[Measuring tooth wear with regular intra-oral 3D scanners: for still in the future, or is it already possible?] / Serie: Innovatieve technieken en ontwikkelingen in de mondzorg. Meten van gebitsslijtage met reguliere 3D-scanners: toekomstmuziek, of al mogelijk?

Quantitative tooth wear measurement is a method of increasing importance when measuring tooth wear progression. The Radboud university medical center has developed a protocol that measures height and volumetric differences on regular 3D-scans. Intra-oral scans were made on patients with tooth wear and superimposed. To assess reliability the precision , as well as intra- and inter-rater precision of the protocol was tested. T-tests were performed to determine the structural and random error. Our findings indicate that the method is precise enough to measure height differences in patients with severe tooth wear progression, or tooth wear with an interval longer than 1 year. The method is not precise enough to measure volumetric changes.

Chronic temporomandibular joint pain: two cases of osteoid osteoma and a review of the literature.

Osteoid osteoma is a benign bone tumour with self-limiting growth potential occurring in any part of the body. Two rare cases of a pathologically proven osteoid osteoma invading the temporomandibular joint (TMJ) are reported herein. This article also reviews the cases of osteoid osteoma of the craniofacial complex reported in the English-language literature to date. Although the clinical presentation of osteoid osteoma in the jaw differs from that of osteoid osteoma in the more common locations, the radiographic features are similar. In both cases presented, computed tomography revealed a small round osseous lesion with sharp margins in the TMJ. Bone scintigraphy was performed in order to differentiate the lesions from other osseous lesions. Both patients underwent surgical excision of the lesion with immediate relief of the pain. The importance of early recognition of the clinical and imaging characteristics of an osteoid osteoma of the TMJ is emphasized, in order to prevent misdiagnosis and avoid discouraging therapies.

[Toothache with a neuropathic background]. / Kiespijn met een neuropathische achtergrond.

A 48-year old woman in good general health was referred to the orofacial pain clinic in a centre for special dentistry with a toothache in the premolar region of the left maxillary quadrant. The complaints had existed for 15 years and various dental treatments, including endodontic treatments, apical surgery, extraction and splint therapy, had not helped to alleviate the complaints. As a result of the fact that anti-epileptic drugs were able to reduce the pain it was concluded that this 'toothache' satisfied the criteria of an atypical odontalgia: 'toothache' with a neuropathic background.

Reduced mandibular range of motion in Duchenne Muscular Dystrophy: predictive factors.

Patients with Duchenne muscular dystrophy (DMD) experience negative effects upon feeding and oral health. We aimed to determine whether the mandibular range of motion in DMD is impaired and to explore predictive factors for the active maximum mouth opening (aMMO). 23 patients with DMD (mean age 16.7 ± 7.7 years) and 23 controls were assessed using a questionnaire about mandibular function and impairments. All participants underwent a clinical examination of the masticatory system, including measurement of mandibular range of motion and variables related to mandibular movements. In all patients, quantitative ultrasound of the digastric muscle and the geniohyoid muscle and the motor function measure (MFM) scale were performed. The patients were divided into early and late ambulatory stage (AS), early non-ambulatory stage (ENAS) and late non-ambulatory stage (LNAS). All mandibular movements were reduced in the patient group (P < 0.001) compared to the controls. Reduction in the aMMO (<40 mm) was found in 26% of the total patient group. LNAS patients had significantly smaller mandibular movements compared to AS and ENAS (P < 0.05). Multiple linear regression analysis for aMMO revealed a positive correlation with the body height and disease progression, with MFM total score as the strongest independent risk factor (R(2) = 0.71). Mandibular movements in DMD are significantly reduced and become more hampered with loss of motor function, including the sitting position, arm function, and neck and head control. We suggest that measurement of the aMMO becomes a part of routine care of patients with DMD.

Predictive factors for masticatory performance in Duchenne muscular dystrophy.

Patients with Duchenne muscular dystrophy (DMD) report masticatory and swallowing problems. Such problems may cause complications such as choking, and feeling of food sticking in the throat. We investigated whether masticatory performance in DMD is objectively impaired, and explored predictive factors for compromised mastication. Twenty-three patients and 23 controls filled out two questionnaires about mandibular function, and underwent a clinical examination of the masticatory system and measurements of anterior bite force and masticatory performance. In the patients, moreover, quantitative ultrasound of the tongue and motor function measurement was performed. The patients were categorized into ambulatory stage (early or late), early non-ambulatory stage, or late non-ambulatory stage. Masticatory performance, anterior bite force and occlusal contacts were all reduced in the patient group compared to the controls (all p < 0.001). Mastication abnormalities were present early in the disease process prior to a reduction of motor function measurement. The early non-ambulatory and late non-ambulatory stage groups showed less masticatory performance compared to the ambulatory stage group (p < 0.028 and p < 0.010, respectively). Multiple linear regression analysis revealed that stage of the disease was the strongest independent risk factor for the masticatory performance (R(2) = 0.52). Anterior bite force, occlusal contacts and masticatory performance in DMD are severely reduced.

Validity of functional diagnostic examination for temporomandibular joint disc displacement with reduction.

The choice of approach for diagnosing temporomandibular joint (TMJ) anterior disc displacement with reduction (ADDR), viz. functional examination or TMJ imaging, is debatable and complicated by findings of low agreement between these approaches. Our aim was to investigate the validity of functional ADDR diagnostics using clinical examination and opto-electronic mandibular movement recordings versus magnetic resonance imaging (MRI). 53 participants (32 women and 21 men, mean age ± s.d. of 28.7 ± 10.1 years) underwent a clinical examination, mandibular movement recording and MRI of their TMJs within 1 month. All were performed and analysed in a single-blind design by different experienced examiners for each technique. The sensitivity and specificity of each functional diagnostic method was calculated, with MRI as the gold standard. Anterior disc displacement with reduction was diagnosed in 27.6% of the TMJs clinically, in 15.2% using the movement recordings and in 44.8% on MRI. The specificity of the clinical examination for diagnosing ADDR was 81.0%, and of the movement recordings, 96.6%. The sensitivity was 38.3% and 29.8%, respectively. The chance of having a false-positive functional diagnosis of ADDR compared with MRI is low, and disagreement between the functional methods and MRI is mainly due to the high number of MRI diagnoses in asymptomatic subjects. In view of the fact that ADDR becomes clinically relevant only when it interferes with TMJ function, the functional diagnostic approach can be considered benchmark in ADDR recognition.

Coronoid process hyperplasia: a systematic review of the literature from 1995.

The objective of this study was to review the literature and compare different surgical methods for the management of coronoid process hyperplasia. A literature search was performed for publications since 1995. Case characteristics were extracted (age, sex, duration of symptoms, form, maximal mouth opening and treatment) and entered into a database for analysis. The data were split into two groups (coronoidectomy and coronoidotomy). Maximal mouth opening measurements before and after surgery were analyzed with several statistical tests. 61 cases were entered into the database. The mean age was 23 years and mean duration of symptoms 7 years. The bilateral form occurred 4.1 times more frequently than the unilateral form. The male-female ratio was 3.3 to 1. In 94% of the cases the approach was intra-oral. 84% of the cases received a coronoidectomy. Statistical analysis showed that the preoperative and postoperative differences between the groups were significant. The results were not significant when corrected for the preoperative difference. Postoperative therapy was not comparable due to heterogeneity. Cases that received a coronoidotomy had slightly better postoperative results.

[Occupational differentiation in dentistry 3. Hypermobility of the temporomandibular joint and condylar position at maximal mouth opening]. / Beroepsdifferentiatie in de tandheelkunde 3. Hypermobiliteit van het kaakgewricht en de positie van het caput mandibulae bij maximale mondopening.

Hypermobility of the temporomandibular joint is only noted when it interferes with smooth mandibular movements. These interferences may result from a condylar dislocation beyond the temporal eminence at maximum mouth opening. Aim of this study was to test whether the condyle of a symptomatically hypermobile temporomandibular joint is positioned more anterosuperiorly to the temporal eminence at maximum mouth opening than a condyle without hypermobility. Nine persons with a hypermobile temporomandibular joint and 9 control persons participated. Diagnostics were based upon opto-electronic mandibular movement recordings. Condylar positions at maximum mouth opening were assessed by magnetic resonance imaging. A small significant difference in condylar position was found between groups. Condyles of persons with a hypermobile temporomandibular joint moved beyond the temporal eminence. However, this was also true for nearly half of the control persons. This suggests that condylar position alone is not a sufficient condition for symptomatic hypermobility of the temporomandibular joint. Maybe, symptoms of hypermobility only become apparent in combination with a particular line of action of the masticatory muscles.