Spatial Evaluation of Oral Lichen Planus Patients Referred to Shiraz Dental School, Iran: a Medical Geography Approach

Statement of the Problem: 

Oral lichen planus (OLP) is an important inflammatory disease concerning its tendency to malignancy. The etiopathogenesis of this disease is still unknown. Medical geography uses geographic techniques to study factors related to location that cause uneven distribution of disease.

This study was conducted to map OLP in patients referred to Shiraz Dental School with medical geography techniques and investigate any possible relationship between the number of dentists and health-centers in different regions of Fars province with the number of referrals.

In this cross-sectional study, we evaluated the records of OLP patients referred to Shiraz Dental School from 2007 to 2018. Age, sex, place of residence, occupation, level of education, location of involvement, duration, and cutaneous involvement were recorded. The number of dentists and healthcare centers was obtained from the statistical records of Fars province. A Geographic Information System was used for the assessment of the spatial distribution of OLP. Ordinary least squares (OLS) and geographically weighted regression (GWR) indices were used for evaluating the relationship between the number of dentists and health centers with the number of referrals.

From 1006 records, 457 were studied, from which 71% were female (age range of 41-60). The regression coefficient was 0.937 for the number of dentists in each county compared to OLP referrals indicating a strong relationship. The regression coefficient was 0.983 for the number of health-centers. According to GWR analyses in Shiraz neighboring counties like Marvdasht, Sepidan, and Sarvestan, there is a positive relationship between the number of dentists and OLP patients.

The results revealed that dentists and health care centers had a good cognition of referring patients with OLP (as a premalignant lesion) for definite diagnosis in Fars counties. But both groups need more education in this matter. Moreover, referrals from settlements near Shiraz were more common because of their easier access.