Maxillary Incisor Exposure Research Articles

Dual-action vertical intraarch technique: A multifocal technique for open bite correction

The dual action vertical intra-arch technique (DAVIT) is an innovative non-compliant multifocal mechanics for open bite correction. It is based on simultaneous posterior intrusion and anterior extrusion, which can occur at similar or different rates according to the patient's needs. This report presents the clinical handling of this innovative mechanics. The occlusal and cephalometric effects of the DAVIT device are shown by the treatment of an open bite Class III malocclusion. Six months after DAVIT placement, the open bite was corrected by increasing the overbite 5.1 mm. Dentoalveolar changes associated with open bite correction with DAVIT included maxillary molar intrusion, maxillary incisor extrusion and palatal tipping, uprighting of maxillary posterior teeth, and maxillary occlusal plane rotation. Maxillary incisor exposure and smile esthetics improved significantly. DAVIT efficiency seems to be associated with its non-compliant multifocal mechanical action, which can be adjusted according to the patient's occlusal and esthetic needs.

Determination of Maxillary Incisal Edge Position using Canine Visibility as a Guide – An In vivo Study

Purpose: To evaluate the reliability of the visibility of the central incisor & the canine for the cervico incisal positioning of anterior maxillary teeth related to age & sex while the upper lip was in repose in dentate patients & the development of rehabilitation recommendations for edentulous individuals with regard to the location of the maxillary incisal edge
 Methodology: 308 subjects [152 Males & 156 Females] belonging to the age of 30 to 59 years were selected using a simple stratified random technique. There were three age and sex groups: Group I was 30 to 39 years old, Group II was 40 to 49 years old, and Group III was 50 to 59 years old. The vertical distances (in mm) between the lower border of the upper lip and the right maxillary central incisal edge and canine tip were measured and recorded using adhesive tape marked with millimetres. A single examiner recorded all the measurements and the values were tabulated and subjected to statistical analysis.
 Results: Men in Groups I and II had maxillary central incisor exposure ranging from +6 to -1mm, whereas males in Group III had exposure ranging from +5 to -2mm. There was an exposure range of +6 to -2 mm in females in Group I, +7 to -2 mm in Group II, and +5 to -2 mm in Group III for the central incisors. While the canine exposure in Group I and II and Group III ranged from +2 to -4mm in females, the exposure ranged from +3 to -3mm in men of all ages. In all groups, females had statistically significant (P0.05) more central incisor and canine exposure than men.
 Conclusions: The canine visibility was less variable in all the age groups and in both males and females in comparison to the central incisor. When restoring edentulous individuals, the average canine exposure dimension can be employed for cervico-incisal location of the anterior maxillary teeth.

Development of dentofacial characteristics related to Incontinentia Pigmenti syndrome: A repeated cross-sectional study

This research aimed to investigate the dentofacial characteristics of patients with Incontinentia Pigmenti (IP) (or Bloch-Sulzberger) syndrome in childhood, juvenile, and adulthood developmental stages. Fifteen female patients with a clinical diagnosis of IP, genetically confirmed by molecular testing, were included in this study. The records of 25 nonsyndromic females with Class I occlusion and lateral cephalograms obtained at similar developmental stages were selected from the American Association of Orthodontists Foundation Legacy Collection as a control group. Dentofacial features of subjects with IP and those in the control group were compared statistically using t test and Mann-Whitney rank-sum test (significance was defined as P<0.05). In general, patients with IP had shorter maxillary and mandibular length, straight skeletal profile, hypodivergent growth pattern with a tendency to mandibular protrusion, shorter anterior facial height, Class III compensatory positioning of incisors, more retruded lips, and smaller maxillary incisor exposure. The degree of hypodontia severity had a significant impact on skeletal, dental, and soft-tissue features in patients with IP. The results of this study showed that, since childhood, the dentofacial characteristics of patients with IP were progressively distancing from those of nonsyndromic patients with Class I occlusion, presenting their own orthodontic needs.

New orthopedic and orthodontic treatment modality for adult patients with skeletal Class III malocclusion with insufficient maxillary incisor exposure

This paper aims to offer a new orthopedic and orthodontic treatment modality for treating adult patients with mild-to-moderate skeletal Class III discrepancy and insufficient maxillary incisor exposure who reject orthognathic surgery. For Phase I treatment, a rapid palatal expansion or miniscrew-assisted rapid palatal expansion is activated on the maxilla, and a modified lip bumper is installed on the mandibular dentition. At night, a facemask with a forward and downward orthopedic force is applied, whereas during the day, modified lip bumper and intraoral heavy Class III elastics are used. During Phase II treatment, intraoral elastics from the miniscrews between the mandibular premolars to the hooks between the maxillary lateral incisors and canines are activated to increase the maxillary incisor showing. In addition, activating elastomeric chains between the mandibular miniscrews and hooks between the mandibular lateral incisors and canines, the whole mandibular dentition is distally moved, and the mandibular incisors are intruded. Orthopedic and orthodontic treatment using a facemask, modified lip bumper, and mandibular miniscrews is an efficient way to improve adult skeletal Class III malocclusion and deficient maxillary incisor exposure.

Cephalometric changes during aging in subjects with normal occlusion.

Objective To assess craniofacial changes from early adulthood to the seventh decade of life in individuals with normal occlusion.Methodology The sample comprised lateral cephalograms of 21 subjects with normal occlusion (11 male, 10 female), taken at 17 (T1) and 61 years of age (T2). Anteroposterior and vertical maxillomandibular relationships, and dentoalveolar and soft tissue changes were analyzed. Interphase comparisons were performed using paired t-tests. Differences between sexes, and subgroups with and without tooth loss were evaluated using t-tests (p<0.05).Results Maxillary and mandibular anterior displacement, and facial and ramus height increased from T1 to T2. Maxillary molars showed significant mesial angulation. Maxillary and mandibular molars, and mandibular incisors developed vertically during the evaluation period. Soft tissue changes included a decrease of the nasolabial angle, upper and lower lip retrusion, decrease of upper lip thickness and increase of the lower lip and soft chin thickness. Maxillary incisor exposure by the upper lip decreased 3.6 mm in 40 years. Males presented counterclockwise rotation of the mandible, whereas females showed mandibular clockwise rotation and backward displacement of the chin. The group with tooth loss showed a greater increase of the posterior facial height and ramus height.Conclusion We observed aging changes in dentoskeletal structures and soft tissue, as well as sexual differences for craniofacial changes during the maturational process. Subjects with multiple tooth losses showed a greater increase in mandibular ramus height.

Orthodontic Traction of Impacted Teeth with Modified Nance Appliance : Case Reports

Proper treatment of an impacted tooth is required as it causes functional and esthetic disharmony, as well as it can cause root absorption of adjacent teeth. Treatment options for impacted teeth include periodic observation, surgical exposure, orthodontic traction followed by surgical exposure, tooth transplantation, and extraction. Modified Nance appliance, used for orthodontic traction, is clinically useful because it does not require patient cooperation. Through orthodontic traction combined with surgical exposure of impacted maxillary incisors, canines, and molars using modified Nance appliance, adequate results can be obtained.

Biomechanical considerations for total distalization of the mandibular dentition in the treatment of Class III malocclusion

Class III malocclusions with mild to moderate skeletal discrepancies can be camouflaged by orthodontic tooth movement. Conventional methods using Class III elastics can correct Class III into Class I molar relationships. These mechanics show side-effects such as labioversion and intrusion of the maxillary incisors, extrusion of the maxillary molars, linguoversion and extrusion of the mandibular incisors, and intrusion of the mandibular molars along with flattening of the occlusal plane. Conventional mechanics can improve occlusal relationships and some profile esthetics but may produce detrimental smile esthetics by reducing the amount of maxillary incisor exposure. Recently, with the advent of temporary skeletal anchorage devices (TSADs), clinicians are able to achieve total distalization of the mandibular dentition and therefore improve the occlusal relationship without worsening smile esthetics. With the use of TSADs, the en masse movement of an entire dentition can be easily accomplished using a statically determinate force system, which makes treatment plans easier and treatment results more predictable. Finite element studies have identified the location of the center of resistance of the entire dentition and simulated displacement of the dentition depending on the force angulations (FAs) and have thus provided the theoretical basis for 3-dimensional tooth movement patterns. This article provides the biomechanical considerations and clinical applications of total distalization of the mandibular dentition depending on various FAs to the mandibular occlusal plane for camouflage treatment of various types of skeletal Class III malocclusions.

Soft tissues cephalometric norms for a sample of Sudanese adults. Part I: Legan and Burstone analysis

ABSTRACT Purpose: To establish soft tissues cephalometric norms for orthognathic surgery in a sample of Sudanese adults. Materials and Methods: A total of 106 lateral cephalograms of Sudanese adults (55 females and 51 males) aged between 18 and 25 years (mean 22.8 years) were manually traced and analysed using Legan and Burstone Cephalometric analysis for orthognathic Surgery (COGS). Results: Sudanese sample, in comparison to Caucasian, had a more convex profile with larger angle of convexity and more prognathic maxillae, obtuse lower face-throat angle, more acute nasolabial angle, protrusive upper and lower lips with deeper labiomental sulci and greater maxillary incisors exposure with larger interlabial gap. Males had greater maxillary and mandibular prognathism, more obtuse lower face-throat angle and vertical height depth ratio than females. Females had larger vertical lip chin ratio, maxillary incisor exposure and interlabial gap. Conclusion: Considerable differences between the soft tissue profile configuration of Sudanese and Caucasian adults exist and also between Sudanese and other populations. These variations should be taken into account during diagnosis and treatment planning of orthognathic surgery.

Cephalometric profile norms for southeastern African-Brazilian adults according to the Legan-Burstone analysis: a pilot study

Objective: The aim of this pilot study was to determine cephalometric profile norms for a sample of African-Brazilian young adults with excellent occlusion and compare them to Caucasian standards. Methods: Lateral cephalograms of 43 individuals of both genders (28 male and 15 female), with average age of 22.40 ± 3.40 years, were used to evaluate 13 variables proposed by the Legan-Burstone analysis. Student´s independent t-test was used to compare resulting values with those set by European-American standards. Results: Significant differences were found (p < 0.001) between African-Brazilians and Caucasians as for: maxillary andmandibular prognathism, vertical height ratio, lower face-throat angle, lower vertical height-depth ratio, nasolabial angle, upper and lower lip protrusion, mentolabial sulcus and vertical lip-chin ratio. Facial convexity angle, maxillary incisor exposure and interlabial gap did not present statistical differences whenethnic groups were compared. Males displayed increased lower face-throat angles and vertical lip-chin ratios (p <0.05) while females presented increased maxillary incisor exposures (p <0.05). Conclusion: Caucasian cephalometric norms do not apply to African-Brazilian young adults. Therefore, morphological differences inthe faces of such individuals should be taken into account during diagnosis and orthodontic treatment planning stages.

Without mini-plates, mini-implants and surgery: treatment of severe anterior open bite in an adult patient - a case report

Introduction: Currently, there is a tendency to treat open bite with mini-implants, miniplates, and orthognathic surgeries and build ups when these protocols are not always indicated and to be apply them unnecessarily and excessively. Objectives: This case report describes treatment of a severe anterior open bite in an adult patient with step bends and vertical elastics. Case report: The female patient was 29 years and 8 months old and reported that she had low self-esteem; therefore, she wanted to have her untreated open bite closed. By examination, a convex profile, vertical growth pattern, dental midline deviation, and tongue exposure could be seen upon smiling. The dental and skeletal sagittal relationship was Class II. The overjet was +5 mm and the anterior overbite was -5.5 mm. The severe skeletal open bite involved the first molars to the anterior teeth, and it was treated only with step bends and vertical elastics over 2 years. Results: Significant facial improvement, maxillary incisor exposure upon aesthetic smiling, and adequate overbite and overjet were observed. The upper and lower dental midlines fit to the sagittal line. A counterclockwise rotation of the mandible was observed. The severe skeletal open bite was treated. Conclusions: Severe skeletal open bite malocclusion treated with step bends and vertical elastics in adult patient demonstrated efficient, predictable and stable open bite correction.

Post-orthodontic cephalometric variations in bimaxillary protrusion cases managed by premolar extraction - A retrospective study.

Bimaxillary protrusion is a common dentofacial condition associated with proclination of maxillary and mandibular incisors in relation to the dental and cranial bases resulting in soft tissue procumbency. The present retrospective study aimed to investigate dental and soft tissue profile changes using cephalometric analysis to evaluate bimaxillary protrusion patients after extraction of the first four premolars and subsequent retraction of the anterior teeth. Pre-treatment and post-treatment cephalometric radiographs of 46 Saudi patients (16 males and 30 females), 18-30 years of age with bimaxillary protrusion, were selected based on inclusion criteria. Dental and soft tissue landmarks were traced using the Dolphin® imaging software and statistically analyzed with SPSS® 21 software. The upper and lower incisors retroclined by a mean value of 9.6° and 9.65°, respectively, and an average distance of 4.1 mm. The level of maxillary incisor exposure was reduced by approximately 1.1 mm after treatment. A mean increase of 6.6° in the nasolabial angle was also observed. Multiple regression analysis showed that retraction of both upper and lower incisors by 1 mm would result in a 0.44 mm retraction of the upper and lower lips. A statistically significant increase in the nasolabial angle and upper lip length was found in relation to upper and lower incisor retraction and retroclination. A significant reduction was also evident in the post treatment upper incisor exposure, facial convexity angle and mentolabial sulcus depth.

Legan-burstone soft tissue profile values in a Circassian adult sample.

OBJECTIVE:To determine the mean soft tissue facial profile for Circassian adults as determined by Legan–Burstone cephalometric analysis.MATERIALS AND METHODS:71 lateral cephalometric radiographs for nongrowing Circassian adults with normal occlusion were traced and accurately measured.RESULTS:With regard to facial form analysis, Circassian adults showed higher facial convexity angle, retruded mandible, and obtuse lower face–throat angle. When compared with lip form norms, Circassians showed increased nasolabial angle, deeper mentolabial sulcus, and increased maxillary incisor exposure. Comparison between men and women showed that mentolabial sulcus depth was significantly increased in Circassian men compared with Circassian women.CONCLUSION:The results of this study showed that soft tissue facial profiles for Circassians and Caucasians are different in certain values. Such differences should be taken into account when formulating a treatment plan for Circassian patients seeking orthodontic treatment and orthognathic surgery.

Clinical and Cephalometric Analysis of Facial Soft Tissue.

This study aimed to provide average of standard values in planning orthognathic surgery in Asians. Thirty-three Asians with well-balanced facial profile, combined with class I occlusion and stabilized condylar head were evaluated using lateral cephalograms. Facial length (Nasion'-Menton') was 138.8 and 127.0 mm in male and female, respectively. Upper and lower lip length were 24.5 and 49.8 mm for male, and 22.2 and 45.1 mm for female, and maxillary incisor exposure was 2.0 and 4.0 mm in male and female, respectively. Nasolabial angle was 77.7° and 84.1° in male and female, respectively. Alar base, A point', and maxillary incisor were placed posteriorly to true vertical line by 10.6, 1.0, and 8.0 mm for male and 9.0, 0.8, and 6.9 mm for female. The horizontal distance between upper lip anterior and lower lip anterior was 2.1 mm for male and 2.6 mm for female, and the horizontal distance between A point' and B point' was 5.3 mm for male and 3.9 mm for female. Orbital rim' to A-point' was 12.4 and 11.3 mm in male and female, respectively. Pogonion' located posteriorly to glabella' by 2.7 mm for male and anteriorly to glabella' by 3.2 mm for female, and facial angle was 156.7° and 147.0° in male and female, respectively. This quantitative analysis of facial profile in Asian will be helpful in evaluation of facial soft tissue and establishment of treatment plans for orthognathic surgery.

Soft tissue cephalometric analysis applied to Himachali ethnic population

Introduction: The modern society considers facial attractiveness as an important physical attribute. The great variance in soft tissue drape of the human face complicates accurate assessment of the soft tissue profile, and it is a known fact that facial features of different ethnic groups differ significantly. This study was undertaken to establish norms for Himachali ethnic population. Materials and Methods: The sample comprised lateral cephalograms taken in natural head position of 100 normal individuals (50 males, 50 females). The cephalograms were analyzed by Arnett soft tissue cephalometric analysis for orthodontic diagnosis and treatment planning. Student's t-test was used to compare the means of the two groups. Results: Statistically significant differences were found between Himachali males and females in certain key parameters. Males have thicker soft tissue structures and a more acute nasolabial angle than females. Males have longer faces and females have greater interlabial gap and maxillary incisor exposure. Males have more deep-set facial structures than females. Conclusions: Statistically significant differences were found between Himachali males and females in certain key parameters. Differences were also noted between other ethnic groups and Himachali faces.

Clinical and radiographic evaluation of maxillary central incisors exposure in patients undergoing maxillary advancement.

Introduction: Patients with dentofacial deformities may undergo orthodontic or orthodontic-surgical treatment. Both modalities can affect esthetics. Objective: This study aims to evaluate clinical and radiographic changes in exposure of maxillary central incisors occurring after orthognathic surgery for maxillary advancement. Methods: A total of 17 patients who underwent orthognathic surgery for maxillary advancement between September, 2010 and July, 2011 were selected. Exposure of maxillary central incisors was evaluated clinically and by lateral cephalograms. Measurements were taken one week before and three months after surgery. Data were paired in terms of sex, age, nasolabial angle, height and thickness of the upper lip, the amount of maxillary advancement, clinical exposure and inclination of maxillary central incisor by statistical tests (CI 95%). Results: After maxillary advancement, incisor clinical exposure had increased even with relaxed lips and under forced smile. Moreover, there was a mean increase of 23.33% revealed by lateral cephalograms. There was an inverse correlation between upper lip thickness and incisors postsurgical exposure revealed by radiographic images (p = 0.002). Conclusions: Significant changes in the exposure of maxillary central incisors occur after maxillary advancement, under the influence of some factors, especially lip thickness.

Multidimensional esthetic evaluation of patients with a cleft lip and palate wearing a maxillary partial removable dental prosthesis: A 5-year retrospective study

Statement of problemNo published quantitative or qualitative studies are available of the 2-dimensional (2D) and 3D esthetic evaluation of patients with a cleft lip and palate (CLP) wearing a maxillary partial removable dental prosthesis (MPRDP). PurposeThe purpose of this retrospective clinical study was to qualitatively and quantitatively evaluate the facial esthetic improvements of patients with CLP wearing an MPRDP for 5 years by using 2D cephalometric and 3D photogrammetry methods. Material and methodsSix patients, 2 men and 4 women, with CLP deformity were recruited and treated with an MPRDP by the same dentist over 5 years. Results of the clinical examination were recorded before and after wearing the MPRDP. Sella-nasion-A (SNA) point, the U1-SN, 0-meridian to SN, nasolabial angle, and maxillary incisor exposure were measured by 2D cephalometric analysis before and after wearing the MPRDP. 3D photographs were captured by 3dMD software. Geomagic Spark Studio software was also used to measure the patients’ improved upper lip projection after the MPRDP was worn. The paired sample t test was used to compare the participants (α=.05). ResultsU1-SN (P<.05) and 0-meridian to SN (P<.01) had significant deviation statistically. After patients underwent clinical examination, SNA and nasiolabial angles were found to have improved, although no statistical significance was observed. ConclusionsA maxillary partial removable dental prosthesis (MPRDP) can advance the upper lip forward, restoring the subnasal and upper lip projection. Patients’ nasiolabial angles with MPRDPs were decreased, which led to a more harmonious facial contour.

Prospective assessment of maxillary advancement effects: Maxillary incisor exposure, and upper lip and nasal changes

Our aim was to assess changes in maxillary incisor exposure, and upper lip and nasal soft tissues with maxillary advancement with or without impaction, accounting for the use of cinch sutures and VY closures. This was a prospective study of 41 consecutive patients undergoing maxillary advancement with or without impaction. Lateral cephalometric radiographs and clinical measurements were taken preoperatively and up to 6 months postoperatively by 1 examiner. Thirty-one patients (19 female, 12 male) with a mean age of 25.5 years (range, 16.9-49.9 years) completed the study. Twenty-six received bimaxillary surgery. Fifteen had simple closures, 6 had cinch sutures, and 10 had alar base cinch and VY closures. The mean amounts of maxillary advancement and impaction were 3.34 and 1.6 mm, respectively. Soft tissues followed increasingly more closely the hard tissue advancement from pronasale to stomion superius. Mean maxillary incisor exposure increased at rest (0.5 mm) and on smiling (1.0 mm). The nasolabial angle increased (1.88°) because of columella upturning. Alar base width (3.09 mm) significantly increased. Soft to hard tissue horizontal ratios increased progressively from pronasale to stomion superius. Alar base cinch and VY closures increased these further. Maxillary incisor display changes were partly explained by presurgical upper lip thickness and soft tissue manipulation. Nasolabial angle increased, and cinch sutures seemed to increase this further. Alar base width increased significantly, and the cinch sutures did not significantly limit this.

THE ORTHODONTIC TREATMENT AND ONE YEAR FOLLOW UP OF AN ADULT CASE WITH SEVERE OPENBITE

Anterior open bite is an abnormal condition that is caused by dental, skeletal, functional, and pathological factors in dental arches and jaws. An adult woman having Class I relationship on the right side, Class II relationship on the left side and severe anterior open bite with inadequate maxillary incisor exposure demanded treatment without surgical approach. Treatment was performed with preadjusted edgewise appliances accompanying extraction of maxillary left first premolar. As a result, open bite abnormality was treated with satisfactory esthetic outcome coupled with an ideal overjet and overbite relationship.

Evaluation of smile esthetics in central India

Objectives: This study was undertaken: (1) To establish static norms in the central India population for the various smile parameters. (2) To analyze and quantify the sexual dimorphism of esthetic smile. Settings and Design: Hundred subjects (50 males and 50 females) with an average age of 14.5 years with a pleasing smile were selected for the study. Static photographs with posed smile in natural head position (NHP) were taken. Materials and Methods: Following smile parameters were quantified using Adobe Photoshop ruler software: Maxillary incisor exposure (MIE) (mm), smile index (SI) (mm), smile arc, buccal corridor ratio (%), Most posterior maxillary tooth visible, anterior height of the smile (%), posterior height of the smile (%). Statistical Analysis: The data were compiled systematically. Statistical analysis was done using Statistical Package of Social Sciences (SPSS version 17.0). For MIE and SI, Unpaired t-test was applied. Chi-square test was applied for most posterior maxillary tooth visible, smile arc buccal corridor, anterior height of smile, and posterior height of smile. Results: The mean value of MIE was found to be 7.76 mm and 8.82 mm in boys and girls, respectively. SI showed a mean value of 8.26 for boys and 7.91 for girls. Girls displayed second premolar commonly in contrast to boys, who displayed first premolar. Parallel smile arc was noted more frequently in females, while males displayed flat smile arc commonly. Conclusion: Orthodontists, being smile architects, have the responsibility to design and create smiles. Smile analysis should be an integral part of dental/orthodontic treatment planning and mechanotherapy.

Arnett's Soft-tissue Cephalometric Analysis Norms for the North Indian Population: A Cephalometric Study

Objective: To determine the soft-tissue cephalometric norms as per Arnett’s analysis for male and female subjects of North Indian population and to compare these cephalometric norms with Arnett’s norms for Caucasian population. Materials and methods: Frontal and profile photographs of 150 subjects with normal occlusion and pleasing profile were rated by a panel of judges, from which 50-male and 50-female subjects were selected and their lateral cephalograms were taken for the present study. Arnett’s soft-tissue cephalometric analysis (STCA) was done on these cephalograms using Nemotech cephalometric software. Mean values of various parameters were obtained and these values were compared to Arnett’s norms for Caucasian population using Student t-test. These values were also compared among males and females of North Indian population. Results: High overjet, thicker soft-tissue, less facial length, retruded lower face and midface and convex profile were observed in the North Indian population as compared to Caucasian population. Males of North Indian population have thicker soft-tissue structures, more acute nasolabial angle, longer faces and more deep-set facial structures than females whereas females have greater interlabial gap and maxillary incisor exposure. Conclusion: Statistically significant differences in certain parameters were found between North Indian population and Caucasian population and also between males and females of North Indian population.