Abstract
Purpose
Orthopantomograms (OPT) are used to assess the anatomical relationship between the inferior alveolar nerves (IAN) and the roots of third molars and the related risk of postextraction iatrogenic neurological lesions. When the risk is high, computed tomography (CT) or conebeam CT may be warranted. We investigated how dentists judged the need for CT from OPT to ascertain whether they comply with criteria of justification, appropriateness and optimisation in prescribing examinations involving radiation.
Materials and methods
A total of 2,713 letters were sent to Italian dentists (Veneto region), inviting them to access an Internet Web site showing 20 OPTs and answer a questionnaire on the need for CT or periapical X-ray. The gold standards were CT images corresponding to the OPTs. The respondents’ answers were rated for appropriateness and their tendency to over- or underprescribe CT.
Results
The questionnaire was completed by 11.9% of the dentists contacted. The response rate was compatible with a Web survey. Their answers generally came close to the gold standard, achieving a mean appropriateness rating of 0.636 (range 0–1). An overlap between the mandibular canal and the third-molar root was the anatomical relationship most often noted. Recommendations for CT were proportional to the number of radiographic signs indicating a risk of inferior alveolar nerve injury. Periapical X-ray was considered useful by 54.9% of dentists not recommending CT. The main reason stated for not recommending CT was that it was unnecessary for the purposes of the extraction.
Conclusions
Our survey revealed a cautious approach among the professionals interviewed, who tended to overprescribe CT.
Riassunto
Obiettivo
L’ortopantomografia (OPT) è utilizzata per valutare la vicinanza del nervo alveolare inferiore (NAI) alle radici del terzo molare e il rischio di una lesione neurologica iatrogena post-estrattiva. Quando il rischio è elevato, può essere richiesta la tomografia computerizzata (TC) o TC cone beam. Lo scopo del nostro lavoro è di verificare come viene percepita la necessità di TC dopo visione di OPT da parte di un campione di dentisti, ovvero se vi è rispetto dei criteri di giustificazione, appropriatezza e ottimizzazione nella prescrizione di esami radiologici.
Materiali e metodi
Sono state inviate 2713 lettere a dentisti italiani (regione Veneto), chiedendo di accedere ad un sito internet contenente 20 OPT ed un questionario riguardanti l’indicazione alla TC o alla radiografia endorale. Come gold standard si sono utilizzate le TC corrispondenti alle OPT. Le risposte degli intervistati sono state valutate per correttezza e tendenza a prescrivere o non prescrivere la TC.
Risultati
Ha risposto l’11,9% della popolazione oggetto d’indagine. Il tasso di risposta è compatibile con un sondaggio web. I rispondenti si sono avvicinati al gold standard e l’indice di correttezza totale è stato pari a 0,636 (range di 0–1). La sovrapposizione del canale mandibolare e della radice è la relazione più rilevata. La richiesta di TC è proporzionale al numero di segni rilevati. Il 54,9% di chi non prescrive la TC ritiene utile una radiografia periapicale. Il motivo principale per cui non viene prescritta la TC è per la mancanza di necessità ai fini dell’estrazione.
Conclusioni
Il nostro studio ha rivelato una certa cautela dei professionisti che tendono a sovra-prescrivere la TC.
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References/Bibliografia
Caissie R, Goulet J, Fortin M, Morielli D (2005) Iatrogenic paresthesia in the third division of trigeminal nerve: 12 years of clinical experience. J Can Dent Assoc 71:185–190
Libersa P, Savignat M, Tonnel A (2007) Neurosensory disturbances of the inferior alveolar nerve: a retrospective study of complaints in a 10-year period. J Oral Maxillofac Surg 65:1486–1489
Tay AB, Go WS (2004) Effect of exposed inferior alveolar neurovascular bundle during surgical removal of impacted lower third molars. J Oral Maxillofac Surg 62:592–600
Valmaseda-Castellón E, Berini-Aytés L, Gay-Escoda C (2001) Inferior alveolar nerve damage after lower third molar surgical extraction: a prospective study of 1117 surgical extractions. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 92:377–383
Renton T, McGurk M (2001) Evaluation of factors predictive of lingual nerve injury in third molar surgery. Br J Oral Maxillofac Surg 39:423–428
Koong B, Pharoah MJ, Bulsara M, Tennant M (2006) Methods of determining the relationship of the mandibular canal and third molars: a survey of Australian oral and maxillofacial surgeons. Aust Dent J 51:64–68
Monaco G, Montevecchi M, Bonetti GA et al (2004) Reliability of panoramic radiography in evaluating the topographic relationship between the mandibular canal and impacted third molars. J Am Dent Assoc 135:312–318
Ohman A, Kivijärvi K, Blombäck U, Flygare L (2006) Pre-operative radiographic evaluation of lower third molars with computed tomography. Dentomaxillofac Radiol 35:30–35
Sedaghatfar M, August MA, Dodson TB (2005) Radiographic tips on predicting inferior alveolar nerve exposure. J Evid Based Dent Pract 5:222–223
Bell GW (2004) Use of dental panoramic tomographs to predict the relation between mandibular third molar teeth and the inferior alveolar nerve. Radiological and surgical findings, and clinical outcome. Br J Oral Maxillofac Surg 42:21–27
Gomes AC, Vasconcelos BC, Silva ED et al (2008) Sensitivity and specificity of pantomography to predict inferior alveolar nerve damage during extraction of impacted lower third molars. J Oral Maxillofac Surg 66:256–259
Mahasantipiya PM, Savage NW, Monsour PA, Wilson RJ (2005) Narrowing of the inferior dental canal in relation to the lower third molars. Dentomaxillofac Radiol 34:154–163
Better H, Abramovitz I, Shlomi B et al (2004) The presurgical workup before third molar surgery: how much is enough? J Oral Maxillofac Surg 62:689–692
Susarla SM, Dodson TB (2007) Preoperative computed tomography imaging in the management of impacted mandibular third molars. J Oral Maxillofac Surg 65:83–88
Ngan DC, Kharbanda OP, Geenty JP, Darendeliler MA (2003) Comparison of radiation levels from computed tomography and conventional dental radiographs. Aust Orthod J 19:67–75
Gijbels F, Jacobs R, Debaveye D et al (2005) Dosimetry of digital panoramic imaging. Part II: Occupational exposure. Dentomaxillofac Radiol 34:150–153
The Council of the European Union (1997) Council Directive 97/43/Euratom of 30 June 1997 on health protection of individuals against the dangers of ionizing radiation in relation to medical exposure, and repealing Directive 84/466/Euratom. http://ec.europa.eu. Accessed March 2011
American Dental Association (1997) Guidelines for prescribing dental radiographs. http://ada.org/ (Accessed March 2011)
Sedentexct Project (2009) Radiation protection: cone beam CT for dental and maxillofacial radiology. Provisional guidelines (V 1.1 May 2009). http://www.sedentexct.eu/ (Accessed March 2011)
de Melo Albert, Amorim Gomes AC, Cavalcanti B et al (2006) Comparison of orthopantomographs and conventional tomography images for assessing the relationship between impacted lower third molars and the mandibular canal oral. Maxillofac Surg 64:1030–1037
Pawelzik J, Cohnen M, Willers R, Becker J (2002) A comparison of conventional panoramic radiographs with volumetric computed tomography images in the preoperative assessment of impacted. J Oral Maxillofac Surg 60:979–684
Kendall M, Stuart A (1979) The advanced theory of statistics. Hafner, New York
Goodman LA, Kruskal WH (1954) Measures of association for cross classifications. J Am Stat Assoc 49:732–764
Wilcoxon F (1945) Individual comparisons by ranking methods. Biometrics 1:80–83
Robert RC, Bacchetti P, Pogrel MA (2005) Frequency of trigeminal nerve injuries following third molar removal. J Oral Maxillofac Surg 63:732–735
Blondeau F, Daniel NG (2007) Extraction of impacted mandibular third molars: postoperative complications and their risk factors. J Can Dent Assoc 73:325
Susarla SM, Kaban LB, Donoff RB, Dodson TB (2007) Functional sensory recovery after trigeminal nerve repair. J Oral Maxillofac Surg 65:60–65
Jerjes W, Swinson B, Moles DR et al (2006) Permanent sensory nerve impairment following third molar surgery: a prospective study. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 102:1–7
Hillerup S (2008) Iatrogenic injury to the inferior alveolar nerve: etiology, signs and symptoms, and observations on recovery. Int J Oral Maxillofac Surg 37:704–709
Nakamori K, Fujiwara K, Miyazaki A et al (2008) Clinical assessment of the relationship between the third molar and the inferior alveolar canal using panoramic images and computed tomography. J Oral Maxillofac Surg 66:2308–2313
Rood JP, Shehab BA (1990) The radiological prediction of inferior alveolar nerve injury during third molar surgery. Br J Oral Maxillofac Surg 28:20–25
Flygare L, Ohman A (2008) Preoperative imaging procedures for lower wisdom teeth removal. Clin Oral Investig 12:291–302
Au-Yeung KM, Ahuja AT, Ching AS, Metreweli C (2001) Dentascan in oral imaging. Clin Radiol 56:700–713
Schulze D, Heiland M, Thurmann H, Adam G (2004) Radiation exposure during midfacial imaging using 4- and 16-slice computed tomography, cone beam computed tomography systems and conventional radiography. Dentomaxillofac Radiol 33:83–86
Stratemann SA, Huang JC, Maki K et al (2008) Comparison of cone beam computed tomography imaging with physical measures. Dentomaxillofac Radiol 37:80–93
Suomalainen A, Vehmas T, Kortesniemi M et al (2008) Accuracy of linear measurements using dental cone beam and conventional multislice computed tomography. Dentomaxillofac Radiol 37:10–17
Carrafiello G, Dizonno M, Colli V Strocchi S et al (2010) Comparative study of jaws with multislice computed tomography and cone-beam tomography. Radiol Med 115:600–611
Tantanapornkul W, Okouchi K, Fujiwara Y et al (2007) A comparative study of cone-beam computed tomography and conventional panoramic radiography in assessing the topographic relationship between the mandibular canal and impacted third molars. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 103:253–259
Hapcook CP (2006) Dental malpractice claims: percentages and procedures. J Am Dent Assoc 137:1444–1445
ISTAT (2008) Le tecnologie dell’informazione e della comunicazione: disponibilità nelle famiglie e utilizzo degli individui. http://www.istat.it/ (Accessed March 2011)
Cook C, Heath F, Thompson RL (2000) A meta-analysis of response rates in web- or internet-based surveys. Educ Psychol Meas 60:821–826
Couper M (2000) Web surveys: a review of issues and approaches. Public Opinion Quarterly 64:464–494
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Sivolella, S., Boccuzzo, G., Gasparini, E. et al. Assessing the need for computed tomography for lower-third-molar extraction: a survey among 322 dentists. Radiol med 117, 112–124 (2012). https://doi.org/10.1007/s11547-011-0678-5
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DOI: https://doi.org/10.1007/s11547-011-0678-5