The goniomaxillar length/goniomandibular length ratio in normal newborn infants: A clinical tool for defining chin position abnormalities.

Retrognathia (recessed chin) and prognathism (prominent chin) often present as signs of an underlying condition. Accurate clinical definitions are important. Yet their definitions were according to "clinical impression", or to seldom used X-ray criteria. We propose a statistical and anthropometric definition of retrognathia and prognathism based upon the ratio between the goniomaxillar length (distance between the gonion at the mandible angle and the subnasale and the goniomandibular length (distance between the mandible angle and the most anterior point of the bony chin). We assumed that an increase in the ratio indicates retrognathia and a decrease reflects prognathism. We conducted a prospective, observational, anthropometric study in 204 consecutive healthy term infants. Measurements took place on the second day of life, using sliding calipers. Mean ± SD of goniomandibular length (5.1 ± 0.3 cm), goniomaxillar length (5.4 ± 0.3 cm), were calculated. All measurements correlated significantly with gestational age, and with infant birthweight. The mean ± SD goniomaxillar length/goniomandibular length ratio was 1.06 ± 0.05. We defined a normal ratio as being within 2 SD of the mean, that is, between 0.96 and and 1.16. This ratio correlated with neither gestational age nor with birthweight. We conclude that the goniomaxillar length/goniomandibular length ratio can be calculated whenever retro - or prognathism is suspected. A ratio outside of the 95% confidence interval should help in making this diagnosis. An increase in this ratio beyond 2 SD above the mean (1.16) could be interpreted as retrognathia and a decrease beyond 2 SD below the mean (0.96) as prognathism.

Dentoskeletal morphology in adults with Class I, Class II Division 1, or Class II Division 2 malocclusion with increased overbite.

INTRODUCTION: The treatment options for adults with increased overbite are limited to dentoalveolar changes that camouflage the condition. Because of high relapse tendency, defining the problem area is important when creating a treatment plan. This study aimed to evaluate dentoskeletal morphology in skeletal Class I and II anomalies associated with Angle Class I, Class II Division 1 (Class II/1), and Class II Division 2 (Class II/2) malocclusions with increased overbite compared with normal occlusion. METHODS: Pretreatment cephalograms of 306 patients (131 men, 175 women; overall ages 18-45 years) were evaluated. Four groups were constructed. Three groups had increased overbite (>4.5 mm): group 1 (n = 96) skeletal Class I (ANB = 0.5°-4°), group 2 (n = 85) skeletal Class II (ANB >4.5°) with Class II/1; and group 3 (n = 79) skeletal Class II with Class II/2 malocclusion. Group 4 as a control (n = 46) skeletal Class I normal overbite. Dental and skeletal characteristics of the groups were compared by sex. For statistical evaluations, analysis of variance followed by Tukey post hoc, Mann-Whitney U, and Kruskall-Wallis tests were used. Additionally correlation coefficients between overbite and skeletal/dental parameters were calculated. RESULTS: Between sexes, with regard to skeletal parameters, the men had greater values in millimetric measurements, and the women had higher SN/GoGn values. Maxillary/mandibular molar heights and the mandibular incisor heights were higher in men. In group 1, decreased lower anterior facial height (LAFH), retrusive mandibular incisors, and increased interincisal degree were determined. The maxillary molars were intrusive, whereas the vertical position of the mandibular molars and incisors in both jaws were normal. In group 2, retrognathic mandible, increased LAFH and mandibular plane angle, extrusive maxillary/mandibular incisors, protrusive mandibular incisors, and decreased interincisal degree were found. In group 3, decreased LAFH, increased interincisal degree, and retrusive incisors in both jaws were determined. There were significant negative correlations between SN/GoGN, palatal plane, and overbite in group 2 and between ANS-SN and overbite in group 3, and positive correlation between interinsical angle and overbite in all increased overbite groups. CONCLUSIONS: Dental morphology seems to be the main factor of increased overbite. Differences between groups were related primarily to inclinations and vertical positions of the incisors, rather than molar positions.

Improvement of facial profile by nonextraction orthodontic treatment with temporary skeletal anchorage devices and visual treatment objectives.

A 15-year-old girl with a convex profile and a retrognathic chin was referred for improvement of her profile. Nonextraction orthodontic therapy with temporary skeletal anchorage devices was used to improve her facial balance in a total active treatment time of 26 months. Her occlusion and profile were significantly improved by the treatment. Posttreatment records after 12 months showed excellent results with good occlusion and facial harmony.

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.

Perception of facial esthetics by different observer groups of Class II malocclusion with mandibular retrusion.

AIM: To compare the esthetic perception of different observer groups of 14 photos of two patients with Class II, division 1 malocclusion with severe mandibular retrusion. MATERIALS AND METHODS: A sample of 441 participants, of which 191 were laypeople, was obtained through a snowball sampling method. Fourteen photos of two children with Class II, division 1 malocclusion with severe mandibular retrusion were used, before and after orthodontic treatment (OT), with advance genioplasty simulation. For the evaluation of esthetic perception, the photos were rated using a numerical scale from 0 (very unesthetic) to 10 (extremely esthetic). RESULTS: Despite a parallelism of opinions, there were statistically significant differences (P < 0.05) in the assessments made by the different observer groups. Laypeople tended to attribute higher values (statistically significant difference of P < 0.05) compared to the other observer groups, with the exception of the girl's lateral profile and smile photos before OT (P > 0.05). Although they did not agree on all the photos, the other groups expressed similar scores between them. Pretreatment photos obtained the lowest scores, and those with advance genioplasty simulation obtained the highest. CONCLUSIONS: Mandibular retrusion has a strong impact on the perception of facial attractiveness. The esthetics of the lateral profile in children with severe mandibular retrusion is improved by OT. As a rule, laypeople tend to assign higher ratings.

Relationship between matrilin-1 gene polymorphisms and mandibular retrognathism.

INTRODUCTION: Mandibular retrognathism is a type of malocclusion that refers to an abnormal posterior position of the mandible as a result of a developmental abnormality. From the literature, it is evident that the mandibular growth pattern is determined by the intramembranous ossification of the mandibular body and endochondral ossification of the condyle. Matrilin-1 is a cartilage extracellular matrix protein, and matrilin-1 gene (MATN1) polymorphisms have been found to be involved in dental malocclusions of humans. In this study, we aimed to examine the association between MATN1 polymorphisms and the risk of mandibular retrognathism, in a case-control study with a South Indian population. METHODS: Eighty-one patients with mandibular retrognathism (SNB, <78°) and 71 controls having an orthognathic mandible (SNB, 80° ± 2°) were recruited. In both the patient and control groups, subjects with an orthognathic maxilla (SNA, 82° ± 2°) were included. Three single nucleotide polymorphisms of the MATN1 gene (rs1149048, rs1149042, and rs1065755) were genotyped using polymerase chain reaction-restriction fragment length polymorphism. The statistical association analysis was performed using the chi-square test. Pair-wise linkage disequilibrium was computed, and haplotypes were compared between subjects and controls. Nonparametric tests were used to compare cephalometric measurements between groups. RESULTS: No polymorphic site deviated from Hardy-Weinberg equilibrium in the controls. The rs1149042 genotypes and alleles were found to be associated with reduced risk of mandibular retrognathism. Furthermore, rs1149042 genotypes were associated with mandibular measurements (SNB and ANB). There was no strong and consistent linkage disequilibrium linkage disequilibrium across two different single nucleotide polymorphisms and haplotypes were not associated with mandibular retrognathism. CONCLUSIONS: The results of our study suggest an association between the MATN1 gene polymorphisms and mandibular retrognathism.

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.

Thin-plate spline analysis of mandibular shape changes induced by functional appliances in Class II malocclusion : A long-term evaluation.

AIMS: The purpose of this work was to evaluate the long-term morphological mandibular changes induced by functional treatment of Class II malocclusion with mandibular retrusion. METHODS: Forty patients (20 females, 20 males) with Class II malocclusion consecutively treated with either a Bionator or an Activator followed by fixed appliances were compared with a control group of 40 subjects (19 females, 21 males) with untreated Class II malocclusion. Lateral cephalograms were available at the start of treatment (T1, mean age 9.9 years), at the end of treatment with functional appliances (T2, mean age 12.2 years), and for long-term follow-up (T3, mean age 18.3 years). Mandibular shape changes were analyzed on lateral cephalograms of the subjects in both groups via thin-plate spline (TPS) analysis. Shape differences were statistically analyzed by conducting permutation tests on Goodall F statistics. RESULTS: In the long term, both the treated and control groups exhibited significant longitudinal mandibular shape changes characterized by upward and forward dislocation of point Co associated with a vertical extension in the gonial region and backward dislocation of point B. CONCLUSION: Functional appliances induced mandible's significant posterior morphogenetic rotation over the short term. The treated and control groups demonstrated similar mandibular shape over the long term.

Analogue simulation of pharyngeal airflow response to Twin Block treatment in growing patients with Class II(1) and mandibular retrognathia.

The flow dynamics of respiratory airflow is the basic factor that influences the ventilation function of the upper airway. This research aimed to investigate the pharyngeal flow field characteristics after Twin Block (TB) treatment in growing patients with Class II(1) and mandibular retrognathia by computation fluid dynamics (CFD) simulation. Cone beam computed tomography (CBCT) scans of patients who have completed TB treatment (n = 30) and about to accept TB treatment (n = 30) were reconstructed. After CFD simulation, correlations between the pharyngeal pressure drop and morphological parameters were further analyzed. During inspiration, we found that the pressure minimum occurred in the hypopharynx, while the maximum pressure drop and velocity was located in the oropharynx. After TB treatment, the oropharynx and hypopharynx showed significant differences in airflow features, and the most obvious change was observed in the oropharynx. A significant correlation was discovered between the change amount of oropharyngeal pressure drop and volume (r = 0.694, p = 0.001), mean cross-sectional area (r = 0.859, p = 0.000), and ratio of the minimum and mean cross-sectional area (r = 0.898, p = 0.000) of the oropharynx. Our research suggested that the pharyngeal airflow characteristics response positively to mandibular advancement with the enlargement in volume, cross-sectional area and more uniform oropharyngeal area distribution.

Phenotypic characteristics of adolescents with concave and convex facial profiles - The National Health Examination Survey.

It has been suggested that facial traits are informative on the inherited susceptibility to tuberculosis and obesity, two current global health issues. Our aim was to compare the phenotypic characteristics of adolescents with dental markers for a concave (n=420), a convex (n=978), and a straight (n=3542) facial profile in a nationally representative sample of United States adolescents. The results show that adolescents with a concave facial profile, when compared to a straight facial profile, had an increased waist-to-height ratio (Δ, 1.1 [95% CI 0.5-1.7], p<0.003) and an increased acne prevalence (OR, 1.5 [95% CI 1.2-1.9], p<0.001). Adolescents with a convex facial profile, when compared to a straight facial profile, had an increased prevalence of tuberculosis (OR, 4.3 [95% CI 1.4-13.1], p<0.02), increased ectomorphy (Δ, 0.3 [95% CI 0.2-0.4], p<0.0001), increased left-handedness (OR, 1.4 [95% CI 1.1-1.7], p<0.007), increased color-blindness (OR, 1.7 [95% CI 1.3-2.3], p<0.004), and rhesus ee phenotype (OR, 1.3 [95% CI 1.1-1.5], p<0.008). Adolescents with a concave facial profile, when compared to a convex profile, had increased mesomorphy (Δ, 1.3 [95% CI 1.1-1.5], p<0.0001), increased endomorphy (Δ, 0.5 [95% CI 0.4-0.6], p<0.0001), lower ectomorphy (Δ, 0.5 [95% CI 0.4-0.6], p<0.0001), and lower vocabulary test scores (Δ, 2.3 [95% CI 0.8-3.8], p<0.008). It is concluded that population-based survey data confirm that distinct facial features are associated with distinct somatotypes and distinct disease susceptibilities.

[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.

Facial morphology in children and adolescents with juvenile idiopathic arthritis and moderate to severe temporomandibular joint involvement.

INTRODUCTION: The aims of this study were to (1) assess lateral facial morphology in children and adolescents with juvenile idiopathic arthritis and moderate to severe temporomandibular joint (TMJ) involvement, (2) compare the lateral facial morphology of these subjects with and without TMJ involvement using cephalograms and 3-dimensional (3D) facial photographs, and (3) compare and correlate the results of the 3D photographic and cephalometric analyses. METHODS: Sixty patients with juvenile idiopathic arthritis were included and grouped as follows: group 1, juvenile idiopathic arthritis patients without TMJ involvement; group 2, juvenile idiopathic arthritis patients with moderate to severe unilateral TMJ involvement; and group 3, juvenile idiopathic arthritis patients with moderate to severe bilateral TMJ involvement. Lateral cephalograms were used to assess and compare lateral facial morphologies between the groups. Lateral projections of oriented 3D photographs were superimposed on the lateral cephalograms. The results of the lateral 3D photographic analysis were correlated with those of lateral cephalometric analysis. RESULTS: Group 3 showed the most severe growth disturbances, including more retrognathic mandible and retruded chin, steep occlusal and mandibular planes, and more hyperdivergent type (P <0.01). Group 2 showed similar growth disturbances, but to a lesser extent than did group 3. Photographic variables were significantly correlated with the soft tissue and skeletal variables of cephalograms (0.5 < r < 0.9; P <0.001). CONCLUSIONS: Subjects with juvenile idiopathic arthritis and unilateral or bilateral moderate to severe TMJ involvement had significant growth disturbances. Early intervention is recommended for these patients to prevent unfavorable facial development. Furthermore, with proper orientation, 3D photographs can be used as an alternative to conventional lateral cephalograms and 2-dimensional photographs.

Antero-posterior and vertical facial type variations influence the aesthetic preference of the antero-posterior lip positions.

UNLABELLED: SummaryObjectives: The purposes of this study were to investigate whether the antero-posterior and vertical facial type variations influenced the favoured lip positions and to elucidate whether the favoured lip positions differed between orthodontists and laypersons. METHODS: An average profile was constructed from a Japanese female with Class I occlusion and a well-balanced profile, as assessed by several cephalometric analyses. Nine facial types were composed by morphing the chin antero-posteriorly and/or vertically. Thirteen morphed lip profiles were constructed by moving the lips antero-posteriorly in the nine facial types, respectively. Seventy-seven Japanese laypersons and 30 orthodontists were asked to choose the top three most-favoured lip positions for each facial type. RESULTS: The protruded lip positions were significantly favoured for all the mandibular protrusive facial types. The retruded lip positions were significantly favoured for the short facial type of the antero-posteriorly average and mandibular retrusive-short facial types. Among the mandibular protrusive facial types, the protruded lip positions were significantly favoured for the long facial type. The retruded lip positions were statistically more attractive for orthodontists than laypersons on the antero-posteriorly average-short, mandibular protrusive-short, mandibular retrusive-vertically average, antero-posteriorly average-vertically average, and mandibular retrusive-long facial types. LIMITATIONS: Our data were limited by the specific ethnic groups and variety of facial types. CONCLUSION: The favoured antero-posterior lip position was affected by not only the antero-posterior facial disproportion but also by the vertical dimensions. The favoured lip positions differed between orthodontists and laypersons. These results might be helpful in deciding between extraction and non-extraction treatment in borderline cases.

Comparison of short-term effects between face mask and skeletal anchorage therapy with intermaxillary elastics in patients with maxillary retrognathia.

INTRODUCTION: The aim of this study was to compare the short-term dental and skeletal effects of a face mask (FM) with those of skeletal anchorage (SA) therapy with intermaxillary elastics in prepubertal patients with skeletal Class III malocclusion. METHODS: Fifty patients with skeletal Class III malocclusion and maxillary deficiency were divided into two groups. In the FM group, an FM was applied by a bite plate with a force of 400g for each side. In the SA group, mini-plates were placed between mandibular lateral incisors and canines, and mini-implants were inserted between maxillary second premolars and first molars. A bite plate was inserted into the upper arch, and Class III elastics were applied with a force of 200g between each mini-plate and mini-implant. RESULTS: Mean treatment durations were 0.52±0.09 years for FM and 0.76±0.09 years for SA. After the treatment, statistically significant increases in SNA°, ANB°, A-y, 1-NA, SnGoGn°, Co-A, Co-Gn, and A-Nperp, and reductions in SNB° and FH┴N-Pg were observed in both groups, and these changes were similar in both groups. In the FM group, 1-NB decreased significantly, and in the SA group, it increased significantly (P < 0.05). CONCLUSIONS: The undesired dentoalveolar effects of the FM treatment were eliminated with SA treatment, except with regard to lower incisor inclination. Favourable skeletal outcomes can be achieved by SA therapies, which could be an alternative to the extraoral appliances frequently applied to treat skeletal Class III patients with maxillary deficiency.

Factors influencing molar relationship behavior in the mixed dentition.

INTRODUCTION: Our objectives were to compare different patterns of molar relationship changes from the mixed dentition to the permanent dentition and to discriminate the contributing dentoskeletal factors. METHODS: In this retrospective cohort study, we used a sample selected from 1212 untreated subjects who were longitudinally followed from the mixed to the permanent dentition. Eighty subjects (mean age, 8.69 years) had their right and left dental arch sides divided into 6 groups, according to molar relationship behavior: distal step kept in Class II (group 1A) or changed to Class I (group 1B); flush terminal plane kept in Class II (group 2A) or changed to Class I (group 2B); and mesial step kept in Class I (group 3A) or changed to Class III (group 3B). The groups were statistically evaluated at P <0.05. RESULTS: Class I and Class II defined by mesial and distal steps were stable. The flush terminal plane groups had a similar probability of maintaining the Class II relationship or changing to Class I. Groups 2A and 2B had significantly different changes in molar relationship, maxillary width, and mandibular skeletal traits as a whole. Class II maxillomandibular discrepancy, maxillary narrowing, and sagittal mandibular deficiency were the disadvantageous factors for favorable molar relationship adjustment. CONCLUSIONS: Mesial and distal steps produced stable molar relationships from the mixed to the permanent dentition. There were 2 distinct dentoskeletal parameters of subjects with flush terminal planes regarding transverse maxillary and sagittal mandibular dimensions that should be diagnosed early to define the prognosis for molar relationship adjustment and orthodontic treatment need.

Growth-related changes of skeletal and upper-airway features in bilateral cleft lip and palate patients.

INTRODUCTION: The craniofacial morphology of subjects with cleft lip and palate differs from that of subjects without clefts. Subjects with bilateral cleft lip and palate tend to have maxillary retrognathism, a smaller mandible with an obtuse gonial angle, greater anterior upper and lower facial heights, and retroclined maxillary incisors. The purposes of this research were to compare the skeletal and upper-airway features of subjects with bilateral cleft lip and palate with the same features in control subjects without clefts and to determine the growth-related changes at different growth stages. METHODS: The sample comprised 212 subjects divided into 2 groups: 68 with bilateral cleft lip and palate, and 144 controls without clefts; each group was further divided into 4 subgroups according to growth stage using the cervical vertebral maturation stage method. The subgroups were defined as early childhood (stage 1), prepubertal (stage 2), pubertal (stage 3), and postpubertal (stage 4). The cephalometric variables were evaluated with 2-way analysis of variance and the Bonferroni test. RESULTS: Maxillary position showed no significant differences between the male groups. The maxilla was more prognathic at stage 2 and became more retrognathic at stages 3 and 4 in the females. The mandible was more retrusive in the bilateral cleft lip and palate subjects at stage 1 in males and at stages 3 and 4 in females. ANB was larger at stages 1 and 2, and it became similar to the controls at stages 3 and 4 in male and female bilateral cleft lip and palate subjects. Vertical growth was seen in the bilateral cleft lip and palate subjects regardless of sex, and no change was observed with age. Posterior airway space was narrower in all stages (except for stage 1 in females). Middle airway space was wider after stage 1 in the male and female bilateral cleft lip and palate subjects. Inferior airway space was narrower in the male bilateral cleft lip and palate patients at the early childhood and pubertal stages. CONCLUSIONS: Age- and sex-dependent differences in skeletal morphology and upper-airway widths of the bilateral cleft lip and palate subjects were identified when compared with the control subjects without clefts.

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.

Influence of temporomandibular joint disc displacement on craniocervical posture and hyoid bone position.

INTRODUCTION: The purpose of this study was to evaluate craniocervical posture and hyoid bone position in orthodontic patients with temporomandibular joint (TMJ) disc displacement. METHODS: The subjects consisted of 170 female orthodontic patients who consented to bilateral magnetic resonance imaging of their TMJs. They were divided into 3 groups based on the results of magnetic resonance imaging of their TMJs: bilateral normal disc position, bilateral disc displacement with reduction, and bilateral disc displacement without reduction. Twenty-five variables from lateral cephalograms were analyzed with 1-way analysis of variance to investigate differences in craniocervical posture and hyoid bone position with respect to TMJ disc displacement status. Pearson correlation coefficients were calculated to analyze the relationships between craniofacial morphology and craniocervical posture or hyoid bone position. RESULTS: Subjects with TMJ disc displacement were more likely to have an extended craniocervical posture with Class II hyperdivergent patterns. The most significant differences were found between patients with bilateral normal disc position and bilateral disc displacement without reduction. However, hyoid bone position in relation to craniofacial references was not significantly different among the TMJ disc displacement groups, except for variables related to the mandible. Pearson correlation coefficients indicated that extended craniocervical posture was significantly correlated with backward positioning and clockwise rotation of the mandible. CONCLUSIONS: This suggests that craniocervical posture is significantly influenced by TMJ disc displacement, which may be associated with hyperdivergent skeletal patterns with a retrognathic mandible.