Bone-anchored maxillary protraction in a patient with complete cleft lip and palate: A case report

Sagittal maxillary deficiency is frequently observed in patients with operated unilateral complete cleft of the lip and palate. Treatment for moderate to severe Class III malocclusion usually relies on LeFort I surgery for maxillary advancement after the end of growth. This case report describes bone-anchored maxillary protraction in a 10-year-old white boy with unilateral complete cleft of the lip and palate. His interarch relationship was diagnosed as GOSLON index 5 before treatment with a negative overjet of 3.2 mm. The orthopedic traction was started 4 months after secondary alveolar bone graft surgery and before comprehensive orthodontic treatment. Class III elastics were used full time for 18 months. After treatment, the interarch relationship was GOSLON index 1 with a positive overjet. The SNA angle increased by 6.50° and A-Na Perp increased by 3.8 mm, leading to marked improvement in facial convexity (+14.6°). No posterior rotation of the mandible occurred with a slight closure of the gonial angle. Visualization of 3-dimensional color-coded maps showed an overall forward maxillary displacement. The bone-anchored maxillary protraction results for this patient are a promising orthopedic therapy for patients with unilateral complete cleft of the lip and palate, with the advantage of achieving much earlier improvement of facial esthetics and functional occlusion, compared with LeFort I surgery at skeletal maturity.

Highlights

  • Bone-anchored maxillary protraction (BAMP) was used in a patient with CLP.

  • The protocol for BAMP therapy in patients with CLP is provided.

  • BAMP therapy produced important maxillary protraction in the patient.

  • BAMP could reduce the need for orthognathic surgery in CLP patients.

Maxillary growth of patients with unilateral complete cleft lip and palate (CLP) is often negatively influenced by primary surgeries of the soft tissues, leading to a Class III malocclusion. In noncleft Class III patients, the most common orthopedic intervention is facemask therapy. The effects of 1 year of facemask therapy include an average of 2 mm of forward movement of the maxilla and downward and backward rotation of the mandible. Maxillary protraction anchored in the teeth may also cause dental effects, including proclination of the maxillary incisors and retroclination of the mandibular incisors. In children with CLP, the facemask protocol has little therapeutic effect on the maxilla associated with clockwise rotation of the mandible.

As a new treatment option, bone-anchored maxillary protraction (BAMP) pulls the maxilla forward by using intraoral intermaxillary elastics anchored in bone plates. This therapy has been shown to cause an average maxillary protraction of 4 mm in Class III patients without oral clefts, but its effects in cleft patients are not clear because of scar tissue and often severe maxillary deficiency. The purpose of this article is to report the treatment outcomes of the BAMP protocol in a 10-year-old patient with complete CLP.

Diagnosis and etiology

A 10-year-old white boy came with a left unilateral complete CLP combined with a right incomplete cleft lip; he was receiving rehabilitation in a single center. Bilateral lip repair was performed at 4 months of age using the Spina technique. Palatal repair was performed at 13 months of age using the Von Langenbeck technique. At the age of 6.5 years, secondary lip repair and a palatal fistula closure were performed.

At the age of 8 years, the patient demonstrated a Class III skeletal pattern and a sagittal interarch relationship of GOSLON index 5. Transverse maxillary constriction was treated with rapid maxillary expansion, and a fixed transpalatal arch was used as a retainer. Secondary alveolar bone graft surgery was performed at 10 years of age using 1.5 mg per milliliter rh-BMP2 in collagen membrane (Infuse Bone Graft kit; Medtronic, Memphis, Tenn).

At 10.6 years of age, the extraoral examination showed a Class III skeletal pattern with moderate to severe midface deficiency. The mandible was well positioned, and the face was normodivergent. In the frontal facial view, no asymmetry was observed ( Fig 1 ). The patient was in the late mixed dentition. The intraoral examination showed an interarch relationship of GOSLON index 5 with overjet of −3.2 mm, overbite of 4.5 mm, and a complete crossbite ( Fig 1 ). No shift between centric relation to maximal intercuspation was observed. The panoramic radiograph showed agenesis of the maxillary permanent left lateral incisor and both maxillary second premolars ( Fig 2 ). The cephalometric analysis showed a skeletal Class III discrepancy (ANB angle, −8.4°; Wits appraisal, −6.5 mm) with a retrognathic maxilla, a well-positioned mandible, and a horizontal growth pattern ( Fig 2 ; Table ). The maxillary incisors were slightly proclined, and the mandibular incisors were retroclined ( Table ). At this time, the patient was at prepubertal stage CS1 of skeletal maturity according to the cervical vertebral maturation method.

Fig 1
Initial facial and intraoral photographs. Interach relationship GOSLON index 5.

Fig 2
Panoramic and cephametric radiographs. Observe the Class III facial profile with sagittal maxillary deficiency, with a 5.8-mm negative overjet. The patient was in the mixed dentition with agenesis of the maxillary second premolars and maxillary left lateral incisors.

Table
Conventional cephalometric analysis
Variable T1 T2 T2–T1
Maxilla
SNA (°) 74.7 81.2 6.5
A-Nperp (mm) −4.00 −0.20 3.8
Co-A (mm) 46.50 56.10 9.6
Mandible
SNB (°) 83.1 81.2 −1.9
P-Nperp (mm) 0.80 0.40 −0.4
Mandibular length (Co-Gn) (mm) 119.8 118.1 −1.7
Co-Go (mm) 30.2 33.3 3.1
Ar-Go-Gn (°) 128.3 125.7 −2.6
Maxillomandibular relationship
ANB (°) −8.4 −0.1 8.3
Convexity (NA-APo) (°) −15.9 −1.3 14.6
Wits appraisal (mm) −6.5 −2.5 4.0
Facial pattern
FMA (MP-FH) (°) 26.3 25.6 −0.7
SN-GoGn (°) 32.4 31.5 −0.9
Occlusal plane to FH (°) 3.8 5.1 1.3
Anterior face height (NaMe) (mm) 66.2 72.9 6.7
Teeth
U1-SN (°) 107.3 110.4 3.1
IMPA (°) 81.2 82.5 1.3
Overbite (mm) 4.5 1.9 −2.6
Overjet (mm) −3.2 3.1 6.3
Molar relationship (mm) −2.1 3.6 5.7
Soft tissue
Facial convexity (G′-Sn-Po’) (°) −4.4 −2.2 2.2
Nasolabial angle (Col-Sn’-ULA) (°) 82.5 73.6 −8.9
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Dec 12, 2018 | Posted by in Orthodontics | Comments Off on Bone-anchored maxillary protraction in a patient with complete cleft lip and palate: A case report
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