Bone-anchored maxillary protraction in cleft maxillary hypoplasia: An evaluation of dentoskeletal, soft-tissue, and functional effects

Abstract

Introduction: Maxillary hypoplasia is a common finding secondary to cleft lip and palate. The resultant Class III skeletal pattern worsens during adolescence due to unaffected mandibular growth. Bone-anchored maxillary protraction (BAMP) involves the intraoral use of orthopedic Class III intermaxillary elastics by means of skeletal anchorage to the zygoma and anterior mandible bilaterally. Aim: The aim of this study was to assess the facial esthetic and functional effects of 1-year of BAMP therapy in growing cleft individuals. Subjects and Methods: Eighteen subjects (mean age: 11.9 years) with cleft maxillary hypoplasia were selected for BAMP. Cephalometric facial assessment of 26 parameters (by an orthodontist), perceptual and lateral videofluoroscopic instrumental speech analyses (by a speech-language pathologist), and clinical temporomandibular joint (TMJ) evaluation were performed before (T1) and after 12 months of BAMP therapy (T2). Paired t-test and Pearson’s Chi-squared test were used for the statistical analyses of the quantitative and qualitative variables, respectively. Pearson’s correlation coefficients were used to assess the associations between cephalometric parameters. Results: Twenty cephalometric variables showed significant change from T1 to T2 toward positive dentoskeletal and soft-tissue Class III facial correction. The mean increase in “SNA” was 3.03°, and maxillary length (“Ptm-A”) and sagittal maxillary position (“N-perp to A”) increments were 3.65 mm and 4.02 mm, respectively. The mean improvement in the dental overjet was 3.86 mm. Backward positioning of the mandible was noted with a mean reduction of “SNB” and “N-perp to Pog” by 1.38° and 1.16 mm, respectively, with a mean 3.8° closure of the gonial angle. The airway changes were insignificant. Speech and TMJ observations remained constant from T1 to T2. Conclusions: BAMP therapy in cleft patients exhibited significant orthopedic maxillary protraction with effective sagittal and vertical mandibular growth control. The positive esthetic effects of BAMP did not have any negative influence over the functions of airway, velopharyngeal (speech) mechanism, and the TMJ in the stipulated 12-month period.

Keywords

• airway
• bone-anchored maxillary protraction
• cephalometric analysis
• cleft maxillary hypoplasia
• growth modulation
• speech
• temporomandibular joint