Use of interdental distraction osteogenesis for orthodontic tooth alignment and correction of maxillary hypoplasia: a case report

Interim use of Hyrax Screw Assembly for Single-Step Closure of Small Alveolar Cleft before Anterior Maxillary Distraction Osteogenesis

Anterior maxillary distraction osteogenesis (AMDO) is often used for the correction of maxillary retrognathia in select cleft lip and palate cases. The restoration of alveolar arch continuity is desirable before the initiation of AMDO in these cleft maxillary deformities; however, AMDO is technically difficult in a patient with coexisting alveolar cleft where there is a discontinuity of the defect that presents a challenge in terms of adequate vector control of the movement of the anterior segment and the potential risk of tipping of teeth, which already have compromised anchorage/bone support on the cleft side. The treatment becomes more challenging when ongoing management is compounded by failed previous alveolar cleft grafting procedures, along with the patient's reluctance to undergo further grafting of alveolar clefts. This technical note demonstrates a novel application of the modification of the Hyrax screw where an initially fully opened Hyrax screw was utilised as an interim assembly for accomplishing the single-step closure of a small alveolar cleft before the commencement of anterior maxillary distraction osteogenesis. This technique may prove to be feasible for patients presenting with alveolar cleft defects of smaller widths of up to 5 mm and relatively well-aligned upper arches.

How Is the Created Alveolar Space Finally Restored After Maxillary Anterior Segmental Distraction Osteogenesis?

OBJECTIVE

Maxillary anterior segmental distraction osteogenesis (MASDO) for cleft and palate patients is the alternative treatment option to correct malocclusion with maxillary arch deficiency and severe crowding. After MASDO, prosthetic considerations are crucial for patients with cleft lip and palate because it is related to facial esthetics and occlusal function. The objectives of this study were to investigate the final restoration type for created alveolar space by MASDO.

METHODS

Thirteen patients with cleft lip and palate who underwent MASDO and orthodontic treatment from the years 2000 to 2010 in Yonsei University were examined. Final restorations are classified as dental implants, conventional prosthesis, and orthodontic space closure. The relationship between the distracted areas and final restoration type was investigated. The authors evaluated lateral cephalograms obtained at predistraction osteogenesis (pre-DO; T1), postdistraction osteogenesis (post-DO; T2), and debond (T3), and measured changes from T1 to T2 and from T2 to T3.

RESULTS

There was no significant difference of final restoration percentage of dental implants, conventional prosthesis, and space closure with orthodontic treatment. However, dental implants and conventional prostheses were applied more frequently in the posterior area and in the anterior area, respectively. The relapse rate was observed as 36.7% and 22.4% in the values of N-A distance and ANB angulation in T2-T3 stage.

CONCLUSION

The MASDO site should be decided, based on final restoration goal. Among the created alveolar spaces, implants were applied mainly to the posterior site and the conventional prostheses were mostly restored to the anterior site. For space closure by orthodontic approach, the area could be both anterior or posterior.

Midfacial Changes Through Anterior Maxillary Distraction Osteogenesis in Patients With Cleft Lip and Palate

Maxillary hypoplasia is a major issue in cleft lip and palate patients, and predictable surgical maxillary advancement is required. In the present study, the changes and stability of the maxilla and soft tissue profile achieved after the application of anterior maxillary distraction osteogenesis (AMDO) using intraoral expander in unilateral cleft lip and palate and isolated cleft palate patients were investigated by comparing to the Le Fort I osteotomy (LFI) and maxillary distraction osteogenesis (DO) with rigid external distraction (RED) system.Ten patients who underwent orthognathic treatment with AMDO were examined (AMDO group). Changes in the positions of soft and hard tissue landmarks were calculated from the lateral cephalograms taken before the distraction, at the end of the distraction, and 1 year after the surgery. They were compared with the changes in 7 other unilateral cleft lip and palate patients who underwent LFI (LFI group) and 6 others who underwent DO with RED (RED group).The mean maxillary advancement of the AMDO group was similar to that of the RED group, judged by the change of point A. During DO, the AMDO group showed less clockwise rotation of mandible compared to the RED group. The soft tissue advancement of the upper lip and nose in the AMDO group was similar to that in the RED group, which was significantly larger than that in the LFI group.Our results indicate that AMDO can be surgical option to cleft lip and palate patients with less invasive but excellent improvement in both midfacial skeletal and soft tissue similar to DO-RED.

Nasopharyngoscopic Analyses through Anterior Maxillary Distraction Osteogenesis for Adolescent Patients With Cleft Palate

Anterior maxillary distraction osteogenesis (AMDO) is a novel technique for correcting hypoplastic maxilla by sagittal expansion of the maxilla. Recent reports suggest that AMDO does not have an effect on fragile velopharyngeal function in patients with cleft palate. Furthermore, no studies have evaluated the impact of AMDO on velopharyngeal function.We adopted AMDO to correct severe hypoplastic maxilla in adolescent patients with cleft palate and evaluated its impact on velopharyngeal space and function in 8 patients aged 12 to 21 years who underwent AMDO from 2006 to 2014. All the patients had received treatment for cleft palate; however, they still exhibited marginal velopharyngeal insufficiency. The mean activation of the distractor was 10.9 ± 0.9 mm.We determined changes in velopharyngeal closure ratio and closure pattern via nasopharyngoscopy. Additionally, skeletal changes were evaluated using lateral cephalograms.The mean horizontal advancement in the cephalogram obtained 1 year after the distraction was +6.4 mm. Nasopharyngoscopic examination revealed that no deterioration of velopharyngeal gap had occurred after AMDO in all 8 patients. The velopharyngeal closure pattern changed from coronal to circular in 1 patient.Our results indicate that AMDO achieved correction of hypoplastic maxilla without deterioration in velopharyngeal gap and function. Therefore, AMDO is an effective and optimal approach for correcting hypoplastic maxilla especially in patients with fragile velopharyngeal function, such as those with cleft palate.

Orthodontic Treatment and Maxillary Anterior Segmental Distraction Osteogenesis of a Subject with Williams-Beuren Syndrome and Isolated Cleft Palate: A Long-Term Follow-Up from the Age of 5 to 24 Years

Williams–Beuren syndrome (WBS) is a rare multisystem disorder caused by a hemizygous deletion of the elastin gene on chromosome 7q11.23. WBS patients have characteristic skeletal features and dental anomalies accompanied by mental retardation, a friendly outgoing personality, and mild to moderate intellectual disability or learning problems. In this case report, we present the combined orthodontic and surgical treatment of a WBS patient with an isolated cleft palate through a long-term follow-up from the age of 5 to 24 years. During the period of active treatment, comprehensive orthodontic treatment combined with maxillary anterior segmental distraction osteogenesis and prosthetic treatment using dental implants were effective in dramatically improving the patient's malocclusion. The patient's mental abilities and the cooperation shown by the patient and her family were crucial for the success of this complex and long-term treatment course.

Maxillary Anterior Segmental Distraction Osteogenesis to Correct Maxillary Deficiencies in a Patient With Cleft Lip and Palate

This report describes a case of successful orthodontic treatment using maxillary anterior segmental distraction osteogenesis with an internal maxillary distractor and bilateral sagittal split ramus osteotomy in a girl with cleft lip and palate. A 16-year-old girl with unilateral cleft lip and palate exhibited midface retrusion because of growth inhibition of the maxillary complex and mandibular excess. After the presurgical orthodontic treatment, 6.0-mm advancement of the maxillary anterior segment and 4.0-mm set back of the mandible were performed. After a retention period, the patient's midface convexity was greatly improved and the velopharyngeal competence was preserved without relapse.

Accelerated Bone Formation in Distracted Alveolar Bone After Injection of Recombinant Human Bone Morphogenetic Protein-2

BACKGROUND

This study evaluates the effect of recombinant human bone morphogenetic protein-2 (rhBMP-2) on the quality and quantity of regenerated bone when injected into distracted alveolar bone.

METHODS

Sixteen adult beagle dogs were assigned to either the control or rhBMP-2 group. After distraction was completed, an rhBMP-2 dose of 330 μg in 0.33 mL was injected slowly into the distracted alveolar crest of the mesial, middle, and distal parts of the alveolar bone in the experimental group. Histologic and microcomputed tomography analyses of regenerated bone were done after 2 and 6 weeks of consolidation.

RESULTS

After 6 weeks of consolidation, the vertical defect height in the middle of the regenerated bone was significantly lower in the rhBMP-2 group (2.2 mm) than in the control group (3.4 mm) (P <0.05). Additionally, the width of the regenerated bone was significantly greater in the rhBMP-2 group (4.3 mm) than in the control group (2.8 mm) (P <0.05). The bone density and volume of regenerated bone in the rhBMP-2 group were greater than in the control group after 6 weeks of consolidation (P <0.001).

CONCLUSION

Injection of rhBMP-2 into regenerated bone after a distraction osteogenesis procedure significantly increased bone volume in the dentoalveolar distraction site and improved both the width and height of the alveolar ridge and increased the bone density.

Premaxillary Distraction Osteogenesis Using an Intraoral Appliance for Unilateral Cleft Lip and Palate: Case Report

OBJECTIVE

Premaxillary distraction osteogenesis was introduced using intraoral devices to correct maxillary hypoplasia and lengthen the alveolar bone horizontally in a patient with unilateral cleft lip and palate.

METHODS

For premaxillary distraction osteogenesis, Le Fort I osteotomy was performed. Vertical osteotomy lines were located distally of the upper right canine and left first premolar to separate the anterior segment of the maxilla. After a 7-day latency period, distraction was allowed to continue for 20 days at a rate of 0.5 mm/d, followed by a 3-month consolidation period. After consolidation, orthodontic treatment and bilateral intraoral vertical ramus osteotomy were performed for the mandibular setback. The implant and prosthodontic treatments were applied to the alveolar ridge area created by the distraction osteogenesis.

RESULTS

The A-point moved 8.0 mm forward during the distraction osteogenesis period, and the recurrence rate was 25% after the retention period. The transverse dimension of the upper arch was expanded during orthodontic treatment. The quality of the alveolar bone created by distraction osteogenesis was acceptable for the prosthodontic implant.

CONCLUSIONS

Premaxillary distraction osteogenesis and arch expansion is an effective treatment strategy, improving function, aesthetics, and stability for cleft patients with multiple missing teeth.

Maxillary anterior segmental distraction osteogenesis with 2 different types of distractors

OBJECTIVE

Maxillary anterior segmental distraction osteogenesis (DO) has been the alternative treatment option for patients with midfacial retrusion. To investigate a potentially more effective maxillary anterior segmental DO, a newly designed intraoral alveolar distractor was applied. The objectives of this study were to investigate the skeletal and dental effects of maxillary anterior segmental DO and the relapse pattern.

METHODS

The study was carried out for 8 patients with unilateral cleft lip and palate (mean age, 16 years 7 months). Four patients were treated with an intraoral appliance (IA), and the remaining with a rigid external distractor (RED). Dental and skeletal measurements were obtained for both groups. These measurements were compared for different time points including pre-DO (T1), post-DO (T2), postconsolidation (T3), and 1-year follow-up (T4).

RESULTS

Horizontal change of A point was significantly larger after distraction period (T2) in the RED group (mean, 11.0 mm; median, 10.1 mm) than in the IA group (mean, 6.6 mm; median, 7.4 mm) (P < 0.05). Relapse of A point was observed in both RED (mean, -2.3 mm; median, -2.3 mm) and IA groups (mean, -2.6 mm; median, -1.5 mm) at T4. The vertical position of the anterior nasal spine was found to have moved downward in the RED group (mean, 5.5 mm; median, 4.9 mm) but upward in the IA group (mean, -2.5 mm; median, -2.7 mm) after distraction, showing a significant difference between groups (P < 0.05). Axis of upper incisor increased at T2 in the IA group (mean, 10.4 degrees; median, 11.3 degrees), but decreased in the RED group (mean, -10.2 degrees; median, -9.0 degrees) (P < 0.05). It recovered in the RED group at T4.

CONCLUSIONS

Maxillary anterior segmental DO is effective for the treatment of patients with cleft lip and palate. The alveolar space is regained, and the facial profile is improved without velopharyngeal problems. Superior results are obtained using the RED appliance for maxillary anterior segmental DO relative to the use of the intraoral distractor appliance.

Distraction Osteogenesis in Adolescents with Maxillary Arch Deficiency and Dental Crowding: A 3-Year Follow-Up

BACKGROUND

In this study, the authors evaluated the long-term results after using anterior segmental osteotomy and distraction osteogenesis for the correction of sagittal maxillary deficiency associated with dental crowding.

METHODS

Six young adolescents (four boys and two girls) underwent surgery and distraction at a mean age of 11.2 years (range, 10 to 12 years) and were followed up for 3 years. A tooth-borne distraction device was used for interdental distraction. The evaluation consisted of hard- and soft-tissue profile analysis and dental arch measurements before, immediately after, and 3 years after distraction.

RESULTS

The results showed that the facial profile, the occlusion, and the dental crowding could be successfully corrected and that the results were stable after 3 years' follow-up. The mean facial convexity angle was changed from 1 to 8 degrees. The average advancement at point A was 4 mm and the SNA increased by an average of 4 degrees. Lengthening of the dental arch by an average of 4 mm created approximately 8 mm of new space, sufficient to resolve the dental crowding in all patients, thus avoiding an extraction of healthy teeth.

CONCLUSION

The results of this study demonstrated that anterior segmental maxillary osteotomy combined with distraction osteogenesis offers an alternative for the treatment of adolescents suffering from sagittal maxillary deficiency with dental crowding.