Influence of dental occlusion on postural control and plantar pressure distribution.

OBJECTIVE: The number of studies investigating correlations between the temporomandibular system and body posture, postural control or plantar pressure distribution is continuously increasing. If a connection can be found, it is often of minor influence or for only a single parameter. However, small subject groups are critical. This study was conducted to define correlations between dental parameters, postural control and plantar pressure distribution in healthy males. METHODS: In this study, 87 male subjects with an average age of 25.23 ± 3.5 years (ranging from 18 to 35 years) were examined. Dental casts of the subjects were analyzed. Postural control and plantar pressure distribution were recorded by a force platform. Possible orthodontic and orthopedic factors of influence were determined by either an anamnesis or a questionnaire. All tests performed were randomized and repeated three times each for intercuspal position (ICP) and blocked occlusion (BO). For a statistical analysis of the results, non-parametric tests (Wilcoxon-Matched-Pairs-Test, Kruskall-Wallis-Test) were used. A revision of the results via Bonferroni-Holm correction was considered. RESULTS: ICP increases body sway in the frontal (p ≤ 0.01) and sagittal planes (p ≤ 0.03) compared to BO, whereas all other 29 correlations were independent of the occlusion position. For both of the ICP or BO cases, Angle-class, midline-displacement, crossbite, or orthodontic therapy were found to have no influence on postural control or plantar pressure distribution (p > 0.05). However, the contact time of the left foot decreased (p ≤ 0.001) while detecting the plantar pressure distribution in each position. CONCLUSIONS: Persistent dental parameters have no effect on postural sway. In addition, postural control and plantar pressure distribution have been found to be independent postural criteria.

Interdisciplinary cooperation exemplified by two complex cases of enamel erosion.

OBJECTIVE: Students of the Frankfurt am Main University Hospital participate in an interdisciplinary instructional unit in which they are presented with complex interdisciplinary findings and previous diagnostic records that are discussed in the patient's presence. We have recently observed a growing number of patients presenting defects of dental hard tissue in the form of erosions, defined as a loss of dental hard tissue due to the frequent and direct effect of acids not involving micro-organisms. These patients also presented marked malocclusions. For the most part, the diagnoses involve operative dentistry, dental prosthetics, orthodontics, oral, maxillofacial and plastic surgery. The clinicians discuss causes and therapeutic alternatives, at which point the therapeutic course is determined in consultation with the patient. CASE HISTORIES: We present herein two exemplary cases complex in etiology, as well as in treatment planning and realization. The case descriptions illustrate the importance of interdisciplinary agreement and cooperation in difficult courses of therapy, illustrating that, in the interest of the patient, it makes sense to establish interdisciplinary networks.

Frequency of and complications in the use of RPE appliances--results of a survey in the Federal State of Hesse, Germany.

AIM: A questionnaire was sent to orthodontists with private practices in the German State of Hesse to obtain information about the frequency of rapid palatal expansion and complications during treatment with rapid palatal expansion appliances (RPE-A). MATERIAL AND METHOD: A series of questions therein inquired as to the types of RPE-As used, their activation rhythm, the extent and the duration of the active expansion and retention; what their age limit was, starting from when surgical assistance was deemed necessary. Another series of queries concerned any technical and medical complications observed. RESULTS: The most frequently used type was the Hyrax screw (75%) soldered to bands. Technical problems arose with all applied indicated types. Although the answers to the first series of questions showed great variance, the majority of the orthodontists activated the screw twice a day (range 1-6 times a day) by a quarter turn for 2-3 (range 1-12) weeks. The retention phase amounted to 12 (range 4-26) weeks and the age limit for the indication of a surgical intervention was on average 17 years, with a range of 10-35 years. Medical complications such as pain and decubitae were reported by a third of the inquired offices, a non-opening suture was observed in one of every five practices. This meant that 1.7% of the sutures failed to open, and tooth tilting and rarely, extreme root resorptions and/or bone dehiscences were observed. Solid carious lesions were observed in one case after removal of an adhesive RPE. Extraoral changes such as those in the nose were reported by one in every ten practices. CONCLUSIONS: The RPE represents a common treatment means during which side effects are often temporary and permanent damages rather rare. It is important to inform the patient about both positive effects and possible complications, in particular pain and extraoral changes.

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.

Allergies induced by orthodontic alloys: incidence and impact on treatment. Results of a survey in private orthodontic offices in the Federal State of Hesse, Germany.

BACKGROUND: The incidence of allergies in general is on the increase. An allergic reaction can also occur during any dental and orthodontic treatment. However, the allergic potential of orthodontic appliances is frequently overestimated. MATERIAL AND METHOD: The incidence of suspected allergic reactions during fixed appliance therapy in 68 orthodontic offices in the German State of Hesse was determined by questionnaire at approximately 0.3% of the 60,000 patients covered. RESULTS: More extraoral (45%) than intraoral (17%) skin changes were registered, with both intraoral and extraoral changes being observed in 38%. In 53% of the affected cases the therapy was adapted to nickel-free materials, whereas it was continued as planned after a brief recovery period in 33%. The treatment was discontinued in 14% of the affected patients, corresponding to one in every 3150. The individual tolerance can often be tested by inserting one bracket or one band. In addition, early orthodontic treatment seems to promote a certain immune tolerance, especially towards extraoral nickel contacts. However, if a patient is known to have a nickel allergy, materials containing nickel should be renounced on principle in the orthodontic appliances. CONCLUSION: Skin changes occurring in the course of orthodontic treatment should be examined and verified if necessary by a dermatologist. Gold plating and other coatings (titanium nitride) of the metal elements even encourage corrosion after a brief protection period. Soldering should be avoided.

Evaluation of two siblings with Papillon-Lefèvre syndrome 5 years after treatment of periodontitis in primary and mixed dentition.

BACKGROUND: This case report describes the clinical and microbiologic long-term outcome 5 years after periodontal therapy of two siblings diagnosed with Papillon-Lefèvre syndrome (PLS) and tinea capitis. METHODS: In 2005, two brothers diagnosed with PLS and tinea capitis began periodontal treatment. Both of them showed premature mobility of the primary dentition, markedly increased probing depths, and subgingival Aggregatibacter actinomycetemcomitans (previously Actinobacillus actinomycetemcomitans; Aa). Initial therapy consisted of scaling and root planing based on the concept of full-mouth disinfection, extraction of periodontally hopeless deciduous teeth, and systemic antibiotics. Reevaluation of clinical parameters revealed a dramatic improvement. After that, the patients were enrolled in a stringent maintenance program. Microbiologic monitoring was performed 1 and 5 years after treatment. RESULTS: Five years after initial treatment, the periodontal situation was stable in both patients. Residual deciduous teeth, with the exception of one tooth, could be retained and no further teeth were lost. Further disease progression on the previously involved teeth was controlled, and development of periodontitis on erupting teeth was prevented for a period of 5 years. CONCLUSIONS: Even periodontally affected deciduous teeth can be treated successfully in patients with PLS. Suppression of Aa and a stringent maintenance program are of high importance.

Deletion of Atoh1 disrupts Sonic Hedgehog signaling in the developing cerebellum and prevents medulloblastoma.

Granule neuron precursors (GNPs) are the most actively proliferating cells in the postnatal nervous system, and mutations in pathways that control the GNP cell cycle can result in medulloblastoma. The transcription factor Atoh1 has been suspected to contribute to GNP proliferation, but its role in normal and neoplastic postnatal cerebellar development remains unexplored. We show that Atoh1 regulates the signal transduction pathway of Sonic Hedgehog, an extracellular factor that is essential for GNP proliferation, and demonstrate that deletion of Atoh1 prevents cerebellar neoplasia in a mouse model of medulloblastoma. Our data shed light on the function of Atoh1 in postnatal cerebellar development and identify a new mechanism that can be targeted to regulate medulloblastoma formation.

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.

exma: an X-linked insertional mutation that disrupts forebrain and eye development.

Formation of the neural tube plays a primary role in establishing the body plan of the vertebrate embryo. Here we describe the phenotype and physical mapping of a highly penetrant X-linked male-lethal murine mutation, exma (exencephaly, microphthalmia/anophthalmia), that specifically disrupts development of the rostral neural tube and eye. The mutation arose from the random insertion of a transgene into the mouse X Chromosome (Chr). Eighty-three percent of transgenic male embryos display an open, disorganized forebrain and lack optic vesicles. No transgenic males survive beyond birth. Hemizygous females show a variable phenotype, including reduced viability and occasional exencephaly and/or microphthalmia. Altered or reduced expression patterns of Otx2, Pax6, Six3, and Mrx, known markers of early forebrain and eye development, confirmed the highly disorganized structure of the forebrain and lack of eye development in affected exma male embryos. Physical mapping of the transgene by FISH localized a single insertion site to the interval between Dmd and Zfx on the X Chr. A 1-Mb contig of BAC clones was assembled by using sequences flanking the transgene and revealed that the insertion lies close to Pola1 and Arx, a gene encoding a highly conserved homeobox protein known to be expressed in the developing forebrain of the mouse. Data from Southern blots of normal and transgenic DNA demonstrated that a large segment of DNA encompassing Arx and including part of Pola1 was duplicated as a result of the transgene insertion. From the physical mapping results, we propose a model of the gross rearrangements that accompanied transgene integration and discuss its implications for evaluating candidate genes for exma.