We thank Drs. Woo and Natarajan for expounding on their original research regarding alveolar ridge keratosis (ARK). In our reported series of 477 ARK cases, we assigned a provisional clinical diagnosis of ARK to white patches or plaques limited to the retromolar pad or an edentulous area of the alveolar ridge and devoid of erythema or ulceration. We also asserted that ARK is a clinicopathologic entity, and thus histopathologic confirmation is needed to confirm the diagnosis.
Therefore, what Drs. Woo and Natarajan refer to as ARK and benign alveolar ridge keratosis (BARK) corresponds to what we would refer to as a provisional clinical diagnosis of ARK and a confirmed diagnosis of ARK based on clinical and pathological features. Regardless of preferred terminology, the important point is that ARK (or BARK) is a clinicopathologic entity distinct from oral leukoplakia.
In addition to an absence of dysplasia, the microscopic features described by Drs. Woo and Natarajan—including hyperorthokeratosis, wedge-shaped hypergranulosis, papillary acanthosis and absence of significant inflammation—are indeed characteristics we typically see in ARK. As mentioned in the discussion section of our study, we plan to report an objective, quantitative analysis of these microscopic parameters in our ARK and oral leukoplakia cases in a future publication.
We suspect that many clinicians and pathologists alike are intuitively familiar with the characteristic clinicopathologic features of ARK. However, objective analyses of such lesions will help formalize a reproducible definition of ARK. Broader recognition of this entity as a lesion distinct from oral leukoplakia is necessary for refining our concept of oral leukoplakia.
