Study of condylar positional changes after sagittal split osteotomy for mandibular advancement: A prospective cohort study.

PURPOSE: To analyse the possible morphologic and positional changes of the mandibular condyles after orthognathic surgery. MATERIAL AND METHODS: A prospective cohort study was performed. Patients with mandibular retrognathism were surgically treated to advance the mandible. The study group included seventeen patients (34 condyles) treated with sagittal split osteotomies alone (4 patients) or in combination with maxillary osteotomies (13 patients). Only condyles located on the mandibular side that advance during surgery were studied, therefore only 25 condyles entered this prospective study. Beside it, a group of 6 patients undergoing maxillary surgery as only procedure, maxillary group, was also studied to determinate the influence of maxillary surgery on condylar displacement. Computed tomographies and lateral cephalometric radiographs were performed two weeks before surgery and one year after the surgical procedures. Different variables which analyse the position and morphology of the mandible were studied. The data obtained were analysed statistically by computing R2 values. RESULTS: In the maxillary group they were small displacements in magnitude and not significant. In the study group, 8 condyles showed morphological changes with alteration on reference points. In the remainder 17 condyles different displacements were noted after surgery. Several of these positional changes were predictable and did not affect postoperative mandibular stability. CONCLUSIONS: condylar displacements that occur after sagittal split osteotomies for mandibular advancement show significant correlation with the degree of mandibular advancement and can be defined by mathematical formulae. Maxillary osteotomies do not seem to influence condylar position when bimaxillary procedures take place.

Differences in attractiveness comparing female profile modifications of Class II Division 1 malocclusion.

INTRODUCTION: Our objective was to study the perceptions of laypeople for digital alterations and the amount of nasolabial angle increase that is tolerable and how much chin-neck length increase is needed to achieve a desirable profile in Class II Division 1 women with mandibular retrognathia. METHODS: The profile image of a white woman with a Class II Division 1 mandibular rethrognatic profile was digitally modified to create 6 images: 3 with stepwise increased nasolabial angles of 113°, 121°, and 129°, and 3 with stepwise increased chin-neck distances of 51, 54, and 57 mm. These images were assessed and ranked by 155 white laypeople. RESULTS: The baseline profile was judged significantly as the least attractive. A nasolabial angle of 129° was judged as unattractive as the baseline profile. Profiles with a chin-neck length of 54 and 57 mm were equally judged as most attractive. CONCLUSIONS: The untreated (baseline) profile was found to be least esthetic, as well as the profile with the largest nasolabial angle. Nasolabial angle increases up to 121° seem to be acceptable. Profiles simulating a chin-neck length increase as produced by surgery seem to be most favored.

[Maxillo-facial surgery in skeletal Class II: repercussions on the temporo-mandibular joints]. / La chirurgie des cas de classe II et ses répercussions sur les articulations temporo-mandibulaires.

These interventions usually aimed at the correction of the skeletal discrepancy by mandibular retrognatism with an advancement of the distal portion of the mandible after mandibular osteotomy. The position of the condyle is determined during the osteosynthesis with miniplates. Condyles are set back in relation with the supine position of the patient and the weakness of his (her) curarized muscle. All studies show that surgery of mandibular advancement causes a lateral, torque and backward movement of the condyles, all harmful to the condyles. Factors that predispose to condylar resorption are "the patient": a woman, young (between 15 and 40), high mandibular angle, with a history of temporo-mandibular disorders and surgical overload applied to the condyles. What are the possible solutions to avoid failures? Patient preparation before surgery and surgery simulation with an articulator, condylar position control during surgery, working with surgeons to achieve a condylar portion stabilization system (with the CAD), quickly set up a mobilization of the mandible by physiotherapy.

Effect of Secondary Alveolar Bone Grafting on the Maxillary Growth: Unilateral Versus Bilateral Cleft Lip and Palate Patients.

The purpose of this study was to investigate the effect of secondary alveolar bone grafting (SABG) on the maxillary growth in patients with unilateral (UCLP) and bilateral cleft lip and palate (BCLP). The samples consisted of 40 Korean boy cleft patients who had the similar initial skeletal characteristics and were treated with the identical treatment protocol. They were divided into UCLP group (N = 25; mean SABG age, 9.9 years; mean follow-up duration, 42.3 months) and BCLP group (N = 15; mean SABG age, 10.2 years; mean follow-up duration, 40.6 months). In the lateral cephalograms taken 1 month before (T1) and at least 2 years after SABG (T2), cephalometric variables were measured. At T1 stage, the 2 groups did not exhibit significant differences in the cephalometric variables except posterior maxillary height (P-HRP) (P < 0.05). At T2 stage, both groups exhibited the reduced sagittal growth (UCLP, ANB, P < 0.001; AB to facial plane angle (AB-FPA), P < 0.01; BCLP, A to N perpendicular, P < 0.05; ANB and AB-FPA, P < 0.001) and the undisturbed vertical growth (A-HRP and P-HRP, all P < 0.001) of the maxilla. During T1 to T2, BCLP group experienced more aggravation of Class III skeletal pattern than UCLP group (ΔAB-FPA, P < 0.05). There, however, were no differences in the amounts of changes in the maxillary vertical position and mandibular plane angulation between the 2 groups. Two-stage SABG procedure subgroup in patients with BCLP demonstrated a more retrusive maxilla compared with 1-stage SABG procedure subgroup (ΔSNA, P < 0.05). Patients with BCLP, especially who underwent 2-stage SABG procedure, might have a possibility of poor sagittal growth of the maxilla compared with patients having UCLP.

Characteristics of Maxillary Morphology in Unilateral Cleft Lip and Palate Patients Compared to Normal Subjects and Skeletal Class III Patients.

This study is to investigate the anatomical features of maxillae in unilateral cleft lip and palate (UCLP) patients with maxillary retrusion. Additionally, the dissimilarities of retruded maxillae between the UCLP patients and the skeletal class III patients were compared. Craniofacial measurements were carried out among 32 UCLP adult patients with maxillary retrusion (GC), 24 adult patients in class III (SNA < 80°, ANB < 0°) patients (GIII), and 32 normal controls (GN). The authors measured the width and length of the maxillae, as well as their relative positions to the coronal plane passing through basion. The independent sample group t test was performed, and P < 0.05 was regarded as statistically significant. In the GC group, the anterior and posterior maxillary length (A1-P3M⊥CP and P3M-P6M⊥CP) and overall maxillary length (A1-P6M⊥CP) at the dental level, the interdental widths of the maxillae, the maxillary volume (GM), and the volume consisting of maxilla and maxillary sinus (GT) significantly reduced compared with the GN group (P < 0.05). The distances from the points on the maxillae to the coronal plane (A1⊥CP, P3M⊥CP, and P6M⊥CP) in the GC and GIII groups were smaller than those in the GN group (P < 0.05). In summary, for the UCLP patients, the decreased prominence of maxillary complex could be mainly caused by the shortened maxillary length; meanwhile, posterior position of the maxillary body may have some influence on the maxillary protrusion. While for the class III patients, maxillary retrusion was resulted from malposition and malmorphology on an equal basis.

Bone mineral density and mandibular advancement as contributing factors for postoperative relapse after orthognathic surgery in patients with preoperative idiopathic condylar resorption: a prospective study with preliminary 1-year follow-up.

OBJECTIVES: The aim of this study was to analyze contributing factors for postoperative relapse after orthognathic surgery in patients with preoperative idiopathic condylar resorption (ICR). STUDY DESIGN: Sixteen female patients with mandibular retrognathism and ICR were included in this prospective study. For patient factors, serum 17 ß-estradiol (E2), bone mineral density, and the preoperative posterior condylar inclination were evaluated. Bone mineral density was measured using dual-energy x-ray absorptiometry (DEXA) bone densitometry and expressed by T-score. Surgical changes and postoperative relapse were measured with cephalometric analysis. The correlation between postoperative relapse and measured parameters was statistically analyzed. RESULTS: The lowest T-score exhibited a significant correlation with postoperative clockwise rotation and posterior relapse tendency of the mandible (P < .05). The amount of mandibular advancement showed a significant correlation with the postoperative clockwise rotation of the mandible (P < .05). CONCLUSIONS: The postoperative relapse tendency in patients with preoperative ICR is significantly related to the lowest T-score and the amount of mandibular advancement.

Craniofacial cephalometric morphology in 8-year-old children with operated sagittal synostosis.

OBJECTIVES: To evaluate cephalometrically craniofacial morphology in children with operated sagittal synostosis and to compare the findings with age- and sex-matched controls. SETTING AND SAMPLE POPULATION: Forty-two children (37 boys) with operated primary sagittal synostosis were compared retrospectively with age- and sex-matched controls from lateral cephalograms taken at a mean age of 8.1 (range 7.0-8.9) years. MATERIAL AND METHODS: The operations had been performed between the ages of 2 months and 6.3 years at three Finnish hospitals. The surgical methods included strip craniectomy, pi-plasty and cranial vault expansion. A paired Student's t-test and Pearson's correlation analysis were used in the statistical analyses. RESULTS: Children with operated sagittal synostosis had wide cranial base angles and their mandibles were retrognathic with labially inclined lower incisors relative to the controls. Age at craniosynostosis operation did not correlate with the cranial base angle. CONCLUSION: This study suggests that children with operated sagittal synostosis have minor distinctive morphological features in the cranial base and mandible. Orthodontic evaluation of craniofacial growth is recommended.

Assessment of 2D:4D in subjects with anteroposterior mandibular dysplasia.

OBJECTIVES: To compare 2D:4D ratio which is determined by testosterone levels with patients having orthognathic, retrognathic and prognathic mandibles. MATERIALS AND METHODS: The study was performed at Chennai, on 320 subjects of which, 60 subjects (32 males and 28 females) had retrognathic mandible; 55 subjects (25 males and 30 females) had prognathic mandible and 205 subjects (98 males and 107 females) had normal mandible. All the subjects had a normal maxilla and were in the age group of 18 to 25 years. 2D:4D ratio was determined using the photocopies of the ventral surface of right hand made with vernier calipers of 0.01 mm accuracy. Statistical analysis was undertaken using Student's t- test, ANOVA test and TukeyHSD test. RESULTS: (i) Low 2D:4D is seen in subjects with mandibular prognathism, (ii) Among females, low 2D:4D is seen only in prognathic mandible. CONCLUSION: These findings highlight the fact that testosterone plays an important role in mandibular growth. Thus 2D:4D, a least invasive and reproducible procedure can be used as an early marker for mandibular progathism, and as a diagnostic tool in correlating the mandibular growth with causal relations between hormones and craniofacial development.

3-dimensional facial simulation in orthognathic surgery: is it accurate?

PURPOSE: The purpose of this study was to measure the accuracy of 3D computer simulation of soft tissue changes after orthognathic surgery. MATERIALS AND METHODS: Consecutive patients who underwent orthognathic surgery were studied by photogrammetric facial scanning and cone-beam computed tomography before and after surgery. The photogrammetric scan was then fused to the cone-beam computed tomogram, creating a patient-specific image. The surgery was simulated in 3D form and the simulated soft tissue face was compared with the actual facial scan obtained 6 months postoperatively. Absolute millimeter differences between the simulated and actual postoperative changes in selected cephalometric skin markings were computed. RESULTS: The study was composed of 23 subjects (mean age, 31 yr; 13 women and 10 men). Eighteen different cephalometric landmarks were measured (total, 28). For 15 landmarks, the difference between actual and simulated measurements was smaller than 0.5 mm. Only 3 landmarks had a difference of 0.5 mm, and these were in the region of the labial landmarks. CONCLUSION: Based on the present study, 3-dimensional computer surgical simulation of the soft tissue of the face for routine orthognathic surgery is accurate enough for routine clinical use.

Gender differences in dentofacial characteristics of adult patients with temporomandibular disc displacement.

PURPOSE: The purpose of this study was to assess gender differences in dentofacial characteristics of adult patients according to temporomandibular joint (TMJ) disc displacement (DD) status. MATERIALS AND METHODS: The sample consisted of 293 adult patients (80 male and 213 female). Male and female patients were divided into 3 groups based on magnetic resonance images of bilateral TMJs: bilateral normal disc position (BN), bilateral DD with reduction (DDR), and bilateral DD without reduction (DDNR). Seventeen variables from lateral cephalograms were analyzed by 2-way analysis of variance to identify differences in dentofacial morphologies with respect to gender and TMJ DD status. RESULTS: Patients with TMJ DD had short ramus height, short mandibular body length, and backward positioning of the ramus and mandible. These dentofacial characteristics became more severe as TMJ DD progressed to DDNR. In addition, dentofacial characteristics associated with TMJ DD were not significantly different between men and women except for effective mandibular length (Articulare to pogonion). Effective mandibular length even tended to decrease as TMJ DD progressed, but male patients showed a larger difference in effective mandibular length between BN and DDR than female patients. CONCLUSIONS: This study's findings suggest that dentofacial morphology is strongly associated with TMJ DD status and that skeletal Class II hyperdivergent pattern with a short ramus and mandible may be a potential indicator of TMJ DD regardless of gender.

Craniofacial morphology in unilateral hemifacial microsomia.

Hemifacial microsomia (HFM) is a complex three-dimensional congenital condition that is characterized by mandibular hypoplasia and unilateral or bilateral microtia; although, other facial structures may be affected. Little is known about craniofacial growth and morphology in patients with HFM; therefore, we examined 75 HFM patients by means of a cephalometric analysis in a longitudinal study on serial lateral cephalograms. We hypothesized that the growth of several facial structures on both sides of HFM patients would be different compared to Dutch controls. We determined patients with HFM had more retruded mandibles and maxillae and a more vertical morphology compared to the reference population. In addition, there was a more retruded and vertical pattern on the affected side compared to the unaffected side and in patients with a severe condition compared to those with a mild condition. 'Mild' HFM patients were more similar to the Dutch reference population than the 'severe' HFM patients. Individual HFM growth curves showed very high inter-variability, further strengthening the need for individualized treatment plans that consider all three dimensions and the severity of the condition.

Orofacial findings and dental management of Williams-Beuren syndrome.

Williams-Beuren syndrome is a rare congenital disorder involving the cardiovascular system, mental retardation, distinctive facial features, and tooth anomalies. The aim of the present report is to show a 10-year-old girl with Williams-Beuren syndrome, her general and orofacial clinical characteristics and the dental management.

Auriculo-condylar syndrome.

The auriculo-condylar syndrome is caused by abnormalities of the first and second pharyngeal arches during embryonic development. Its inheritance follows the autosomal dominant pattern. Both familial and individual cases are reported in the literature. The syndrome is characterized by wide phenotypic variation, with affected individuals expressing clinical signs of variable severity due to variable expressivity of the responsible genes. Clinical signs of the syndrome include auricular malformation, hypoplasia of the mandibular condyles, anomalies of the temporomandibular joints, malocclusion, and, in more severe cases, cleft palate, glossoptosis, facial asymmetry, and respiratory problems. The aim of this article is to report a case of a female patient with signs of the auriculo-condylar syndrome and to present the pedigree of her family. Clinical findings, diagnosis, treatment plan, and final treatment are analyzed.

Dental or skeletal relapse after sagittal split osteotomy advancement surgery? Long-term follow-up.

PURPOSE: To evaluate the short- and long-term stability of mandibular advancement surgery with sagittal split osteotomy (SSO), and to investigate when relapse occurs and identify variables contributing to relapse. PATIENTS AND METHODS: Thirty-six patients with Class II anomalies were included; the mean age at surgery was 33.0 years. All underwent SSO surgery and clinical and radiologic follow-up at 8 weeks, 1 year, and 13 years. Model analysis, cephalometric analysis, and clinical examinations were performed at each control. RESULTS: Mean overjet relapse from 8 weeks to 13 years was 2.3 mm (range, 0 to 7.0 mm). Between 8 weeks and 1 year, mean overjet relapse was 0.6 mm (range, -1.0 to 4.0 mm), and it was 1.7 mm (range, -1.0 to 6.0 mm) between 1 year and 13 years. Overjet relapse greater than 4 mm was found in 13.9% of the patients. Mean overjet 1 year after surgery was 2.6 mm and was significantly increased compared with 8 weeks (P = .006). Mean overjet 13 years after surgery was 4.3 mm and was significantly increased compared with 1 year (P < .001). Inferior incisor line to nasion-B-point was 29.0° at 8 weeks after surgery and 25.4° at 13 years (P = .001). Insignificant changes in the other cephalometric variables were found at follow-up. CONCLUSION: SSO advancement surgery is a relatively stable technique over time. Mean overjet relapse was found to be 2.3 mm after 13 years, following a continuous pattern over time. The cephalometric variables showed insignificant changes during follow-up, indicating that relapses are mainly of dental and not skeletal origin.

Maxillofacial characteristics affecting chin deviation between mandibular retrusion and prognathism patients.

OBJECTIVE: To examine and compare the maxillofacial characteristics affecting chin deviation three-dimensionally in facial asymmetry patients with mandibular retrusion and mandibular prognathism. MATERIALS AND METHODS: Maxillofacial computed tomography (CT) scan data were obtained from 48 orthognathic surgery patients (24 cases of mandibular retrusion and 24 cases of mandibular prognathism) with facial asymmetry. Although chin deviation was assessed on the basis of the ANS-to-menton line on frontal cephalograms, its contributing factors were evaluated on three-dimensional CT images. Maxillary height, ramus length, frontal ramal inclination, lateral ramal inclination, mandibular body length, and body height were defined on each side, and right-left differences were calculated and analyzed. RESULTS: In an assessment of chin deviation, subjects in this study showed predominantly left side deviation regardless of the group, and the degree of menton deviation did not reveal significant differences between groups. In a comparison of right-left differences in contributing factors, all values were noted to be greater in the retrusion group, except for body height, which showed no difference between chin-deviated and contralateral sides. In particular, ramus length presented a statistically significant difference between the two groups. CONCLUSION: Based on the same degree of chin deviation in mandibular prognathism and retrusion in this study, results of right-left differences in contributing factors indicate that chin deviations are expressed easily in mandibular prognathism, whereas they occur only with significant right-left differences in relevant maxillofacial structures in individuals with mandibular retrusion.

Cephalometric variables discriminate among magnetic resonance imaging-based structural characteristic groups of the temporomandibular joint.

OBJECTIVE: The aim of this study was to assess retrospectively whether, in patients with temporomandibular joint (TMJ) arthralgia, commonly used cephalometric variables of dentofacial morphology can discriminate among magnetic resonanace imaging (MRI)-based TMJ structural characteristic groups of "uni- or bilateral disc displacement without reduction (DDwoR) associated with bilateral osteoarthrosis (OA)" and "uni- or bilateral disc displacement with reduction (DDwR) without OA." STUDY DESIGN: Bilateral MRI of the TMJ was performed in 56 consecutive TMJ arthralgia patients to identify individuals with specific structural characteristic of uni- or bilateral TMJ DDwoR, DDwR, and OA. Application of the criteria resulted in a study group of 31 patients with "uni- or bilateral DDwoR with bilateral OA" and 25 with "uni- or bilateral DDwR without OA." Linear and angular cephalometric measurements were taken from lateral cephalograms to apply selected criteria of dentofacial morphology. One-way analysis of variance was used to assess differences in cephalometric variables by MRI-based TMJ group. Then, discriminant function analysis predicted TMJ group membership. RESULTS: A-B plane to facial plane angle, palatal plane to occlual plane, and interincisal angle produced a significantly discriminant function that predicted TMJ group membership (P < .001). This function correctly classified 85.7% of original grouped cases. CONCLUSIONS: Cephalometric variables may discriminate among MRI-based TMJ structural characteristic groups. Additional diagnostic information related to MRI-based classification groups was generated.

Oropharyngeal airway dimensions after treatment with functional appliances in class II retrognathic children.

Class II skeletal malocclusion and respiratory disorders owing to the obstruction of the upper airway at early growth stages have been correlated. The retro/micrognathism can be treated with functional appliances. However, the effects of an early functional orthopedic treatment on the airway dimensions have not been evaluated before the growth peak. Therefore, the objective of this study was to evaluate the changes in the airway dimensions of class II retrognathic children who received treatment with either Klammt or Bionator on a pre-pubertal stage. The sample consisted of 50 lateral cephalograms of class II retrognathic patients in a pre-puberal stage, before and after the use of a Klammt or Bionator II treatment for 1 year. The data were evaluated by Student's t-test or Mann-Whitney test, and significance was set at 5% (P < 0·05). When the measurements before and after treatment were compared, a statistically significant increase in the airway dimensions was found at the space where the adenoid tissue was located. The only airway dimensions that increased after treatment with functional appliances were the ones located at the nasopharynx. The adenoid tissue is still in the peak of growing at the ages of the subjects included in this study. However, the measurements along the nasopharynx increased when compared with the initial ones. Still, similar retrospective and prospective studies are needed at older stages.

[Möbius syndrome]. / Le syndrome de Möbius.

Möbius syndrome is a rare congenital disease characterized by facial and abducens nerve palsy. Children are unable to smile, frown, suck, grimace, blink their eyes, and to move their eyes laterally. The aim of this study was to analyze the diagnosis and treatment of this disease. Maxillofacial examination reveals: facial diplegia, retrognathism, palatine and dental malformations. Möbius syndrome is usually associated with multiple cranial nerve involvement, limb or orofacial malformation, and Poland syndrome. Although the pathogenesis of the syndrome is unclear, a number of mechanisms have been suggested including vascular and genetic hypotheses. Symptomatic treatment is used to manage this syndrome. The diagnosis of Möbius syndrome may be difficult in some patients with atypical signs of facial diplegia and other cranial nerve palsies, it requires a multidisciplinary approach.

Craniofacial morphology and adolescent facial growth in Pierre Robin sequence.

INTRODUCTION: The purpose of this research was to analyze craniofacial morphology and adolescent facial growth in subjects with Pierre Robin sequence (PRS). The research was conducted at the Center for Craniofacial Care and Research at The Hospital for Sick Children, Toronto, Ontario, Canada, and the Burlington Facial Growth Research Center, Faculty of Dentistry, University of Toronto. METHODS: Longitudinal lateral cephalometric tracings of 34 Caucasian subjects with nonsyndromic PRS were compared with those of unaffected control subjects, matched for age, sex, and ethnicity, and representing the range of occlusions in an untreated population. Cephalometric measurements were obtained before orthodontic treatment (age, 11.8 years) and after orthodontic treatment but before any surgical treatment (age, 16.6 years). Between-group differences of craniofacial measurements were analyzed with paired t-tests, and longitudinal growth differences were analyzed with analysis of variance (ANOVA) adjusted for the growth interval. RESULTS: Significant differences were noted, with the PRS group showing smaller cranial base length, shorter maxillary and mandibular lengths, increased palatal and mandibular plane inclinations, and more open mandibular flexure. Mandibular body length and height were smaller as were ramal length and width, anterior basal thickness, and chin thickness. The ramus-to-body ratio was greater. With growth, greater gains in anterior face and symphyseal height were seen, but the mandible showed less closure of its internal flexure. The maxilla and the mandible remained retrusive during adolescent growth, and the maxilla became more retrognathic. Mandibular morphologic differences persisted in spite of additionally adjusting for cranial base length in the analysis. CONCLUSIONS: Subjects with PRS had reduced cranial base and maxillary and mandibular lengths. Mandibular deficiency was most pronounced in the body. Due to bimaxillary retrognathism, the maxillomandibular dysplasia was not significant. A vertical growth pattern worsened the profile. There was no evidence of adolescent mandibular catch-up growth.

Evaluation of mandibular ramus morphology using computed tomography in patients with mandibular prognathism and retrognathia: relevance to the sagittal split ramus osteotomy.

PURPOSE: The purpose of this study was to evaluate and compare the thickness of the mandibular ramus in patients with mandibular prognathism and retrognathia, as well as to assess the distribution of cancellous bone between the external and internal cortical plates above and posterior to the lingula. PATIENTS AND METHODS: The mandibular ramus of 40 patients, of whom 20 had prognathism and 20 had retrognathia, were evaluated by use of high-resolution computed tomography scanning. RESULTS: The mean thickness of the ramus in the prognathism group was 8.17 mm, which differed significantly from the mean value of 8.88 mm in those with retrognathia (P = .014). The mean vertical distance of the point of fusion between the cortical plates above the lingula was 8.95 mm for patients with prognathism and 9.41 mm for those with retrognathia, which was not a significant difference (P = .364). The mean horizontal distance of the point of fusion between the cortical plates posterior to the lingula was 8.32 mm for patients with prognathism and 9.74 mm for those with retrognathia, which was also not a significant difference (P = .066). CONCLUSIONS: The mandibular ramus is thinner in patients with prognathism than in those with retrognathia. The distance of the point of fusion between the cortical plates above and posterior to the lingula is not influenced by the 2 types of mandibular deformity evaluated in this study. Computed tomography has proven to be a valuable tool to evaluate the morphology of the mandibular ramus.