Lateral Cephalometric Headfilms Research Articles

Description of the sagittal jaw relation in cephalometric analysis – a review of literature

Abstract Introductionː Lateral cephalometry is commonly used to analyse craniofacial morphology, soft tissue profile and the direction of facial growth in an attempt to predict the possibilities and limits of orthodontic therapy. The aim of the study was to present the most frequently used cephalometric measurements to assess the skeletal class on a lateral cephalometric headfilm. Materials and methods: A Pubmed search was undertaken to systematize information on ANB angle, WITS appraisal, APDI and Harvold measurements. The keywords used were “cephalometry AND evaluation of sagittal malocclusion AND reference lines AND accuracy OR ANB angle OR WITS appraisal OR APDI”. A manual search was performed from the reference lists of studies found in order to identify and include pioneer studies. Results: A total number of 1258 records were found and finally 23 studies were included in the review. Four of them were descriptive, the other 19 were randomized control trials. Conclusionsː 1. ANB angle cannot be used as the only indicator of sagittal skeletal discrepancy. 2. WITS appraisal is independent of the variability of cranial base structures, thus may be an important supplement to the diagnosis, although it depends on the variability of the occlusal plane. 3. APDI can reliably distinguish between class I, II and III malocclusions.

Association of ABO blood group with crowding among patients with different malocclusions

Introduction: This study correlated ABO blood groups and crowding in the lower anterior region and also to find an interrelationship between ABO blood grouping system and sagittal relation of the jaws. Materials and Methods: The sample size consisted of 138 Maharashtrian patients (60 males and 78 females) age range from 12 to 30 years which were randomly selected. Each patient's records comprised: a lateral cephalometric head film, photographs, and dental casts as standard pretreatment records. Based on ANB angles, patients were divided into Group-1: ANB 1–3° (51 individuals with 27 males and 24 females), Group-2: ANB >3° (60 individuals with 24 males and 36 females), and Group-3: ANB Results: The mean ± standard deviation of age in Group 1, Group 2, and Group 3 was 16.53 ± 2.43 years, 17.60 ± 3.73 years, and 18.67 ± 3.28 years, respectively. The gender distribution of cases studied did not differ significantly across three study groups. The distribution of median ANB did not differ significantly across various blood groups in the study group. The blood group distribution of cases studied did not differ significantly across three study groups. The distribution of Little's index differs significantly across perfect alignment and minimal irregularity as well as between minimal irregularity and moderate irregularity. The distribution of Little's index did not differ significantly between perfect alignment and moderate irregularity. Conclusions: The occurrence of blood group B+ was more in Class I and II skeletal patterns whereas in Class III skeletal pattern individuals have more prevalence of blood group A+. ABO blood groups and Little's Irregularity Index for crowding is found to be correlated between perfect alignment and minimal irregularity individuals as well as between minimal and moderate irregularity subjects.

Establishment of cephalometric norms of Yen, W and Beta angle with assessment of sagittal jaw relationship in Eastern Indian population

Aim: To evaluate the validity of Yen, W and Beta angle and to compare it with other commonly used sagittal measurements in Eastern Indian population. Materials and Methods: Sample size of 100 subjects (males -50, females 50, mean age - 25.5+-2 years) of indo aryan race were taken from the OPD of the College. The lateral cephalograms were traced for ANB, Wits appraisal, Beta angle, W angle and YEN angle. Lateral Cephalometric Head film was obtained with the patient positioned in Natural Head Position, seated Condyle, and with Passive Lips. The cephalograms were further traced by the same operator, this comprised the Cephalometric database for the study. The final results obtained were compared between Males and Females of the study to verify the acceptable standards of them. Results: There was no statistically significant gender wise difference. Hence a common normative range applicable for both the genders can be proposed. The results show that all five-skeletal cephalometric sagittal analyses i.e. ANB angle Wits analysis, BETA angle, YEN angle and W angle are reliable and can used in different populations without any gross deviations in the findings. Conclusion: Based on the present study, it can be concluded that no statistically significant differences in all parameters were found between the subjects of the Local Palamau population and also between the males and females. From the above statement ANB angle, Wits analysis, BETA angle, YEN angle and W angle can be used as they are reliable. All Keywords: Cephalometric norms, W angle, YEN angle, Beta angle.

EVALUATION OF MINI-IMPLANT ANCHORAGE SYSTEM FOR EN-MASSE RETRACTION OF MAXILLARY ANTERIOR TEETH VERSUS CONVENTIONAL METHOD

Objectives: The purpose of this study was to compare the skeletodental and soft tissue changes and the duration needed for closure of extraction space after en-masse retraction of maxillary anterior teeth using mini-implant anchorage system in the treatment of maxillary dentoalveolar protrusion cases compared with two step retraction with conventional method of anchorage reinforcement. Materials and Methods: The study sample consisted of twenty adult orthodontic patients (3 males and 17 females) with maxillary dentoalveolar protrusion and required first premolar extraction and maximum anchorage. They were randomly divided into two treatment groups (10 subjects in each group). Group 1, anterior space closure with en-masse retraction aided by mini- implant anchorage system, or group 2, anterior space closure with two-step retraction technique aided by conventional method of anchorage. Lateral cephalometric head films were taken just before retraction of maxillary anterior teeth and immediately after closure of the extraction space for the evaluation of the treatment changes. Statistical analyses of the data were performed at a significance level of P <0.05. Results: For the skeletal parameters, a statistically significant decrease in the facial vertical dimensions was seen in G1, but the variables in G2 showed no significant differences (P > 0.05). Anchorage loss, in both the horizontal and vertical directions, was noted in G2, whereas G1 showed anchorage gain and intrusion of molars. Group 1 had greater anterior tooth retraction (7.8 mm in 9.6 months) than did the conventional anchorage group (5.5 mm in 12.4 months). However, no significant differences in the mean retraction time were noted between the 2 groups. Upper incisors were intruded in G 1 (2.3 mm) and extruded (1.1 mm) in G 2. The soft-tissue response was greater changes in G1 with significant differences were found in the nasolabial angle and amount of upper lip retraction between the groups (P < 0.05). Conclusion: Mini-implants provided absolute anchorage to allow greater skeletal, dental, and esthetic changes in patients requiring maximum anterior retraction, when compared with other conventional methods of anchorage reinforcement. However no differences in the mean retraction time were noted between the 2 groups.

Pharyngeal Airway Dimensions in Cleft Lip and Palate Patients Compared With Class I Subjects

ABSTRACT Objective: The aim of this study was to analyze and compare the pharyngeal airway dimensions of cleft lip and palate (CLP) and skeletal Class I patients. Materials and Method: The study was carried out in 91 subjects asking for orthodontic treatment in Ankara University, Turkey. The patients were selected from the archives of the Orthodontics Department. Forty-eight of the patients had CLP and 43 were skeletal Class I patients. Both control and CLP groups were divided into 3 subgroups according to the ages 7–11, 11–14, and 15 years and older. The number of subjects was matched in the same age groups. The pretreatment lateral cephalometric head films of the subjects were used in the study. Airway dimensions were evaluated with area measurements using planimeter. The airway was divided into 3 parts, and measurements were done on those areas. SNA, SNB, ANB, and GoGnSN angles were measured in all cephalograms by the same examiner. The values were compared within the same age group in both the CLP and...

Treatment Effects of Distal Movement of Lower Arch With Miniscrews in the Retromolar Area Compared With Miniscrews in the Posterior Area of the Maxillary

The aim of this study was to compare the effects of group distal movement of lower teeth obtained with the aid of direct usage of miniscrews in the retromolar area and indirect usage of miniscrews in the posterior area of the maxillary. Nineteen patients with mild-to-moderate class III malocclusion (4 males and 15 females) were divided into 2 groups. Ten patients (2 males and 8 females; mean age, 20.7 ± 2.5 years) in group 1 were treated by miniscrews in the retromolar area. Nine patients (2 males and 7 females; mean age, 21.5 ± 3.7 years) in group 2 were treated by miniscrews in the posterior area of the maxillary. Lateral cephalometric headfilms were taken at the beginning of treatment and after distal movement of mandibular dentition for the evaluation of the treatment changes. In group 1, the crown and root apex of lower first molars were moved distally by 3.4 mm and 1.2 mm with distal tipping of 8.7 degrees and intruded by 0.7 mm. In group 2, the crown and root apex of lower first molars were moved distally by 3.3 mm (P = 0.8976, P > 0.05) and 0.2 mm (P = 0.0124, P < 0.05) with distal tipping of 10.7 degrees (P = 0.0467, P < 0.05) and extruded by 0.2 mm (P = 0.0124, P < 0.05). Retraction of the mandibular arch lasted 6.31 ± 1.45 months for group 1 and 7.61 ± 1.46 months for group 2. Direct usage of miniscrews in the retromolar area took less time and more bodily movement to retract the lower arch without cooperation of the patients and was a better choice for the patients with potential temporomandibular joint disorders problems.

Relation of Pharynx with Orofacial Structures in Jaipur (India) Population Exhibiting Normal Occlusion with Respect to Sex: A Cross-sectional Study

Objective: To investigate the relation of pharynx with orofacial structures in Jaipur (India) population exhibiting normal occlusion with respect to sex. Materials and Methods: The relation of pharynx with orofacial structures was examined on the lateral cephalometric head films of 180 subjects, 90 males and 90 females. The age groups of the subjects were between 15 to 25 years. The effect of sex on the pharyngeal parameters was analyzed by means of variance analysis (ANOVA). Results and Conclusion: It was observed that five measurements Ba-PNS, apw2-ppw2, t-ppw, hy-apw2 and Ho perp. to ANS-PNS plane were different for males and females.

Comparison of the intrusive effects of miniscrews and utility arches

The aim of this prospective study was to compare the effects of incisor intrusion obtained with the aid of miniscrews and utility arches. Twenty-four patients (10 male, 14 female) with a deepbite of at least 4 mm were divided to 2 groups. In group 1, 13 patients (3 male, 10 female; mean age, 20.90 ± 7.12 years) in the postpubertal growth period were treated by using miniscrews; in group 2, 11 patients (7 male, 4 female; mean age, 15.25 ± 3.93 years) were treated with utility arches. Lateral cephalometric headfilms were taken at the beginning of treatment and after intrusion for the evaluation of the treatment changes. Statistical analyses of the data were performed with a significance level of P<0.05. Intrusion lasted 6.61 ± 2.95 months for group 1 and 6.61 ± 2.46 months for group 2. The changes in the center of resistance of the incisors were 1.75 ± 0.4 mm (P<0.05) for group 1 and 0.86 ± 0.5 mm (P>0.05) for group 2; the difference between the groups was significant (P<0.05). In the miniscrew group, the incisors were protruded 0.79 ± 1.4 mm (P>0.05) relative to pterygoid vertical and 3.85° ± 2.4° (P>0.05) relative to the palatal plane. In group 2, the incisors showed 3.91 ± 0.7 mm (P<0.05) of protrusion relative to pterygoid vertical and 13.55° ± 2.4° (P<0.05) relative to the palatal plane. The maxillary first molars showed significant distal tipping in group 2 (P<0.05). Unlike with utility arches, true maxillary incisor intrusion can be achieved by application of intrusive forces close to the center of resistance by using miniscrews with no counteractive movements in the molars.

Comparison of airway space with conventional lateral headfilms and 3-dimensional reconstruction from cone-beam computed tomography

Changes in the normal pattern of nasal respiration can profoundly affect the development of the craniofacial skeleton in both humans and experimental animals. The orthodontist is often the first clinician to notice that a child is breathing primarily through the mouth, either at the initial examination or later during treatment. The lateral headfilm, part of the patient's normal records, might show increased adenoid masses, suggesting that these could be part of the problem. Previous studies have, however, questioned the validity of the information from lateral headfilm. Our aim was to compare imaging information about nasopharyngeal airway size between a lateral cephalometric headfilm and a 3-dimensional cone-beam computed tomography scan in adolescent subjects. The nasopharyngeal airway area and volume were measured in 35 subjects (8 boys, 27 girls; average age, 14 years). Volumetric measurement errors ranged from 0% to 5% compared with known physical airway phantoms used to calibrate. A moderately high (r = 0.75) correlation was found between airway area and volume; the larger the area, the larger the volume. However, there was considerable variability in the airway volumes of patients with relatively similar airways on the lateral headfilms. Nine of the 35 patients had over 25% of the potential nasopharyngeal airway volume occupied by inferior turbinate protuberances, leading to significant airway restriction in some patients. The cone-beam 3-dimensional scan is a simple and effective method to accurately analyze the airway.

Miniscrews for upper incisor intrusion

The aim of this study was to investigate if true incisor intrusion can be achieved using miniscrews. Eleven patients (three males and eight females; mean age: 19.8 +/- 4.8 years) with normal vertical dimension showing a pre-treatment deep bite of 5.9 +/- 0.9 mm and a 'gummy' smile were enrolled in the study. After levelling of the maxillary central and lateral incisors with a segmental arch, an intrusive force of 80 g using closed coil springs was applied from two miniscrews placed between the roots of the lateral and canine teeth. The amount of incisor intrusion was evaluated on lateral cephalometric headfilms taken at the end of levelling (T1) and at the end of intrusion (T2). Statistical analysis of the data was performed using a paired t and Wilcoxon signed rank tests. A significance level of P < 0.05 was predetermined. The mean upper incisor intrusion was 1.92 mm and the mean overbite decrease 2.25 +/- 1.73 mm in 4.55 months. Upper incisor angulation resulted in a 1.81 +/- 3.84 degree change in U1-PP angle and a 1.22 +/- 3.64 degree change in U1-NA angle. However, these were not statistically significant (P > 0.05). True intrusion can be achieved by application of intrusive forces close to the centre of resistance using miniscrews. However, studies with a larger number of subjects and long-term follow-up are necessary.

Facial growth prediction: A comparison of methodologies

The purpose of this study was to compare 3 methodologies that predict facial growth relative to incremental and positional changes over short- and long-term time periods. The 3 prediction systems that were tested and compared were the Ricketts analysis, the Johnston grid analysis, and the Fishman maturational analysis. Serial lateral cephalometric headfilms and hand-wrist films of 50 untreated subjects from the Burlington Growth Center at the University of Toronto, Toronto, Ontario, Canada, were used. The sample was subdivided by skeletal classification and further subdivided by sex. The sample comprised 19 skeletal Class I subjects (10 female, 9 male), 20 Class II subjects (10 female, 10 male), and 11 Class III subjects (6 female, 5 male). Three serial headplates were traced on each subject, and the associated chronologic and maturational ages were noted. The subjects were divided into a young adolescent subgroup approximately 9 years of age (T1), a midadolescent subgroup approximately 13 years of age (T2), and a late adolescent-adult age group approximately 20 years of age (T3). Predictions were made between the time periods. To measure and compare the predicted amounts of downward and forward skeletal growth vs the actual growth values, anatomic landmarks were chosen in the cranial base and on the maxilla and the mandible (Point A and gnathion), and increases between the respective points were measured. A paired t test was applied to each test group for the statistical analysis. Graphic representations were also created in the form of "positional envelopes" that encapsulated the predictive data for each methodology. To evaluate both incremental and positional accuracy, these data envelopes were subsequently related to the true positions of Point A and gnathion. Although not the case in every instance, it was demonstrated that the maturationally oriented Fishman analysis was superior to both the chronologically based Johnston grid and Ricketts analysis for short- and long-term predictions.

Treatment effects of headgear biteplane and bionator appliances

The purpose of this investigation was to evaluate the dentoalveolar and skeletal cephalometric changes produced by headgear (HG) biteplane and bionator appliances in subjects with Class II Division 1 malocclusion. The sample comprised 60 patients with Class II Division 1 malocclusion; 30 (15 boys, 15 girls; mean age, 10.02 years) were treated with the HG biteplane for a mean period of 1.78 years, and 30 (15 boys, 15 girls; mean age, 10.35 years) were treated with a bionator for a mean period of 1.52 years. For comparison, a control group of 30 untreated Class II children (15 boys, 15 girls) with an initial mean age of 10.02 years, followed for 1.48 years, was established. Lateral cephalometric headfilms were obtained at the beginning and at the end of the treatment or observation period. The results showed that forward growth of the maxilla was restricted in the HG biteplane group. Bionator treatment, however, produced a statistically significant increase in mandibular protrusion. Both appliances provided increases in total mandibular and ramus lengths. There were no statistically significant differences in craniofacial growth direction. The mandibular incisors were tipped labially with bionator treatment and lingually in the HG biteplane group. The maxillary incisors were retruded with both appliances; there also were a significant increase in mandibular posterior dentoalveolar height and a restriction in the vertical development of the maxillary molars. Class II treatment with HG biteplane and bionator appliances is efficient over the short term, with pronounced dentoalveolar movements and smaller but still significant skeletal effects. The stability of these results should be examined in a long-term study.

Efeitos dentoesqueléticos produzidos pelo aparelho de Herbst na dentadura mista

OBJETIVO: o objetivo desta pesquisa clínica prospectiva foi avaliar as alterações cefalométricas dentárias e esqueléticas produzidas pelo aparelho de Herbst em jovens com má oclusão de Classe II, 1ª divisão durante a dentadura mista. METODOLOGIA: trinta jovens (15 do gênero masculino e 15 do feminino) com idade média inicial de 9 anos e 10 meses foram tratados com o aparelho de Herbst por um período de 12 meses. Para a comparação dos grupos utilizou-se uma amostra controle de 30 jovens (15 do gênero masculino e 15 do feminino) Classe II, 1ª divisão, com idade média inicial de 9 anos e 8 meses, que foram mantidos sem tratamento durante 12 meses. Para cada jovem foram utilizadas duas telerradiografias em norma lateral, obtidas ao início e no final do período de acompanhamento. Utilizou-se um método convencional de avaliação cefalométrica e o método proposto por Pancherz. RESULTADOS E CONCLUSÕES: os resultados deste estudo demonstraram que os efeitos do aparelho de Herbst produzidos na dentadura mista foram primariamente de natureza dentoalveolar. Os incisivos inferiores foram inclinados para vestibular e os superiores foram retruídos; também houve uma extrusão significante dos molares inferiores, enquanto os superiores sofreram restrição de desenvolvimento no sentido vertical. Não houve diferença significante de restrição do crescimento anterior da maxila entre os dois grupos. No sentido vertical da face, a altura facial ântero-inferior se comportou de forma similar, não demonstrando alteração significante entre os grupos. O tratamento com o aparelho de Herbst produziu um aumento modesto, porém, significante no comprimento da mandíbula comparado ao grupo controle. Este aumento, entretanto, foi de menor magnitude que aquele observado em pacientes adolescentes utilizando o mesmo protocolo de tratamento. A correção do overjet (Herbst) ocorreu devido a 22% de alterações esqueléticas e 78% de alterações dentárias. A correção da relação molar ocorreu devido a 27% de alterações esqueléticas e 73% de alterações dentárias.

Morphometric Analysis of Mandibular Growth in Skeletal Class III Malocclusion

The craniofacial growth patterns of untreated individuals with skeletal Class III malocclusion have rarely been systemically investigated. This study used morphometric techniques to investigate the growth characteristics of the mandible in individuals with skeletal Class III malocclusion. Lateral cephalometric head films of 294 individuals with untreated skeletal Class III malocclusion (134 males, 160 females) were selected and divided into five triennial age groups (T1-T5) and by gender to identify the morphologic characteristics and sexual dimorphism in changes of mandibular growth. Procrustes, thin-plate spline, and finite element analyses were performed for localization of differences in shape and size changes. Maximum and minimum principal axes were drawn to express the directions of shape changes. From T1 (age 6-8 years) to T4 (age 15-17 years), the distribution of localized size and shape changes of the mandible was very similar between the two genders. From T1 to T2 (age 9-11 years), significant lengthening of the condylar region was noted (23.4-39.7%). From T2 to T3 (age 12-14 years), the greatest size and shape change occurred at the condylar head (27.4-34.9%). From T3 to T4, the greatest size and shape changes occurred in the symphyseal region (23.6-42.1%). From T4 to T5 (age>or=18 years), significant sexual dimorphism was found in the distribution and amount of localized size and shape changes. Females displayed little growth increments during T4. Despite differences in the remodeling process, the whole mandibular configurations of both genders exhibited similarly significant upward and forward deformation from T4 to T5. We conclude that thin-plate spline analysis and the finite element morphometric method are efficient for the localization and quantification of size and shape changes that occur during mandibular growth. Plots of maximum and minimum principal directions can provide useful information about the trends of growth changes.

Reliability of Digital Versus Conventional Cephalometric Radiology: A Comparative Evaluation of Landmark Identification Error

The purpose of this study was to determine whether direct digital lateral cephalometric radiographs are of equal value in diagnosis and treatment planning as conventional cephalometric radiographs by investigating differences in landmark identification on direct digital and conventional cephalometric radiographs. An evaluation of precision and the distribution of landmark identification error at each cephalometric landmark was undertaken. Ten observers, all orthodontists or postgraduate orthodontic residents, identified 19 landmarks twice on 6 digital images and 6 conventional cephalometric films obtained from the records of 6 patients at the University of Alabama School of Dentistry Graduate Orthodontic Clinic. Patient records selected were of adults with existing pretreatment conventional cephalometric films and posttreatment direct digital cephalometric images on file. Landmark identification recordings were transferred into a standardized coordinate system, adjusted for magnification differences, and evaluated separately along both the x- and the y-coordinates. Statistically significant differences in landmark identification error were found along the x-coordinate for A point (Apt) and along the y-coordinate for anterior nasal spine (ANS) and condylion (Co). These statistically significant differences, as well as those found to be not statistically significantly different, were all below 1 mm, indicating that even the statistically significant differences between the two methods of image acquisition were unlikely to be of clinical significance. Each landmark exhibited its own unique pattern of landmark identification error, the magnitude and distribution of which must be taken into consideration when selecting landmarks for use in cephalometric analysis or when interpreting these analyses for diagnostic or treatment planning purposes. The results of the present study indicate similar precision and reproducibility in landmark identification using both direct digital images and conventional lateral cephalometric head films. The purpose of this study was to determine whether direct digital lateral cephalometric radiographs are of equal value in diagnosis and treatment planning as conventional cephalometric radiographs by investigating differences in landmark identification on direct digital and conventional cephalometric radiographs. An evaluation of precision and the distribution of landmark identification error at each cephalometric landmark was undertaken. Ten observers, all orthodontists or postgraduate orthodontic residents, identified 19 landmarks twice on 6 digital images and 6 conventional cephalometric films obtained from the records of 6 patients at the University of Alabama School of Dentistry Graduate Orthodontic Clinic. Patient records selected were of adults with existing pretreatment conventional cephalometric films and posttreatment direct digital cephalometric images on file. Landmark identification recordings were transferred into a standardized coordinate system, adjusted for magnification differences, and evaluated separately along both the x- and the y-coordinates. Statistically significant differences in landmark identification error were found along the x-coordinate for A point (Apt) and along the y-coordinate for anterior nasal spine (ANS) and condylion (Co). These statistically significant differences, as well as those found to be not statistically significantly different, were all below 1 mm, indicating that even the statistically significant differences between the two methods of image acquisition were unlikely to be of clinical significance. Each landmark exhibited its own unique pattern of landmark identification error, the magnitude and distribution of which must be taken into consideration when selecting landmarks for use in cephalometric analysis or when interpreting these analyses for diagnostic or treatment planning purposes. The results of the present study indicate similar precision and reproducibility in landmark identification using both direct digital images and conventional lateral cephalometric head films.

A CASE OF ANTLEY-BIXLER SYNDROME WITH SEVERE SKELETAL CL. III MALOCCLUSION

Antley-Bixler syndrome is a disorder characterized by craniosynostosis, midface hypoplasia, choana blockade, and radiohumeral synostosis. However, the features of occlusion remain unclear. In this paper, we report a case of Antley-Bixler syndrome, a 7-year-old boy, from the viewpoint of orthodontics. From lateral cephalometric head film analysis, remarkable retardation of the anterior subcranial base, infraorbitale, and maxilla were notable, as was vertical growth restriction of the maxilla. The choana blockade tendency was also recognized. Moreover, although reverse occlusion was present, a mandibular retrognathic tendency was also present, and a short ramus mandible, remarkable mandibular vertical growth pattern, and skeletal open bite were present. In the dentition, two of the lower incisors were missing, and the present lower incisors were large. Maxillary and mandibular first molars were delayed in eruption. For treatment, the solutions to such remarkable skeletal problems were limited by the insufficiency of recovery of cranial formation after the operation. We planned a non-surgical treatment to expand the maxilla. It will be necessary to continually consider the treatment of his malocclusion as he continues to grow.

The effects of overjet on dentoalveolar compensation.

The purpose of this study was to investigate the relationship between overjet and dentoalveolar compensation in different overjet patterns. The lateral cephalometric head films of 80 untreated subjects (40 males and 40 females) aged 13-15 years were divided into four groups based on a normal, edge-to-edge, negative, or positive overjet. Seven linear and eight angular cephalometric measurements were used to assess dentoalveolar compensation in the different overjet patterns, and the differences between the groups and between genders were assessed by means of analysis of variance and the least significant difference (LSD) test. In addition, correlation coefficients between overjet and other variables were calculated. The results showed that there were statistically significant differences in measurements of MxAABH (mm), MxPABH (mm), and angles 1-NA, 1-1, 1-SN, 1-SN, 1-MP, and SN-AB among the overjet groups. In addition, significant correlation coefficients were found between overjet and MxAABH (mm), 1-NA (mm), and angles 1-1, 1-SN, 1-SN, 1-MP, and SN-AB. The evaluation of dentoalveolar compensation in different overjet patterns may be useful in treatment planning and treatment success.

Treatment effects produced by Fränkel appliance in patients with class II, division 1 malocclusion.

The purpose of this investigation was to evaluate the dentoalveolar and skeletal cephalometric changes produced by the Fränkel appliance in individuals with a Class II, division 1 malocclusion. Lateral cephalograms of 44 patients of both sexes were divided in two groups of 22 each. The control group was comprised of untreated Class II children with an initial mean age of eight years and seven months who were followed without treatment for a period of 13 months. The Fränkel group had an initial mean age of nine years and was treated for a mean period of 17 months. Lateral cephalometric headfilms of each patient were obtained at the beginning and end of treatment. The Fränkel appliance produced no significant changes in maxillary growth during the evaluation period, while a statistically significant increase in mandibular length was observed. The maxillomandibular relationship improved mostly because of an increase in mandibular length. In addition, there were no statistically significant differences in the craniofacial growth direction between the Fränkel and the control group, both showing a slight downward rotation of the palatal plane. The Fränkel appliance produced a labial tipping of the lower incisors and a lingual inclination of the upper incisors as well as a significant increase in mandibular posterior dentoalveolar height. It was concluded that the main effects of the Fränkel appliance during this time period were mostly dentoalveolar with a smaller but significant skeletal mandibular effect.

Short-term effects of fiberotomy on relapse of anterior crowding

The effects of fiberotomy were evaluated in alleviating dental relapse of incisors after orthodontic treatment. The study sample consisted of 23 patients with crowded maxillary and mandibular incisors before orthodontic treatment. The amount of initial crowding was determined according to Little’s irregularity index. Fiberotomy procedures were performed on 11 of the patients 1 week before debonding. The other 12 subjects served as the control group. All patients wore Hawley retainers. Lateral cephalometric headfilms and dental casts of the patients were taken at the beginning (T1) and at the end (T2) of treatment, 6 months into the retention phase (T3), and 1 year after orthodontic treatment (T4). Significant increase of irregularity index was noted in the control group at T3 and T4 for both maxillary and mandibular anterior segments (P <.05, P <.01). Meanwhile, in the group where circumferential supracrestal fiberotomy was performed, no significant increase of the irregularity index was noted. (Am J Orthod Dentofacial Orthop 2000;118:617-23)

An investigation of mandibular morphology in subjects with different vertical facial growth patterns

Abstract In the present study, mandibular morphology was investigated on lateral cephalometric head films and dental casts of 60 subjects (30 females and 30 males) who had different vertical facial growth patterns. The sample had a mean age of l3 .5 years, with a range of ll to 15.5 years. The subjects were divided into three groups with regard to vertical facial growth by using the SN/GoGn angle to define low-angle, normal, and high-angle groups. In addition, each group was divided into two subgroups according to sex. The effects of the SN/GoGn angle and gender on mandibular morphology were investigated by means of analysis of variances. Tan Go, IMPA, SL, and EL measurements were found to be related to SN/GoGn, and the measurements of Go-Gn, Symphysis depth, and Intermolar width to be related to sex.