Error and Accuracy Rates of Panoramic Radiography As a Screening Method for Mass Surveying of Children

by Sophia Balis, DDS: Journal of Public Health Dentistry Vol. 41, No.4-Fall 1981

Background:
Advantages of Panoramic Radiography:

• Produces a radiograph of the max and mand arches on a single film
  
• Provides comprehensive view of all structures of both arches including condylar processes, TMJ, sinuses, and mastoid region
• Simplicity and speed of operation, patient comfort and reduced radiation
  
• Exposure req. only 22 sec. with overall avg. time of 3-5 min per patient vs. conventional FMX with avg. 15-20 min. per pt.
• Cost of film and processing ~50% less than FMX

Disadvantages:

• Limited definition of images
• Relatively large initial cost with greater space requirements.
• Variability in quality of image, depending on head shape and positioning of pt's head.
• Inferior in diagnosis of carious lesions and damage to the periodontium, but sufficient for interpretation of alveolar bone levels; missing teeth; existing restorations; periapical conditions; malposed, impacted, and supernumerary teeth.

Purpose of This Study: Determine error rates, in terms of false positive and false negative diagnosis; accuracy reates, in terms of sensitivity and specificity; and overall percent agreement of panoramic radiogaphy for each type of oral condition, as compared against two reference criteria of valid diagnoses, under controlled conditions

Materials and Methods:

• 1202 children of both sexes in mixed dentition of 6-13 years, attending public schools in low-income area of mixed black and caucasion population
• Compared panoramic radiographic findings with a and with a difinitive diagnostic reference criterion (DDRC).
  
• SDRC = Clinical Exam + FMX (1176 subjects completed)
  
• DDRC = Clinical Exam and FMX + findings from additional lab and clinical procedures, and treatment intervention to completion (711 subjects completed).
• See article for breakdown of sex/race of subjects. Diverse population.
• Study conducted over 3 year period with a staggered procedure that permitted admission of subjects at a rate of one third of the total sample per year.
• Article describes exact specifics of how to perform panorex, what type was used, and what film type. Performed by trained assistant.
• An experienced dentist (A1)listed all types of oral conditions noted on panoramic radiographs (3 dentists served consecutively)
  

Standard Diagnostic Reference Criterion (SDRC):

• Completed by a different dentist (A2)
  
• Included clinical exam, FMX, any clinical and laboratory procedures used in a dental office in order to reach the criterion diagnosis for various lesions.
  
• Intraoral projections = 5 max and 5 mand radiographs, including all teeth, their periapical and periodontal tissues, and max and mand bone processes + 2 right and 2 left BWs, each including the crowns of max and mand premolar and molar teeth, and part of cuspids.
• Upon completion of SDRC, the same dentist recorded a tx plan and classified each pt. into a priority category of recall for tx on the basisi of a 7-point scale.
• Pts were treated to completion by the same dentist on the basis of their recall schedule. New findings from additional spectialized procedures (i.e. biopsy, medical consultation, systemic evaluations) and from tx intervention were recorded by same dentist. If new pathological conditions develoed, they were classified seperately and excluded from the study.
• Three consecutive dentists used for this phase.

Definitive Diagnosis Reference Criterion (DDRC):

• Obtained after completion of tx and discharge of the pt, at which time, a third dentist (A3) completed independently a seperate definitive diagnostic data form. Based on A3's evaluation of the final revised findings of dentist A2's recorded data, together with all radiographs (FMX and pano) and exam reports on file.
• Two consecutive dentists used for this phase.
• Independed sets of dentists (A1,A2 and A3) used to avoid observer bias. Reliability achieved by regular monitoring of sample analysis conducted by the investigator. Without 95% congruence, differences were discussed for recalibration purposes, without changing already recorded findings. Recalibrarion repeated over intervals varying from 3-6 months. Examiners also utilized investigator designed reference brochure.

Data Reporting and Analysis:

• Oral Pathology Classified as follows:

1. Dental Pathology--Caries of enamel and dentin, pulpitis, traumatic lesions of the teeth, generalized and localized enamel hypoplasia, stains, missing teeth due to loss, retained roots, retained teeth, developmental abnormalities of dentition, and anomalies of spacing of teeth
   
2. Periapical Path--periapical granuloma, cyst, abscess, and osteomyelitis
   
3. Periodontal Path--marginal periodontitis (noncircumscribing, circumscribing, with pocket formation, with advanced bone destrucion), gingival hyperplasia, and calculus
   
4. Malocclusion--excessive overbite (>75%), overjet w/o soft tissue inpingement, OJ w/ sof-tissue impingement, full buccal crossbite, post. crossbite.
5. Soft Tissue Path--classified as mild, mod, severe, and included inflammatory lesions (herpes, apthae, moniliasis, etc.), developmental abnormalities (ankyloglossia, etc.), and neoplastic lesions (benign or malignant).
6. Bone Path--neoplastic and other lesions of jaw bones.
   
7. Systemic Diseases Affecting the Mouth--Infectious, metabolic, nutritional, hormonal, etc.
   

• Data collected and statistically analyzed.

Results:
Conditions Pano was bad at detecting:

• caries of enamel (missed 100%) but no false positives
  
• missed 52 % caries of dentin
• Generalized and localized enamel hypoplasia
• Marginal periodontitis
• Soft tissue pathology
• Systemic disease affecting the Mouth
• Malocclusion
• Malformed teeth (missed 45%)
  

Conditions Pano was good at detecting:

• Pulpitis lesions (only missed 8%)
• Periapical conditions (missed 21%)
• Missing teeth due to loss
• Supernumerary teeth
• Congenitally absent teeth
• Anomalies in spacing
• Bone pathology
• Impacted or ectopically erupting teeth