Frequency and Management of Accidental Incidents in Orthodontics.

BACKGROUND: The present study aims to define through questionnaires the frequency and the variety of accidental incidents occurring in orthodontic clinical practice among Greek practicing orthodontists. METHODS: A questionnaire survey was conducted among orthodontists from the registry of orthodontists in Greece. The questionnaire was divided into two parts. The first part involved three questions relating to the socio-demographic status and the background of the orthodontist, and the second part concerned exclusively the frequency of accidental incidents that have occurred during clinical practice with three possible answers: never, once, more than once. RESULTS: From the 200 initially distributed questionnaires, 124 were finally completed and sent back (response rate: 62%). The results showed that orthodontists with more years of clinical practice had faced more accidental incidents. Among the ingestion incidents caused by foreign objects, the most frequently occurring was the ingestion of elastic separators, followed by the ingestion of elastic ligatures and ingestion of hooks. The most commonly reported traumatic incidents were the trauma-lesion of the mucosa by the orthodontic wire or part of it, followed by trauma-lesion by hooks and wire ligatures. The reported number of incidents with further complications and with patients referred to an emergency room was very low. CONCLUSIONS: The results of the present study determined a high frequency of accidental incidents among Greek orthodontists. The longer clinical experience was accompanied by more accidental incidents. Orthodontists, like other health professionals, must learn and continuously update their knowledge regarding the management protocols of medical emergencies.

IGF-IEc Expression Is Associated With Advanced Differentiated Thyroid Cancer.

BACKGROUND/AIM: Recent knowledge implicates a differential expression of the insulin-like growth factor-I (IGF-I) mRNA splice variants (i.e., IGF-IEa, IGF-IEb and IGF-IEc) in cancerous tissues, implying possible specific roles of the encoded IGF-I protein isoforms in cancer biology. In particular, there is growing evidence that the IGF-IEc isoform may play a distinct biological role in various types of cancers. The present study investigated whether IGF-IEc expression is associated with a particular type of thyroid cancer. MATERIALS AND METHODS: Formalin-fixed paraffin-embedded tissue specimens of different types of thyroid cancers from 92 patients were assessed for IGF-IEc expression by immunohistochemistry. In addition, thyroid cancer biopsies of different TNM staging histological types were evaluated for mRNA expression of the IGF-IEc transcript by real-time polymerase chain reaction (PCR). RESULTS: From the total number of 92 samples, 2 were anaplastic, 10 medullary, 4 hyperplasias of C-cells, 11 follicular, 5 hurtle cell carcinomas, 2 poorly differentiated, 5 nodular hyperplasias, 1 lymphoma and 52 were papillary thyroid cancers. The age of cancer diagnosis or tumor size did not significantly affect the IGF-IEc expression. Among all types of cancers, IGF-IEc was expressed in papillary differentiated thyroid cancer. Its expression/localization was mainly cytoplasmic and significantly associated with TNM staging and the presence of muscular and capsule cancerous invasion (p<0.05). Similarly, a differential profile was revealed regarding the mRNA expression of the IGF-IEc transcript, that exhibited a higher expression in aggressive compared to the non-aggressive papillary cancers. CONCLUSION: IGF-IEc isoform expression in thyroid cancer is positively associated with more advanced stages of papillary thyroid cancer.

The anterior component of occlusal force revisited: direct measurement and theoretical considerations.

BACKGROUND: The anterior component of occlusal force (ACF), considered to result from the mesial inclination of teeth relative to the occlusal plane, has been estimated by indirectly measuring contact point tightness (CPT) through interproximal insertion of metal strips. ACF has been observed concurrently with a posterior component, whose theoretical origin is difficult to explain. OBJECTIVES: Evaluate ACF by measuring CPT directly, and integrate current data to propose a theoretical basis for ACF. MATERIALS AND METHODS: The sample comprised 14 females (age: 22.3±2.8) and 16 males (age: 20.8±2.5). Our device consisted of two force sensors: one for measuring maximum bite force (MBF) (overall thickness: 4mm), and one for measuring CPT directly (0.2mm thick), inserted between the lower first molar and second premolar. ACF was computed as the difference in CPT between the biting (at 75 per cent of MBF) and non-biting conditions. RESULTS: Averages of MBF, CPT, and ACF were 666.67 [standard deviation (SD): 36.06], 6.74 (SD: 1.17), and 20.59 (SD: 4.60) N, respectively. ACF, CPT, and MBF were higher in males by approximately 28, 18 and 7 per cent, respectively. A positive correlation was observed between ACF and MBF (R (2): 0.64). CPT was also significantly correlated to MBF (R (2): 0.40). Biomechanical analysis indicates that previously offered explanations do not unriddle the concurrent increase of CPT at anterior and posterior contact points. CONCLUSIONS: ACF was related to bite force by a logarithmic model. We speculate that CPT increases during biting through a combination of mesial tipping of teeth and mandibular bending.