Bone-anchored maxillary protraction in unilateral cleft lip and palate: a cephalometric appraisal

Abstract

Objectives: The aim of this study was to evaluate the cephalometric outcome of bone-anchored maxillary protraction (BAMP) in individuals with unilateral complete cleft lip and palate (UCLP).

Material and methods: The experimental group (EG) comprised 23 individuals (17 males and 6 females) with UCLP and a mean age of 11.7 years. At least 6 months after secondary alveolar bone grafting, Bollard miniplates were installed in the posterior region of the maxilla and in the anterior region of the mandible. Class III elastics were recommended to be worn for 24 hours/day for a mean time of 18 months. Cone beam computed tomography (CBCT) was obtained before (T1) and after treatment (T2). The control group (CG) consisted of 23 individuals with UCLP matched by initial age and gender with the EG and without any orthopaedic or surgical intervention performed between T1 and T2. The interval between T1 and T2 observations was 18 months for both groups. Twenty-one cephalometric variables were analysed. Intra- and intergroup comparisons were performed using paired and independent t-tests, respectively (P < 0.05).

Results: BAMP caused a greater maxillary protrusion (SNA) and a greater decrease of Class III maxillomandibular discrepancy (ANB and Wits appraisal) compared with the CG. BAMP also caused a counterclockwise rotation of the occlusal plane (Occ Plane to FH) and an improvement in the molar relationship compared with controls.

Conclusions: BAMP therapy demonstrated a significant orthopaedic maxillary protraction and an improvement in the Class III skeletal pattern in UCLP.

Figure 1.

Bollard miniplates and Class III elastics used in the bone-anchored maxillary protraction group.

Figure 2.

Cephalometric variables: (A) 1, SNA; 2, SNB; 3, ANB; 4, Wits appraisal; 5, Co-A; 6, Co–Gn; 7, Co–Go; 8, NAP; 9, Occlusal Plane to Francfurt Horizontal (Occ Plane to FH); 10, mandibular plane to Francfurt Horizontal (MP–FH); 11, gonial angle (Ar–Go–Gn); 12, face height (N–Me); 13, nasolabial angle; (B) 14, maxillary incisor inclination (U1–Palatal Plane); 15, incisor to mandibular plane angle; 16, overbite; 17, overjet; 18, molar relation; 19, soft tissue convexity (G’–Sn–Po’); 20, subnasal prominence (G’–Sn) and 21, soft pogonium prominence (G’–Pg’).