Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “PROGNATHISM”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 73 records · Page 4Linked to original sources
PubMed1980

Obwegeser II method for correction of mandibular prognathism. Case reports.

In case of severe mandibular prognathism with open bite requiring more than 15 mm of mandibular posterior repositioning, it is said that the sagittal splitting methods (Obwegeser I method (1955, 1957) and Obwegeser-Dal Pont (1958) method) are not indicated. In our two cases manifesting severe mandibular prognathism with open bite we performed the Obwegeser II (1964) method. In one of these case we performed partial tongue resection to prevent postoperative relapse. The desired results with regards to facial appearance and occlusion were achieved in both cases.

Adolescent↗
PubMed2006

Treatment of mandibular prognathism.

Mandibular prognathism (MP) or skeletal Class III malocclusion with a prognathic mandible is one of the most severe maxillofacial deformities. Facial growth modification can be an effective method of resolving skeletal Class III jaw discrepancies in growing children with dentofacial orthopedic appliances including the chincup, face mask, maxillary protraction combined with chincup traction and the Fränkel functional regulator III appliance. Orthognathic surgery in conjunction with orthodontic treatment is required for the correction of adult MP. The two most commonly applied surgical procedures to correct MP are sagittal split ramus osteotomy (SSRO) and intraoral vertical ramus osteotomy. Both procedures are suitable for patients in whom a desirable occlusal relationship can be obtained with a setback of the mandible, and each has its own advantages and disadvantages. In bilateral SSRO, the intentional ostectomy of the posterior part of the distal segment can offer long-term positioned stability. This may be attributable to reduction of tension in the pterygomasseteric sling that applies force in the posterior mandible. While various environmental factors have been found to contribute to the development of MP, heredity plays a substantial role. The relative contributions of genetic and environmental components in the etiology of MP are unclear. The recent identification of the genetic susceptibilities to MP constitutes the first step toward understanding the molecular pathogenesis of MP. Further studies in molecular biology are needed to identify the gene-environment interactions associated with the phenotypic diversity of MP and the heterogenic developmental mechanisms thought to be responsible for them.

Humans↗
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↗
PubMed1993

Craniofacial morphology of adolescent mandibular prognathism.

Morphological features of the craniofacial complex during orthopedic chin cup therapy were investigated in growing patients with mandibular prognathism. Lateral cephalograms of 30 subjects (15 boys and 15 girls, mean age: 9.04 +/- 1.29 years), taken at four different stages during treatment, were analyzed for 14 measurements. These measured values were standardized by use of Japanese controls and then evaluated to investigate longitudinal changes in the craniofacial morphology at the four different stages. Further, factor analysis was used to compare factors describing the craniofacial morphology for the initial and final stages. Dimensional changes of the mandible were not easily produced even if orthopedic treatment was conducted, whereas the maxilla exhibited a tendency to approach the normal range of the controls. Positional changes of the complex, the backward and downward repositioning of the mandible in particular, played an important role in altering a profile from prognathic before treatment to orthognathic at the end of treatment. Craniofacial morphology was similar pretreatment and posttreatment, although the orthognathic factor became more prominent when associated with positional changes of the mandible at the end of treatment.

Adolescent↗
PubMed2004

Surgical orthodontic correction of acromegaly with mandibular prognathism.

A male (30 years five months) who complained of mandibular prominence and masticatory dysfunction was diagnosed as a mandibular prognathic with acromegaly after cephalometric and endocrine examinations. The level of growth hormone (GH) subsequent to a transsphenoidal hypophysectomy had been controlled by medicines for about five years. Surgical orthodontic correction improved his occlusion and profile, but magnetic resonance imaging detected a recurrent adenoma in the cranial base during the retention period. The recurrence resulted in slight prognathic changes of the patient with a high level of GH. This is a case report of the treatment of an acromegalic patient discussing growth considerations that could influence the orthodontic treatment plan and long-term stability.

Acromegaly↗
PubMed2000

Evaluation of skeletal stability following surgical correction of mandibular prognathism.

This retrospective study was designed to assess skeletal stability after the correction of mandibular prognathism by sagittal split osteotomy (SSO) and intraoral vertical subsigmoid osteotomy (VSO). We used lateral cephalographs of 31 patients taken before, immediately after, and at least one year after the operation. We recorded euclidean distance matrix analysis, linear and angular measurements, and x and y co-ordinates of cephalometric landmarks for each cephalograph. There were no significant differences in extent of the mandibular retrognathia or magnitude of change between the two groups. The main significant changes in both groups were reduction of the total mandibular length, and posterior shifting in the mandible. One year after the operation the main change was the mean forward relapse of 2.5 mm in the SSO group and the mean posterior relapse of 0.5 mm in the VSO group. The difference in skeletal stability between the groups was significant (P< 0.05), and we conclude that VSO is the more effective technique for correcting mandibular prognathism.

Adolescent↗
PubMed2002

Treatment of severe mandibular prognathism in combination with maxillary hypoplasia: case report.

We performed a Le Fort I osteotomy and sagittal split ramus osteotomy (Obwegeser-Dal Pont) combined with mandibular anterior segmental osteotomy without tooth extraction for a patient with severe mandibular prognathism accompanied by a hypoplastic maxilla, anterior open bite and normal anterior mandibular vertical dimension. The results of facial appearance and occlusion were excellent. This combined surgical method appears to be satisfactory for treating severe mandibular prognathism with hypoplastic maxilla.

Adolescent↗
PubMed2004

Validity of measurements for cycle-by-cycle variability of jaw movements: variability of chewing cycles in cases of prognathism.

Objective assessments of masticatory jaw movements for patients with a high degree of occlusal abnormalities are critical to elucidate the relationship between occlusal function and morphology. This study aimed to test the reliability and validity of measuring specific cycle-by-cycle variability of chewing jaw movements of patients with mandibular prognathism. The lower incisor-point movements were monitored using a 3D tracking device. Analyses consist of evaluations for the planarity of each cycle, cycle-by-cycle variances in orientations of the best-fit planes and instantaneous curvature of the trajectories. These spatio-temporal variabilities of chewing cycles for 12 adult females with good occlusion were compared with those for 12 female adult patients with mandibular prognathism. Five of the control subjects performed chewing on two separate occasions. Measurement outcomes were repeatable within each subject. For both groups, each single chewing cycle was characterized as reasonably planar. Orientations of the best-fit planes and curvatures of the trajectories during closing were more variable for patients than those for the control subjects. These findings suggest certain effectiveness of the present measurements of orientations of the best-fit planes and movement curvatures for scaling the variable nature of patients' masticatory jaw movements.

Adult↗
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↗
PubMed2006

Morphological differences in the temporomandibular joints in asymmetrical prognathism patients.

OBJECTIVE: To investigate the morphology of the temporomandibular joints (TMJ) in skeletal asymmetry with prognathism. DESIGN: Three-group observational clinical study. SETTING AND SAMPLE POPULATION: University setting. Thirty-five patients undergoing orthognathic surgery without signs and symptoms of TMJ disorder were assigned to three groups (right deviation, n = 11; left deviation, n = 14; and non-deviation; n = 10) based on anteroposterior cephalometric analysis. OUTCOME MEASURE: Positional and morphological differences of the TMJs were evaluated using a total of 70 bilateral sagittal TMJ magnetic resonance images. RESULTS: In both the right and left deviation groups, the TMJ on the deviated side showed a significantly steeper eminence than that on the non-deviated side (p < 0.05). The anterior joint space was narrower on the deviated side than on the non-deviated side whereas the posterior joint space did not differ markedly, indicating an anterior position of the condyle in the glenoid fossa of the TMJ on the deviated side. Disk displacement comparisons revealed no significant differences between left and right sides in the symmetry or asymmetry group. CONCLUSION: Asymmetrical prognathism patients exhibit significant morphological differences between the right and left TMJs concerning the slope of the articular eminence, which correspond to facial asymmetry.

Adolescent↗
PubMed1993

On the genetics of mandibular prognathism: analysis of large European noble families.

Mandibular prognathism is assumed to be a polygenic trait in the vast majority of cases. In a few families, this phenotype and perhaps a syndrome with a broader spectrum of facial anomalies seems to be determined by a single dominant gene of very low frequency (McKusick No *176700). The phenotype is known to have occurred independently in several European noble families. We constructed a pedigree comprising 13 of these families with 409 members in 23 generations in which mandibular prognathism has been segregating. Obviously, the presumed dominant gene is not fully penetrant in the heterozygous state. Pedigree analysis using the Elston-Stewart algorithm yields a maximum likelihood estimate (MLE) of p = 0.955 (SE 0.038) of the penetrance parameter.

Europe↗
PubMed1988

Natural head position, posture, and prognathism: the Chapman Prize Essay, 1986.

Natural head position and natural head posture are terms which have been used synonymously to describe the spatial relationships of the head with reference to the true vertical, the cervical column, or both. This is confusing, and it would seem logical to ascribe one term to one reference and consider the phenomena separately. For the purposes of this prospective cephalometric survey, natural head position will describe the relationship of the head to the true vertical, while natural head posture will describe the relationship of the head to the cervical column. In order to investigate these two relationships of the head, five groups were formed, three representing horizontal discrepancies selected on ANB differences (class I, II and III dental base relationships) and two representing vertical discrepancies selected on Bjork's posterior angles ('high angle' and 'low angle' groups). Despite the marked differences in 'skeletal' pattern shown between the five groups, the values obtained for the saddle angles (N-S-Ar) showed no significant difference. However, the natural head positions and natural head postures were significantly different (P less than 0.01). Natural head position affected cranial base orientation and this alone produced class II or III effects. Natural head position was also associated with maxillary prognathism whilst natural head posture appeared more closely related to mandibular prognathism. These phenomena may help to explain an apparent class II or III tendency in cases where the saddle angle is normal.

Adolescent↗
PubMed2006

[Positional changes of the lower and upper anterior teeth after surgical correction of mandibular prognathism].

BACKGROUND/AIM: To establish the influence of surgical corrections of mandibular prognathism upon the position of the lower and upper anterior teeth (incisors). METHODS: The changes in position of the lower and upper anterior teeth (incisors) after the surgical correction of mandibular prognathism were analyzed by means of x-ray craniometry in 183 patients (female: n = 110, male: n = 73) in which the correction had been made in accordance with the principles of sagital osteotomy of the mandibular ramus. There were 4 angular and 2 linear parameters determined in the pre- and postoperative tele-x-ray-pictures. The changes of these parameters were tested by means of the parametric statistic tests. RESULTS: The performed surgical procedures did not cause statistically significant changes in the angular parameters. The changes of both linear parameters were thought highly statistically significant. CONCLUSION: Under the influence of the performed surgical procedures no changes were found in the position of anterior teeth (incisors) in relation to SN and the mandibular plane. They were actually moved along with the medium fragment of the lower jaw and that fragment was moved linearly backwards along the occlusal plane with a practically insignificant rotation in the cranial direction.

Adult↗
PubMed1987

Surgical correction of mandibular prognathism in Norway, 1975-1984. A national survey.

The estimated need for surgical correction of mandibular prognathism in Norway is 500 patients each year. A questionnaire sent to the maxillofacial surgical units performing orthognathic surgery in Norway showed that in the decade from 1975 to 1985 altogether 1169 patients underwent surgical correction of mandibular prognathism; that is, only 117 patients were treated yearly [corrected]. Extraoral vertical subcondylar osteotomy of the mandibular ramus was the preferred surgical technique, performed on 57% of the patients. Intraoral vertical subcondylar osteotomy of the ramus increased in use and thus seems to be taking over for the extraoral technique. Sagittal split osteotomy was used on 25% of the patients. The different units showed great variation in their preference for the different surgical techniques. Preoperative orthodontics was widely used, on a mean of 77% of the patients. The average hospital stay was 8.5 days, somewhat longer than reported from other countries; however, geographical conditions should be taken into consideration.

Adolescent↗
PubMed1987

The surgical technique of vertical subcondylar osteotomy for correction of mandibular prognathism. A 10-year survey.

In the period 1975-1985 extraoral vertical, subcondylar osteotomies of the mandibular ramus (EVSO) were performed in 203 patients with mandibular prognathism at Haukeland University Hospital, Bergen. Refinements of this surgical technique are described. Clinical and surgical observations were analyzed as to preoperative orthodontic treatment, operation time, pre-/post-operative complications, and hospital stay. The findings confirm that the EVSO procedure is a safe technique, with minimal discomfort and morbidity for the patients. Even though intraoral procedures are the trend for surgical correction of mandibular prognathism at present, there are substantial indications for the use of EVSO.

Adolescent↗
PubMed1996

[Condylar movement in patient with skeletal mandibular prognathism during maximum opening and closing movement before and after surgery].

Condylar movement of patients with mandibular prognathism who received sagittal splitting ramus osteotomy (SSRO) was investigated using computer aided diagnostic axiography (CADIAX). Linear and angular parameters were used to evaluate the maximum opening and closing paths of the condyle projected on the sagittal plane. The motion paths of six subjects with mandibular prognathism (MP group) were examined immediately before surgery and during the retention period. The results were compared with the recording from six normal subjects (control group). The results were as follows: (1) The average change in the maximum translating distance of the condyle in the retention period was 99.4 +/- 14.5% of the presurgical value on right side and 97.8 +/- 20.8% on the left side. The difference was not significant. (2) The shape of the opening translating curve of the MP group was flatter than that of the control group, however, no significant differences were found between the pre- and postsurgical curves of the MP group. (3) The coordination between the maximum opening and closing paths of the control group was fairly stable and smooth. However, although some improvement was observed, the paths of the MP group were unstable even after surgical treatment and large individual variations were observed.

Adult↗