Long-term results of ORIF of condylar head fractures of the mandible: A prospective 5-year follow-up study of small-fragment positional-screw osteosynthesis (SFPSO).

BACKGROUND: Optimum treatment of condylar head fractures (CHF) remains subject to controversy. There are currently a variety of alternative techniques applied, data in literature are often inconsistent and especially systematic long-term data on results after treatment by open reduction and internal fixation (ORIF) have so far not been available. This study in hand is the first long-term prospective study of ORIF after CHF based on osteosynthesis with 1.7 mm small-fragment positional screws (SFPSO)via a retroauricular transmeatal approach (RA). METHODS: The study made use of radiologic, anatomic and objective functional parameters (axiography and MRI) to assess vertical height, disk mobility, protrusive and translatory movement as well as potential physical complaints. Included were surgical long-term sequelae after RA, such as incidence of stenosis of the auditory canal, the facial nerve and resulting disturbance of facial skin sensitivity. Retroauricular scars were evaluated according to the Vancouver Scar Scale. Helkimo and RDC/TMD indices were applied for patient's self-assessment of quality of life aspects after ORIF via RA. The sample in the first follow-up trial (FFT) in the years 2003-2004 comprised 26 patients (36 CHF). 22 patients (31 CHF) were re-evaluated in a second follow-up trial (SFT) between 2006 and 2008. A reference collective (43 patients, 56 CHF) treated with ORIF from 1993 to 2000 mainly by mini- or microplates (MMP) served as a surgical control group. RESULTS: Five years after ORIF all fractured condyles (FC) continued to show stable anatomic restoration of the pre-trauma vertical height. FC treated with SFPSO exhibited a significantly superior range of motion (p < 0.05) of disk and condyle during mouth opening and protrusion compared to a previous MMP reference collective. Also, no difference was found between condylar mobility of FC five years after surgery and non-fractured condyles (NFC). SFPSO had thus successfully achieved a sustainable, stable physiological restoration of protrusive mobility of the articular disk and condyle. Remarkably, these long-term results were even slightly better in SFT vs. FFT (p < 0.05). Except for sporadically occurring minor complaints, the patients' subjective overall long-term perception of the success of the treatment was equally positive to the surgeons' objective assessment. CONCLUSIONS: This first long-term prospective follow-up study, based on objective assessment tools, demonstrates that in all cases the major goals of ORIF in CHF could be fully achieved. These goals are: restoration of vertical height viz. prevention of occlusal disorders, physiological function of disk and condyle as well as of the lateral pterygoid muscle. Accordingly, ORIF of CHF e.g. with SFPSO and via the RA secures both a long-term functionally and anatomically stable result and as best as possible pain-free result for the patient, a central prerequisite of optimum perceived HRQoL. The paper has been amended by an extensive review part that covers the current knowledge of the major surgical aspects regarding the treatment of condylar head fractures.

Thirty-year follow-up of a TMD case treated based on the neuromuscular concept.

AIM: Occlusal therapy is employed to alleviate the symptoms of a temporomandibular disorder (TMD) at times. However, the long-term effect of occlusal therapy in the masticatory system is not well understood. This case study aims to present a 30-year follow-up of a TMD case. METHODOLOGY: The patient developed TMD with intermittent closed lock of the left temporomandibular joint (TMJ). Chief complaints included trismus, pain, and noise of the left TMJ during function. The patient's occlusal disharmony was assessed with use of electronic instruments and corrected based on the neuromuscular concept. A minimum-invasive and reversible approach using adhesive occlusal restorations was used. RESULTS: The jaw movement and masticatory muscle activity assessed at the 7- and 23-year follow-ups revealed that the established occlusion was well adapted, and re-established the patient's functional occlusion system. The patient has been free from TMD symptoms with the corrected occlusion for 30 years. CONCLUSIONS: Occlusal reconstruction based on the neuromuscular concept can be stably integrated into the patient's functional occlusion system.

The effects of ULF-TENS stimulation on gnathology: the state of the art.

AIMS: The aim of this study was to evaluate the state of the art in the current literature regarding the effect of ultra low frequency-transcutaneous electrical nerve stimulation (ULF-TENS) on patients with temporomandibular disorders (TMD). METHODOLOGY: The authors reviewed the literature through a thorough manual and electronic research on PubMed database (using the Medical Subject Headings thesaurus) and subsequent analysis of all the found papers regarding the effect of TENS on TMD patients. No randomized controlled trials on the investigated topic were found. Only eight papers regarding controlled clinical trials (CCT) were selected according to the search strategy selection criteria. RESULTS: According to the available literature and the authors' experience, ULF-TENS seems to be a valid support in the management of TMD patients, but also a 'provocative' tool, so its application should always be monitored by electromyographic and electrognathographic analysis (before and after TENS). CONCLUSIONS: Further clinical studies (mainly randomized controlled trials) on ULF-TENS application in neuromuscular gnathology are needed.

Registro de mordida neuromuscular para ortopedia con Tens / Neuromuscular bite recording for orthopedics with Tens

El propósito de este artículo es difundir la odontología neuromuscular, su fundamento, filosofía y en esta oportunidad, aplicarla a la toma del registro de mordida para la confección de aparatología de ortopedia funcional.(AU)

Registro de mordida neuromuscular para ortopedia con Tens / Neuromuscular bite recording for orthopedics with Tens

El propósito de este artículo es difundir la odontología neuromuscular, su fundamento, filosofía y en esta oportunidad, aplicarla a la toma del registro de mordida para la confección de aparatología de ortopedia funcional.

The muscle engram: the reflex that limits conventional occlusal treatment.

The engram (the masticatory "muscle memory") is shown to be a conditionable reflex whose muscle conditioning lasts less than two minutes, far shorter than previously thought. This reflex, reinforced and stored in the masticatory muscles at every swallow, adjusts masticatory muscle activity to guide the lower arch unerringly into its ICP. These muscle adjustments compensate for the continually changing intemal and external factors that affect the mandible's entry into the ICP. A simple quick experiment described in this article isolates the engram, enabling the reader to see its action clearly for the first time. It is urged that every reader perform this experiment. This experiment shows how the engram, by hiding the masticatory muscles' reaction (the hit-and-slide), limits the success of the therapist in achieving occlusion-muscle compatibility. This finding has major clinical implications. It means that, as regards the muscle aspect of treating occlusion, the dentist treating occlusion conventionally is working blind, a situation the neuromuscular school of occlusal thought seeks to correct. The controversy over occlusion continues.

Comparative study of intermaxillary relationships of manual and swallowing methods.

This study compared the mandibular displacement from three methods of centric relation record using an anterior jig associated with (A) chin point guidance, (B) swallowing (control group) and (C) bimanual manipulation. Ten patients aged 25-39 years were selected if they met the following inclusion criteria: complete dentition (up to the second molars), Angle class I and absence of signs and symptoms of temporomandibular disorders and diagnostic casts showing stability in the maximum intercuspation (MI) position. Impressions of maxillary and mandibular arches were made with an irreversible hydrocolloid impression material. Master casts of each patient were obtained, mounted on a microscope table in MI as a reference position and 5 records of each method were made per patient. The mandibular casts were then repositioned with records interposed and new measurements were obtained. The difference between the two readings allowed measuring the displacement of the mandible in the anteroposterior and lateral axes. Data were analyzed statistically by ANOVA and Tukey's test at 5% significance level. There was no statistically significant differences (p>0.05) among the three methods for measuring lateral displacement (A=0.38 +/- 0.26, B=0.32 +/- 0.25 and C=0.32 +/- 0.23). For the anteroposterior displacement (A=2.76 +/- 1.43, B=2.46 +/- 1.48 and C=2.97 +/- 1.51), the swallowing method (B) differed significantly from the others (p<0.05), but no significant difference (p>0.05) was found between chin point guidance (A) and bimanual manipulation (C). In conclusion, the swallowing method produced smaller mandibular posterior displacement than the other methods.

Comparative study of intermaxillary relationships of manual and swallowing methods

This study compared the mandibular displacement from three methods of centric relation record using an anterior jig associated with (A) chin point guidance, (B) swallowing (control group) and (C) bimanual manipulation. Ten patients aged 25-39 years were selected if they met the following inclusion criteria: complete dentition (up to the second molars), Angle class I and absence of signs and symptoms of temporomandibular disorders and diagnostic casts showing stability in the maximum intercuspation (MI) position. Impressions of maxillary and mandibular arches were made with an irreversible hydrocolloid impression material. Master casts of each patient were obtained, mounted on a microscope table in MI as a reference position and 5 records of each method were made per patient. The mandibular casts were then repositioned with records interposed and new measurements were obtained. The difference between the two readings allowed measuring the displacement of the mandible in the anteroposterior and lateral axes. Data were analyzed statistically by ANOVA and Tukey's test at 5 percent significance level. There was no statistically significant differences (p>0.05) among the three methods for measuring lateral displacement (A=0.38 ± 0.26, B=0.32 ± 0.25 and C=0.32 ± 0.23). For the anteroposterior displacement (A=2.76 ± 1.43, B=2.46 ± 1.48 and C=2.97 ± 1.51), the swallowing method (B) differed significantly from the others (p<0.05), but no significant difference (p>0.05) was found between chin point guidance (A) and bimanual manipulation (C). In conclusion, the swallowing method produced smaller mandibular posterior displacement than the other methods.

Este estudo comparou o deslocamento mandibular a partir de 3 métodos de registro da relação cêntrica usando um jig anterior associado com: (A) guia da ponta do mento; (B) deglutição grupo controle (C) manipulação bimanual. As moldagens dos arcos maxilares e mandibulares foram feitas com hidrocolóide irreversível. Os modelos de estudo de cada paciente foram obtidos e montados em máxima intercuspidação como uma posição de referência no microscópio. Foram obtidos 5 registros de cada método em 10 pacientes. Os modelos mandibulares foram reposicionados com os registros interpostos e novas medidas foram obtidas. A diferença entre as duas leituras permitiu a medida do deslocamento mandibular nos eixos ântero-posterior e laterais. ANOVA não demonstrou diferença estatisticamente significativa entre os 3 métodos em relação ao registro do deslocamento lateral (A = 0,38 ± 0,26, B = 0,32 ± 0,25 e C = 0,32 ± 0,23). Quanto ao deslocamento anteroposterior, ANOVA e o teste de Tukey (a=0,05) indicaram diferença estatisticamente significante entre os três métodos (A=2,76 ± 1,43, B=2,46 ± 1,48 e C=2,97 ± 1,51). Não houve diferença estatisticamente significante entre A e C. A deglutição propiciou menor deslocamento mandibular posterior que os outros métodos.

Clinical study of location and reproducibility of three mandibular positions in relation to body posture and muscle function.

Clinical studies have confirmed the adequate reproducibility of both centric occlusion and centric relation when used as reference positions during treatment; however, the reproducibility of the neuromuscular position has been found inadequate. This study evaluated the location and reproducibility of these three mandibular positions in relation to body posture, sitting and supine, and bilateral muscle activity before and after the insertion of a flat mandibular positioning device equilibrated to balance the muscle functions, as shown by two electromyography biofeedback instruments. Intraoral recordings were made in 11 young subjects with complete natural dentition. Acrylic resin clutches that supported a screw point in the maxillary arch and painted glass in the mandibular arch were used and positioned not to interfere with the occlusion. The distances of the screw scratch from two of the edges of the painted glass were used to measure the anteroposterior and mediolateral locations with a micrometer. The reproducibility was evaluated by measuring the scratch surface by measuring the weight of the print cutouts made from photographs of the scratches taken with a stereoscope. The location and reproducibility of centric occlusion and centric relation were not affected by body posture. A more precise posterior neuromuscular position was obtained in the supine position. The insertion of a mandibular positioning device did not affect centric occlusion but gave a more precise centric relation. Neuromuscular position became as precise as centric occlusion and was located anteroposteriorly between centric occlusion and centric relation.