Philip Lamey

Temperature changes in bovine mandibular bone during implant site preparation: an assessment using infra-red thermography

OBJECTIVES Changes in bone temperature during the sequence of drilling for implant site preparation using the Branemark technique were monitored using infra-red thermography. METHODS Bovine mandibles were used to provide cortical bone of a similar quality to human mandibular bone. To ensure the consistency in the drilling procedure, one operator used a conventional dental handpiece with a motor provided by Nobelpharma. The manufacturers specifications were followed during the implant site preparation, except that no irrigation was employed since infra-red radiation does not transmit through water. Thermal images were recorded using the Thermovision 900 system. A sequence of images was recorded during implant site preparation. Three drills were examined in terms of temperature changes during drilling over the entire area involved. The three drills used were a round bur, which determines the site of the fixture, a spiral drill (2 mm twist drill) which establishes the direction of the implant and finally a pilot drill (3 mm) which progressively increases the diameter of the site. RESULTS Average values (n = 10 drill sequences) for maximum recorded temperature (Max T degrees C), change in temperature (delta T degrees C) from baseline and the area of involvement (mm2) for each drill in the 10 drill sequences were as follows: round, spiral (2 mm) and pilot (3 mm) drills gave maximum temperatures of 82.7 degrees C, 130.1 degrees C and 126.3 degrees C, respectively. The changes in temperature, delta T degrees C, were 45.7 degrees C, 79.0 degrees C and 78.9 degrees C for the round, 2 mm twist and 3 mm pilot drill, respectively. The average areas recorded for the round, spiral and pilot drills were 49 mm2, 140.1 mm2 and 273.0 mm2, respectively. CONCLUSIONS It is concluded that the methodology employed accurately recorded temperature changes at and around the dental implant site, and provided preliminary baseline data against which the cooling efficacy of different irrigant systems may be compared.

Effect of Tear Hyperosmolarity and Signs of Clinical Ocular Surface Pathology upon Conjunctival Goblet Cell Function in the Human Ocular Surface

PURPOSE To investigate the effect of tear hyperosmolarity and signs of clinical ocular surface pathology on conjunctival goblet cell population. METHODS 111 participants were assessed using tear osmolarity (TO) measurements and a comprehensive selection of clinical ophthalmic tests. The resultant clinical database was assessed for evidence of patterns of composite increasing pathology. The total, filled, and empty goblet cell numbers were measured: total number of goblet cells as per cytokeratin 7 (CK7) immunofluorescence and number of filled goblet cells as per periodic acid Schiffs reagent (PAS) or lectin helix pomatia agglutinin (HPA). Goblet cell profile was correlated with composite clinical pathologic grades. RESULTS No significant correlation was found between TO and goblet cell number or function (as indicated by number of filled or unfilled goblet cells). Distinct composite clinical pathologic groups 0-IV with increasing pathology were created based on the frequency of positive pathologic signs, which adhered to the Dry Eye Workshop purported mechanism. Only in group IV was there significantly increased mean tear osmolarity of 344 mOsm/L (P < 0.000) along with significantly decreased empty goblet cell number (CK7+ and HPA-) compared to filled (CK7+ and HPA+, P = 0.000). When the number of filled goblet cells (PAS+) was analyzed there was significant increase in tear osmolarity for the two most severe grades; 3 and 4. CONCLUSIONS The goblet cell population does not appear to be affected by isolated tear hyperosmolarity. Hyperosmolarity when combined with other ocular surface pathology or inflammation alters the goblet cell population.

A patient-administered Medical Risk Related History questionnaire (EMRRH) for use in 10 European countries (multicenter trial).

OBJECTIVE The objective of this study was to produce a standardized medical risk-related history (MRRH) in order to identify the medically compromised patient (MCP) attending the general dental practitioner for treatment, to develop such a history (EMRRH), and to validate it in dental practices in 10 European countries. STUDY DESIGN The Dutch MRRH, adapted to allow for legal and cultural differences of the participating countries was introduced. After consensus and repeated testing, the questionnaire was validated. In this last phase, 1000 patients older than 18 attending dental practices were selected, 100 per country; 994 medical histories were suitable for statistical analysis. Validation was carried out by a physician accustomed to making preoperative assessments, including the ASA risk classification. RESULTS Mean specificity per country was 99.1 and per EMRRH item was 99.0. Mean sensitivity per country was 93.2 and per item was 93.7. Cohens kappa for the countries involved was 0.81 to 0.98 and for subsequent questions was 0.81 to 0.97. CONCLUSION The EMRRH was found to be valid in the detection of medically compromised patients in 10 European countries.

Evaluation of major parotid glycoproteins in patients with burning mouth syndrome

OBJECTIVE This study was to investigate the potential role of salivary glycoproteins in burning mouth syndrome. STUDY DESIGN This study compared major parotid glycoproteins in a group of patients with burning mouth syndrome and age-, sex-, race-matched healthy controls. RESULTS By use of a glycoprotein detection kit, saliva from both patients and controls exhibited three major parotid glycoprotein banding patterns consisting of either one or two bands, molecular weights 58 kDa and 77 kDa. The strong lectin reactivity of major parotid glycoproteins with Ricinus communis agglutinin suggests that galactose is the most prevalent terminal sugar. In addition, major parotid glycoproteins were shown to express blood group antigen H. On the basis of metachromatic characteristics and immunologic reactivity, major parotid glycoproteins appear to be members of the proline rich protein multigene family, proline rich glycoprotein, genetic polymorphism G1. No qualitative difference was observed in major parotid glycoprotein banding patterns between patients and controls. CONCLUSION These findings do not support a role for major parotid glycoproteins in burning mouth syndrome.

Masseter and Temporalis Muscle EMG Levels and Bite Force in Migraineurs

The purpose of this study was to compare absolute and proportional electromyography (EMG) levels in the masseter and temporalis muscles during performance of a variety of oral functions for migraineurs and age‐ and sex‐matched controls. Both groups consisted of nine women and one man, with a mean age of 43 years (range, 29 to 51 years). Absolute resting EMG levels and those levels during swallowing and speech were not significantly different between the groups, but the levels of the group with migraine were significantly higher during maximum voluntary effort contractions on the anterior teeth and on the posterior teeth for both muscles. When expressed as a percentage of those levels obtained at maximal posterior contraction (ie, proportional levels), no difference in functional activity was demonstrated between groups. It was concluded that the two groups studied had similar levels of EMG activity in the masseter and temporalis muscles during the normal oral functions investigated, but that the group with migraine had higher levels of absolute EMG activity during anterior and posterior maximum voluntary contractions. Furthermore, the group with migraine demonstrated higher levels of anterior and posterior bite force, although not correlated with EMG levels.

Migraine and masticatory muscle volume, bite force and craniofacial morphology

The purpose of this investigation was to compare the masticatory muscle volume, bite force, and craniofacial morphology of migrainous subjects with age‐ and sex‐matched controls. Ten adult dentate migraineurs were matched with 10 dentate age‐ and sex‐matched controls. The groups consisted of nine women and one man (mean age, 43 years; range, 29 to 51 years). Volumetric analysis of the masseter and medial pterygoid muscles was performed using magnetic resonance imaging. Craniofacial morphology was analyzed from standard cephalometric radiographs using 30 angular and linear variables. Recordings of bite force were made using a strain gauge transducer. There was a significant difference in the volume of both masseter and medial pterygoid muscles between the two subject groups (P<.0001), with the muscles of the migraineurs nearly 70% larger. The migraineurs recorded significantly higher maximal bite forces (P<.0001) than did the controls. No significant differences for any craniofacial morphological measurement were demonstrated between the two groups. It was concluded that the migraineurs had larger masseter and medial pterygoid muscle volumes, and greater bite forces than the controls, which could not be explained by any change in craniofacial morphology.

A comparison of four extraction methods for substance P, neurokinin A and calcitonin gene-related peptide from human dental pulp tissue.

Measuring neuropeptides in biological tissues by radioimmunoassay requires efficient extraction that maintains their immunoreactivity. Many different methods for extraction have been described, but there is little information on optimal extraction methods for individual neuropeptides from human dental pulp tissue. The aim was therefore to identify an effective extraction procedure for three pulpal neuropeptides; substance P, neurokinin A and calcitonin gene-related peptide. Tissue was obtained from 20 pulps taken from teeth freshly extracted for orthodontic reasons. The pulp samples were divided into four equal groups and different extraction methods were used for each group. Boiling whole pulp in acetic acid gave the highest overall yield and, in addition, offered an easy and rapid means of pulp tissue processing. The use of protease inhibitors did not increase the recovery of the immunoreactive neuropeptides but did provide the best combination of maximal recoveries and minimal variability. These results should be useful for planning the extraction of these neuropeptides from human pulp tissue in future studies.