Normal Jaw Relationship Research Articles

Interdisiplinary collaboration of orthodontics and oral and maxillofacial surgery for the correction of severe class III skeletal pattern in an adult male with an hapsburg jaw - A case report on surgical orthodontics

This case report, aims to present a combined orthodontic and surgical approach in the treatment of an adult male patient with skeletal class III malocclusion with an Hapsburg jaw. The malocclusion was decompensated by pre-surgical orthodontic treatment and then normal jaw relationship was achieved by Bilateral Sagittal Split Osteotomy Setback followed by debonding after 4 months. The treatment lasted for over 14months, it improved facial esthetics and profile of the patient significantly and resulted in a normal occlusion, overjet, and overbite and a pleasant smile.

Lip Prominence Using Different Reference Planes

Introduction: Facial beauty lies on lip prominence which in turn is the reflection of dental and skeletal relation of the jaws beside the lip morphology. Thus, orthodontist has control over lip prominence to enhance beauty by altering skeletal and dental relation. Hence analyzing lip prominence is essential for the success of orthodontic treatment. The aim of the present study is to determine lip prominence using different reference planes and secondly to assess sexual differences in lip prominence.
 Materials & Method: lateral cephalograms of 43 (23 males and 20 females) Brahmins aged 18 - 27 years were collected. They were having dentally: Angle’s Class I molar and canine relation with normal overjet and overbite and skeletally: normal jaw relationship, symmetric face with acceptable facial profile, without craniofacial abnormalities. Linear distance was measured in lateral cephalograms from most prominent point of the lip to reference planes of different analysis system. Comparative test was conducted within Brahmins to check gender diversity at significance level p ≤ 0.05.
 Result: Comparison of lip prominence of male and female Brahmins were found to have no statistically significant differences except for the upper lip to Burstone B line (p ≤ 0.05) and lower lip to Holdaway H line (p ≤ 0.05). When means of males and females were compared males were found to have more protrusive lips.
 The Result of this study indicates protrusive lips of Brahmins compared to the established norms of Caucasians as analyzed with reference plane of different analysis system namely Ricketts, Steiners and Burstones. Sushners analysis showed retrusive lips indicating retrusive lips of Brahmins as compared with Black population.
 Conclusion: During orthodontic treatment planning lip prominence should be emphasized based on gender and ethnicity.

Analysis of three dimensional oropharyngeal airway and hyoid position in retrognathic adolescent patients

ObjectiveTo test the null hypotheses that there is no significant difference in the three-dimensional size of the oropharyngeal space or hyoid position when comparing individuals with a normal jaw relationship with individuals with retrognathic mandibles. MethodsIn total, 226 skeletal class I (0.7° ≤ ANB < 4.7°) or class II (ANB > = 4.7°) adolescent patients were examined and categorized into two groups: normal group and retrognathic group. Group classifications were made based on SNA angle, SNB angle, ANB angle, and maxillary length (Ptm-ANS). From the total available cases, 60 subjects met the above classification criteria and had a normo-divergent facial pattern, with 30 cases in each group. Cone beam computed tomography (CBCT) images were collected for each participant and InVivoDental (Anatomage, San Jose, Calif) software was used to analyze 60 CBCT scans. Mimics 17.0 software was used to reconstruct the upper airway, and indices of oropharyngeal airway dimensions and hyoid position were calculated. ResultsThe oropharyngeal airway dimensions of adolescent patients in the retrognathic group were smaller than adolescent patients in the normal group. The hyoid was positioned more superior and posterior in the retrognathic group. With decreases in mandibular length and SNB angle, oropharyngeal space volume tended to decrease, the hyoid tended to be more superior and posterior. ConclusionThe null hypotheses were rejected. Significant differences in the three-dimensional size of the oropharyngeal space or hyoid position when comparing individuals with a normal jaw relationship with individuals with retrognathic mandibles.

Oral dysfunction as a cause of malocclusion.

Structured This narrative review surveys current research demonstrating how oral dysfunction can escalate into malocclusion, acquired craniofacial disorder and contribute to generational dysfunction, disorder and disease.IntroductionBaseline orthodontic consultations are generally recommended beginning age seven. However, the dysmorphic changes that result in malocclusion are often evident years earlier. Similarly, following orthodontic treatment, patients require permanent retention when the bite is not stable, and without such retention, the malocclusion can return.Setting and PopulationNarrative review article including research on infants, children and adults.Materials and MethodsThis review is a brief survey of the symptomology of orofacial myofunctional disorder and outlines 10 areas of oral function that impact occlusal and facial development: breastfeeding, airway obstruction, soft tissue restriction, mouth breathing, oral resting posture, oral habits, swallowing, chewing, the impact of orofacial myofunctional disorder (OMD) over time and maternal oral dysfunction on the developing foetus.ConclusionMalocclusions and their acquired craniofacial dysmorphology are the result of chronic oral dysfunction and OMD. In order to achieve long‐term stability of the face, it is critical to understand the underlying pathologies contributing to malocclusion, open bite and hard palate collapse.

Surgical Occlusion Setup in Correction of Skeletal Class III Deformity Using Surgery-First Approach: Guidelines, Characteristics and Accuracy

The aims of this study were to establish guidelines for the surgical occlusion setup of surgery-first orthognathic surgery, and evaluate the resulting characteristics and accuracy. Skeletal Class III patients (N = 53) underwent Le Fort I osteotomy and bilateral sagittal split osteotomy. Study models before orthognathic surgery were set according to the guidelines. Occlusion was measured and computer-aided surgical simulation was used to evaluate the characteristics and accuracy of the surgical occlusion. The mean age of participants was 25 ± 6 years with 24 males and 29 females. The occlusion was set as positive overjet (4.4 ± 2.0 mm) and overbite (1.4 ± 1.8 mm), Class II or I molar relation, and posterior cross bite (overjet: 4.9 ± 2.0 mm and 4.4 ±1.9 mm, respectively for the right and left second molars) and open bite (overbite: −2.0 ± 1.6 mm and −1.9 ± 1.3 mm, respectively for the right and left second molars). Normal jaw relationship and symmetry were noted after virtual surgery. None of the patients required new occlusal setup. Our data contribute the use of the surgery-first approach for skeletal Class III patients by establishing guidelines for a surgical occlusion setup in three dimensions.

Expressional Analysis of MSX1 (Human) Revealed its Role in Sagittal Jaw Relationship.

Abnormal skeletal jaw relationships is an important factor causing difficulty in speech, mastication, sleep and social interaction, thus affect the overall well being of an individual. The present study was an attempt to decipher the role of human MSX1 in terms of sagittal jaw relationship by employing Polymerase Chain Reaction (PCR) based analysis. Ninety-eight case subjects belonging to North India with skeletal Class II and Class III jaw relationships were selected. Further, thirty-five control subjects of the same region having Class I skeletal and dental relationships (normal Jaw relationships) with good alignment of all teeth were enrolled. MSX1 gene sequencing was performed using the subjects' blood samples. Multiple sequence alignment was performed to find Single Nucleotide Polymorphisms (SNP's). Nine SNP's were obtained of which seven were reported and two novels. Statistical analysis was performed using Chi square test to compare genotype differences between case and control groups. SNP rs186861426 was found to be significantly associated in Class I subjects (p-value=0.02). The sequencing results suggested that individuals having changes from G (guanosine) with A (adenine) genotype had approximately seven times low risk for developing Class II division 1 malocclusion as compared to those alleles having GG genotype and therefore, allele 'A' position on chromosome 4 (rs186861426) seems to have a protective role. The study unfolds an important relationship between MSX1 gene and Class II division 1 malocclusion and Class I normal skeletal relationships. The study tried to interpret the role of human MSX1 and extend the gene pool responsible for the skeletal anomalies related to development of abnormal upper and lower jaws.

Surgical management of Class III malocclusion: A 1 year follow-up

For patients whose orthodontic problems are so severe that neither growth modification nor camouflage offers a solution, surgery to realign the jaws or reposition dentoalveolar segments is the only possible treatment option left. One indication for surgery is a malocclusion too severe for orthodontics alone. It is possible now to be at least semiquantitative about the limits of orthodontic treatment in the context of producing normal occlusion as the diagrams of the “envelope of discrepancy” indicate. In this case report, we have presented orthognathic treatment plan of an adult male patient with skeletal Class III malocclusion and anterior crossbite. Patient's malocclusion was decompensated by orthodontic treatment just before the surgery and then normal jaw relationship achieved by bilateral sagittal split ramus osteotomy. Patient's dental and facial profile was improved in a total of 18 months treatment duration. One-year follow-up showed stable results.

Retention procedures for stabilising tooth position after treatment with orthodontic braces.

Retention procedures for stabilising tooth position after treatment with orthodontic braces.

Systematic Analysis of Clinical Outcomes of Anterior Maxillary and Mandibular Subapical Osteotomy With Preoperative Modeling in the Treatment of Bimaxillary Protrusion

The purpose of this study was to determine the changes in teeth and hard tissues after preoperative modeling and bimaxillary anterior subapical osteotomy for the treatment of bimaxillary protrusion. Cephalometric analysis was used to evaluate the aesthetic effects and occlusal relationships obtained. The subjects included 19 women and 1 man (aged 19-41 years; average, 29 years) with bimaxillary protrusion who underwent anterior subapical osteotomy of both the maxilla and mandible, with simultaneous genioplasty, if required. Based on a preoperative computer-aided manufacturing/design-assisted and model surgical design and an occlusal guide plate, new occlusal relationships were established for the patients. In addition, the preoperative and postoperative cephalometric radiographs were systematically analyzed. In all patients, the surgical incisions underwent primary healing, with no infection or osteonecrosis. Significant differences were observed in the preoperative and postoperative values of all hard tissue and teeth parameters, except for SGn-FH degrees and Co-MP. The most obvious significant differences were seen in L1-OP°, Id-Pog-Go°, IIA°, U1E-Apog, L1E-Apog, U1E-NA, and L1-NA° (P < 0.001). Postoperative follow-up lasted for 12 to 36 months. All patients eventually achieved normal jaw relationships, tooth arch forms, and Spee curves. No evident irregularities of teeth arrangement or abnormal occlusal relationships were observed. All patients were satisfied with their postoperative facial appearance, except for 1 patient, who underwent repeat surgery because of relapse. With the use of a precise preoperative model surgical design, orthognathic surgery, a simple and time-saving technique, can be used to correct bimaxillary protrusion with satisfactory postoperative occlusal relationship and facial aesthetic appearance and minimal postoperative complications.

Surgical-orthodontic treatment of a skeletal class III malocclusion

For patients whose orthodontic problems are so severe that neither growth modification nor camouflage offers a solution, surgery to realign the jaws or reposition dentoalveolar segments is the only possible treatment option left. One indication for surgery obviously is a malocclusion too severe for orthodontics alone. It is possible now to be at least semiquantitative about the limits of orthodontic treatment, in the context of producing normal occlusion as the diagrams of the “envelope of discrepancy” indicate. In this case report we present orthognathic treatment plan of an adult female patient with skeletal class III malocclusion. Patient's malocclusion was decompensated by orthodontic treatment just before the surgery and then normal jaw relationship achieved by bilateral sagittal split osteotomy.

Dependence of the face aesthetic from sagittal and vertical jaw relations

Treatment plan in contemporary orthodontics cannot be imagine without analyzing soft tissue facial characteristics besides assessment of jaw and dental relationships. Aim. Using a questionnaire, we aimed this study at establishing facial characteristics, in relation to sagittal and vertical facial ratios, which are considered aesthetically acceptable, and which could be altered by the means orthodontic treatment. Material and Method. The research was conducted in persons from 23 to 30 years of age whose photographs were taken in standard conditions. Photographs of three patients with different facial profiles were chosen (Class I, Class II and Class III). Every photo was modified in six new profiles by changing facial features. This included mesial and distal shift of maxilla and mandible, as well as increase and decrease of lower facial height. Results. The results showed that straight profile, which is most often present in normal jaw relationships, is considered the most beautiful, furthermore slightly convex profiles are also considered very attractive. Convex profile is connected with distal jaw relationship and its intensity affects facial attractiveness. Concave profile in patients with mesial jaw relationship is aesthetically the least acceptable.

Morphologic adaptation of temporomandibular joint after chincup therapy

The purpose of this study was to clarify the morphologic changes of the temporomandibular joint (TMJ) after chincup application, with longitudinal TMJ cephalometric laminagraphs. The subjects were 19 prepubertal patients with true, mild skeletal Class lIl malocclusions with anterior crossbite. All underwent chincup therapy from the beginning of treatment. The control subjects were 16 patients with functional anterior crossbite, with normal jaw relationships. Cephalometric laminagraphs and lateral cephalograms were obtained before and after treatment. Statistical analysis of the data revealed the results as follows: (1) The chincup therapy changed the direction of growth of the mandible, especially, the ramus swing-back. (2) The chincup group showed a relatively more slender mandibular neck compared with the control group. (3) The condylar heads were bent forward after the chincup application, and the glenoid fossa was deepened and widened. The clearance between condyles and fossae was decreased by the orthopedic force of the chincup appliance. (Am J Orthod Dentofac Orthop 1996;110:541-6.)

An electromyographic investigation of patients with a normal jaw relationship and a Class III jaw relationship

The method of analyzing the electromyographic data from patients has been described, and the results of the investigation of twenty adult patients with normal occlusion, twenty children with normal occlusion, fifteen patients with skeletal Class III malocclusion, and fifteen patients with postural Class III malocclusion have been presented. Each patient was recorded in the protruded contact, retruded contact and intercuspal positions. A group of Class III patients who had received orthodontic treatment were recorded after treatment and out of retention, and this group was also investigated. The results showed that the best jaw position for discrimination between the groups was the intercuspal position and that, following orthodontic treatment, the muscle activity returned to a more normal pattern of activity.

ORTHODONTIC PROBLEMS IN PEDIATRIC PRACTICE

ONE of the most important phases of oral health is the form and function of the oral mechanism. That specialty of dentistry which has as its goal the correction of dental malformations and restoration of the continuity and proper function of the teeth and jaws is called orthodontics. While parents have long been concerned with the obvious esthetic disabilities of malposed teeth, the pathologic implications of these malposed teeth have been the primary concern of the orthodontist. Frequently, tooth malpositions or dental malocclusions reflect growth and developmental disturbances of the upper and lower jaws. Crooked teeth are unsightly, but more important, they probably are functioning improperly, or not at all, which seriously impairs the health and longevity of the teeth and investing tissues. Recent studies of facial growth indicate that dental malocclusions may be grouped in three morphologic categories, on the basis of jaw development and individual tooth malpositions. First, are those types of disturbances which are primarily skeletal in nature. These are problems where the maxilla or mandible has assumed an abnormal relationship to one another, usually through an upset in the timetable of normal development. The teeth in each dental arch may be normal in their position when compared to their respective jaws, but the abnormal jaw relationship means that the upper and lower teeth meet improperly during mastication, deglutition and speech. The second group consists of relatively local disturbances, with the teeth malposed, but with normal jaw relationship. The third group is a combination of the first two, with both improper jaw relationship and with teeth in abnormal positions. Within these three broad categories one may find all sorts of tooth malpositions and jaw relationships; the premaxillary segment may be displaced anteriorly, the whole lower dental arch may be retruded, the upper cuspids may be erupting in the palate, etc. Such conditions may be separate or occur in combination.