cephalogram were made for each subjects in an open mouth position. Prior to making the lateral cephalogram, radiopaque markers were placed on the superior, middle and inferior tragus points and on the inferior border of the ala of the nose. Cephalometric tracing was done over each cephalogram. Results In mesiocephalic head form the middle ala-tragal line was most parallel to the occlusal plane having a mean angle of (1.96°). In dolichocephalic headform, the superior ala-tragal line was most parallel to the occlusal plane having a mean angle of (0.48°). In brachycephalic head form, the middle ala-tragal line was most parallel to the occlusal plane having a mean angle of (2.08°). The mean angulations of occlusal plane to FH plane is 11.04°, 10.16° and 10.60° in mesiocephalic, dolichocephalic and brachycephalic head forms, respectively. Results and conclusion The study concludes that the middle ala-tragal line can be used as a reference for the mesiocephalic head form and the superior ala-tragal line for the dolichocephalic and brachycephalic head form as a reference to establish the occlusal plane.

Aims and Objectives: The present study aims to evaluate the gender dimorphism of the angle SN-FH between the sella-nasion (SN) plane and the Frankfort horizontal (FH) plane among the three types of skeletal malocclusion in South Indian population. The objectives included measurement of angle SN-FH, FH to the nasion (NFH), FH to the sella (SFH), and the difference of NFH and SFH (Δ). The null hypothesis was that there exists no variation of the angle SN-FH, NFH, SFH, and Δ between males and females and in the different skeletal relationship of jaws. Materials and Methods: Cephalometric data were retrieved from the archived records of 180 patients, comprising 90 males and 90 females, within three subgroups. Class I (60), Class II (20), and Class III (10) in each of the gender class were examined. Student's “t” test was used to analyze means of the gender differences and analysis of variance between subgroups, and significance was set at P Results: The average values obtained from this study for the overall population are 8.06 ± 3.34; for males, it is 7.42 ± 3.62, and for females, it is 8.7 ± 3.48. The gender difference is statistically significant only in Class I malocclusion (0.002). There is no statistical difference between different skeletal classes of malocclusion. Conclusion: The null hypothesis is partially rejected for as significant difference is established only for some of the parameters under the study.

Aim: The aim of this study was to compare the accuracy of the angle made by Frankfort horizontal plane-occlusal plane on maxillary casts, mounted using the respective facebows on Artex Amann Girrbach and Hanau Wide-vue semi-adjustable articulators with cephalometrically derived Frankfort horizontal plane-occlusal plane angle as a control. Subjects and Methods: Maxillary casts of 30 subjects were mounted on Hanau Wide-vue and Artex Amann Girrbach semi-adjustable articulators following facebow transfer using respective facebows. The Frankfort horizontal plane-occlusal plane angles of these casts were measured using Wixey's digital angle gauge. They were also subjected to a lateral cephalogram, and the occlusal cant was measured using RadiAnt DICOM software. Statistical Analysis: Using Pearson correlation, the accuracy of the angle made by upper member of the articulator and occlusal plane of mounted maxillary casts in each of the articulator was compared to the Frankfort horizontal plane-occlusal plane angle in lateral cephalogram. Results: A mean difference of 1.9° was found between Hanau Wide-vue articulator and lateral cephalogram and a mean difference of 3.6° was found between Artex Amann Girrbach articulator and lateral cephalogram. Statistically, Pearson correlation value ( r ) obtained between Hanau Wide-vue and lateral cephalogram was 0.46 and between Artex Amann Girrbach and lateral cephalogram was 0.25. Conclusion: From the statistical value ( r ) derived, it can be inferred that the Frankfort horizontal plane-occlusal plane angle of the casts articulated on Hanau Wide-vue articulator was more accurate in comparison to that on Artex Amann Girrbach articulator.

Statement of problem The optimal procedure for the transfer of the sagittal inclination of the occlusal plane (OP) to semiadjustable and fully adjustable articulators is unclear. Purpose The purpose of this clinical study was to evaluate and compare the sagittal inclination of the OP with the Frankfort horizontal plane (FHP) on a facebow transfer to semiadjustable and fully adjustable articulators. Material and methods Facebow transfers (Hanau Spring-Bow; Whip Mix Corp) of 30 participants were recorded and transferred to a semiadjustable articulator (Hanau Wide-Vue; Whip Mix Corp) using the indirect method. Another set of facebow transfers from the same set of 30 participants using another facebow (Denar Slidematic Facebow; Whip Mix Corp) was recorded and transferred to a fully adjustable articulator (Denar D5A; Whip Mix Corp). The angle between the OP of the mounted cast and the upper member of the articulator was measured in each participant with a digital protractor on both articulators. Standardized lateral cephalograms of each participant were made as a control. The FHP and OP were traced on each standardized lateral cephalogram. The angle on the cephalogram between the FHP and OP was measured. These values were compared with previously measured values for the Hanau Wide-Vue and the Denar D5A articulators. The data were analyzed using ANOVA. Intergroup comparisons between and among the Hanau Wide-Vue, Denar D5A, and lateral cephalograms were performed using the independent t test. Results No statistically significant difference was found between the Hanau Wide-Vue and Denar D5A articulators compared with the lateral cephalograms (P=.06). In the intergroup comparison, no statistically significant differences were found between the Hanau Wide-Vue and Denar D5A articulators (P=.18). No statistically significant differences were found between the values obtained on the Hanau Wide-Vue and lateral cephalograms (P=.06). When the Denar D5A articulator was compared with the lateral cephalograms, there was a statistically significant difference (P=.02). Conclusions The Hanau Wide-Vue articulator most closely replicated the inclination of the OP. Regarding the sagittal inclination of the OP, the semiadjustable articulator can provide more accurate results than a fully adjustable articulator and thus eliminates occlusal errors.

Superimposition of radiographic imaging is used to evaluate patient growth and the effects of surgical and/or orthodontic treatment. The purpose of this study was to compare the outcomes of superimposition between two-dimensional (2D) and three-dimensional (3D) superimpositions. 2D lateral cephalograms were generated from the initial and final cone beam computed tomography scans (CBCT) of 18 patients and superimposed. Both 3D CBCT and 2D CBCT generated lateral cephalograms were oriented to the Frankfort horizontal plane and superimposed according to the American Board of Orthodontics recommendations. Changes in landmark position were quantified from the resulting superimposition outcomes via linear measurements made with Dolphin software. Differences between the two methods were analyzed using paired t-tests. Measurements were repeated twice for 10 randomly selected scans to assess reliability by intra-class correlation coefficient (ICC) analysis. Intra-examiner reliability was high for all measurements (ICC>0.84). Agreement between 2D and 3D superimposition outcomes, as measured by P-values, was low for ANS (P=0.026), B-point (P

Objective This study reported an intraoperative navigation system for single-splint two-jaw orthognathic surgery, and assessed the accuracy of transferring the computer assisted surgical simulation. Methods A skull model was used for validation, and twenty patients receiving such procedure were enrolled. The procedure contained five phases, including virtual surgery on three-dimensional images, fabrication of surgical positioning guides, preparation of registration and validation landmarks, confirmation of bony position during surgery, and postoperative assessment. Target registration error (TRE) and differences between simulation (T0) and postoperative images (T1) were measured from landmarks to Frankfort horizontal plane (FHP), mid–sagittal plane (MSP), and coronal plane (COP). Results For the model experiment, mean TRE was lowest using the hard tissue landmarks (0.60 ± 0.27 mm), and the mean difference (T1-T0) was less than 1 mm to all three planes. For the patients, mean TRE was 1.07 ± 0.18 mm from the hard tissue landmarks. The mean difference was 0.96. ± 0.60 mm from MSP, 1.39 ± 1.11 mm from FHP, and 2.12 ± 1.82 mm from COP. The differences were not significant. Both surgeons and patients were satisfied with the surgical outcome. Conclusion This study showed that the navigation system had acceptable accuracy and was useful for the two-jaw orthognathic surgery using single-splint method.

Aims and Objectives: To ascertain norms in cephalometry for 11- to 13-year-old Lingayat children in natural head position (NHP). Materials and Methods: Lateral cephalograms of children were obtained by using fluid level device. We determined the variance in Frankfort horizontal plane (FHP) inclination to extracranial horizontal in NHP. The GFNx01Power, version 20 for Windows was used for analysis. Results: Reduced facial convexity was observed when the analysis was carried out in relation to true horizontal with significant difference of “t” value of 3.05 and percentage difference of 1.1 (P < 0.01) and for girls “t” value of 9.69 and percentage difference of 2.5 (P < 0.001). The highest correlation coefficient for Lingayat boys (r = 0.77) was seen between palatal plane and occlusal plane. We found least correlation coefficient among FHP and Sella–nasion plane (SNP). The coefficient was r = 0.62 and correlation coefficient of r = 0.70 was between FHP and determination coefficient r2 = 0.38 or 38%. For girls, highest correlation coefficient of r = 0.70 was seen among FHP and palatal plane. Conclusion: Conventional study of craniofacial forms of Lingayat children showed the average skeletal pattern as Class II with retrognathic mandible in comparison to Caucasians. However, when seen in NHP by new method of analysis based on the true horizontal, the skeletal model was Class III in comparison to Caucasians.

Introduction The Frankfort horizontal (FH) is a plane that intersects both porions and the left orbitale. However, other combinations of points have also been used to define this plane in 3-dimensional cephalometry. These variations are based on the hypothesis that they do not affect the cephalometric analysis. We investigated the validity of this hypothesis. Methods The material included cone-beam computed tomography data sets of 82 adult subjects with Class I molar relationship. A third-party method of cone-beam computed tomography-based 3-dimensional cephalometry was performed using 7 setups of the FH plane. Six lateral cephalometric hard tissue measurements relative to the FH plane were carried out for each setup. Measurement differences were calculated for each pair of setups of the FH plane. The number of occurrences of differences greater than the limits of agreement was counted for each of the 6 measurements. Results Only 3 of 21 pairs of setups had no occurrences for the 6 measurements. No measurement had no occurrences for the 21 pairs of setups. Setups based on left or right porion and both orbitales had the greatest number of occurrences for the 6 measurements. Conclusions This investigation showed that significant and undesirable measurement differences can be produced by varying the definition of the FH plane.

We measured the gonial angle (GA) on panoramic radiography (PR) and analyzed the correlation between the GA on PR and lateral cephalometric radiography (LCR). In total, 49 PR films and LCR films from dentate young adults were evaluated. Orthodontists plotted four points (articulare, menton, posterior gonion, and lower gonion) on the PR and carefully traced them. Using a protractor, two radiologists measured the GA on LCR images. A simultaneous experimental study of two dry skulls was performed to compare the GA on LCR and PR. The GA was slightly smaller on the PR of the dry mandible than on the LCR and tended to decrease continuously with magnitude toward the Frankfort horizontal plane. The mean GA was 115.1 ± 5.2° on PR and 122.2 ± 6.4° on the LCR. The values were highly correlated (Pearson product-moment correlation coefficient, 0.801). The GA on PR was nonsignificantly smaller than that measured on LCR. The difference may be due to head position, the inclination angle of the mandibular body, and/or the direction of the incident X-ray beam.

Establishment of the cranial base references and the coordinate system is important for measurement of events occurring on the face. The literature suggests that the horizontal axis is obtained by tracing a line in clockwise direction at seven degrees from the Sella-Nasion line, and the vertical axis is perpendicular to this former axis passing through the Sella point. However, could this standardization better represent the angle between the Sella-Nasion line and Frankfort Horizontal Plane in a Brazilian population and be employed in cephalometric studies? Thus, the present study had two purposes: to identify the cranial base inclination in adult patients presenting with intermaxillary anteroposterior skeletal disharmony and to evaluate the reliability of a protocol to reproduce the cranial base reference. Lateral cephalograms of three different times were traced: T0) onset of orthodontic treatment and immediately before the orthognathic surgery, T1) six months after surgery, and T2) one year after surgery. The results displayed a mean cranial base inclination of 7.91 degrees. Variation of the intraindividual data allowed the conclusion that the protocol proposed by utilization of an individual template of the cranial base reference was effective for the exactness of measurements in cephalometric studies.

The goal was to investigate whether the three-dimensional (3D) reliability of the landmarks defining the Frankfort horizontal plane (FH) can be enhanced by reducing variance with the help of nearby anatomical structures. Twenty multislice computed tomography (MSCT) datasets of evidently symmetrical patients (11 female and 9 male patients, 6.1–16 years old) were selected from 695 datasets archived at our department. In the 3D reconstructions, we located the anthropometric landmarks orbitale and porion, then these were modified with the help of frontomalare temporale, radiculare and the most anterior border of the left and right external acoustic pore. The resultant orbitale* and porion* reference points for the Frankfort horizontal plane were then compared to the original landmarks. Statistical analysis was performed. The superior reliability in the sagittal y-axis and in the transversal x-axis of the new reference points was confirmed. Based on the covariance matrices, the mean maximum standard deviation (square root of the maximum eigenvalue) in the direction of maximum variance was reduced from 0.77/0.94 mm to 0.47/0.48 mm for left/right orbitale, and similar reductions from 0.85/0.92 mm to 0.29/0.30 mm were noted for left/right porion (p

Accurate occlusal plane orientation is an essential factor in the fabrication of complete denture prosthesis. Over the years, it has received a number of methodologies by several researchers utilizing various anatomical landmarks however none of them is considered as perfect that could orient ideal occlusal plane. The presented literature review is an attempt to enlighten historical perspectives, pioneer researches, different controversies, difficulties and current trends for re‑establishment of lost occlusal plane in edentulous patients. An extensive literature search was performed using Medline/PubMed interface and other scholarly research bibliographic databases using Medical Subject Headings. Studies describing research studies, case series and assorted clinical reports were retrieved and evaluated from 1963 to 2013. Most of the studies have suggest and evidence to consider Camper’s plane for artificial orientation of occlusal plane however there is a substantial lack of genuine long term studies and authentic data that could recommend a single reliable landmark for perfect occlusal plane reorientation in a variety of cases.Keywords: Camper plane, Complete denture, Esthetics, Frankfort horizontal plane, Occlusal plane

Aim: To evaluate the degree of the reliability of the S–N reference line by using highly stable reference lines (vertical and horizontal cranial axes). Materials and Methods: The sample of the study comprised of lateral cephalometric radiographs of patients 13–18 years, 12 males and 12 females for each of the three skeletal relationships. The ANB angles were 0–2, more than 2 and less than zero respectively. The method was conducted by localization of the anterior superior of anterior wall of sella turcica point (As), which is stable at age 5–6 years, drawing the Vertical Cranial Axis (VCA) which pass through the point As and tangent to the upper part of the anterior wall of the sella turcica (at least for 3 mm); then, drawing the Horizontal Cranial Axis (HCA), which is perpendicular to the VCA at the As point. The deflection and the sagittal dimension of the S–N line were measured to evaluate the variation in the location of the points S and N, which are the determinant of the S–N line. Results: Point N had significantly local variation between gender and among the three skeletal relationships, but that point S had insignificant local variation between gender and among the three skeletal relationships. Conclusion: The S–N line is not stable due to unstability of the location of point N.

Esthetic features are different from one race to another, and this should be considered during the treatment planning. The great variance in soft tissue drape of the human face complicates accurate assessment. The nose-lip-chin relationships are exceedingly important in determining the facial esthetics. One important soft tissue parameter in orthodontic diagnosis is the nasolabial angle. The purpose of this study was to establish norms for nasolabial angle as proposed by Fitzgerald for the Komarapalayam population. Normative data for the three nasolabial parameters were produced from a sample of 40 (20 male and 20 female) adults determined by the authors to have well-balanced faces. Mean and standard deviation values from this pooled sample demonstrated a lower border of the nose to Frankfort horizontal plane angle of 18° ± 7°, upper lip to Frankfort horizontal plane angle of 98° ± 5°, and nasolabial angle of 116° ± 10°. No statistically significant difference was demonstrated between the values for men and women in this study, but men did have a slightly larger nasolabial angle.

The aims of this study were to measure the three-dimensional (3-D) loads exerted on the implants supporting an overdenture during function in vivo and to clarify the effect of the number of the implants on the loads. The load-measuring devices were mounted on the implants inserted in the mandible of a 62 aged female subject. Either two or four implants connected with a bar were used for supporting her overdenture. The loads on the implants were expressed three dimensionally as load vectors and were analyzed in the coordinates based on the Frankfort horizontal plane and sagittal plane. The tasks examined were maximum voluntary clenching (MVC) and gum chewing (GC). The total load exerted on the implants with a four-implant supported overdenture (4I-Od) was larger than that with a two-implants supported overdenture (2I-Od) at MVC. The maximum occlusal force on the overdenture showed the same manner (p

Os autores estudaram possíveis influências em mensurações angulares e lineares verticais do Plano Horizontal de Frankfurt (PHF) quando utilizado como plano de orientação em telerradiografias póstero-anteriores. Foram utilizadas 90 telerradiografias póstero-anteriores, obtidas de trinta pacientes em 3 posições: PHF paralelo ao Plano Horizontal, PHF formando ângulos de mais 5 graus e PHF formando ângulos de menos 5 graus em relação horizontal. Os resultados mostraram que 5 dentre as 6 medidas angulares e 3 dentre as 11 medidas lineares verticais estudadas não mostraram diferença estatisticamente significante. Os autores concluíram que, em casos de inclinação do plano de orientação em telerradiografias póstero-anteriores, as medidas angulares são mais confiáveis do que as medidas lineares verticais. As medidas lineares verticais mostram-se altamente sensíveis às inclinações quando os planos coronais não são muito próximos; as angulares só mostram perda de confiabilidade quando os pontos cefalométricos estão em planos coronais bem distantes. The authors studied possible influences on angular and vertical linear measurements of the Frankfort Horizontal Plane (FHP) when used as an orientation plane in posteroanterior cephalometric radiographies. Ninety posteroanterior cephalometric radiographies were used, obtained from thirty patients in three positions: FHP parallel to the Horizontal Plane, FHP forming angles of plus and minus five degrees with the Horizontal Plane. After statistical treatment, five out of the six angular measurements and three out of the eleven vertical linear ones did not show statistically significant differences at a five percent level, in spite of the inclinations. The authors concluded that, in cases of inclination of the plane of orientation in posteroanterior cephalometric radiography, the angular measurements are more reliable than the vertical linear ones. As to the anatomic coronal planes, on which are located the cephalometric points considered for the measurements, the vertical linear measurements proved to be highly sensitive to the inclinations when the coronal planes are not quite close, and the angular measurements present only loss of reliability when the cephalometric points are on coronal points quite distant.

BACKGROUND The nasolabial angle is the angle between the line drawn through the midpoint of the nostril aperture and a line drawn perpendicular to the Frankfort horizontal plane while intersecting subnasale. Previous analysis by the authors' department yielded closer ranges between men and women of 96 and 98 degrees, respectively. This study further refines the ideal nasolabial angle using the opinions of a highly select group of seasoned rhinoplasty surgeons. METHODS Lateral photographs of 10 men and 10 women of various ethnic backgrounds who had undergone a rhinoplasty were studied. The photographs were digitally altered to various angles. Members of the Rhinoplasty Society evaluated the photographs. Raters selected their top choice based on the most aesthetically pleasing nasolabial angle. In addition, they were asked to estimate the angle of the photograph they selected as most ideal. Data analysis was performed using the distribution of means of ideal nasolabial angle values. RESULTS Based on the 95 percent confidence interval for the ideal means, the ideal nasolabial angle would be 93.9 to 97.3 degrees for male subjects and 96.8 to 100.2 degrees for female subjects. Twenty-four raters provided angle estimations; the mean ± SD angle was 2.76±2.49 degrees larger than the actual angle. CONCLUSIONS The authors' results were consistent with their previous findings, indicating a much closer range of nasolabial angle between men and women than previously reported in the literature. The overestimation in the nasolabial angle versus actual may be one factor accounting for the difference between the authors' findings and the previously accepted standards.

Introduction The aims of this study were to investigate and compare the anterior facial heights of children with long, normal, and short faces during growth and to discover whether long-faced subjects have long dimensions in both the upper and lower anterior facial heights compared with the others. Methods Longitudinal lateral cephalometric data of 167 children (83 girls, 84 boys) from 6 to 14 years of age were used. Total anterior face height, upper anterior face height, lower anterior face height, and the closest distance from the Frankfort horizontal plane to nasion were measured. The samples were classified as long-faced, normal-faced, and short-faced according to the ratio of lower to total face heights at 14 years old. All data were analyzed statistically and compared between the groups according to age. Results The mean lower anterior face height in the long-faced group was larger than in the normal-faced and short-faced groups for all ages in both sexes. In contrast, subjects in the normal-faced group had a longer mean upper anterior face height than did subjects in the long-faced and short-faced groups. In addition, the mean upper anterior face height of the short-faced group was larger than the long-faced group for girls at all ages and for boys at 12 to 14 years. Conclusions The long-faced children did not have longer upper facial heights compared with normal-faced and short-faced children, and their long faces were mainly determined by the length of the lower face.

The name of the seventh author is spelled incorrectly. The correct author name is: Mohamad Habes.

The purpose of this study was to evaluate the reliability of different anatomic reference planes in determination of Occlusal plane in dentulous and edentulous subjects with Angle’s class I and class II Maxillomandibular relationship. Eighty subjects were included in the study which was divided into four Groups based on dentition and skeletal relationship. The Group I (n = 20) and Group II (n = 20) includes young and completely dentulous subjects in Angle’s class I and class II relationship, respectively. The Group III (n = 20) and Group IV (n = 20) subjects were completely edentulous in Angle’s class I and class II relationship, respectively. For all subjects, right lateral cephalograms were taken and cephalometric analysis was done and data obtained from cephalometric tracings were then statistically analyzed. The results showed no significant difference of angle between Occlusal plane and Frankfort Horizontal plane, Camper’s plane and Palatal plane when Group I and Group III, and Group II and Group IV subjects were compared. The Frankfort Horizontal plane, Camper’s plane and the Palatal plane may be used as a reliable guide to establish Occlusal plane in edentulous subjects in both Angle’s class I and class II Maxillomandibular relationships.

Objective To evaluate the long-term maxillomandibular changes after maxillary distraction osteogenesis in growing children having cleft lip with or without cleft palate. Patients Eight Japanese patients with cleft lip with or without cleft palate aged 9.3 to 13.1 years. Measures The maxillary and mandibular positions before (TO), immediately after (T1), and 1, 3, and 5 years after distraction osteogenesis (T2, T3, and T4, respectively) measured on cephalograms superimposed at the sella turcica with the Frankfort horizontal plane as the horizontal reference. The anterior nasal spine (x, y), pogonion (x), and menton (y) were used for linear measurements, and sella turcica-nasion-point A, sella turcica-nasion-point B, and point A-nasion-point B angles were used for angular measurements. Results The mean horizontal maxillary advancement (anterior nasal spine [x]) was 12.3 mm during TO to T1, but -2.7, -1.1, and -0.1 mm of the posttreatment changes were observed during T1 to T2, T2 to T3, and T3 to T4, respectively. Anterior nasal spine (y) shifted 2.3 mm downward during TO to T1, and further downward changes were observed during T1 to T2 and T2 to T3 ( P < .05). Pogonion (x) did not show distinct changes due to individual variance, but menton (y) shifted downward from T1 to T4. Sella turcica-nasion-point A significantly decreased during T1 to T2 and T2 to T3 but not during T3–T4. Point A-nasion-point B significantly decreased only during T2 to T3, and sella turcica-nasion-point B did not show any distinct change. Conclusions There was no further maxillary advancement after distraction osteogenesis in the growing children with cleft lip with or without cleft palate. Therefore, long-term observation and management of occlusion in case of the mandibular growth pattern are important.

There is disagreement concerning the effect of premolar extractions on the dentofacial vertical dimension. It has been suggested that orthodontic forward movement of the posterior teeth after first premolar extraction leads to reduction in vertical dimension. The purpose of this study was to examine cephalometrically the dentofacial vertical changes in Class I Indian subjects treated with and without extractions.The extraction group included 31 normodivergent patients (26 female, 5 male; pretreatment age, 17.19 +/- 3.89 years) with maxillary and mandibular first premolar extractions. The nonextraction group included 29 patients (18 female, 11 male; pretreatment age, 18.48 +/- 3.61 years). A coordinate system with the Frankfort horizontal plane and a mandibular fiduciary line was used for the cephalometric calibration. To determine vertical dimension changes due to treatment and to compare differences between the 2 groups, paired and unpaired t tests were performed, respectively.Both groups had increases in linear vertical dimensions (P0.05), but the change was comparatively greater in the extraction group (P0.05). Mesial movement of the maxillary and mandibular posterior teeth was coincidental with the extrusion to such an extent that it increased the vertical dimension, although the mandibular plane angle remained unchanged during treatment.Extraction of teeth only to increase the overbite or decrease the mandibular plane angle might not be justified.

Background: The Endotine Forehead device (Coapt Systems, Inc., Palo Alto, Calif.) is an implantable bioabsorbable fixation device designed to provide intuitive, multipoint, distributed tension and repeatable and predictable brow fixation during endoscopic and open browplasty. The purpose of this study was to evaluate early results in a series of endoscopic brow lift cases using the Endotine Forehead device. Methods: Two versions of the Endotine device were used in this study. One was composed of polylactic acid, and the other was a smaller version consisting of 82/18 L-lactide/glycolide). In a consecutive series of endoscopic brow lift cases, preoperative and postoperative standardized photographs were taken in the Frankfort horizontal plane and three measurements were compared: midpupil to superior brow, midpupil to hairline, and lateral canthus to superior brow. Results: A total of 21 patients (19 women and two men) underwent endoscopic browplasty. Photographs were obtained preoperatively and 54 to 174 days postoperatively. Brow elevation measurements were obtained postoperatively. No significant adverse events were encountered in the follow-up period. Conclusion: The Endotine Forehead device provides significant and reproducible brow elevation, with no significant adverse events, as measured at three points in excess of 14 weeks postoperatively.

The objective of this study was to investigate the possibility of enhancing the clinical versatility of the panoramic radiograph, which is an indispensable tool for dental diagnosis. The material of this study consisted of lateral cephalograms and panoramic radiographs obtained from 30 patients. A correlation test was performed between the parametric measurements, and the predictability level of the cephalometric measurements from panoramic radiograms was determined by using regression equations. The equations showed that the Go-Gn/S-N, ANS-PNS/Go-Me (palatal plane/mandibular plane), and Co-Go/Go-Me parameters could be predicted from panoramic radiographs within statistically significant levels, and their predictability levels were 20.6%, 15.6%, and 11.2%, respectively. Statistically significant correlations and predictability levels were also determined for the cephalometric and corresponding panoramic parameters in which Frankfort horizontal plane was used. It can be concluded that even though panoramic radiographs provide information on the vertical dimensions of craniofacial structures, clinicians should be vigilant when predicting skeletal cephalometric parameters from panoramic radiographs, because of their lower predictability percentages.

Objectives: In three-dimensional computed tomography (3D-CT), the cant is evaluated by measuring the distance between the reference plane (or line) and the tooth. The purpose of this study was to determine the horizontal skeletal reference plane that showed the greatest correlation with clinical evaluation. Materials and Methods: The subjects were 15 patients who closed their eyes during the CT image taking process. The menton points of all patients deviated by more than 3 mm. In the first evaluation, clinical cant was measured. The distance from the inner canthus to the ipsilateral canine tip and the distance from the eyelid to the ipsilateral first molar were obtained. The distance between the left and right sides was also measured. In the second evaluation, skeletal cant was measured. Six reference planes and one line were used for the evaluation of occlusal cant: 1) FH plane R: Or.R ? Or.L ? Po.R; 2) FH plane L: Or.R ? Or.L ? Po.L; 3) F. Ovale plane R: Rt.F.Ovale ? Lt.F.Ovale ? Or.R; 4) F. Ovale plane L: Rt.F.Ovale ? Lt.F.Ovale ? Or.L; 5) FZS plane R: Rt.FZS ? Lt.FZS ? Po.R; 6) FZS plane R: Rt.FZS ? Lt.FZS ? Po.L, and; 7) FZS line: Rt.FZS ? Lt.FZS. Results: The clinical and skeletal cants were compared using linear regression analysis. The FH plane R, FH plane L, and FZS line showed the highest correlation (P Conclusion: The FH plane R and FH plane L are the most appropriate horizontal reference plane in evaluation of occlusal cant on 3D-CT.

Objective: To evaluate the precision of dimensional measurements of the mandible in two different positions on orthopantomogram (OPG) (one with mandibular plane parallel to the floor and the other with Frankfort horizontal plane parallel to the floor) and determine the dimensional reliability. Materials and Methods: Anatomical landmarks were used to denote points for measurements on mandible as well as OPG and respective measurements made. Magnification was hence calculated and compared with magnification factor (1.2) listed by the manufacturer. Results: Vertical measurements and anterior horizontal and oblique measurements showed minimal magnification. Posterior horizontal and oblique measurements showed increased magnification. The difference in measurements in the two positions and on comparison with the one given by the manufacturer was statistically significant for posterior horizontal measurements but not for posterior oblique. Horizontal measurements crossing the midline were highly magnified and the difference was statistically significant for the two positions and on comparison to the one given by manufacturer. Conclusion: Magnification factor given by the manufacturer is not uniform in all locations and varies with changes in positioning and hence should not be relied upon when accurate measurements are to be made.

OBJECTIVE: The purpose of this study was to determine the accuracy and reliability of Frankfort horizontal plane identification using displays of multi-planar reconstructed MRI images, and propose it as a sufficiently stable and standardized reference plane for craniofacial structures. MATERIALS AND METHODS: MRI images of 43 subjects were obtained from the longitudinal population based cohort study SHIP-2 using a T1-weighted 3D sequence. Five examiners independently identified the three landmarks that form FH plane. Intra-examiner reproducibility and inter-examiner reliability, correlation coefficients (ICC), coefficient of variability and Bland-Altman plots were obtained for all landmarks coordinates to assess reproducibility. Intra-examiner reproducibility and inter-examiner reliability in terms of location and plane angulation were also assessed. RESULTS: Intra- and inter-examiner reliabilities for X, Y and Z coordinates of all three landmarks were excellent with ICC values ranging from 0.914 to 0.998. Differences among examiners were more in X and Z than in Y dimensions. The Bland-Altman analysis demonstrated excellent intra- as well as inter-examiner agreement between examiners in all coordinates for all landmarks. Intra-examiner reproducibility and inter-examiner reliability of the three landmarks in terms of distance showed mean differences between 1.3 to 2.9 mm, Mean differences in plane angulation were between 1.0° to 1.5° among examiners. CONCLUSION: This study revealed excellent intra-examiner reproducibility and inter-examiner reliability of Frankfort Horizontal plane through 3D landmark identification in MRI. Sufficiently stable landmark-based reference plane could be used for different treatments and studies.

SUMMARY Mean facial depth distance of a balanced face was introduced and the relationship with anterior facial height was investigated. The distance between the projections of Condylion (Co’) and Nasion (N’) points on Frankfort Horizontal plane was defined as facial depth distance and this distance was compared with anterior facial height to identify a proportion. The lateral cephalometric radiographs of 1061 individuals (577 female, 484 male) with skeletally class-I (0°≤ANB≤4°) relationship and vertically normal according to the Jaraback proportion (62%≤S-Go/N-Me≤65%) were selected for the study. The two gender groups were divided into four subgroups according to their periods of growth and development. Due to identify the term of ‘’normal’’ in facial depth distance, the relation between the facial depth distance (Co’-N’) and the anterior facial height (N-Me) was examined separately in each group. A proportion of 69,32±4,15% was found between the facial depth distance and the anterior facial height. Besides, gender did not affected this proportion and age depended relation was found insignificant. Using this proportion could facilitate the detection of the facially balanced individuals.

The purpose of this study was to develop a consistent and reproducible method of constructing a nasolabial angle that would also permit an evaluation of the relative inclination of the lower border of the nose and the upper lip, as well as their relationship to each other. Comparison of repeated individual measurements of soft tissue profile landmarks on 15 subjects, as completed by four orthodontists, revealed that the proposed method of constructing the nasolabial angle was consistent and reproducible by the same orthodontist and among different orthodontists. Normative data for the three nasolabial parameters were produced from a sample of 104 young white adults determined by the authors to have well-balanced faces. Mean and standard deviation values from this pooled sample demonstrated a lower border of the nose to Frankfort horizontal plane angle at 18 degrees +/- 7 degrees, upper lip to Frankfort horizontal plane angle 98 degrees +/- 5 degrees, and nasolabial angle 114 degrees +/- 10 degrees. No statistically significant difference was demonstrated between the values for men and women in this study, but the women did have a slightly larger nasolabial angle. A linear comparison of the three nasolabial parameters with six skeletal measurements revealed no significant relationship between the soft tissue profile of the nasolabial region and the underlying skeletal relationships.

Tilting of the head has been suggested as a potential source of error when the clinician assesses the angulation of teeth in the panoramic radiograph. If a reference line that could be stable in variations of head positioning during the radiographic exposure could be found, then the examination of the radiograph would be more accurate. We examined the effects of three different head positions on the panoramic image in ten volunteer patients. Our findings suggest that the upper and lower margins of the film are useful reference lines in estimating the mesiodistal angulation of six anteriors, and the mandibular plane is more useful in assessing the angulations of posterior teeth and canines.

In this study we measured the dimensions of the articular eminence before and after eminectomy in order to establish a guideline for the surgical reduction of this structure. Among the 38 cadaver half-heads studied, there was a range before reduction of 89° to 16° in the angle of the anterior slope of the fossa (the posterior incline of the eminence) relative to the Frankfort horizontal plane. The depth of the fossa ranged from 3 to 15 millimeters. After reduction was completed, the change in the angle of the slope ranged from 0° to 44°, and the change in the depth of the fossa ranged from 1 to 6 millimeters.

For the analysis of physical configuration of facial soft tissue, an automatic system for taking standardized photographs of a face at five different angles has been developed.This system consists of;1) the head-holding unit with ear rods, 2) the chair with height adjustment and rotation mechanisms, 3) the electronic control system, 4) the single-lens reflex camera, and5) the background screen.The head of a patient will be fixed by ear rods inserted to the ear holes at the position that the Frankfort horizontal plane parallels the floor level.The focal distance for photographing is 1. 5 meter from the center of the line connecting the ear rods which is equal to the distance from the anode to the midsagittal plane of roentgenographic cephalometry.Photographs are automatically taken in sequence at angles of 0 (full face), 90° & 45° to the left, and 45° & 90° to the right.At the front angle, when the exposure button is pressed and the photograph is taken, the chair automatically turns to the next angle. Thus, five standardized photographs in sequence at different angles can be taken.The comparison of pre- and post-operative facial configurations can be done by examining these photos, and quantative comparison of the face at five different angles is also available.

The purpose of this study was to explore the changes in points A′ and B′ which occur in the soft-tissue profile of the face and their interrelationship to concomitant changes in the underlying hard tissue after orthodontic treatment. Pre- and posttreatment lateral cephalometric radiographs of forty Class II, Division 1 patients were studied to determine the relationships between the distal movements of osseous points A and B and the corresponding overlying labial soft tissues. Perpendicular lines were drawn to sella, point A, superior labial sulcus (point A′), point B, and the inferior labial sulcus (point B′) from the Frankfort horizontal plane. Linear measurements were taken from the above-mentioned four intersects to the sella intersect. Pretreatment and posttreatment measurements were analyzed statistically and it was found that the average ratios between hard- and soft-tissue changes were point A to point A′, 1.40 to 1.00, and point B to point B′, 1.09 to 1.00.

A technique has been described for making standardized sectional laminagraphs of temporomandibular joints. This method makes use of a Franklin laminagraphic head stand unit to which custom made ear-rods are attached. The patient is oriented in such a way that the Frankfort horizontal plane is parallel to the floor, and this position is maintained by two head-holders. The sections are projected onto film by a multi-film cassette. This cassette permits the simultaneous exposure of five matched films, which are spaced 0.5 cm. apart, and records the shape of the bony structures in the joint in five different sagittal planes.

The purpose of this investigation is to study the relation (if any) between the widths of the cleft (as measured before palatoplasty) and the facial and dental relations of a sample of female individuals with clefts of the palate only (CPO) all having the same palatoplasty and operated by the same surgeon. Lateral cephalograms were taken on a total of 85 patients with the head oriented to Frankfort horizontal plane and the teeth in occlusion. Two groups were compared: Group A ( n = 15) with clefts narrower than 5.25 mm (mean − 1 s.d.) and Group B ( n = 15) with clefts wider than 14.03 mm (mean +1 s.d.). The findings in this investigation led to the following conclusions; (1) In general, the shorter the anteroposterior extent of the palatal cleft, the narrower is the cleft width. (2) Difference in cleft width does not affect the skeletal anteroposterior and vertical relations of the craniofacial complex. (3) Dental examination of individuals in Group A (with narrow clefts) revealed that nine had normal occlusions, three had Class I and three had Class II malocclusions. On the other hand, in Group B (with wide clefts) only one case had normal occlusion, nine had Class I, three had Class II and one had Class III malocclusions. This presents almost a 200 % increase in the incidence of malocclusion in the group with wider clefts.

Cephalometric information, specifically, vertical facial types and the Frankfort-mandibular plane angle, pertinent to prosthodontics has been discussed. The Frankfort-mandibular plane angle (FMA) is formed by the intersection of the Frankfort horizontal plane and the mandibular plane. This angle can be traced and measured by means of a diagnostic overlay. An FMA of 25 +/- 5 degrees is within normal range. A high-angle patient has an FMA of 30 degrees or more, and a low-angle patient has an FMA of 20 degrees or less. A high FMA is characterized by open-bite skeletal patterns, and a low FMA by closed-bite skeletal patterns. The clinical manifestations pertinent to prosthodontics in high- and low-angle (FMA) patients are shown in Table I. However, not all clinical characteristics are present in a given patient. The classification in Table I is a beginning. The authors consider the prosthodontic study of cephalometrics an unexploited research tool. Hopefully, in the future, it will help to bridge the gap of the biological-technical interplay that is such an integral part of prosthodontics.

Cranial bone thickness at nasion is difficult to measure by the conventional method of drawing a line at right angles to the tangent at nasion on the outer table. The difficulty arises from a lack of uniformity of the arc in this region. The proposed use of a constructed line, drawn at 30 degrees to the anterior projection of the Frankfort horizontal plane, provides an accurate, easily reproducible, and compatible alternative method of measurement.