Maxillary Prognathism Research Articles

RELATIONSHIP BETWEEN HEAD POSTURE AND PARAMETERS OF SAGITTAL POSITION AND LENGTH OF JAWS.

Head posture in relation to the cervical spine is correlated with the morphology of the face and jaw, the position and the mutual relationship of the maxilla and mandible, their length and inclination. The aim of this study is to examine the relationship between the head posture and parameters of the sagittal position and length of the jaws. The study included 90 subjects (30 for I, II and II skeletal class each) between the ages of 8 and 14 years, who were examined at the Department of Dentistry of Vojvodina inNovi Sad. Each subject had the lateral cephalogram made, and the analysis was performed by means of the computer program "Onyx Ceph." The following parameters were analyzed: craniocervical angle, angle of maxillary prognathism, angle of mandibulary prognathism, the difference angles of maxillary and mandibulary prognathism, length of maxillae, and length of mandible. The angle of maxillary prognathism was in positive correlation with the craniocervical angle in the patients with class I and II, and they were negatively correlated in the patients with class III. The angle of mandibulary prognathism was in positive correlation with the craniocervical angle in the patients with class I and III, but they were negatively correlated in the patients with class II. The patients wi th class II had a statistically significant positive correlation between the craniocervical angle and length of the maxilla, and a significant, but negative correlation between the craniocervical angle and length of the mandible. Increased extension of the head in relation to the cervical spine can be a contributing factor to the formation of class II malocclusion.

Cranial base topology and basic trends in the facial evolution of Homo

Facial prognathism and projection are important characteristics in human evolution but their three-dimensional (3D) architectonic relationships to basicranial morphology are not clear. We used geometric morphometrics and measured 51 3D-landmarks in a comparative sample of modern humans (N = 78) and fossil Pleistocene hominins (N = 10) to investigate the spatial features of covariation between basicranial and facial elements. The study reveals complex morphological integration patterns in craniofacial evolution of Middle and Late Pleistocene hominins. A downwards-orientated cranial base correlates with alveolar maxillary prognathism, relatively larger faces, and relatively larger distances between the anterior cranial base and the frontal bone (projection). This upper facial projection correlates with increased overall relative size of the maxillary alveolar process. Vertical facial height is associated with tall nasal cavities and is accommodated by an elevated anterior cranial base, possibly because of relations between the cribriform and the nasal cavity in relation to body size and energetics. Variation in upper- and mid-facial projection can further be produced by basicranial topology in which the midline base and nasal cavity are shifted anteriorly relative to retracted lateral parts of the base and the face. The zygomatics and the middle cranial fossae act together as bilateral vertical systems that are either projected or retracted relative to the midline facial elements, causing either midfacial flatness or midfacial projection correspondingly. We propose that facial flatness and facial projection reflect classical principles of craniofacial growth counterparts, while facial orientation relative to the basicranium as well as facial proportions reflect the complex interplay of head-body integration in the light of encephalization and body size decrease in Middle to Late Pleistocene hominin evolution. Developmental and evolutionary patterns of integration may only partially overlap morphologically, and traditional concepts taken from research on two-dimensional (2D) lateral X-rays and sections have led to oversimplified and overly mechanistic models of basicranial evolution.

Tutankhamun's Dentition: The Pharaoh and his Teeth.

Tutankhamun was a Pharaoh of the 18th Dynasty (New Kingdom) in ancient Egypt. Medical and radiological investigations of his skull revealed details about the jaw and teeth status of the mummy. Regarding the jaw relation, a maxillary prognathism, a mandibular retrognathism and micrognathism have been discussed previously. A cephalometric analysis was performed using a lateral skull X-ray and a review of the literature regarding King Tutankhamun´s mummy. The results imply diagnosis of mandibular retrognathism. Furthermore, third molar retention and an incomplete, single cleft palate are present.

Correction of facial asymmetry associated with vertical maxillary excess and mandibular prognathism by combined orthognathic surgery and guiding templates and splints fabricated by rapid prototype technique

Correction of facial asymmetry associated with vertical maxillary excess and mandibular prognathism by combined orthognathic surgery and guiding templates and splints fabricated by rapid prototype technique

Evaluation of upper and lower pharyngeal airway in hypo and hyper divergent Class I, II and III malocclusions in a group of Egyptian patients

IntroductionSignificant relationships between the pharyngeal structures and both dento-facial and craniofacial structures have been reported. Hyper-divergent patients may lead to narrower antero-posterior dimensions of the airway. Some authors associated vertical growth pattern with obstruction of the upper and lower pharyngeal airways others associated mouth breathing and Class II malocclusion. So the aim of this study was to assess the upper and lower pharyngeal airway width in different antero-posterior and vertical growth patterns and to evaluate sexual dimorphism in a group of Egyptian patients. Patients and methodA sample of 300 Egyptian patients had divided into (5) groups (each group 60 patients) group 1 Class I, group 2 and 3 Class II division 1 (maxillary prognathism and mandibular deficiency), group 4 and 5 Class III (maxillary deficiency and mandibular prognathism). Each group was divided into three sub groups (hypo-hyper and normal divergent) vertical growth pattern. Each subgroup consists of 10 male and 10 female. The upper and lower pharyngeal airway widths were measured and compared for all groups. ResultsSignificant differences had exist regarding lower pharyngeal airway between Class I and class II division 1, Class I and Class III mandibular prognathism, Class II and Class III maxillary deficiency, Class II and Class III mandibular prognathism. Significant differences between hypo, hyper and normal vertical growth pattern. ConclusionsIn all groups hyper-divergent growth had narrower airway than normal and hypo-divergent growth. Class III had wider airway than Class I malocclusion. Class I had wider airway than Class II division 1 malocclusion. Lower pharyngeal airway in class II division 1 had the narrowest width in all groups. Lower pharyngeal airway in class III mandibular prognathism had the widest width in all groups. Males have wider pharyngeal airway than females.

Orthodontic Camouflage Treatment of Class II Malocclusion in Non-growing Patient - A Case Report

The prevalence of skeletal Class II malocclusion is high amongst Asian population. Various treatment modalities have been presented for the treatment of Class II malocclusions in adult patients. We come across many adult patients who desire a costeffective and non-surgical correction and they accept dental camouflage as a treatment option to mask skeletal discrepancy. This case report presents a 26-year-old non-growing female who had a skeletal Class II malocclusion with prognathic maxilla and retrognathic mandible with an overjet of 7 mm, severe crowding, but did not want surgical treatment. We considered the camouflage treatment by extracting upper first premolars. Following the treatment, a satisfactory result was achieved with an acceptable static and functional occlusion, facial profile, smile and lip competence with patient satisfaction.

Evaluation of Pharyngeal Space in Different Combinations of Class II Skeletal Malocclusion.

Objectives:The study was aimed to evaluate the pharyngeal airway linear measurements of untreated skeletal class II subjects with normal facial vertical pattern in prognathic maxilla with orthognathic mandible and orthognathic maxilla with retrognathic mandible.Materials and method:the sample comprised of lateral Cephalograms of two groups (30 each) of class II malocclusion variants. Group 1 comprised of class II malocclusion with prognathic maxilla and orthognathic mandible, whereas group 2 comprised of class II malocclusion with orthognathic maxilla and retrognathic mandible. Each group was traced for the linear measurements of the pharyngeal airway like the oropharynx, nasopharynx and soft palate. The obtained data was subjected to independent t test and the Mann Whitney test to check the difference between the two groups and within the groups respectively.Results:there was significant difference between all the linear measurements at the soft palate region and the distance between the tip of soft palate to its counter point on the pharyngeal wall in oropharynx region (p-ppm).Conclusion:the pharyngeal airway for class II malocclusion with various combination in an average growth pattern adult showed significant difference. The present results suggested, that the pharyngeal airway space might be the etiological factor for different sagittal growth pattern of the jaws and probable usage of different growth modification appliance can influence the pharyngeal airway.

Influence of craniofacial and upper spine morphology on mandibular advancement device treatment outcome in patients with obstructive sleep apnoea: a pilot study.

The aim of the study was to assess cephalometric predictive markers in terms of craniofacial morphology including posterior cranial fossa and upper spine morphology for mandibular advancement device (MAD) treatment outcome in patients with obstructive sleep apnoea (OSA). Twenty-seven OSA patients were treated with MAD for 4 weeks. Apnoea-hypopnoea index (AHI) was recorded before and after MAD treatment. The criteria of treatment success were 75 per cent reduction of AHI. Accordingly, two groups occurred: the success treatment group of 8 patients and the no success treatment group of 19 patients. Before MAD treatment lateral cephalograms were taken and analyses of the craniofacial morphology including the posterior cranial fossa and upper spine morphology were performed. Differences between the groups were analysed by Fisher's exact test, t-test, and multiple regression analysis. Upper spine morphological deviations occurred non-significantly in 25 per cent in the success treatment group and in 42.1 per cent in the no success treatment group. Body mass index (BMI; P < 0.05), maxillary prognathism (S-N-Ss; P < 0.01), mandibular prognathism (S-N-Pg; P < 0.05 and S-N-Sm; P < 0.01), and the distance between sella turcica and the deepest point in posterior cranial fossa (S-D; P < 0.05) was significantly smaller in the success treatment group. The maxillary prognathism (P < 0.05) was the most important factor for the MAD treatment outcome (R (2) = 0.47). Relatively small sample size. The results indicate that BMI, posterior cranial fossa morphology, and retrognathia of the jaws are factors related to MAD treatment outcome. Furthermore, OSA patients with upper spine morphological deviations may respond poorer to MAD treatment.

Maxillary complete denture rehabilitation of a patient with marked maxillomandibular discrepancy: a clinical case report

Dentistry is constantly concerned with enabling better living conditions for patients, as well as providing comfort so that functions such as chewing, speaking, and swallowing may be executed properly and esthetically satisfactory. In edentulous patients, many of these functions are lost, but can be restored by prosthodontics. Within this context, the present article seeks to report a clinical case in which a maxillary complete denture was made for a patient presenting with maxillomandibular discrepancy and marked maxillary prognathism.

Cephalometric norms for orthognathic surgery in North Indian population using Nemoceph software

BackgroundCephalometric norms, useful in providing guidance to orthodontist during diagnosis and treatment planning are subjected to variability in morphologic characteristics in different ethnic and racial groups, hence norms established for one population group are not applicable for all. Aims and objectivesTo compare and correlate the established hard tissue cephalometric norms for orthognathic surgery (COGS analysis) given by Legan and Burstone with norms obtained for North Indian population. MethodsPre-treatment digital lateral cephalograms of 100 orthodontically untreated subjects having pleasing profile and normal occlusion in the age range of 18–25 yrs (mean age of 21 ± 2.62 years) were selected. 16 linear and 6 angular hard tissue parameters of COGS analysis were analyzed using nemoceph software for the males and females separately. The data obtained were compared with previously established norms for Orthognathic Surgery using SPSS Version 15.0. ResultsNorth Indian males and females had smaller anterior cranial base length with prognathic maxilla and mandible, protrusive chin with poor chin form, decreased facial height, decreased posterior maxillary height with anticlockwise rotation of mandible, increased anterior and posterior maxillary dental heights, decreased ramal and corpus length, clockwise rotation of occlusal plane, presence of sagittal discrepancy between maxillary and mandibular denture bases in comparison to Caucasian males and females respectively. North Indian females had more proclination of mandibular incisors than Caucasian females. Sexual dimorphism was also evident in the present study with males exhibiting significantly larger cranial base length, greater middle third facial height and posterior maxillary height, counterclockwise rotation of mandibular plane, greater anterior and posterior mandibular dental heights and longer ramal and corpus length in comparison to females. ConclusionNorth Indian population showed significant differences in facial morphology as compared to Caucasians population. Sexual dimorphism was also evident in North Indian populations. Thus the need to develop separate Orthognathic Surgical norms for better treatment planning of North Indian population is justified.

A Chromosomal Region on ECA13 Is Associated with Maxillary Prognathism in Horses

Hereditary variations in head morphology and head malformations are known in many species. The most common variation encountered in horses is maxillary prognathism. Prognathism and brachygnathism are syndromes of the upper and lower jaw, respectively. The resulting malocclusion can negatively affect teeth wear, and is considered a non-desirable trait in breeding programs. We performed a case-control analysis for maxillary prognathism in horses using 96 cases and 763 controls. All horses had been previously genotyped with a commercially available 50 k SNP array. We analyzed the data with a mixed-model considering the genomic relationships in order to account for population stratification. Two SNPs within a region on the distal end of chromosome ECA 13 reached the Bonferroni corrected genome-wide significance level. There is no known prognathism candidate gene located within this region. Therefore, our findings in the horse offer the possibility of identifying a novel gene involved in the complex genetics of prognathism that might also be relevant for humans and other livestock species.

Extraction and non-extraction therapy in class II/1 patients

Introduction: Class II malocclusion is characterized by distoclusion and is divided into two divisions depending on the inclination of the upper front teeth. The first division is characterized by protrusion of the upper front teeth. Treatment possibilities of class II/1 malocclusion depend on the skeletal form. Therapy of dentoalveolar types of class II/1 malocclusion is exclusively orthodontic. More emphasized skeletal forms of class II/1 malocclusion may require surgery apart from orthodontic therapy. Casse raport: In this paper, the extraction and nonextraction treatment of 13 years old patients - M.P.(boy) and I.T. (girl) was shown, respectively. The diagnosis was based on clinical and functional intraoral findings, analysis of dental casts, face photos, orthopatomogram and profile x-ray. Nonextraction therapy was suggested for a boy and extraction therapy for a girl, combined with the use of upper and lower fixed appliances. In the treatment, technique of straight arch, Dentaurum brackets, root prescriptions, slot 22 were used. In the male patient, there was a slight maxillary prognathism, mandibular retrognathism, anterior type of growth, protrusion of the upper incisors and retrusion of the lower ones. The body of maxilla was shorter by 4 mm with regard to the cranial base. In the female patient the extraction of the upper first premolars was performed because of maxillary prognathism, mandibular retrognathism, increased length of the body of maxilla, decreased length of the body of maxilla and severe protrusion of the upper frontal teeth. After the treatment, functional occlusion and improvement in facial aesthetics was achieved in both patients. Facial changes were more apparent in the patient who underwent the extraction treatment. After completion of treatment, it is necessary to maintain the obtained results.

Sella turcica shape, linear dimensions, and cervical vertebrae staging in preorthodontic patients in Benin City, Nigeria

Background: The sella turcica is one of the commonly used orthodontic landmarks in determining and diagnosing various problems of the facial skeleton; with the shape and linear dimensions found to vary in different types of skeletal classes especially during puberty where significant changes of the sella turcica occur. These pubertal changes can be assessed using the stage of maturation of the cervical vertebrae and a method; the Cervical vertebrae Maturation (CVM) method which could aid in the clinical determination of optimal treatment modalities. Materials and Methods: The sella turcica and first six cervical vertebrae were assessed on the cephalometric radiographs of 106 untreated orthodontic patients. Correlations between variables were determined by using the SPSS (version 16) software. Results: A normal sella turcica shape was the most frequently occurring in 65 (61.3%) of the total sample population. Skeletal Class II was the most predominant craniofacial problem in 53 (50%) and in 13 (46.4%) in CVM Stage 3, with a significant difference in the diameter, P < 0.05 in females with a skeletal Class I pattern. Maxillary prognathism with an increased sella-nasion-maxillary point A (SNA) value >90° was highest in 50 (47.2%). There was a significant difference in the diameter of the sella turcica among gender with skeletal Class II. The largest diameter of 18 mm was observed in females and in CVM Stage 4. The mean area of the sella turcica is the same for both CVM Stages 1 and 5 (74.07 mm 2 ). The difference in the area of the sella turcica was highest in the transition between Stages 1 and 2 (8.81 mm 2 ) and similar between Stages 2, 3, and 4 (2.38 mm 2 ). The mean area of the sella turcica demonstrated a sequential increase from CVM Stages 2-6. Conclusion: The CVM stages may be utilized as a diagnostic tool in the clinic to differentiate the pubertal growth spurt and determining the best time for treating certain orthodontic problems. The linear dimensions of the sella turcica cannot be used as a diagnostic tool in determining skeletal classes.

Cephalometric analysis of the middle part of the face in patients with mandibular prognathism

The middle part of the face, that is the maxilla, has always been mentioned as a possible etiologic factor of skeletal Class III. However, the importance of the relationship of maxillary retroposition towards the cranial base is still unclear, although it has been examined many times. The aim of this study was to conduct cephalometric analysis of the morphology of maxilla, including the whole middle part of the face in patients with divergent and convergent facial types of mandibular prognathism, as well as to determine differences betweeen them. Lateral cephalometric teleradiograph images of 90 patients were analyzed at the Dental Clinic of the Military Medical Academy, Belgrade, Serbia. All the patients were male, aged 18-35 years, not previously treated orthodontically. On the basis of dentalskeletal relations of jaws and teeth, the patients were divided into three groups: the group P1 (patients with divergent facial type of mandibular prognathism), P2 (patients with convergent facial type of mandibular pragmathism) and the group E (control group or eugnathic patients). A total of 9 cephalometric parameters related to the middle face were measured and analyzed: the length of the hard palate--SnaSnp, the length of the maxillary corpus--AptmPP, the length of the soft palate, the angle between the hard and soft palate--SnaSnpUt, the angle of inclination of the maxillary alveolar process, the angle of inclination of the upper front teeth, the effective maxillary length--CoA, the posterior maxillary alveolar hyperplasia--U6PP and the angle of maxillary prognathism. The obtained results showed that the CoA, AptmPP and SnaSnp were significally shorter in patients with divergent facial type of mandibular prognathism compared to patients with convergent facial type of the mandibular prognathism and also in both experimental groups of patients compared to the control group. SnaSnp was significantly shorter in patients with divergent facial type of mandibular prognathism compared to the control group, whereas SnaSnp was significantly smaller in patients with convergent facial type of mandibular prognathism compared to the control group. Additionally, there was a pronounced incisor dentoalveolar compensation of skeletal discrepancy in both groups of patients with mandibular prognathism manifested in the form of a significant upper front teeth protrusion, but without significant differences among the groups, while the maxillary retrognathism was present in most patients of both experimental groups. A pronounced UGPP was found only in the patients with divergent type of mandibular prognathism. The maxilla is certainly one of the key factors which contributes to making the diagnosis, but primarily to making a plan for mandibular prognathism treatment Accurate assessment of the manifestation of abnormality, localization of skeletal problems and understanding of the biological potential are key factors of the stability of/the results of surgical-orthodontic treatment of this abnormality.

Orthodontic camouflage treatment of skeletal class II malocclusion with severe maxillary dentoalveolar protrusion

This case report describes the orthodontic treatment of a 14-year-old male patient who presented with prognathic maxilla, severe dentoalveolar proclination, deepbite and retained deciduous tooth. We selected headgear and fixed appliance to correct malocclusion but cooperation towards headgear was found less during treatment. So we chose orthodontic camouflage treatment to correct dentoalveolar problems without altering the skeletal base relation. The final treatment results were good and patient had improvement in esthetic and function.

Backward Distraction Osteogenesis in a Patient With Severe Mandibular Micrognathia

Maxillary skeletal prognathism can involve severe mandibular micrognathia with marked mandibular retrognathism or hypoplasia. For patients with such a condition, a conventional treatment is mandibular advancement by sagittal split ramus osteotomy (SSRO). This procedure has problems such as insufficient advancement, instability of jaw position, and postoperative relapse. Thus, in recent years, mandibular distraction osteogenesis has been used in some patients. Mandibular distraction has many advantages, but an ideal occlusion is difficult to achieve using this procedure. That is, 3-dimensional control cannot be attained using an internal device that is unidirectional. This report describes a case of severe mandibular micrognathia in a 14-year-old girl treated using backward distraction osteogenesis. This procedure was first reported by Ishii et al (Jpn J Jaw Deform 2004; 14:49) and involves a combination of SSRO and ramus distraction osteogenesis. In the present study, intermaxillary fixation in centric occlusion was performed after osteotomy, and proximal bone segments were distracted in a posterosuperior direction. This procedure is a superior surgical technique that avoids the drawbacks of SSRO and conventional mandibular distraction. However, it applies a large load to the temporomandibular joints and requires thorough management. Thus, careful evaluation needs to be made of the indication for backward distraction osteogenesis.

Craniofacial Morphology of Class II Division 1 Nepalese Population

Introduction: Class II Div 1 is a deviation from normal occlusion and may arise from combination of di" erentcraniofacial components.The objective of this study was to findnd out the different possible dental and skeletalcomponents that lead to Class II Div 1 malocclusion in Nepalese population.Methods: The lateral cephalogramradiographs consisted of 30 males and 30 females between the age group of 18 to 32 years. All the radiographswere traced with hand on acetate paper sheets. All the landmarks were identified, located and marked. Steiner’s analyses and McNamara analysis were done for the cephalometric measurements. The mean valueswere obtained and were compared with the established available values of the Nepalese and Caucasian normsusing independent t-test.Results: Size of the mandible was found to be lesser than the established normalvalues. Prognathic maxilla with retrognathic upper incisors and retrognathic mandible with proclined lowerincisors and was found to be the most common combinations of Class II Div 1 component.Conclusion: Size of the mandible is less than the normal value which is the main cause of the Class II Div 1 pattern in Nepalese population. Medical Journal of Shree Birendra Hospital; July-December 2012/vol.11/Issue2/10-13 DOI: http://dx.doi.org/10.3126/mjsbh.v11i2.7901

A Cephalometric Study on the Relationship Between the Occlusal Plane, Ala-Tragus and Camper's Lines in Subjects with Angle's Class I, Class II and Class III Occlusion.

Considering the importance of the occlusal plane orientation in complete denture prostheses, a study was conducted on the relationship between this plane with ala-tragus and Camper's lines in soft tissue among individuals with class I, class II and class III occlusion. The aim of the present study was to define the best soft tissue index by which the location and inclination of the occlusal plane in complete dentures could be established. A total of 60 subjects were selected for the study. Lateral cephalograms of these subjects were obtained. Tracings and analysis was done to confirm to the skeletal relationship of subjects to be class I (normal), class II (prognathic maxilla) and class III (retrognathic maxilla). 20 Subjects of each group were screened for further analysis. Radiopaque markers were attached to the intended points on soft tissue and then standard lateral cephalograms were obtained from each subject. The angles between the following lines were measured: Occlusal line, Camper's line (ala-porion), AT1 (ala-superior border of tragus), AT2 (ala-mid-tragus) and AT3 (ala-inferior border of tragus). The mean values and standard deviations were calculated for all the groups. The mean values calculated were subjected to repeated ANOVA test and significance was evaluated. Comparison of the results by the ANOVA test exhibited a significant difference. In class I subjects, it was evaluated that in 75% individuals, the posterior reference point was found to be the mid-tragus; of class II subjects, in 60% individuals, the posterior reference point was found to be the mid-tragus; and of class III subjects, in 75% individuals, the posterior reference point was found to be the inferior border of tragus.

Orthodontic treatment for a mandibular prognathic girl of short stature under growth hormone therapy

This report presents a case of a 12-year-old girl with maxillary deficiency, mandibular prognathism, and facial asymmetry, undergoing growth hormone (GH) therapy due to idiopathic short stature. Children of short stature with or without GH deficiency have a deviating craniofacial morphology with overall smaller dimensions; facial retrognathism, especially mandibular retrognathism; and increased facial convexity. However, a complete opposite craniofacial pattern was presented in our case of a skeletal Class III girl with idiopathic short stature. The orthodontic treatment goal was to inhibit or change the direction of mandibular growth and stimulate the maxillary growth of the girl during a course of GH therapy. Maxillary protraction and mandibular retraction were achieved using occipitomental anchorage (OMA) orthopedic appliance in the first stage of treatment. In the second stage, the patient was treated with a fixed orthodontic appliance using a modified multiple-loop edgewise archwire technique of asymmetric mechanics and an active retainer of vertical chin-cup. The treatment led to an acceptable facial profile and obvious facial asymmetry improvement. Class I dental occlusion and coincident dental midline were also achieved. A 3½-year follow-up of the girl at age 18 showed a stable result of the orthodontic and dentofacial orthopedic treatment. Our case shows that the OMA orthopedic appliance of maxillary protraction combined with mandibular retraction is effective for correcting skeletal Class III malocclusion with midface deficiency and mandibular prognathism in growing children with idiopathic short stature undergoing GH therapy.

Soft tissue Cephalometric Norms for Orthognathic Surgery

Cephalometric norms are different for different ethnie groups. They help making the deformity assessment and surgical planning procedures more appropriate for a particular individual. Hence, the present study was aimed at the development of the soft tissue cephalometric norms for orthognathic surgery for north India. The study sample consisted of fifty adult males and fifty adult females. Standardized lateral cephalogram was taken, traced and analysed for each subject. The statistical analysis involved calculation of mean and standard deviation for thirteen parameters. This data was compared with that reported by Legan and co-workersl using Normal (z) test. Male and female subjects were also compared with each other. For male subjects, all the parameters except facial convexity angle, lower vertical height to depth ratio, nasolabial angle and vertical lip chin ratio; the statistical difference varied from highly significant to most highly significant. For female subjects, five parameters viz. facial convexity angle, maxillary prognathism, lower vertical height to depth ratio, nasolabial angle and maximum incisor exposure have not been found to be significantly different from Legan and co-worker's datai. For all the remaining parameters, the statistical difference varied from highly significant to most highly significant. Comparison between male and females also led to distinctive differences. The soft tissue cephalometric norms for orthognathic surgery were derived for the population of eastern Uttar Pradesh region of north India. Hence, while planning combined orthodontic-orthognathic surgical approach for this particular population, it appears more appropriate to use the norms as developed or modified in the present study.