Prognathism

Although chincups are the preferred treatment for growing children with mandibular prognathism, the mechanism by which chincups improve this condition remains unclear. The aim of this study was to use geometric morphometrics to evaluate changes in the shape of the mandible of prognathic children treated with a chincup.Geometric morphometrics were used to evaluate the short-term mandibular shape changes in 50 prognathic children treated with chincups compared with 40 untreated matched controls. Twenty-one 2-dimensional mandibular landmarks from cephalograms taken before and after 36 months of treatment or observation were analyzed by Procrustes superimposition and thin plate spline.Permutation tests of the treated patients showed highly significant differences in the mandibular shapes before and after treatment, and compared with the control group after the observation period. The thin plate spline grid deformations indicated more rectangular mandibular configuration, forward condyle orientation, condyle neck compression, gonial area compression, and symphysis narrowing.Early chincup treatment widely modifies the mandibular shape of prognathic children to improve Class III malocclusion.

The skeletal Class III malocclusion may be characterised by mandibular prognathism, maxillary deficiency or both. To describe the early treatment of a skeletal Class Ill patient. This case report presents a 10 year-old boy with a Class III malocclusion comprising a combination of maxillary deficiency and mandibular prognathism. Two treatment plans were considered. The first was to correct maxillary deficiency at an early age, while the second aimed to postpone treatment until after skeletal growth completion and then offer bimaxillary surgery. The case was treated early and a tongue appliance was used for maxillary protraction. The post-treatment SNA angle showed a 5 degree increase and a positive overbite and overjet were achieved after 23 months of active treatment. However, mandibular prognathism was still evident. Both treatment options have advantages and disadvantages which require informed clinical consideration.

The purpose of this study was to evaluate the changes in vertical and sagittal maxillomandibular relationship of the patients who had been wearing dentures for an extensive period. Fifteen edentulous patients (seven men and eight women; mean age 63.5 years) who had worn dentures for six to 16 years (mean 10 years) were selected for this study. New prostheses were fabricated by conventional methods, and the patients were evaluated cephalometrically before and after the new prosthesis. The results were compared by Wilcoxon signed rank test (P < .05). Results indicated that a prognathic mandible and a pseudo Class III relationship with a reduced occlusal vertical dimension became a normal Class I maxillomandibular relation when the new prosthesis was inserted. A better facial profile was achieved.

When the Mini Nutritional Assessment (MNA) was developed, the authors did not specifically focus on the nursing home setting. Due to a number of particularities of nursing home residents, such as cognitive and linguistic disabilities, a number of uncertainties with regard to its application await clarification. The aim of this study was to compare the results of two different modes of MNA application in nursing homes: resident interviews versus assessment by nursing staff. The MNA was applied to 200 residents of two municipal nursing homes in Nuremberg, Germany. First one-on-one interviews of the residents were conducted by two researchers from our group. Next, the MNA was applied by the attending nursing staff who was blinded to the results of the first MNA. To evaluate the prognostic properties of the two different approaches, data on mortality of the screened residents were collected during a six-month follow-up period. Among 200 residents (f 147 m 53, f 86.5 +/- 7.4 y. m 83.0 +/...

Setback of the mandible to correct mandibular prognathism is a well-known procedure. The 2 most frequently used techniques are the intraoral vertical ramus osteotomy (IVRO) and the sagittal split ramus osteotomy (SSRO). Although SSRO has been performed for many years, few data exist concerning long-term skeletal stability, and different hypotheses have been suggested to explain potential relapse. The literature published between 1985 and the present concerning this procedure was reviewed, and the authors analyze and discuss skeletal stability and factors contributing to relapse.

The purpose of this study was to describe the craniofacial growth changes of subjects with Class II malocclusion associated with maxillary skeletal protrusion at the circumpubertal growth period. The records of 25 untreated subjects with normal Class I occlusion and 25 untreated Class II subjects (14 boys and 11 girls in each group) were selected from the longitudinal records of the University of Michigan Growth Study. All Class II subjects had maxillary protrusion. Measurements were made on lateral and posteroanterior cephalograms and on dental casts at 2 times. The first observation (T1) was during the prepubertal growth phase (vertebral stages CS1 to CS3). The second observation (T2) was during the postpubertal phase of growth (vertebral stages CS4 to CS6). The following comparisons were made: Class I vs Class II at T1, Class I vs Class II at T2, and growth changes in Class I vs Class II. No dentofacial feature studied showed any statistically significant difference when comparin...

The purpose of this study was to determine the facial profile preferences in a sample of 1,189 Asian teenagers (aged 15.3 +/- 3.2 years). Five facial profile types were computer-generated by trained personnel (orthodontists and oral maxillofacial surgeons) to represent distinct facial types. Subjects were asked to rank the profiles in descending order of attractiveness. The ranking was as follows: orthognathic profile, bimaxillary retrusive profile, bimaxillary protrusive profile, mandibular retrognathic profile, and mandibular prognathic profile. The differences in rank scores between all the profile types were statistically significant (p < 0.05). Assessment of profile types among lay personnel could provide clinicians an indication into the relative attractiveness among profile types and health care workers in treatment prioritization among dysmorphic facial types.

The purpose of this study was to assess the transverse displacement and angulation of the proximal segment after a bilateral intraoral vertico-sagittal ramus osteotomy (IVSRO) and its relation with mandibular setback. Sixty patients were recruited into this study and underwent a mandibular setback with bilateral IVSRO with wire fixation. Posteroanterior and lateral cephalometric radiographs were obtained 1 month before and 1 month after surgery. The transverse displacement and angulation of the proximal segments after surgery were measured on posteroanterior radiographs, via the best-fit method. The correlation of the amount of mandibular setback with the amount of transverse displacement and angulation of proximal segment was also assessed. A statistically significant increase was seen in intergonial width (P < .001), and inter-ramus width (P < .001) with a mean of 2.25 mm (SD, 0.82) and 4.45 mm (SD, 1.18), respectively. Both the right and left ramus angles showed an increased angle on average: mean, 1.70° (SD, 0.91) and 1.43° (SD, 0.66), respectively. There was a statistically significant increase in both angles 1 month after surgery (P < .001). There was a statistically significant relation between the amount of mandibular body setback measured at B point and increase in intergonial width (P = .012, r = 0.45), inter-ramus width (P = .018, r = 0.42), left ramus angle (P = .007, r = 0.48), and right ramus angle (P = .008, r = 0.47). This study suggested that IVSRO leads to an increase in intergonial width and inter-ramus width, as well as the outward angulation of the condylar fragment. In addition, there was a significant correlation between the amount of setback and intergonial width, inter-ramus width, and medial ramus angles.

Patients whose facial esthetics are not severely compromised but who need surgical intervention for the correction of a dentoskeletal problem can be treated by repositioning of the whole mandibular alveolar segment in the direction needed to allow for such correction. The challenge to achieve efficient and relatively stable results with the use of combined orthodontic and surgical methods has been met by the use of various surgical techniques. The lower total alveolar osteotomy is another viable surgical technique that could be considered when treatment is being planned in an orthognathic surgical case. Its indications, contraindications, advantages, and disadvantages are described, and cases are reported to exemplify problems that can be corrected with this approach.

Mandibular prognathism is often corrected by surgical orthodontics. Correction of the sagittal facial profile has received wide attention. However, vertical changes remained undefined and thus, were investigated. Subjects included 18 patients with mandibular prognathism who had surgical correction (S group, mean age: 20.1 +/- 3.2 years) and 18 patients with Class I malocclusion (C group, mean age: 21.2 +/- 3.6 years). Cephalograms were taken at the initial visit (T1) for both the groups and one year after surgery (T2) for the S group and analyzed by standard protocols. The vertical differences between the S and C groups at T1 and within the S group at T1 and T2 were compared. Additionally, the C group at T1 and the S group at T2 were compared. Comparison between groups at T1 revealed no difference in the anterior and posterior upper facial heights (58 mm and 50 mm, respectively). However, the S group exhibited a longer anterior lower facial height and a shorter posterior lower facia...