Clinical Application Of Thermography In Dentistry

Clinical Application Of Thermography In Dentistry

Thermography measurement in the clinical set up can be done on a given spot or over an extended area of interest. Infrared telethermography of the face in normal subjects have shown that men have higher temperatures than females. The rationale behind this is that men have more basal metabolic than women and his skin dissipates more heat per unit area of body surface. Similarly age and ethnicity variations in facial temperature can also occur. [14-16]

In Chronic Orofacial pain patients

Gratt and his colleagues in 1996 developed a classification system using telethermographs for patients with chronic pain. [17] They classified them as normal when selected anatomic area (∆T) values range from 0.0 to +0.250C, hot when it is >0.350C, and cold when it is <0.350C. When a selected anatomic area value is 0.26- 0.350C, the finding is classified as equivocal. Moreover they also found that hot thermographs had the clinical diagnosis of (1) sympathetically maintained pain, (2) peripheral nerve mediated pain, (3) TMJ arthropathy, or (4) maxillary sinusitis. Subjects classified with cold subareas on their thermographs were found to have the clinical diagnosis of (1) peripheral nerve-mediated pain (2) sympathetically independent pain. Subjects classified with normal telethermographs included patients with the clinicaldiagnosis of (1) cracked tooth syndrome (2) trigeminal neuralgia (3) pretrigeminal neuralgia (4) psychogenic facial pain. This system of thermal classification resulted in 92% agreement in classifying pain patients making it as an important diagnostic parameter. [12,17]

In TMJ disorders

Normal TMJ examination using thermography had showed symmetrical thermal patterns with a mean

∆T values of 0.10C. [12, 14, 18] On the other hand, patients affected with internal derangement and TMJ osteoarthritis showed ∆T values of +0.40C. [19, 20] Beth and Gratt in 1996 conducted a double-blinded clinical study to compare the ∆T values among active orthodontic patients, TMD patients and symptomatic TMJ controls. The results showed that the average TMJ area ∆T values as +0.20C, +0.40C, and +0.10C in these groups respectively.(21) The above findings suggest that tele-thermography can distinguish between patients undergoing active orthodontic treatment and patients with TMD. [12,21]

In quantification of thermal insult to pulp

Dental pulpal tissue is exposed to variety of thermal insult during various dental treatment modalities.

Of late for debonding of orthodontic brackets Eelectro Thermal Ddebonding (ETD) method is widely used, this technique although has many advantages than the conventional mechanical method can pose serious thermal damage to pulp. Cummings and his colleagues in 1999 performed an in-vitro study on extracted human premolar teeth applying ETD. Thermal imaging analysis was done using mercury cadmium terullide detector showed that the pulpal temperature increased from 16.80C- 45.60C, which can pose serious threat to pulpal vitality. It can be stated from the study that, ETD methods needs intermittent cooling of the teeth with simultaneous thermal imaging to prevent pulpal damage. [22] Similarly the use of ultra high speed air-driven instrumentation during cavity preparation can result in serious thermal insult to the pulp. To overcome this, it is believed that various coolants (air water spray or air/water alone) can be used to reduce the intrapulpal temperature and prevent subsequent damage to the pulp. It was only until 1979, when Carson and his colleagues performed a study employing thermography to determine the pattern of heat distribution and dissipation during ultra-speed cavity preparation using both an air-water spray and air only coolants to determine if a point heat source is generated. This study stated that the mean magnitude of temperature increases with both types of coolant, 2.80C and 3.670C, probably does not exceed the physiologic limits of the pulp. [23] 

In assessing inferior alveolar nerve deficit

Over the years numerous studies have shown that thermal imaging technique can play a vital role in effective assessment of inferior alveolar nerve deficit. [12,24] Gratt and his colleagues in 1994 stated that patients with inferior alveolar nerve deficit when examined showed ∆T values of +0.50C on the affected side whereas subjects with no inferior alveolar nerve deficit showed a symmetrical thermal ∆T value of +0.10C. [25] The authors stated that the changes are due to blockage of the vascular neuronal vasoconstriction and this was confirmed by the same colleagues in the same year when similar thermological picture was obtained in normal subjects by temporary blockage of the inferior alveolar nerve using 2% lidocaine. [26]

Qualitative evaluation of N2O concentration

N2O is a highly insoluble gas which is rapidly absorbed and is eliminated swiftly by the lungs, thus it is used widely either alone or in combination with other anesthetic agents. [27] Results of various studies have shown that leakage of N2O into the workplace can lead to adverse health effects such as reproductive, hematologic and nervous dysfunctions. [28] Studies on acute and chronic occupational exposures have shown that N2O air concentration levels as low as 50 parts per million (ppm) can result in bone marrow depression, paresthesias, altered concentration, impaired visual effects, alterations in vitamin B12 and plasma homocysteine concentrations. [29-31]

In response to these findings and in order to effectively control exposures several guidelines have been published that define appropriate use and control criteria for N2O usage. The ADA made 10 recommendations that address the use of appropriate engineering controls for proper scavenging. [32] However, they are proved futile and health hazards secondary to N2O exposure is still on the rise. Rademaker et al in 2009 conducted a study using infrared thermography to determine the effectiveness of two N2O scavenging systems- The Safe Sedate Dental Mask (Airgas, Radnor, Pa.) system (System I) and Porter Nitrous Oxide Sedation System (Porter Instrument, Hatfield, Pa.) (System II). The results suggested that neither of the system was able to control occupational exposure of N2O oxide below the NIOSH REL. [33]

Additional applications of telethermography

- Evaluation of cranio mandibular disorders. [34]

- Detection of carotid occlusal disease. [35]

- Quantification of the effects of post-surgical inflammation. [36]

- Quantification of the effects of analgesics, anti-inflammatory drugs, etc.

- In the diagnosis of myofacial symptoms.

Conclusion

Thermography aids in the assessment and staging of various dysfunctions of the head and neck region.The unique significance of thermography is both qualitative and quantitative assessment which helps in estimation of progression of the disease in a systematic manner. With the innovation of novel equipments and the state of the art facility, thermography in the near future will certainly re-emerge as a unique research tool in dentistry.

References

[1] Anbar M. Diagnostic thermal imaging: A historical technological perspective. In: Anbar M (ed). Quantitative Dynamic Telethermography in Medical Diagnosis. CRC Press: BocaRaton. 1994), pp 1-9.

[2] Adams F. Hippocratic Writings, In: Hutchins RM (ed). (Hippocrates, Galen, Vol. 10 of Great Books of the Western World, Univ. of Chicago, Encyclopedia Britannica Inc. 1952),pp 66-77.

[3] Wolf A. A History of Science and Technology and Philosophy in the 16th & 17th Centuries. 2nd ed., McKee D (ed). George Allen & Unwin: London. 1950, pp 66-77.

[4] Bedford RE. Thermometry. In: The New Encyclopedia Britannica, 15th ed, Chicago. Ill. 1992; 11: 702-703.

[5] Hardy JD. The radiation of heat from the human body: I-IV. J Clin Invest. 1934; 13: 593-620.

[6] Hardy JD, Muschenheim C. The radiation of heat from the human body: V. J Clin Invest. 1936; 15: 1-8.

[7] Weinstein SA. Standards for neuromuscular thermographic examination. Modern Medicine: supplement. 1986; 1: 5-7.

[8] Anbar M, Gratt BM, Hong D. Thermology and facial telethermography. Part I: history and technical review. Dento maxillofac Radiol. 1998; 27: 61-67.

[9] Anbar M. Fundamentals of computerized thermal imaging. In: Anbar M. Quantitative Dynamic Telethermography in Medical Diagnosis. CRC Press: Boca Raton. 1994, pp 99-131.

[10] Anbar M. Dynamic area telethermometry: a new field in clinical thermology: Part II. Medical Electronics. 1994; 147: 73-85.

[11] Anbar M. Dynamic area telethermometry and its clinical applications. SPIE Proc. 1995; 2473: 312-331

[12] Gratt BM, Anbar M. Thermology and facial telethermography: Part II: Current and future clinical applications in dentistry. Dento maxillofac Radiol. 1998; 27: 68-74.

[13] Ongole R, Praveen BN. Chapter 21- Specialized imaging techniques. In: Clinical manual for Oral Medicine and Radiology. Jaypee Brothers, New Delhi. 2007, pp 439-441.

[14] Gratt BM, Sickles EA. Electronic facial thermography: an analysis of asymptomatic adult subjects. J Orofacial Pain. 1995; 9: 255-265.

[15] Blaxter K. Energy exchange by radiation, convection, conduction, and evaporation. In: Energy Metabolism in Animals and Man Cambridge Univ. Press: New York, 1989: pp 86- 99.

[16] Blaxter K. The minimal metabolism. In: Energy Metabolism in Animals and Man. Cambridge Univ. Press: New York, 1989, pp 120-146.

[17] Gratt BM, Graff-Radford SB, Shetty V, Solberg WK, Sickles EA. A six-year clinical assessment of electronic facial thermography Dentomaxillofac Radiol. 1996; 25: 247 -255.

[18] Gratt BM, Sickles EA. Thermographic characterization of the asymptomatic TMJ. J Orofacial Pain. 1993; 7: 7-14.

[19] Gratt BM, Sickles EA, Ross JB. Thermographic characterization of an intemal derangement of the temporomandibular joint. J Orofacial Pain. 1994; 8: 197-206.

[20] Gratt BM, Sickles EA, Wexler CA. Thermographic characterization of osteoarthrosis of the temporomandibular joint. J Orofacial Pain. 1993; 7: 345-353.

[21] McBeth SA, Gratt BM. A cross-sectional thermographic assessment of TMJ problems in orthodontic patients. Am J Orthod Dentofac Orthop. 1996; 109: 481-488.

[22] Cummings M, Biagioni P, Lamey PJ, Burden DJ. Thermal image analysis of electrothermal debonding of ceramic brackets: an in vitro study. European Journal of Orthodontics. 1991; 21: 111-118.

[23] Carson J, Rider T, Nash D. A Thermographic Study of Heat Distribution during Ultra-Speed Cavity preparation. J Dent Res. 1979; 58; 16-81.

[24] Gratt BM, Shetty V, Saiar M, Sickles EA. Electronic thermography for the assessment of inferior alveolar nerve deficit. Oral Surg Oral Med Oral Pathol. 1995; 80: 153-160.

[25] Gratt BM, Sickles EA, Shetty V. Thermography for the clinical assessment of inferior alveolar nerve deficit: A pilot study. J Orofacial Pain. 1994; 8: 369- 374.

[26] Shetty V, Gratt BM, Flack V. Thermographic assessment of reversible inferior alveolar nerve deficit. J Orofacial Pain. 1994; 8: 375-383.

[27] Emmanouil DE, Quock RM. Advances in understanding the actions of nitrous oxide. Anesth Prog. 2007; 54(1):9-18.

[28] Cohen EN, Brown BW Jr, Bruce DL, et al. A survey of anesthetic health hazards among dentists. JADA. 1975; 90(6):1291-1296.

[29] McGlothlin JD, Crouch KG, Mickelsen RL. Control of nitrous oxide in dental operatories. Cincinnati: National Institute for Occupational Safety and Health; U.S. Department of Health and Human Services (NIOSH) publication.1994; 94-129.

[30] Krajewski W, Kucharska M, Pilacik B, et al. Impaired vitamin B12 metabolic status in healthcare workers occupationally exposed to nitrous oxide. Br J Anaesth. 2007;99(6):812-818.

[31] Myles PS, Chan MT, Leslie K, Peyton P, Paech M, Forbes A. Effect of nitrous oxide on plasma homocysteine and folate in patients undergoing major surgery. Br J Anaesth. 2008; 100(6):780-786.

[32] ADA Council on Scientific Affairs; ADA Council on Dental Practice. Nitrous oxide in the dental office. JADA. 1997; 128(3):364-365.

[33] Rademaker MA et al. Evaluation of Two Nitrous Oxide Scavenging systems Using Infrared Thermography to Visualize and Control Emissions. J Am Dent Assoc. 2009; 140; 190-199.

[34] Biagioni PA, Longmore RB, McGimpsey JG, Lamey PJ. Infrared thermography. Its role in dental research with particular reference to craniomandibular disorders. Dentomaxillofac Radiol. 1996; 25: 119-124.

[35] Friedlander AH, Gratt BM. Panoramic dental radiography and thermography as an aid in detecting patients at risk for stroke. J Oral Maxillofac Surg. 1994; 52: 1257- 1262.

[36] Sudhakar S, Bina kayshap, Sridhar reddy P. Thermography in dentistry-revisited. Int J Biol Med Res. 2011; 2(1): 461-465

Evaluation of provocation test monitoring palmoplantar temperature with the use of thermography for diagnosis of focal tonsillar infection in palmoplantar pustulosis.

J Dermatol Sci. 2003 Aug;32(2):105-13.

Evaluation of provocation test monitoring palmoplantar temperature with the use of thermography for diagnosis of focal tonsillar infection in palmoplantar pustulosis.

Asada H, Miyagawa S, Tamura M, Azukizawa H, Tanemura A, Yamaguchi Y, Sumikawa Y, Itami S, Kubo T,Yoshikawa K.

Source

Department of Dermatology, Nara Medical University, 840 Shijo-cho Kashihara, 634-8522, Nara, Japan. asadah@naramed-u.ac.jp

Abstract

BACKGROUND:

Since focal tonsillar infections are often associated with palmoplantar pustulosis (PPP), provocation tests have been performed for preoperative evaluation of tonsillectomy. However, these tests have not been fully established.

OBJECTIVES:

To introduce a more sensitive operative indication for tonsillectomy to the patients with PPP, we have monitored the temperature after provocation tests at palmoplantar sites, as measured by thermography, and we hypothesized that this methodology may lead to a more sensitive marker for tonsillectomy.

METHODS:

Twenty-two PPP patients with/without clinical tonsillitis were included in this study. After mechanical tonsillar massage, using infrared thermography, we have monitored the surface temperature at palmoplantar sites of 22 patients with PPP, five chronic tonsillitis patients without PPP, and four healthy controls, to compare the findings with the skin lesional outcome after tonsillectomy.

RESULTS:

There was a significant relationship between the effects of tonsillectomy and the results of provocation tests assessed by thermography. The sensitivity, specificity, and efficiency of the provocation tests with thermography of detecting a favorable outcome of tonsillectomy were 75.0, 83.3, and 77.3%, respectively, while those of the provocation tests as estimated with the conventional criteria were 37.5, 83.3, and 50.0%, respectively.

CONCLUSION:

Our results suggest that a new indicator using non-invasive thermography for the provocation tests is useful in predicting the effects of tonsillectomy for PPP.

Intracoronary thermography: does it help us in clinical decision making?

J Interv Cardiol. 2005 Dec;18(6):485-9.

Intracoronary thermography: does it help us in clinical decision making?

Toutouzas K, Drakopoulou M, Stefanadi E, Siasos G, Stefanadis C. Source 1st Department of Cardiology, Medical School of Athens University, Hippokration Hospital, Athens, Greece. ktoutouz@otenet.gr

Abstract
The concept of the "vulnerable" plaque has recently emerged to explain how quiescent atherosclerotic lesions evolve to cause clinical events. The morphologic and immunologic determinants specific for the vulnerable plaque have been reported: a large lipid core (>or=40% plaque volume) composed of free cholesterol crystals, cholesterol esters, and oxidized lipids impregnated with tissue factor; a thin fibrous cap depleted of smooth muscle cells and collagen; an outward (positive) remodeling; inflammatory cell infiltration of fibrous cap and adventitia (mostly monocyte-macrophages, some activated T cells, and mast cells); and increased neovascularity. Despite the large amount of information regarding the morphological characteristics of remote lesions, we lack studies with functional assessment of non-culprit lesions. Coronary thermography is a technique for functional assessment of coronary atherosclerotic plaques. Several catheter designs have been proposed. There are catheters with thermistor(s) and wires with thermal sensors at the distal tip. All designs have several advantages and disadvantages. Despite the current limitations of coronary thermography, we gained important pathophysiological and clinical information regarding the vulnerability of atheromatic plaques. It has been documented both experimentally and clinically that increased heat generation is associated with increased macrophage concentration within the plaque. The correlation between local inflammatory involvement and local heat generation has also been observed with the peripheral inflammatory markers such as C-reactive protein. Whether systemic treatment, with agents such as statins or interventional techniques, such as drug-eluting stents, will have an impact on stabilizing vulnerable plaques need to be determined in future studies.

Conclusion
Although there are several techniques for evaluating morphologically atheromatic plaques, thermography is a promising method for the functional assessment of vulnerable plaque and has been introduced into clinical practice, with a good predictive value for clinical events in patients with increased temperature in the atherosclerotic plaque.

(J Interven Cardiol 2005;18:485-489).

PMID: 16336430 [PubMed - indexed for MEDLINE]

Contact-free infrared thermography for assessing effects during acupuncture: a randomized, single-blinded, placebo-controlled crossover clinical trial.

Acupuncture:

Anesthesiology. 2009 Sep;111(3):632-9.

Contact-free infrared thermography for assessing effects during acupuncture: a randomized, single-blinded, placebo-controlled crossover clinical trial.

Agarwal-Kozlowski K, Lange AC, Beck H. Center for Palliative Care and Pain Management, Doerenberg Medical Center, Bad Iburg, Germany.

BACKGROUND:
Although evidence of its effects is tentative, acupuncture has long been used in the treatment of
multiple maladies. So far, it has not been possible to discriminate the effects of the venue from
specific results of needling itself, thus physicians merely depend on patients' statements. The
authors investigated the efficacy of infrared thermography in distinguishing response to true
acupuncture as compared to nonacupoint cutaneous and muscular needling (sham or minimal
acupuncture), as well as without manipulation.

METHODS:
Thermographic imaging was performed in 50 healthy volunteers randomly assigned to four
groups: Acupuncture of Hegu (LI 4), needling of a cutaneous and a muscular point where no
acupuncture point has been described yet, and without manipulation. In a crossover protocol,
each proband completed all four arms of the protocol in a random order. Infrared thermograms
were gathered at defined points in each group.

RESULTS:
A significant increase in surface temperature occurred within 2 min after needling the
acupuncture point Hegu (from 30.1 +/- 2.7 degrees C [SD] to 31.2 +/- 3.0 degrees C and to 31.9
+/- 2.5 degrees C after 10 min, P < 0.001), whereas needling of the cutaneous and muscular
point, as well as without any manipulation resulted in a decrease of temperature in the monitored
area.

CONCLUSION:
Contact-free infrared thermographic imaging is a reliable and easy-to-handle tool to
distinguish between needling at Hegu and needling of a nonacupoint ("sham"
acupuncture).

Thermography and Return to Play Decisions
Dr. William A. Sands

Inflammation is a consistent indicator of injury and ongoing healing. Thermal imaging is
used for the characterization of inflammation. Thermal imaging can be used to monitor
the location, status, and progress of an injury by comparisons of the size of the injured
area and its temperature.

• Injuries foster a number of decisions that suffer from uncertainty, yet may require firm commitment, vigilance, and follow-through to resolve the injury. Uncertainty arises from variations in diagnoses, healing capacities, pain tolerance, effectiveness of healing modalities and medications, and
psychological support (1,3,6,8,9). Those who treat athletic injuries, coaches, athletes, and parents are often faced with return to play decisions that are wrought with pitfalls due to the lack of pertinent information regarding the athlete’s current injury state, his/her current performance status, and the risks and benefits of returning to activity. However, thermography technology may reduce the uncertainty.

Thermography involves the use of a special camera that can detect a portion of the
electromagnetic spectrum that lies just below the region of visible light–infrared light. Infrared light is the product of heat; all objects show heat, unless the object is at the temperature of absolute zero.

People are terrific heat sources. The heat that people produce is variable depending on the region of the body, metabolism, and other factors. One of the greatest sources of heat is that due to inflammation. Inflammation is derived from the same word as “flame” and accompanies all types of pain and injury. Inflammation is detectable as a heat source in the injured athlete, particularly when the temperature of the inflamed area is higher than that of the surrounding skin.

One of the interesting properties of inflammation and the detection of the heat produced by inflamed tissues is that even deep tissues often show a “signature” of heat in the overlying skin. In athletic injury, inflammation is usually reasonably close to the skin surface and easily detectable by thermal imaging equipment (2,4,5,10,11,12).

Thermal imaging has been used for injury and disease detection, malingering, and other
characteristics (2,4,5,7,10,11). Recent experience has shown that thermal imaging can be
used to assess the status and change of active inflammation that can reduce the
uncertainty regarding return to play decisions. Pain and inflammation have always been
coincident; thermal imaging can assess the presence of inflammation and thus provide
information about the progress of injury healing.

Monitoring the healing and recovery from injury with thermal imaging can help determine
whether an athlete’s injury has ceased the active inflammation period. Clearly, if
inflammation is still present, return to play should be postponed, further medical
consultation is needed, and increased vigilance and caution are merited. Injuries that have
become mostly or completely pain-free have been monitored with thermal imaging and the
injuries have shown a return of inflammation after premature return to play.

In conclusion, thermal imaging can provide a window into the world of injury recovery and
reduce the uncertainty involved in return to play decisions. Thermal imaging equipment
has been dropping in price for years and is available in a variety of camera-types and
configurations. Those concerned with return to play decisions are encouraged to consider
thermal imaging.

Viscero-cutaneous reflexes in relation to abdominal and pelvic pain. A study from 1982 with females with IUD insertions

• 
  

Phe van der Veen

Thermology International 08/2013; 23(3):87-92.

ABSTRACT OBJECTIVES: The aim of this study was to establish whether there is a relationship between a specific area of the abdominal wall and the uterus as the accompanying organ. The null hypothesis in this study was: the uterus has no specific area of skin which relates to viscero- cutaneous reactivity. The study had to able to take place in a G.P.'s practice, and had to comply with strict medical ethics requirements (a medical ethics review board did not exist at that time), particularly the study must not constitute any risk or cause any discomfort to the participants.

STUDY DESIGN: The target group consisted of 31 healthy women between 20 and 45 years of age who wanted an IUD inserted or replaced. The study took place in a G.P.'s practice where IUDs had already been inserted over a period of many years.

INTERVENTION: The IUD-insertion procedure was not changed during the study. After oral consent had been obtained from the patient, infrared thermographic images were recorded of the the abdominal wall immediately before and after IUD insertion.

STATISTICS: The average temperatures of four areas were measured and analysed in 1982 and 2012 with the Wilcoxon Signed Rank test.

RESULTS: There is one specific area where the skin temperature changes significantly more than elsewhere (p<0.001). This area is the same area as the one in which temperature changes have been measured in a study with pregnant women.

CONCLUSIONS: The null hypothesis must be rejected. This study shows the potential of mapping 'referred zones' with infrared thermography. The findings also question abdominal wall pain as an independent disease entity. Changes of inner organs should be considered as cause of abdominal wall pain.

Viscerocutaneous reflexes with abdominal wall pain: A study conducted in 1981 on pregnant women from a general practice

Viscerocutaneous reflexes with abdominal wall pain: A study conducted in 1981 on pregnant women from a general practice

Phe van der Veen

Thermology International 04/2013; 23(2):56-63.

ABSTRACT BACKGROUND: This is an article regarding an unpublished study that was designed and conducted in 1981, but publication in time was not possible due to the workload in the busy practice of the author. Temperature changes on the abdominal wall could be caused by nociceptive sensations in the viscera which are transfered to the surface via viscerocutaneous reflex pathways. Two aspects play a role in this: 1. An internal organ’s proximity to the skin, 2. That organ’s registration of function to the skin. This study addresses the registration of function of an organ on a specific site of the skin. The aim of the study was to investigate if infrared thermography can measure temperature changes associated with the functional status of a pregnancy. The null hypothesis was: during the course of pregnancy, there is no difference in skin temperature between the skin areas selected.

METHODOLOGY: The occurrence of viscerocutaneous reflexes was investigated by means of infrared thermography in a group of pregnant women who were cared for in a general medical practice.This observational study started on the first visit for a pregnancy check-up and at every check-up visit, the temperature was measured. Because the check-ups were scheduled by the doctor based on indications or on woman’s request, the number of measurement differs among women. We used a linear mixed-effects model to model the difference in temperature between the genital zone and navel zone, with week and complaint group as fixed effects.

INTERVENTION: On four areas of the abdominal wall, infrared thermography temperature measurements were taken on the abdominal skin.

RESULTS: During pregnancy, a significant temperature difference developed between the genital zone and the navel zone (t=-6.019), caused by lower temperature in the genital zone that became visible approximately in the 34th week of the pregnancy.

CONCLUSIONS: The null hypothesis should be rejected. Infrared thermography seems to be able to measure the viscero- cutaneous consequences of a visceral process on a physiological level. The investigation with pregnant women reported in this publication is relevant for two reasons, because the evidence based data show that: 1. Infrared thermography can play a role in the detection of processes in the viscerum. 2. Chronic pain of the abdominal wall cannot be an isolated entity. This confirms extensively documented literature published previously. Abdominal wall pain continues to be a major problem medically, economically, and socially. Abdominal problems must be ruled out explicitly when searching for the location of abdominal wall pain. Differential diagnostics are a prerequisite for determining a specific solution.

Infrared thermography in newborns: the first hour after birth.

Christidis I, Zotter H, Rosegger H, Engele H, Kurz R, Kerbl R. Department of Pediatrics, University of Graz, Austria.

OBJECTIVE: It was the aim of this study to investigate the surface temperature in newborns within the first hour after delivery. Furthermore, the influence of different environmental conditions with regard to surface temperature was documented.

METHODS: Body surface temperature was recorded under several environmental conditions by use of infrared thermography. 42 newborns, all delivered at term and with weight appropriate for date, were investigated under controlled conditions.

RESULTS: The surface temperature immediately after birth shows a uniform picture of the whole body; however, it is significantly lower than the core temperature. Soon after birth, peripheral sites become cooler whereas a constant temperature is maintained at the trunk. Bathing in warm water again leads to a more even temperature profile. Radiant heaters and skin-to-skin contact with the mother are both effective methods to prevent heat loss in neonates.

CONCLUSIONS: Infrared thermography is a simple and reliable tool for the measurement of skin temperature profiles in neonates. Without the need of direct skin contact, it may be helpful for optimizing environmental conditions at delivery suites and neonatal intensivecare units."

Ref. S. Karger AG, Basel

Thermology and facial telethermography: Part II. Current and future clinical applications in dentistry.

Gratt BM, Anbar M Section of Oral Radiology, UCLA School of Dentistry 90095-1668, USA.

Selected clinical applications using thermal imaging as an aid in dentistry are reviewed. Facial skin temperature can easily be measured in a clinical setting, without direct skin contact, by monitoring the emitted infrared radiation. This is the basis of static area telethermography (SAT) and dynamic area telethermography (DAT). SAT has recently been shown to be of help to the dentist in (1) the diagnosis of chronic orofacial pain, (2) as a unique tool in assessment of TMJ disorders, (3) as an aid in assessment of inferior alveolar nerve deficit, and (4) as a promising research tool. DAT, recently made possible by advances in computing technology combined with advanced infrared sensor technology, extracts quantitative information about hemodynamic processes from hundreds to thousands of digital thermal images of the affected facial areas, measured and collected within less than 3 min. DAT has promise of offering a better insight into aberrations of the neuronal control of facial skin perfusion and aiding our understanding of the correlation between orofacial pain and facial thermal abnormalities. This promising new insight may help in the management of orofacial pain.