Head Orthosis Therapy in Positional Plagiocephaly: Influence of Age and Severity of Asymmetry on Effect and Duration of Therapy.

BACKGROUND: Only a few studies investigating the optimal time point at which to start orthotic treatment for deformational plagiocephaly take into account the severity of skull asymmetry. The present study performs a three-dimensional analysis of the effects of age and severity of asymmetry on the final outcome. METHODS: A total of 144 patients with deformational plagiocephaly treated by molding orthosis were examined and divided into three age groups (group I, <24 weeks; group II, ≥24 to <32 weeks; and group III, ≥32 weeks) and two severity levels (mild to moderate, 30-degree cranial vault asymmetry ≥3 mm to ≤12 mm; and moderate to severe, 30-degree cranial vault asymmetry >12 mm). The extent of the reduction of asymmetry was analyzed using three-dimensional stereophotogrammetry. RESULTS: Therapy with molding orthosis led to a significant reduction in asymmetry in all defined age groups. Efficacy of reduction decreased with increasing age. Successful treatment (cranial vault asymmetry index <3.5 percent) was achieved in 83, 69, and 40 percent of patients with mild to moderate asymmetry in groups I, II, and III, respectively; and in 50, 30, and 7 percent of patients with moderate to severe asymmetry in groups I, II, and III, respectively. The average duration of treatment increased from 18.6 weeks to 25.3 weeks (age groups I and III). CONCLUSION: Age at the beginning of treatment and severity of asymmetry have a definite impact on the duration and effectiveness of molding orthosis therapy. CLINICAL QUESTION/LEVEL OF EVIDENCE: Risk, II.

PTH1R Mutants Found in Patients with Primary Failure of Tooth Eruption Disrupt G-Protein Signaling.

AIM: Primary failure of tooth eruption (PFE) is causally linked to heterozygous mutations of the parathyroid hormone receptor (PTH1R) gene. The mutants described so far lead to exchange of amino acids or truncation of the protein that may result in structural changes of the expressed PTH1R. However, functional effects of these mutations have not been investigated yet. MATERIALS AND METHODS: In HEK293 cells, PTH1R wild type was co-transfected with selected PTH1R mutants identified in patients with PFE. The effects on activation of PTH-regulated intracellular signaling pathways were analyzed by ELISA and Western immunoblotting. Differential effects of wild type and mutated PTH1R on TRESK ion channel regulation were analyzed by electrophysiological recordings in Xenopus laevis oocytes. RESULTS: In HEK293 cells, activation of PTH1R wild type increases cAMP and in response activates cAMP-stimulated protein kinase as detected by phosphorylation of the vasodilator stimulated phosphoprotein (VASP). In contrast, the PTH1R mutants are functionally inactive and mutant PTH1R/Gly452Glu has a dominant negative effect on the signaling of PTH1R wild type. Confocal imaging revealed that wild type PTH1R is expressed on the cell surface, whereas PTH1R/Gly452Glu mutant is mostly retained inside the cell. Furthermore, in contrast to wild type PTH1R which substantially augmented K+ currents of TRESK channels, coupling of mutated PTH1R to TRESK channels was completely abolished. CONCLUSIONS: PTH1R mutations affect intracellular PTH-regulated signaling in vitro. In patients with primary failure of tooth eruption defective signaling of PTH1R mutations is suggested to occur in dento-alveolar cells and thus may lead to impaired tooth movement.

Spectrum of positional deformities - is there a real difference between plagiocephaly and brachycephaly?

AIM: This study analyses pathomorphological and physiological head shapes and classifies the pathomorphology in positional plagiocephaly and brachycephaly. PATIENTS AND METHODS: 78 infants with a positional plagiocephaly (5.99 months) and 32 infants with a positional brachycephaly (6.53 months) with a Cephalic index > 94% were investigated in this study and compared to a matched control group of 35 infants. The head shapes were analysed by stereophotogrammetry 3D data. RESULTS: The cephalic index, the total width, and coronal circumference were the highest values in patients with brachycephaly and the lowest values in the control group. The asymmetry of the head showed that the diagonal difference in brachycephalic patients more than doubled, and in patients with plagiocephaly almost tripled compared to the controls. A significantly higher total volume and vertex height was found for the patients with plagiocephaly and the patients with brachycephaly compared to the controls. CONCLUSION: The cephalic index is a valuable and reliable parameter in order to differentiate positional deformities from unaffected skulls. Pathomorphology of a plagiocephaly is associated with the most severe asymmetry of the head. Plagiocephaly and brachycephaly overlap in several criteria. Therefore it seems justified to speak of a continuum rather than to differentiate between plagiocephaly and brachycephaly.

Short-term pharyngeal airway changes after mandibular advancement surgery in adult Class II-Patients--a three-dimensional retrospective study.

The purpose of this study was to investigate volume changes in posterior airway space (PAS) after bilateral mandibular advancement surgery. Measurements were taken based on three-dimensional (3D) records available for a large and homogeneous cohort of patients. Pre- and postoperative CBCT scans of 102 adult patients with Class II dysgnathia were visualized and analyzed using 3D software (Mimics® Innovation Suite 14.1; Materialise, Leuven, Belgium). The PAS was divided into three segments by three planes parallel and one plane perpendicular to the Frankfort horizontal plane. Total volume, partial volumes, and cross-sectional areas were calculated from the pre- and postoperative scans. Dahlberg coefficients were obtained to verify each parameter for the measurements' reliability. The statistical significance of the changes observed was analyzed by Wilcoxon's rank-sum test. Highly significant (p=0.000) increases in total posterior airway volume (+32.0%) were noted as an effect of mandibular advancement surgery, amounting to 45.6% in the lower PAS third compared to 38.8% in the middle and 12.5% in the upper PAS third. We also obtained highly significant (p=0.000) increases in all the cross-sectional areas investigated, amounting to 48.5% on the soft-palate level compared to 21.6% on the level of the epiglottis tip, and 14.6% on the hard-palate level. These results demonstrate that bilateral mandibular advancement surgery in Class II-Patients leads to significant increases in PAS volume and significant widening of the narrower sites inside the pharynx.

Three-dimensional analysis of positional plagiocephaly before and after molding helmet therapy in comparison to normal head growth.

OBJECTIVE: Stereophotogrammetry enables a simple and radiation free longitudinal analysis of skull asymmetries: in a three-dimensional coordinate system various distances (length, breadth, cephalic index, oblique diameters, ear shift, head circumference) can be analyzed. We also defined separate volume sections in order to further quantify the degree of asymmetry in the posterior and anterior components of both sides of the head. PATIENTS AND METHODS: In 51 infants (mean age, 6 months; SD 0.97) with positional plagiocephaly, we determined these parameters at the beginning as well as at the end of molding helmet therapy (mean therapy time 4.9 months). Thirty-seven infants without positional deformity (mean age, 6.4 months; SD 0.3) served as control group and provided data about what appears to be normal and how these parameters change during growth over a comparable period of time. RESULTS: Compared with the control group, the plagiocephalic heads were more brachycephalic, but closely approximated the normal shape under molding therapy. The striking volume difference between the left and right posterior sections in the plagiocephalic children (the mean volume of the flattened side being 21% smaller than the one on the contralateral side) improved as well (to a residual difference of mean 8%) and ended up with a value close to the control group (mean 6%). CONCLUSION: There is a broad clinical application area for stereophotogrammetry analyzing skull morphology: In plagiocephalic infants we demonstrate impressive changes of head shape under molding therapy; in normal-looking infants we describe the extent of unperceived asymmetry.

Three-dimensional perception of facial asymmetry.

In orthodontic diagnosis, facial symmetry is important. The aim of the present study was to analyse the perception of various degrees of facial asymmetry exhibited by carefully designed virtual three-dimensional (3D) material. Three groups of raters (30 orthodontists, 30 maxillofacial surgeons, and 30 laymen) rated, using a six-point scale, the degree of asymmetry of eight randomly presented 3D faces exhibiting incremental soft tissue alterations. The faces were created by gradually transforming the nose or chin in increments of 2 mm away from the computed symmetry plane. Differences between the groups in analysis of facial asymmetry, the rating of facial stimulus, and right and left facial asymmetry were determined using a t-test. The results demonstrated that raters' profession did not influence the point at which they identified asymmetry. Even laymen were able to detect asymmetries when located near the midline of 3D faces. All raters identified asymmetries of the nose as more negative than those of the same degree of the chin. A left-sided deviation of the nose along the facial symmetry plane lead to a more negative rating of facial appearance, whereas a right-sided deviation of the chin was rated as less attractive. Nasal architecture plays a crucial role in the perception of symmetry. These findings provide clinicians with a greater understanding of how faces are perceived, a process which is of particular interest in treating orthognathic patients, and those with congenital anomalies.

New model for surgical and nonsurgical therapy in adults with Class III malocclusion.

INTRODUCTION: Not all adult Class III malocclusion patients are candidates for surgical correction. In patient assessment and selection, major issues remain regarding diagnosis and treatment planning. The purpose of this investigation was to ascertain whether adding a transverse parameter to a discriminant analysis could improve the classification of adults with Class III malocclusion into 2 groups of patients: those who can effectively be treated by orthodontic therapy and those who require orthognathic surgery. METHODS: Cephalograms, plaster casts, and extraoral photos of 69 adults with Class III malocclusion were analyzed. A discriminant analysis was performed to identify the variables that best separate the 2 groups. RESULTS: Stepwise variable selection resulted in a new, highly significant (P <0.0001) model of 4 variables that provided the best discriminant function to distinguish between patients with and without indications for surgical correction. The resulting equation was the following: score = -10.988 + 0.243 * Wits + 0.055 * M/M ratio + 0.068 * NSAr - 0.589 * mand MLD. The percentage of patients correctly classified by this equation was 91.3%. The sensitivity was 0.92, and the specificity was 0.89. CONCLUSIONS: In the discriminant analysis, the mandibular midline deviation as a transverse component was included. The addition of the transverse variable led to an improved model concerning the predictive value in Class III malocclusion patients with surgical requirements.

Face perception in patients with unilateral cleft lip and palate and patients with severe Class III malocclusion compared to controls.

Although there is principal agreement that increased facial asymmetry is associated with decreased facial attractiveness, there are no studies analysing face perception in patients with a unilateral cleft lip and palate (CLP) (uCLP) compared to orthognathic Class III patients. To this end, three-dimensional (3D) data on the faces of 30 adults with a complete uCLP, 20 orthognathic patients with a severe skeletal Class III, and 20 adults with a skeletal Class I as a control group were generated. The 3D asymmetry of the facial soft-tissue was analysed. These data were compared with subjective ratings for attractiveness carried out by 100 laypersons. Compared to the controls, uCLP patients and orthognathic patients had a significantly higher facial asymmetry. No difference was found between uCLP patients and orthognathic patients. The attractiveness ratings showed that uCLP patients and orthognathic patients were rated less attractive compared to the controls. However, although there were no differences in the facial asymmetry between uCLP patients and orthognathic patients, the uCLP patients were rated significantly less attractive. This leads to the conclusion that not only the extent of asymmetry has an influence on attractiveness but also the location of asymmetry. For clinical use, these findings underline the importance of accurate as possible surgical reconstruction of the nasal morphology in uCLP patients.

How others perceive orthognathic patients: an eye-tracking study.

AIM: To test the hypothesis that the faces of patients with a severe Class III are contemplated differently from and assessed more negatively than skeletal Class I patients in direct face-to-face interaction. METHOD: The eye movements of 24 randomly recruited evaluators were analyzed with a noninvasive, infrared high-speed camera while looking at 18 standardized frontal photographs of adult orthognathic Class III patients and 18 photographs of adults with skeletal Class I relationships as controls. Additionally, all images were assessed for appearance, symmetry, and facial expression. RESULTS: The Class III patients were rated significantly more negatively in terms of appearance, symmetry, and facial expression than the Class I individuals. The eye movement data revealed that orthognathic patients were appraised differently from the Class I individuals, with fewer fixations in the face center, especially around the mouth. CONCLUSION: Skeletal Class III patients were characterized as less attractive than Class I individuals. Faces of Class III patients were visually perceived with different eye movements. These differences in visual perception are described for the first time in the present study. Although they were small, they are an indication of an objectively different perception of faces that are rated subjectively as less attractive and more asymmetric and exhibiting a more negative expression.

Interaction between otorhinolaryngology and orthodontics: correlation between the nasopharyngeal airway and the craniofacial complex.

In terms of pathophysiology, an anatomically narrow airway is a predisposing factor for obstruction of the upper respiratory tract. The correlation between the nasopharyngeal airway and the craniofacial structures is discussed in this context. Thus a mutual interaction between the pharynx and the mandibular position was demonstrated, whereby the transverse dimension of the nasopharynx was significantly larger in patients with prognathism than in patients with retrognathism. The influence of chronic obstruction of the nasal airway on craniofacial development was also discussed. The form-and-function interaction, which ought to explain the causal relationship between nasal obstruction and craniofacial growth, appears to be of a multifactorial rather than a one-dimensional, linear nature. It is not disputed, however, that expanding the maxilla improves not only nasal volume and nasal flow, but also the subjective sensation of patients, although it is not possible to make a prognostic statement about the extent of this improvement because of the differing reactions of individuals. Orthodontic appliances for advancing the mandible can also be successfully used in the treatment of mild obstructive sleep apnea syndrome. This treatment method should be considered particularly for patients who are unwilling to undergo or cannot tolerate CPAP (continuous positive airway pressure) treatment.

Applications for direct composite restorations in orthodontics.

BACKGROUND AND AIM: Besides prosthetic and indirect, laboratory-produced restorations, the focus of dental therapy is increasingly on restorative measures and direct restorations as minimally invasive treatment concepts. Thus, the use of direct composite restorations with modern restorative materials for the shaping and recontouring of teeth in combination with orthodontic treatment offers a diversified, extensive sphere of application. The aim of the study was to demonstrate applications for direct composite restorations with reference to selected cases. MATERIAL AND METHODS: The composites used were hybrid composites, which offer increased abrasion resistance and color stability and are applied incrementally. Special attention was paid to the shape, color and structure of the tooth. CASE REPORTS: The case reports present patients in whom relatively narrow or peg-shaped teeth were built up with composite to correct various tooth size discrepancies or cuspids were recontoured by means of direct composite restorations following orthodontic space closure in cases with missing lateral incisors. Similarly, space closure was achieved using orthodontically repositioned lateral incisors recontoured to resemble central incisors after traumatic loss of upper central incisors. Finally, direct composite restorations were used for retention following completion of orthodontic treatment. CONCLUSIONS: Observations over recent years confirm the stability of composites in both form and color, as well as their ability to maintain gingival health. Our case reports demonstrate that, subject to a corresponding indication, recontouring single teeth using direct composite restorations can optimize orthodontic treatment results.

Patterns of maxillary alveolar arch growth changes of infants with unilateral cleft lip and palate: preliminary findings.

OBJECTIVE: Because of significant differences in pathomorphology at birth, it may be that a better treatment outcome prognosis exists for patients with incomplete versus complete cleft forms. Can reaction patterns be extracted from changes in maxillary dimensions of different cleft forms within the first year of life to support this hypothesis? SUBJECTS: Chronologically consecutive casts of the maxilla (1 week and 3, 6, and 12 months of life) of 15 patients with complete unilateral cleft lip and palate (cUCLP) and 13 patients with incomplete unilateral cleft lip and palate (iUCLP). All patients were treated with passive palatal plates. Cheiloplasty was performed at 6 months of age. No primary osteoplastic surgery was carried out. INTERVENTIONS: Following digitizing with a three-dimensional laser scanner, all cast surfaces were computer reconstructed, aligned, and superimposed. Distances between the surfaces were determined and expressed graphically. Computer-aided determination of defined maxillary dimensions was performed. The volumes of segmented surfaces were determined and compared. RESULTS: Within the first year of life, decreased sagittal but increased transverse alveolar growth for patients with iUCLP was found. The increase in alveolar crest length in patients with iUCLP was 50% less within the first year of life than in patients with cUCLP. In the same patients, the volumes of the molar segments were, on average, larger at each registration stage and the increase in these volumes larger within the first year of life. CONCLUSION: Conclusions regarding the direction and extent of growth cannot be drawn from the visible level of severity of the malformation.

Children with class III malocclusion: development of multivariate statistical models to predict future need for orthognathic surgery.

Until now, the literature does not provide an accurate model to predict the future need for orthognathic surgery in prepubertal patients with class III malocclusion. Because not all of these patients are candidates for later surgical correction, patient assessment and selection remain arbitrary with respect to diagnosis and treatment planning. The purpose of the present investigation was to analyze the value of classifying class III children before puberty into patients who can be effectively treated by orthopedic/orthodontic therapy alone and those who require orthognathic surgery. To obtain a robust model, the study design was multicentric (University Orthodontic Departments of Frankfurt, Heidelberg, and Würzburg). A total of 88 patients with class III malocclusion were grouped into orthopedic/orthodontic (n = 65) and surgery patients (n = 23), according to their records after puberty (mean age, 17 years three months). Discriminant analysis (DA) and logistic regression (LogR) were applied to 20 landmarks of the patients' cephalograms before puberty (mean age, nine years eight months) to identify the dentoskeletal variables that provide the best group separation and the best predictability of group membership, respectively. Both models were highly significant (P < .001), classifying 93.3% (DA) and 94.3% (LogR) of the patients correctly. The extracted variables were identical for both procedures: Wits appraisal, palatal plane angle, and individualized inclination of the lower incisors. The resulting equation of LogR was individual score = -7.968 - 1.323Wits - 0.363NL-NSL + 0.153[180 - (LI-ML) - (L1-ML(ind))]. We concluded that by means of multivariate statistics, prepubertal children with class III malocclusions may be classified into nonsurgery and surgery patients with high accuracy.

Treatment decision in adult patients with Class III malocclusion: orthodontic therapy or orthognathic surgery?

Class III malocclusion is one of the most difficult anomalies to understand. Because not all Class III patients are candidates for surgical correction, patient assessment and selection remain main issues in diagnosis and treatment planning. The purpose of this study was to separate Class III patients who can be properly treated orthodontically from those who require orthognathic surgery. A large sample size was a necessary to obtain a sufficiently robust model. Thus, a multicentric study design was chosen (Orthodontic Departments of the Universities of Frankfurt, Heidelberg, and Würzburg, Germany). The cephalograms of 175 adult patients with Class III malocclusions were analyzed. The orthodontic group comprised 87 patients, and the surgery group, 88 patients. Twenty linear, proportional, and angular measurements were made. Stepwise discriminant analysis was applied to identify the dentoskeletal variables that best separate the groups. The discriminant function model was highly significant (P <.0001); 92% of the patients were correctly classified. The following variables were extracted: Wits appraisal, length of the anterior cranial base, maxillary/mandibular (M/M) ratio, and lower gonial angle. The resulting equation was: Individual score = -1.805 + 0.209. Wits + 0.044. S-N + 5.689. M/M ratio - 0.056. Go(lower). By means of discriminant analysis, correct classification of adult Class III malocclusion patients succeeded to a very high degree. Of all the variables, the Wits appraisal was the most decisive parameter.