Date of Completion


Embargo Period



Kamran E. Safavi; Blythe Kaufman

Field of Study

Dental Science


Master of Dental Science

Open Access

Open Access


Apical periodontitis is the most common pathological process in the periapical region. Disciplined clinical and radiographic evaluations and appropriate diagnostic tests can detect lesions related to apical periodontitis. Aside from this, lesions mimicking pulp-related pathology but unrelated to pulpal infection and necrosis are occasionally discovered in the periapical region. The objective of this study was two-fold: (1) to determine the prevalence of diverse periapically located pathological entities, and (2) to apply that information to evaluate the rationale for routine submission of surgically obtained tissue for histological examination and diagnosis. Methods: A 5-year retrospective analysis of pathology reports from the UCONN Oral Pathology biopsy service was conducted. Periapical lesions were categorized as (a) odontogenic inflammatory, (b) odontogenic non-inflammatory, (c) non-odontogenic non-neoplastic, or (d) non-odontogenic neoplastic in nature, respectively, and the prevalence of lesions in each pathologic category was determined. The correlations among prevalence of specific lesions, patient demographic data and anatomic location in the jaws were analyzed. Also, the correlation between the final diagnoses and the general category of submitting clinicians’ provisional diagnoses was assessed to determine the efficacy of clinicians’ index of suspicion. Results: A total of 21649 pathology reports were reviewed, of which 2979 lesions (13.8%) met the criterion of being located at the apices of teeth. Of these, 2693 lesions (90.4%) carried diagnoses associated with apical periodontitis. A total of 286 cases (9.6%) from the periapical region represented a wide range of pathological conditions unrelated to apical periodontitis. Periapical granuloma was the most common odontogenic inflammatory lesion (51.5%); odontogenic keratocyst was the most common odontogenic non-inflammatory lesion (2.08%); and nasopalatine canal cyst was the most common non-odontogenic periapical lesion (1.1%). Six malignant neoplasms were diagnosed in periapical locations. Periapical pathology was more common in the maxilla than the mandible. There was no correlation among specific periapical pathological entities, age and gender. A majority (84%) of the final diagnoses were in the general category of the provisional clinical diagnoses provided by the clinicians; 16% of clinical impressions were inconsistent. Conclusions: In the course of assessing a tooth for non-surgical endodontic therapy, careful clinical evaluation aids in diagnosing a large majority of odontogenic inflammatory lesions. However, lesions unrelated to apical periodontitis also occur in the periapical region. Histopathologic examination of periapical specimens remains the gold standard for establishing accurate diagnoses and differentiating amongst the various periapical pathoses. Routine submission of periapical biopsies is required to establish a specific diagnosis any time a recoverable amount of tissue can be removed from a periapical surgical site. In addition to dictating further management, histopathologic examination helps to rule out uncommon, potentially destructive and/or life-threatening lesions.

Major Advisor

Easwar Natarajan