Eligibility for publicly funded orthodontic treatment determined by the handicapping labiolingual deviation index

Access to orthodontic care for Medicaid patients has been limited, in part because of orthodontists' reluctance to treat severe malocclusions for low reimbursements. Limited orthodontic treatment in the mixed dentition (phase 1 treatment) has been proposed to address this issue, because the intent of phase 1 treatment is to improve or prevent severe malocclusions. Orthodontists might be more willing to provide shorter, simpler treatment. The purpose of this study was to determine whether phase 1 treatment would reduce malocclusion severity to the extent that eligibility for subsequent Medicaid-funded treatment was significantly reduced.

Eligibility was determined by the handicapping labiolingual deviation (HLD) index, which is used by several states for this purpose. Eligibility was also determined with the index of complexity, outcome, and need (ICON). This allowed us to compare these 2 indexes. Pre-phase 1 and post-phase 1 index scores were calculated by using study casts from 193 patients treated at the University of Washington orthodontic clinic and the Odessa Brown Children's Dental Clinic, both in Seattle.

Using the HLD index, we found that eligibility for orthodontic treatment decreased by 62% after phase 1 treatment. This change was statistically significant at P < .0001. The ICON found significantly more treatment need before phase 1 (90%) than did the HLD index (35%) (P < .0001).

Early interceptive treatment significantly reduces eligibility for comprehensive Medicaid-funded orthodontic treatment. The HLD index is a useful tool for determining Medicaid eligibility.