Eva Piehslinger

Computerized Axiography: Principles and Methods

This paper reviews earlier methods for the analysis of mandibular movement and gives a detailed account of state-of-the-art procedures. Special emphasis is given to computerized axiography and the application of this method to the diagnostics of the temporomandibular joint (TMJ). The article discusses the advantages of computerized axiography over the mechanical device and points out the limitations of the axiographic method. One major advantage of the computerized system is having the enlarged diagram of tracings on the computer screen. This means that small changes such as initial disk displacements can be diagnosed more readily than with the mechanical device.

Treatment of recurrent mandibular dislocation, part I: Leclerc blocking procedure

Nine patients with recurrent mandibular dislocation, who underwent the blocking procedure of Leclerc and Girard, as modified by Gosserez and Dautrey, are presented. The follow-up period range from 2.5 to 5 years. An axiographic study revealed significant postoperative limitation of translation of the condyle when opening, while maximal mouth opening as measured between the incisors, as well as translation of the condyle in protrusion and mediotrusion, showed no significant limitation. Long-term evaluation showed a high incidence of clicking and pain, not evident prior to surgery. The causes for recurrence in three cases were analysed.

Dental implants in patients with rheumatoid arthritis: clinical outcome and peri‐implant findings

PURPOSEnImplant prosthodontic treatment outcomes for patients suffering from autoimmune rheumatoid arthritis (RA) with or without concomitant connective tissue diseases (CTD) were evaluated.nnnMATERIAL AND METHODSnThirty-four female patients (25 isolated RA; nine RA+CTD) implant survival/success rate, peri-implant conditions (marginal bone loss, pocket depth, plaque index, gingiva index and bleeding index) and incidence of prosthodontic maintenance were retrospectively evaluated.nnnRESULTSnImplants evaluated presented a high implant survival (100%) and a 3.5-year success (93.8%) rate during the follow-up programme (mean 47.6 month) without difference between isolated RA (94.6%) and RA and concomitant CTD (92.3%), respectively. In isolated RA, acceptable marginal bone resorption (mean: 2.1 mm; SD: 0.5 mm), pocket depth (mean: 2.8 mm; SD:3.2 mm) and healthy soft-tissue conditions (plaque/bleeding/gingiva index Grade 0 in 80%) were noticed. However, patients with RA+CTD presented increased bone resorption (mean: 3.1 mm; SD: 0.7 mm) and more vulnerable soft-tissue conditions (higher bleeding index) differing significantly to patients with isolated RA (p<0.01). Peri-implant parameters were significantly influenced by the patients underlying disease (RA, RA+CTD; Kruskal-Wallis test, Jonckheere-Terpstra test).nnnCONCLUSIONSnIn contrast to isolated RA, in RA patients with concomitant CTD, differences in the peri-implant parameters such as pronounced marginal bone resorption and bleeding may be anticipated and appear to be significantly influenced by the patients underlying disease.

Comparison of magnetic resonance tomography with computerized axiography in diagnosis of temporomandibular joint disorders

This study compared the accuracy of two noninvasive methods, computerized axiography and magnetic resonance tomography (MRT), in diagnosing temporomandibular joint (TMJ) disorders. Forty-seven subjects underwent axiography and subsequent assessment of the TMJ by MRT. The statistical analysis referred to the correlations of the most relevant clinical diagnoses, i.e., no appreciable disease, disk displacement with reposition, disk displacement without reposition, morphologic alterations, and hypermobility of the condyle. In 70% of the disk-displacement-with-reposition and disk-displacement-without-reposition patient groups, axiography and MRT gave the same information. In other patient groups, the axiography findings agreed with the MRT findings in 45% of the cases. It was concluded that although a large percentage of morphologic alterations could be detected by MRT, axiography determined the dysfunctional dynamics more clearly.

Sonography of nonneoplastic disorders of the salivary glands

We examined 637 patients with salivary gland disorders by real-time sonography. In 270 patients, the possibility of neoplasia of the salivary glands could not be excluded by ultrasound. In the remaining 367 patients, the following disorders were diagnosed sonographically: acute inflammation (72 patients), Sjögrens syndrome or chronic inflammation (81 patients), abscess (9 patients), sialolithiasis (192 patients), and cysts (13 patients). The present study discusses the ultrasound appearances of a variety of diseases and the indications and limits of sonography in the evaluation of salivary gland pathology.

Computer simulation of occlusal discrepancies resulting from different mounting techniques

The effect of arbitrary mounting of maxillary casts on occlusal relationships was investigated in this study. Maxillary casts of 31 volunteers were mounted on an articulator by use of two split cast bases. This mounting was done first with the arbitrary face bow and second with a hinge bow. Three reference points were defined and measured on each maxillary cast with a three-dimensional digitizer. The measurements were taken from the arbitrarily mounted cast and from the cast mounted according to the hinge axis. Opening and closing movements that were transferred according to the hinge axis. Opening and closing movements that were transferred from the articulator to the mouth of the patient were simulated by a computer based on measurements of the reference points. The results revealed that the use of an arbitrary face bow causes a deviation of the hinge-axis points from the precise axis of more than 5 mm in 77% of the cases. Resulting occlusal errors depended on the angles between the arbitrary and precise axes and the direction of the axis shifts. The occlusal error is roughly proportional to the shift or tilting of the hinge axis in millimeters or degrees. For a given deviation of the arbitrary and precise axes, the occlusal error is proportional to the record height. For a record height of 2 mm or more, an occlusal error of more than 0.1 mm will occur. An average occlusal error of more than 0.1 mm would most likely lead to the necessity of extensive selective grinding of occlusal discrepancies in the patients mouth.

Soft tissue development around abutments with a circular macro-groove in healed sites of partially edentulous posterior maxillae and mandibles: a clinical pilot study.

OBJECTIVESnThe aim of this study was to evaluate soft tissue development at concave circular macro-grooved titanium abutments in healed sites.nnnMATERIAL AND METHODSnIn a split-mouth pilot study 10 patients received two implants each at healed posterior sites in contralateral maxillary or mandibular jaw quadrants. Either circular macro-grooved concave study abutments or conventional convex control abutments were immediately provisionalized and received permanent crowns 3 months postimplantation. Marginal bone level, papilla index, modified plaque and bleeding index were recorded. The esthetic outcome was evaluated with standardized perpendicular pictures according to the Pink Esthetic Score (PES). Statistical analysis included the description of all variables by mean value, standard deviation and range. PES values were compared using the Wilcoxon signed rank test for paired data.nnnRESULTSnCumulative survival rate for all 20 implants was 100%. At the 1-year follow-up, there was no statistical significant difference of marginal bone levels between sites restored with the study (-0.11 ± 0.77 mm) vs. the control (-0.34 ± 0.53 mm) abutments (P>0.05). Esthetic evaluation (PES) revealed statistically significant differences in scores between the study group [study abutment group] (7.2 ± 2.82, 8 ± 1.89) and the control group [control abutment group] (9.5 ± 1.58, 10.5 ± 1.72) at the time of prosthetic delivery and the 1-year follow-up. Whereas PES scores for mesial papilla at control sites at the 1-year follow-up demonstrated statistically significant higher values, both soft tissue level and soft tissue contour at control sites revealed statistically significantly higher PES values (P<0.05) at time of prosthetic delivery and at 1-year follow-up when compared with study sites.nnnCONCLUSIONSnConcave macro-grooved abutments in healed posterior maxillary and mandibular sites did not exhibit a superior soft tissue development compared with standard convex abutments.

Orthopedic Jaw Movement Observations. Part I: Determination and Analysis of the Length of Protrusion

An analysis and quantitation of protrusive and retrusive mandibular movement is provided. This report is one study along with four other parts analyzing the mandibular opening movement, the transversal shift during protrusion and retrusion, the mediotrusive movement and mastication. Protrusive movements of 225 individuals (180 patients, 45 volunteers) were analyzed using computerized axiography. Investigating both asymptomatic volunteers and patients with abnormal joint mobility helps to improve evaluation of these abnormalities. With the aid of diagnostic computer software, the length of the pathways was measured and the characteristics of the curves were analyzed. An average group was defined based on the values found in asymptomatic individuals, comprising 50% of our volunteers. The interquartile range for the male volunteers was 8.79-12.27 mm for the right joint and 9.43-12.93 mm for the left joint; for female volunteers it was 8.32-10.64 mm and 9.2-11.26 mm, respectively.

Orthopedic Jaw Movement Observations. Part III: The Quantitation of Mediotrusion

The objective of this series is to observe and analyze movements of the temporomandibular joint (TMJ). With the information from these studies, orthopedic standards for jaw movements will be established in further investigations according to the neutral-zero method used in general orthopedics. Any restricted range of motion can thus be defined as a deviation from these standards. Direct interpretation and objective evaluation of joint functions has major practical implications. With the aid of computerized axiography, mediotrusive movements of 48 asymptomatic volunteers and 66 jaw patients were evaluated. The movements performed were either free or guided. The mean curve lengths, as well as the Bennett angles at 3 mm and at the end point were recorded. An average group was defined, containing the values of 50% of all volunteers. The interquartile range was calculated for lengths of mediotrusive movements as well as for Bennett angles. The average range of free mediotrusive movement for female volunteers was 11.06-11.98 mm (mean 11.55 mm) on the right side and 10.47-11.75 mm (mean 11.24 mm) on the left side. Male volunteers showed an average range of 10.23-11.54 mm (mean 11.1 mm) on the right side and 10.24-11.73 mm (mean 11.12 mm) on the left side. The values for female patients amounted to 9.95-1.66 mm (mean 10.8 mm) on the right side and 9.75-11.28 mm (mean 10.55 mm) on the left side. The average range for male patients was 9.06-9.71 mm (mean 9.54 mm) on the right side and 9.17-10.23 mm (mean 9.73 mm) on the left side. The average range for Bennett angles at maximum excursion in free mediotrusive movement was between 0.41 and 5.89 degrees (mean 4.43 degrees) in the volunteers on the right side and between 2.45 and 10.07 degrees (mean 6.87 degrees), respectively, on the left side. The values for patients amounted to 0.19-12.65 degrees (mean 6.93 degrees), on the right side and 1.71-14.15 degrees (mean 6.73 degrees) on the left side.

The Effect of Occlusal Splint Therapy on Different Curve Parameters of Axiographic TMJ Tracings

Computerized axiography was used as an objective instrumental method of evaluating the response of patients with temporomandibular joint (TMJ) symptomatology to occlusal splint therapy. Diagnosis was performed in a standardized manner by systematically analyzing TMJ path tracings obtained by computerized axiography. Thirty-six patients were axiographed before and after therapy with full-arch occlusal stabilizing appliances, followed by assessing the effect of therapy on various path curve parameters. The data obtained for the patient group treated with splints was compared to that of six patients also axiographed, but left untreated for a period of six weeks before a second TMJ tracing was obtained. The results show that splints have a certain effect on reciprocal TMJ clicking (response rate 67%). Retral stability and path characteristics are also substantially improved (response rates 44% and 40%). Less influence was noted on hypomobile joint paths (response rate 29%), the quality of movements (response rate 28%) and Bennett angle values (response rate 23%). Patients with disk displacements without reduction were not treated with splints, they underwent surgery. Their results will be reported later. By contrast, TMJ tracings in the control group remained essentially unchanged.