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At least 19 recordsLinked to original sources
PubMed1977

Differential treatment planning for mandibular prognathism.

The treatment records of thirty-eight cases of mandibular prognathism treated by orthodontics means only (ORTHO) were evaluated. The pretreatment records of twenty cases of mandibular subapical esteotomy (SUB) and twenty cases of mandibular setback (SET) were evaluated for comparison and contrast with the pretreatment ORTHO records and with each other. Dental, skeletal, and soft-tissue parameters in the vertical and horizontal planes of space were recorded. Statistical analysis of means of parameters of the pretreatment records provided documentation of the discriminant variables in each of the following paired groups: ORTHO-SUB, ORTHO-SET, and SUB-SET. Analysis of the data as indicated above led to the following conclusions: 1. Three discriminant groups of mandibular prognathism of various degrees of severity were discernible when comparisons of treatment categories simulating clinical decisions were made. The ORTHO group was distinguished from the SUB group in the horizontal plane and, more strongly, in the vertical plane. The ORTHO group was distinguished from the SET group in the vertical plane and, more strongly, in the horizontal plane. The SUB group was distinguished from the SET group in the horizontal plane. 2. The physiologic developmental status of the patient should be carefully evaluated. 3. Anteroposterior dysplasias should be assessed relative to the cant of the mandibular plane. True denture base discrepancies can be noted relative to the occlusal plane. 4. Documentation of vertical dysplasias should include measurements of craniofacial divergence (SN-MP, FH-MP, and OP-MP). 5. In assessing the profile evaluation of the patient with mandibular prognathism, particular attention should be focused on facial contour angle (FCA), nasolabial angle (NLA), and relative lower lip protrusion (LLP). 6. Any numerical values obtained in the evaluation of the dental, skeletal, or soft-tissue characteristics of mandibular prognathism should be considered only as descriptive, diagnostic guides and not as components of a diagnostic formula.

Alveolar Process↗
PubMed1977

Tooth-size discrepancy in mandibular prognathism.

A Bolton analysis of seventy-eight cases of Angle Class III malocclusion, twenty-six cases of Angle Class I malocclusion, and twenty-six cases of Angle Class II malocclusion was recorded. Frequency of excess mandibular tooth structure, magnitude of the excess, over-all ratios, and anterior segment ratios were computed and analyzed. Two clinical cases were presented to show the advantage of tooth-size harmony in mandibular prognathism. Analysis of the data as presented above suggests the following conclusions: 1. The frequency of mandibular tooth-size excess (over-all ratio) in this sample was greater in cases of mandibular prognathism than in Angle Class I and Angle Class II cases. 2. In those cases with mandibular tooth-size excess, there was a suggestion that the magnitude of the excess was greater in cases of mandibular prognathism than in Angle Class I and Angle Class II cases. 3. A tooth-size discrepancy analysis should be included as one part of the diagnostic records for mandibular prognathism.

Adolescent↗
PubMed1990

Reaction of mastication to occlusal changes induced by correction of mandibular prognathism.

Incisor-point masticatory movements of 22 patients were recorded before and after correction of mandibular prognathism. Chewing patterns and movement parameters were compared between preoperative and postoperative states and to corresponding quantities of 85 persons with normal dentitions. The prognathism patients most frequently revealed "chopping-type" patterns characterized by nearly vertical closing strokes, whereas mastication in the reference group was dominated by lateral grinding-type movements. There were no significant differences in the pattern distributions and parameter values between the preoperative and postoperative states. An individual assessment, considering random fluctuations of chewing behavior, showed that only five patients had changed their chewing mode possibly because of the treatment. Only a minor part of these changes could be directly related to the altered occlusion. It is concluded that the characteristic chewing mode of persons with mandibular prognathism does not interfere with the occlusal profile, and hence does not react to alterations.

Adult↗
PubMed1976

Indications for reduction of tongue in surgical treatment of mandibular prognathism.

The literature suggests that the tongue plays an important role in the recurrence after operative correction of mandibular prognathism. To prevent such a recidivism a reduction of tongue can be considered. However, it is difficult to decide how the tongue is involved. Size, strength and function are difficult to measure, and the literature on this subject is not concerned with these properties. A number of methods are given with which an impression can be acquired about the above-mentioned properties of the tongue. Special attention is paid to the type of the ostectomy, and the arguments for this procedure are exemplified by the investigation of 75 patients in whom a surgical correction of mandibular prognathism was performed. It is concluded that tongue reduction is more readily indicated preparatory to correction of mandibular prognathism by a modified Kole procedure than before correction by means of a stepped ostectomy or an Obwegeser-Dal Pont procedure.

Glossectomy↗
PubMedDate not supplied

A new osteotomy for the correction of mandibular prognathism: techniques and rationale of the intraoral vertico-sagittal ramus osteotomy.

The sagittal split ramus osteotomy (SSRO) and the intraoral vertical ramus osteotomy (IVRO) are long established methods for correcting mandibular prognathism, each having its own advantages. However, both procedures have the same disadvantage: the potential for postoperative condylar displacement. The displacement of the condyle is mainly due to the fact that the osteotomy plane is not parallel to the original sagittal plane in which the mandible is repositioned. The author has developed a new ramus osteotomy since 1985 in which the osteotomy plane is theoretically parallel to the original sagittal plane and thereby attempting to decrease the incidence of condylar displacement. This osteotomy was designed additionally to decrease neurosensory disturbances and has the advantages of both methods, and therefore has been named 'intraoral vertico-sagittal ramus osteotomy (IVSRO)'. Initial experience with the 24 prognathic patients operated on by means of the IVSRO indicated excellent clinical results. It has been noted clinically that the IVSRO is very effective in reducing postoperative iatrogenic TMJ symptoms and in treating preoperative TMJ symptoms. It has the additional effect of reducing neurosensory disturbances. This osteotomy seems to be more applicable in mandibular prognathism with excessive flaring of the ramus, particularly that associated with TMJ dysfunction, because the IVSRO has a 'condylotomy effect' and its splitting plane diverges less from the original sagittal plane than that of the SSRO and the IVRO.

Bone Screws↗
PubMed1977

The role of dental compensations in the orthodontic treatment of mandibular prognathism.

Thirty-six patients with orthodontically treated mandibular prognathism were recalled for cephalometric and clinical evaluation. A comparison group of 32 non-Class III patients was similarly examined. Analysis of variables associated with the anterior dentition and documentationtion of labial gingival recession and tooth mobility led to the following conclusions concerning the role of dental compensations in the orthodontic treatment of mandibular prognathism. 1. Vertical and horizontal dental compensations were quantitated in the dentition of the study group (pretreatment to postretention). 2. Increased labial gingival recession and increased tooth mobility in functional jaw positions were present in anterior maxillary and mandibular teeth of the study group relative to the comparison group. 3. Proper diagnosis and the establishment of realistic treatment objectives by clinician and patient are necessary to avoid undesirable sequelae and/or undesirable facial esthetics in the treatment of mandibular prognathism.

Humans↗
PubMed1991

The functional status of orthodontically treated prognathic patients.

In order to study the prevalence of mandibular dysfunction in orthodontically treated prognathic patients after retention, 60 randomly selected patients were examined clinically. The functional status of the patients was evaluated using the anamnestic, clinical dysfunction index, and the index for occlusal status introduced by Helkimo. Our patients showed a better functional status than the untreated prognathic patients, but one poorer than that of the general population. No difference, as demonstrated by indices, could be found between chin-cup and non chin-cup group, or between the conservatively treated and surgically treated prognathic patients without pre-orthodontic treatment.

Adolescent↗
PubMed1991

Maxillary advancement for mandibular prognathism: indications and rationale.

The surgical correction of mandibular prognathism has traditionally involved posterior repositioning of the mandibular body. This treatment approach corrects the skeletal disproportion at the expense of reducing facial skeletal volume and can unpredictably result in inadequately supported soft tissues with loss of skeletal definition. In an effort to avoid these sequelae of mandibular reduction, 18 patients diagnosed as having mandibular prognathism were treated with maxillary advancement surgery at the Le Fort I level. Mean patient SNB angle was 85.2 degrees, as compared with a normal 79 +/- 3 degrees. Maxillae were documented to be in normal position relative to both cranial base and Frankfort horizontal. The mean maxillary advancement was 6.9 mm, with a range of 4.5 to 8.8 mm. All patients required genioplasty to reduce vertical chin height and/or to laterally shift the chin. At the time of follow-up (mean 16.2 months), all patients retained cephalometric data suggestive of enlarged mandibles and excessive anterior facial divergence. However, maxillomandibular harmony and facial convexity had been restored without sacrificing skeletal volume. Treatment results demonstrated these faces to be skeletally well proportioned despite lower face protrusion that was beyond "normal." Postoperative appearances were characterized by a well-supported soft-tissue envelope and a highlighted skeletal foundation, creating angular, well-defined lower faces. These findings support the credibility of maxillary advancement as the procedure of choice in selected individuals with mandibular prognathism. Indications and an aesthetic rationale for this surgical approach are presented.

Adolescent↗
PubMed1992

Disfigurement and psychosocial handicap of adults with extreme mandibular prognathism.

Questionnaires and psychological tests were used to assess the psychosocial impact of mandibular prognathism. Patients with mandibular prognathism were asked to assess the impediments caused by their dentofacial deformity. In addition, they were asked to rate their appearance and to report the effect that it had on their social contacts. The self-assessment revealed that patients felt esthetically impaired, but that they had a fairly positive autostereotype, as revealed by their self-descriptive choices on a personality scale. These results were compared with the assessments made by two different control groups composed of persons with no esthetic impairment. The attitudes of the control groups toward the patients were more negative than perceived by the patients, indicating that mandibular prognathism does result in a social handicap.

Adolescent↗
PubMed1992

[Psychology and recurrence tendency in relation to age at operation for prognathism].

Within this study patients with mandibular prognathism were studied as to their psychological situation pre- and postoperatively with the help of the Freiburg Personality Evaluation Sheet. Since it was our special interest, whether psychologically it makes a big difference whether the patients were operated during the time of adolescence or after the age of twenty, the postoperative investigation was carried out with special reference to this point. Without any doubt, the correction of prognathism improved the psychological situation of the patients. It was obvious that for those patients in between fourteen and seventeen the improvement was more helpful than for those patients after the age of twenty. On the other hand the rate of recurrence was much higher within the group of those patients operated in between fourteen and seventeen (29.8%) than for those patients which were operated later than at age twenty (8%). The ideal age for the correction of mandibular prognathism must be found individually. While the operation at an early time is more helpful for the psychological situation of the patients, it must on the other hand be seen that for this age-group the danger of recurrence is higher.

Adolescent↗
PubMed1989

[Anterior body ostectomy for mandibular prognathism].

The mandibular body ostectomy is indicated for the correction of select cases of; Mandibular prognathism, Class III open-bite deformity, Anterior crossbite in the adult. The anterior body ostectomy is indicated primarily in selected cases of mandibular prognathism, class III malocclusion when the posterior teeth are not in crossbite or the crossbite is dental in nature and can readily be resolved with conventional orthodontics. As with the correction of other dentofacial deformities, carefully done model surgery and a cephalometric prediction tracing are imperative in planning the anterior body ostectomy. In this paper, a case of mandibular prognathism which is corrected by the technique of anterior body ostectomy is presented.

Adult↗
PubMed1978

Soft-tissue changes related to the surgical management of mandibular prognathism.

A series of fifty patients treated surgically for mandibular prognathism has been analyzed statistically to study relative soft- and hard-tissue changes. Changes in the soft tissue of the chin and in the lower lip position relative to the underlying mandibular structures are well related in a nearly 1:1 ratio. Upper lip modifications have been shown to be less well related to mandibular repositioning. The ratio of change of mandibular landmarks to soft-tissue points and their over-all positional change can be helpful in presurgical treatment planning of patients with mandibular prognathism.

Cephalometry↗
PubMed1978

Correction of prognathism with fixed and removable partial dentures.

Prognathism in those patients for whom surgical orthodontic procedures are contraindicated can be successfully treated by the use of fixed and removable partial denture prosthodontics. Careful neuromuscular evaluation of the patient is necessary for the success of the treatment rendered. The nonsurgical treatment of prognathism by this method was described.

Acrylic Resins↗
PubMed1976

Surgical correction of mandibular prognathism.

Procedures used in the correction of certain forms of mandibular prognathism are described. All but one of these techniques allow an immediate functional healing, which is considered to be most important. Since no single procedure can correct all the different forms of mandibular prognathism, each case is individually planned and a "custom-tailored" technique is applied.

Alveolar Process↗
PubMed1991

Alterations of hyoid bone position and pharyngeal depth and their relationship after surgical correction of mandibular prognathism.

The present investigation studied changes of hyoid bone position and pharyngeal depth at the levels of the second and fourth cervical vertebrae and their relationships in mandibular prognathism patients who received combined orthodontic-surgical treatment. The material consisted of presurgical and 1-year postsurgical profile cephalograms of 52 adult orthognathic surgery patients (40 females and 12 males) who initially had mandibular prognathism and had undergone bilateral vertical ramus osteotomy through an extraoral incision in the retroangular area. Hyoid bone position and pharyngeal depth were assessed on the profile radiographs with 10 cephalometric variables. Paired t tests were used to evaluate the operative changes in all cephalometric parameters. The relationships between pairs of variables describing hyoid bone position and pharyngeal depth were assessed by means of Pearson's product-moment correlation analysis. Significant differences (p less than 0.01) were observed for the distances of the hyoid bone to the maxilla and the mandible. The distances of the hyoid bone with the anterior cranial base, the vertebral column, and the anterior pharyngeal wall, and the measurements representing pharyngeal depth exhibited no significant changes (p greater than 0.05). Moderate correlations were seen between (1) the depth of the pharynx at the fourth cervical vertebra and the hyosymphyseal distance (r = 0.34) and the distance between the point of the projection of the hyoid bone to the mandibular line with its posterior border (r = -0.34), and (2) the depth of the pharynx at the second cervical vertebra and the distance of the hyoid bone with the anterior pharyngeal wall at the level of the fourth cervical vertebra (r = -0.33).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1991

Evaluation of masticatory function following orthognathic surgical correction of mandibular prognathism.

Masticatory function was examined in 17 patients with mandibular prognathism before and after bilateral sagittal splitting osteotomy of the mandibular rami. Masticatory efficiency was measured by means of a spectrophotometer, using adenosine triphosphate (ATP) granules, the biting force and occlusal contact area. Masticatory functions showed a tendency to gradual improvement postoperatively. Concerning masticatory efficiency, mean values of absorbance of ATP granules in patients with mandibular prognathism were inferior to those of subjects who possess a normal occlusion, even 12 months after operation.

Bite Force↗
PubMed1989

Changes in head posture and nasopharyngeal airway following surgical correction of mandibular prognathism.

It was the aim of the present study to cast light on the role of the mandible in relation to head posture and airway space by evaluating patients before and after surgical correction of mandibular prognathism. The material comprised standardized profile cephalograms of 52 patients with mandibular prognathism. All patients had received orthodontic adjustments prior to mandibular osteotomy. Mean age of the patients was 24.3 years, and 12 males and 40 females participated in the study. The first profile radiograph of each patient was obtained the day before surgery in the natural head (mirror) position. All patients underwent mandibular surgery with a bilateral vertical ramus osteotomy. Approximately one year after surgery, the cephalometric investigation was repeated. Head posture was evaluated by the craniocervical angulation (NSL/CVT and NSL/OPT) and airway space as nasopharyngeal airway size (ad1 and ad2). Changes in posture and airway (ex.2-ex.1) were evaluated by paired t-tests. The results showed a mean increase in head posture of 2.7 degrees (p less than 0.001) and a mean reduction in airway space of 2.3 mm (p less than 0.001).

Adolescent↗
PubMed1992

Number and intensity of occlusal contacts following surgical correction of mandibular prognathism.

The aim of the present investigation was to study the changes in the number and intensity of occlusal tooth contacts in the intercuspal position following surgical correction of mandibular prognathism. The study sample consisted of 33 adults with mandibular prognathism whose management included bilateral vertical ramus set-back osteotomy and combined orthodontic treatment. Measurement of the number and intensity of occlusal tooth contacts was performed by means of the photocclusion technique. Recordings of the number and intensity of occlusal contacts were made 1 day before operation and 6 months post-surgery. Testing of the differences of the means for both the number of occlusal contacts and their intensity between the two phases was achieved by means of a paired t-test. The results of the study showed that the combined orthodontic and surgical treatment produced a significant increase (P less than 0.001) in the number and intensity of occlusal contacts (4.54 and 160 kg mm-2 respectively). However, whether this increase in occlusal contacts resulted in an overall improvement in craniomandibular functional status cannot be answered by the present study.

Adolescent↗