BAMP and cleft lip and palate: a clinical challenge under the microscope

Maxillary hypoplasia is an almost systematic sequela in patients with cleft lip and palate (CLP), frequently requiring a LeFort I osteotomy at the end of growth. To circumvent this major procedure, bone-anchored maxillary protraction (BAMP) is used during adolescence to stimulate sutural growth. However, its actual efficacy in this complex setting remains debated.

This retrospective study, conducted over a 10-year period (2015-2024), evaluated the clinical outcomes in 23 patients (mean age 12.4 ± 1.0 years) presenting with varied profiles: 1 isolated cleft palate, 13 unilateral CLP and 8 bilateral CLP. The specific objective was to quantify changes in overjet, but primarily to identify the complication rate, the frequency of hardware revision surgeries and the ultimate need for orthognathic surgery after treatment.

The central hypothesis of this work is based on evaluating the benefit-risk balance of BAMP: does this technique truly prevent the need for the operating theatre in adulthood, or does it add an additional surgical burden without drastically modifying the skeletal prognosis in syndromic patients?

Study methodology

This retrospective study analysed the clinical records of patients treated over a 10-year period, spanning from 2015 to 2024. The objective was to evaluate the clinical efficacy and morbidity of the bone-anchored maxillary protraction (BAMP) protocol in subjects presenting with maxillary hypoplasia related to a cleft lip and palate.

The study population included 23 patients, distributed according to the following cleft types:

• Isolated cleft palate: n = 1
• Unilateral cleft lip and palate: n = 13
• Bilateral cleft lip and palate: n = 8

The experimental protocol was based on the placement of bone anchorage plates at a mean age of 12.4 ± 1.0 years. The mean duration of active treatment was 24.8 ± 14.1 months. The researchers collected demographic data, surgical history and the Veau classification.

The analysis of the results focused on several primary endpoints:

• The evolution of the maxillomandibular relationship (measurement of the overjet) by pre- and post-treatment physical examination.
• The complication rate (hardware failure such as loosened, bent or broken plates).
• The need for revision surgeries and the final recourse to orthognathic surgery (LeFort I) after the end of the BAMP protocol.
• Patient compliance regarding the wearing of intermaxillary elastics.

Clinical results and skeletal efficacy

The study involved a cohort of 23 patients (1 cleft palate, 13 unilateral and 8 bilateral cleft lips and palates) with a mean age of 12.4 ± 1.0 years at the time of BAMP device placement. The mean treatment duration was 24.8 ± 14.1 months.

Improvement in the Class III skeletal relationship, characterised by a reduction in negative overjet, was observed in 57% of patients. Notably: no statistical association was found between the Veau classification or the number of previous cleft-related surgeries and the change in overjet during treatment.

Complications and equipment maintenance

The complication rate is particularly high, affecting 78.3% of patients (n=18). Material failures constitute the major problem, affecting 69.5% of the cohort (n=16).

Type of material complication	Frequency (n=23)	Maxillary location	Mandibular location
Loose, bent or broken plates	69.5%	75%	43%
Surgical revision required	39.1% (n=9)	-	-

The fragility of the construct is more pronounced in the maxilla than in the mandible. Nine patients had to undergo revision surgery to adjust or replace at least one anchor plate, thereby increasing the overall surgical burden.

Compliance and long-term surgical outcome

Patient compliance with the treatment was considered low: 56.5% (n=13) reported inconsistent wearing of intermaxillary elastics. Of the 16 patients who completed the BAMP protocol, the results regarding the need for subsequent orthognathic surgery are as follows:

• 75% of patients (n=12) nevertheless required maxillary advancement via LeFort I osteotomy at skeletal maturity.
• Only 25% of patients (n=4) were able to avoid major surgery.

Conclusion

This study highlights the limitations of the BAMP protocol in patients with cleft lip and palate, emphasising a high rate of hardware complications and poor compliance that limit its preventive benefit against orthognathic surgery.

Analysis of the efficacy and morbidity of BAMP in cleft lip and palate

The results of this retrospective study question the place of the BAMP (Bone Anchored Maxillary Protraction) protocol in the therapeutic arsenal for cleft lip and palate (CLP). Although the treatment improved the Class III relationship in 57% of patients, the main objective — avoiding orthognathic surgery at maturity — was only achieved for 25% of the cohort that completed the protocol. The rate of recourse to LeFort I therefore remains massive (75%), suggesting that the maxillary growth induced by BAMP is insufficient to compensate for the severe skeletal hypoplasia specific to cleft contexts.

The added surgical burden is a critical point: 78.3% of patients experienced at least one complication. The fragility of the hardware is evident, with 69.5% of failures (bent, broken or mobile plates), predominantly affecting the maxilla (75%). These complications necessitated surgical revisions for 9 patients, adding to an already complex care pathway. The study also highlights a major behavioural barrier: non-compliance with wearing elastics reported by 56.5% of subjects, which directly impacts clinical outcomes.

The limitations of this study lie in its retrospective nature and its sample of 23 patients. Nevertheless, the lack of association between the Veau classification or the number of previous surgeries and the change in overjet indicates that the relative failure of BAMP could be intrinsic to the technique or to compliance in this specific population. Contrary to hopes of reducing overall surgical morbidity, BAMP appears here to add an invasive step without guaranteeing the avoidance of the final osteotomy.

This retrospective study conducted on 23 patients (mean age 12.4 years) reveals that BAMP improves the Class III relationship in only 57% of subjects, with an overall complication rate of 78.3%. Despite a mean treatment duration of 24.8 months, 75% of the patients who completed the protocol still required subsequent LeFort I orthognathic surgery.", "actionable_insights": "

BAMP in cleft patients: the illusion of an alternative to orthognathic surgery?

The management of maxillary hypoplasia in patients born with a cleft lip and palate (CLP) is a long-term challenge. While Bone Anchored Maxillary Protraction (BAMP) is often presented as an elegant solution to stimulate growth during adolescence and avoid a major LeFort I osteotomy in adulthood, this retrospective study conducted by the Universities of Arizona and Michigan seriously tempers this optimism.

A decade-long study: mixed clinical results

The analysis included 23 patients (cleft palate n=1, unilateral n=13, bilateral n=8), followed up between 2015 and 2024. With a mean age of 12.4 years at the time of placement and a mean treatment duration of 24.8 months, the results show an improvement in the Class III skeletal relationship in only 57% of the subjects, via a reduction in the negative overjet.

Notably: no correlation has been established between the Veau classification or the number of previous surgeries and the magnitude of overjet change. The skeletal benefit therefore appears unpredictable, regardless of the initial severity of the cleft.

A surgical burden increased by complications

The critical point revealed by this study lies in the complication rate, described as alarming: 78.3% of patients experienced at least one incident. Hardware failures (loosened, bent or broken plates) affected 69.5% of the cohort. These mechanical issues are significantly more frequent in the maxilla (75%) than in the mandible (43%).

This fragility of the device has direct consequences on the care pathway: nine patients had to undergo a revision procedure to adjust or replace the hardware. Added to this is poor compliance, with 56.5% of adolescents reporting inconsistent wear of the dental elastics, which is nevertheless the driving force behind the protraction.

The verdict of skeletal maturity

The ultimate goal of BAMP — avoiding orthognathic surgery — is rarely achieved in this population. Out of the 16 patients who completed the follow-up protocol, 12 (i.e. 75%) still required surgical maxillary advancement at the end of their growth. The BAMP treatment therefore only allowed surgery to be avoided in a quarter of cases, while imposing a high risk of revision and significant daily constraints.

Technical glossary of the study

BAMP (Bone Anchored Maxillary Protraction) : Maxillary protraction protocol relying on bone anchorage (plates and screws) to transmit traction forces directly to the facial skeleton, without relying on the dentition.

Overjet (Sagittal discrepancy): Clinical measurement of the horizontal distance between the upper and lower incisors, used here to assess the transition from a Class III (negative) to a more physiological relationship.

LeFort I osteotomy: Orthognathic surgery procedure consisting of a controlled surgical fracture of the maxilla to allow its repositioning in the three spatial planes.

Veau classification: System for describing orofacial clefts classified from I to IV according to the involvement of the soft palate, hard palate and alveolar arch.

Dental elastics: Elastics stretched between the maxillary and mandibular anchorage plates to generate the traction force required for bone growth.

Maxillary hypoplasia: Developmental deficit of the volume and position of the maxilla, common in CLP patients following surgical scarring from primary repairs.

In practical terms, for the practitioner:

• Reassess the benefit/risk ratio: With a 75% final recourse to orthognathic surgery and a 78% complication rate, the indication for BAMP in CLP patients must be considered with caution.
• Prepare the patient for revision: Routinely inform families of the high probability (nearly 70%) of hardware failure requiring surgical adjustment, particularly in the maxilla.
• Anticipate non-compliance: Wearing dental elastics is the weak link in adolescent treatment (more than one in two patients is inconsistent); motivational reinforcement is essential.

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