Does absence of maxillary lateral incisor affect the status of maxillary canine before and after secondary alveolar bone grafting in patients with unilateral alveolar cleft?

Factors Contributing to Canine Impaction in Patients With Unilateral Cleft Lip and Palate Undergoing Alveolar Bone Grafts

BACKGROUND

Patients with unilateral cleft lip and palate (UCLP) undergo alveolar bone grafting (ABG) to unite the bony segments before eruption of the maxillary permanent canine.

PURPOSE

This study assessed the frequency of canine impaction after ABG in the UCLP patient population and identified associated demographic, anatomical, and operative factors.

STUDY DESIGN, SETTING, SAMPLE

This retrospective cohort study included 257 patients with UCLP who received ABG surgery at a single craniofacial center.

PREDICTOR VARIABLES

The variables were cleft characteristics, pre-ABG procedures, operative factors, and dental anomalies identified through electronic health records, radiographs, and intraoral photographs taken before ABG and at least 2 years after ABG.

MAIN OUTCOME VARIABLE

The primary outcome variable was the presence of an impacted maxillary canine, defined as malposition of a fully developed canine following ABG with full eruption of the contralateral canine.

ANALYSES

The t tests, χ2 tests, and logistic regression analysis were used to evaluate frequency of canine impaction and test for associations with the predictor variables.

RESULTS

Of 257 patients, 56% were male with a mean age of 9.2 years at the time of ABG. The frequency of canine impaction was 27% (n = 69, 95% confidence interval 22 to 33%). Significant associations were found for: complete clefts (30 vs 12%, P = .017), hypodivergent facial patterns (low angle: 46%; high angle: 29 vs 22% normal angle, P = .042), females (adjusted odds ratio [aOR] = 2.1, P = .015), early grafting with less than 1/3 developed canine root (aOR = 3.36, P = .024), pregraft extraction of primary canine (aOR = 2.3, P = .009) and greater permanent canine angulation (odds ratio = 1.1, P < .0001). No significant associations with pregraft orthodontic expansion or regrafting were detected.

CONCLUSION AND RELEVANCE

In this study, about one in four patients with UCLP had an impacted canine. Multiple factors including pregraft extraction of the primary canine and increased canine angulation were associated with impaction of the permanent canine.