Maxillary Distraction Osteogenesis Research Articles

Effect of maxillary distraction osteogenesis and LeFort-1 advancement orthognathic surgery on soft-tissue thickness and anterior soft-tissue to hard-tissue movement ratios among patients with complete unilateral cleft lip and palate

Objectives: The objective of this study was to compare the soft-tissue thickness and anterior soft-tissue to hard-tissue movement ratios in patients with unilateral cleft lip and/or palate (UCLP) following maxillary distraction osteogenesis using rigid external distractor device and maxillary advancement at LeFort I level using lateral cephalograms. Material and Methods: This retrospective study was conducted on 20 patients with UCLP who underwent either LeFort I maxillary advancement or maxillary distraction osteogenesis. Non-syndromic patients with complete UCLP anomalies and skeletal class III patterns due to maxillary hypoplasia were included in the study. The patients with a pre-surgical negative overjet of ≥5 mm were treated by maxillary distraction osteogenesis, while a negative overjet of <5 mm was managed with maxillary advancement orthognathic surgery. The growth completion in all the patients was assessed using the cervical vertebrae maturation index (CS 6) on a lateral cephalogram. The lateral cephalograms taken before surgery at (T0) and after a minimum interval of six months (T1) of surgery were assessed for changes in soft-tissue thickness and hard-tissue to soft-tissue movement ratios among the two groups. Paired t-test was used to compare the mean values obtained within the same group at two different time intervals. Unpaired t-test was used to compare mean values between the Groups 1 and 2. Pearson’s correlation coefficient (r) test was used to assess the associations between the mean changes in hard- and soft-tissue variables. Results: Group 1 showed significantly greater maxillary advancement compared to Group 2 with a mean difference of 5.80 mm at Point A and 7.65 mm at the upper incisal edge. Soft-tissue thickness decreased significantly after advancement in Group 1 at subnasale (P < 0.05), labrale superius, stomion, and labrale inferius (P < 0.01) and at subnasale (P < 0.05), stomion and labrale inferius (P < 0.01) in Group 2. There was a significantly strong correlation between the hard- and soft-tissue movement in sagittal plane in both Group 1 and Group 2. In Groups 1 and 2, a statistical highly significant strong positive correlation was found between vertical change in dU1 to soft-tissue dLs and dStms. In Group 2, a statistical highly significant strong positive correlation was found between vertical change in dA to soft-tissue dC and dStms. Conclusion: The soft-tissue thickness reduced in patients with UCLP after maxillary advancement in both groups. The soft tissue followed the hard tissue in both groups. There was a greater downward movement of the maxillary base and soft-tissue lengthening in Group 1 compared to Group 2.

Novel patient-specific helical maxillary distractor: an in vitro feasibility study

At present, stock linear distractors are used for internal maxillary distraction osteogenesis. However, the authors’ research group has demonstrated, through an in silico analysis, that linear distraction leads to bone deformities and malocclusion, whereas helical distraction can yield ideal outcomes. A system for designing and manufacturing custom helical distractors has recently been developed, and the feasibility of these appliances now needs to be assessed. This study was, therefore, conducted to gain an initial insight into their feasibility. The study had two goals. First, it aimed to demonstrate, in an in vitro model, that the novel system of custom helical distraction can produce appropriate clinical outcomes. The second aim was to compare the performance of custom helical distractors with that of stock devices and hybrid devices (i.e., linear appliances that feature patient-specific footplates). Interpreting the results as trends, this study showed that the system of custom helical distraction resulted in in vitro outcomes that were superior to those obtained with stock and hybrid devices.

Skeletal stability after maxillary distraction osteogenesis or conventional Le Fort I osteotomy in patients with cleft lip and palate: A superimposition-based cephalometric analysis

PurposeThe aim was to assess skeletal stability after maxillary advancement using either distraction osteogenesis (DO) or conventional Le Fort I osteotomy (CO) in patients with cleft lip and palate (CLP) or cleft palate (CP) utilising a new superimposition-based cephalometric method.MethodThis retrospective study included patients who were treated with DO (N = 12) or CO (N = 9). Sagittal and vertical changes after surgery, and skeletal stability at 18 months post-operatively were assessed with superimposition-based cephalometry, comparing lateral cephalograms performed pre-operatively (T0), post-operatively after CO or immediately after completed distraction in DO (T1), and at 18 months of follow-up (T2).ResultsThe mean sagittal movements from T0 to T2 in the DO and CO groups were 5.9 mm and 2.2 mm, respectively, with a skeletal relapse rate of 16% in the DO group and 15% in the CO group between T1 and T2. The vertical mean movement from T0 to T2 in the DO and CO groups was 2.8 mm and 2.0 mm, respectively, and the skeletal relapse rate between T1 and T2 was 36% in the DO group and 32% in the CO group.ConclusionSagittal advancement of the maxilla was stable, in contrast to the vertical downward movement, which showed more-extensive relapse in both groups. Despite more-extensive maxillary advancement in the DO group, the rates of skeletal relapse were similar.

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. Keywords: Distraction Osteogenesis; Cleft Palate; Cleft Alveolar; Maxillary Osteotomy; India.

Cleft Maxillary Hypoplasia: Comparison of Techniques and Proposal of a Novel Treatment Protocol for Management.

This study was designed to compare different techniques of managing cleft maxillary hypoplasia and to propose a treatment protocol taking patient's age of presentation, amount of maxillary hypoplasia, and presence/absence of velopharyngeal insufficiency (VPI) into consideration. Five treatment modalities, viz. facemask therapy (Group I), anterior maxillary distraction (Group II), total maxillary distraction osteogenesis using rigid external distraction devices (Group III) and internal distraction devices (Group IV), and conventional orthognathic surgery (Group V), were assessed retrospectively using lateral cephalograms (taken at 3 intervals) and speech records (studied pre- and post-operatively). The results were subjected to statistical analysis. A P value of less than 0.05 was considered statistically significant. The mean advancement achieved in groups I, II, III, IV, and V was 4.2±1.54, 9.03±2.62, 11.82±1.18, 10.41±1.42, and 7.24±2.44mm, respectively. The mean horizontal relapse noted in Groups I, II, III, IV, and V was 2.3mm (n=8), 2.1mm (n=14), 3.4mm (n=10), 1.4mm (n=5), and 2.4mm (n=24), respectively. Compared to other groups, group II had fewer patients exhibiting relapse, a statistically significant observation. Similarly, statistically significant improvement in speech outcomes was found only in group II compared to other groups. Based on the results, a treatment protocol was proposed. The authors conclude that the proposed protocol would enable surgeons to decide the most appropriate treatment modality paying attention to not only the age of presentation and amount of advancement but also presence/absence of VPI which is instrumental in deciding upon the most appropriate treatment.

Orthodontic Challenges and Management In Anterior Maxillary Distraction Osteogenesis In Cleft Lip And Palate

Orthodontic Challenges and Management In Anterior Maxillary Distraction Osteogenesis In Cleft Lip And Palate

Anterior Maxillary Distraction Osteogenesis With Bone-borne Intraoral Buccal Devices for Maxillary Hypoplasia With Cleft Lip and Palate.

Anterior maxillary distraction osteogenesis (AMDO) surgery for cleft lip and palate involves distraction of a segment of the anterior maxilla and advancement using 2 intraoral buccal bone-borne distraction devices. The anterior part of the maxilla is advanced anteriorly with less relapse which increases maxillary length and does not affect speech. We aimed to evaluate the effects of AMDO, including lateral cephalometric changes. Seventeen patients who had undergone this procedure were included in this retrospective study. The distractors were activated by 0.5mm twice a day after a 3-day latency period. Lateral cephalometric radiographs were evaluated preoperatively, after distraction and removal of distractors, which were compared using the paired Student's t test. Anterior maxillary advancement was obtained in all patients with a median of 8.0mm. Complications included nasal bleeding and loosening of distractors; however, there was no tooth damage or abnormal movement. The mean sella-nasion-A point (SNA) angle increased significantly, from 74.91° to 79.66°, the A point-nasion-B point angle from -0.38° to 4.34°, and the perpendicular line from nasion to Frankfort Horizontal (NV)-A point from -5.11 to 0.08mm. The mean anterior nasal spine-posterior nasal spine length increased significantly from 50.74 to 55.10mm, and the NV-Nose Tip from 23.59 to 26.27mm. The mean relapse rate of NV-A was 11.1%. AMDO with bone-borne distractor resulted in less relapse and effectively corrected the maxillary retrusion.

Easy low-cost surgical guide for anterior maxillary distraction osteogenesis with intraoral buccal devices

Easy low-cost surgical guide for anterior maxillary distraction osteogenesis with intraoral buccal devices

Assessing the Impact of Transcutaneous Maxillary Distraction Osteogenesis on Pharyngeal Airway Volume in Children with Cleft Lip and Palate: A 3D Evaluation Study.

Cleft lip and cleft palate (CLCP) patients often have a retrusive maxilla and a severe skeletal Class III malocclusion, which can result in velopharyngeal insufficiency (VPI). The aim of this study was to evaluate the changes in the volume of the 3D airway in CLCP children after maxilla distraction using the transcutaneous maxillary distraction osteogenesis (TMDO) method. 15 children with bilateral or unilateral CLCP were included in the study. 3D CBCT images were taken before and after distraction and were segmented and reconstructed to create a 3D airway model. The airway was divided into three regions: the upper, oropharyngeal, and hypopharyngeal airway. Pearson correlation tests were used to assess correlations between volume changes and corresponding skeletal and dental landmark movements (Point N, ANS, A, B, Pog, U1, and L1). The results showed that the ANS point advanced 9.85 ± 3.60 mm, and the A point advanced 14.22 ± 4.57 mm. The total airway volume change increased by 2535.06 ± 2791.80 mm3. However, there was no significant correlation between the A/ANS/U1 and the three different airway regions. Only B/Pog/L1 showed a positive correlation with these airway regions, with a high correlation between B/Pog/L1 and the hypopharyngeal airway region. TMDO can result in greater anterior advancement of the maxilla and an increase in airway volume, but the changes in bony landmarks did not show a strong positive correlation with the increase in airway volume as expected. Further investigation is needed to analyze the influence of surrounding soft tissue on the changes in airway volume.

Long-Term Outcomes After External Maxillary Distraction Surgery in Patients With Down Syndrome

Patients with Down syndrome have severe facial deformities that can precipitate functional consequences and social stigmatization. Craniofacial surgical intervention can play a role in improving these symptoms and patient quality of life. The objective of this study was to investigate the long-term outcomes of distraction osteogenesis and orthognathic surgical intervention in patients with Down syndrome. Charts of 3 patients with Down syndrome who were treated with external maxillary distraction osteogenesis were retrospectively reviewed. The patients' caregivers were prospectively interviewed between 10 and 15 years after surgery to determine surgical stability, long-term function, and quality of life status. All patients and their caregivers reported excellent results with improvements in function and quality of life. Facial skeletal changes have been stable over time. The cephalometric analysis demonstrated significant maxillary advancement in all 3 patients and mandibular changes to correct mandibular prognathism and asymmetry in the patient who underwent finishing orthognathic surgery. External maxillary distraction osteogenesis and orthognathic surgery may be considered in select patients with Down syndrome as part of their multidisciplinary health care. These interventions can result in long-term improvements in patient function and quality of life.

Augmented reality hologram combined with pre-bent distractor enhanced the accuracy of distraction vector transfer in maxillary distraction osteogenesis, a study based on 3D printed phantoms.

Vector control is a significant concern in maxillary distraction osteogenesis (DO). Distraction vector planning on the patient's 3D-printed skull phantom is more intuitive for surgeons and cost-efficient than virtual surgical planning. However, the accuracy of transferring the planned vector to intraoperative (vector transfer) according to the shape of the pre-bent footplate alone is relatively limited. The application of augmented reality (AR) in surgical navigation has been studied for years. However, few studies have focused on its role in maxillary DO vector transfer. This study aimed to evaluate the accuracy of AR surgical navigation combined with the pre-bent distractor in vector transfer by comparing it with the pre-bent distractor alone. Ten patients with maxillary hypoplasia were enrolled with consent, and three identical 3D-printed skull phantoms were manufactured based on per patient's corresponding pre-operative CT data. Among these, one phantom was for pre-operative planning (n = 10), while and the other two were for the AR+Pre-bending group (n = 10) and the Pre-bending group (n = 10) for the experimental surgery, respectively. In the Pre-bending group, the distraction vector was solely determined by matching the shape of footplates and maxillary surface. In the AR+Pre-bending group, the distractors were first confirmed to have no deformation. Then AR surgical navigation was applied to check and adjust the vector in addition to the steps as in the Pre-bending Group. For the angular deviation of the distraction vector, the AR+Pre-bending group was significantly smaller than the Pre-bending group in spatial (p < 0.001), x-y plane (p = 0.002), and y-z plane (p < 0.001), and there were no significant differences in the x-z plane (p = 0.221). The AR+Pre-bending group was more accurate in deviations of the Euclidean distance (p = 0.004) and the y-axis (p = 0.011). In addition, the AR+Pre-bending group was more accurate for the distraction result. In this study based on 3D printed skull phantoms, the AR surgical navigation combined with the pre-bent distractor enhanced the accuracy of vector transfer in maxillary DO, compared with the pre-bending technique alone.

Effects of anterior maxillary distraction compared to LeFort-1 osteotomy and total maxillary distraction osteogenesis for treating hypoplastic maxilla in patients with cleft lip and palate- A systematic review and meta-analysis

ObjectiveTo compare the treatment outcomes and effectiveness of Anterior Maxillary Distraction (AMD) with the LeFort I Osteotomy and Total Maxillary Distraction Osteogenesis (TMDO) to treat cleft maxillary hypoplasia. Methods(PROSPERO CRD42020223345) Thorough electronic search of seven databases, unpublished gray literature, and a hand search of the relevant studies reference lists was done. Studies assessing mid-facial skeletal, dentoalveolar, and soft-tissue outcomes of AMD in patients >8 years of age, hypoplastic cleft maxilla, and with either TMDO/LeFort 1/ both as control groups were included. Seven included articles were assessed for the study characteristics and qualitative synthesis. Three studies were analyzed quantitatively using the RevMan 5.4 software. The quality of studies was assessed using Cochrane ROB2 and the overall certainty of evidence using GRADE. ResultsAMD was performed in 241 subjects, LeFort 1 in 145 subjects, and TMDO in 42 subjects. Maxillary advancement for AMD and LeFort 1 groups showed no statistically significant difference (Mean Difference, MD -0.64°) while TMDO showed statistically significant advancement than AMD (MD -1.44°). Statistically significant upward rotation of anterior maxilla was noted with AMD (MD -6.15 degrees) than Lefort 1. Upper incisor inclination improved in both AMD and TMDO groups (MD 1.5°). Improvement in the maxilla-mandibular relationship, convexity of face, lip and nose, and marked dentoalveolar changes in overjet and upper incisor position were noted in all the three groups. Discernible airway alterations were noted in LeFort 1 and TMDOs. Total relapse was the least with AMD. ConclusionDistraction osteogenesis exhibited better dento-skeletal outcomes and minor skeletal relapse than LeFort 1. TMDO is a preferred modality in treating severe maxillary hypoplasia associated with CLP than AMD. Further long-term prospective comparative studies are required, possibly involving the patient-centric merits.

A Comparative Study of Skeletal and Dental Outcome between Transcutaneous External Maxillary Distraction Osteogenesis and Conventional Rigid External Device in Treating Cleft Lip and Palate Patients.

Background: Traditional distraction osteogenesis (DO) with the tooth-borne rigid external device (RED) system was regularly used in treating patients with cleft-related maxillary hypoplasia. However, the bone-borne RED system with miniplates and bone screws has currently become an effective treatment. This retrospective study was to compare bone-borne RED with traditional tooth-borne RED in distraction effectiveness, blood loss, operative time, and long-term stability. Methods: Twenty-two growing patients who underwent RED therapy were divided into two groups: eleven patients utilizing the bone-borne RED system with the transcutaneous wire attached with skeletal anchorage; another eleven patients using the traditional tooth-borne RED system with the intra-oral device attached with dental anchorage. Serial lateral cephalograms were analyzed for comparing treatment outcomes and stability in 1 month, 6 months, and 1.5 years after distraction. Results: In bone-borne RED group, the maxilla was advanced by 19.98 mm with slight clockwise rotation of 0.40° and minimal palatal inclination change of incisor by −3.94°. In traditional tooth-borne RED group, the maxilla showed less advancement by 14.52 mm, with significant counter-clockwise rotation of −11.23° and excessive palatal inclination change of incisor by −10.86°. Although operative time was longer in the bone-borne RED group by 38.4 min, this did not bring about greater blood loss. Conclusions: the bone-borne RED via transcutaneous wire system provides an easy, simple, and comfortable procedure as well as favorable long-term stability in maxillary distraction.

A Comparative Study of Skeletal and Dental Outcome between Transcutaneous External Maxillary Distraction Osteogenesis and Conventional Rigid External Device in Treating Cleft Lip and Palate Patients

A Comparative Study of Skeletal and Dental Outcome between Transcutaneous External Maxillary Distraction Osteogenesis and Conventional Rigid External Device in Treating Cleft Lip and Palate Patients

A Case of Long-term Follow-up after Maxillary Distraction Osteogenesis and Mandibular SSRO for a UCLP Patient

A Case of Long-term Follow-up after Maxillary Distraction Osteogenesis and Mandibular SSRO for a UCLP Patient

Factors associated with the outcome of maxillary distraction osteogenesis in cleft lip and palate patients

Since distraction osteogenesis had been used in maxillofacial surgery in the 1990s,it has become an important option for treating maxillary hypoplasia in cleft lip and palate (CLP) patients. Numerous domestic and international studies reported that the prognosis of distraction osteogenesis might be affected by various factors, including the design of osteotomy line, type of distractor, advancement of maxillary bone and the age of patients, etc. Therefore, the present article reviewed possible impact factors that affect the effectiveness and outcomes of maxillary distraction osteogenesis of CLP from three aspects: treatment methods, type of patients and adjuvant therapy, which hopefully might benefit the formulation of treatment strategies in clinical work and improve the prognosis of distraction osteogenesis.

Cleft Lip and Palate Midfacial Hypoplasia: Criteria to Choose the Treatment.

A series of skeletal and dentoalveolar/occlusal criteria were proposed for choosing the treatment modality for the management of midface hypoplasia in cleft lip/palate patients, focusing on functional improvement, aesthetics, and minimizing the risk of recurrence and secondary alterations. For which, 42 patients with nonsyndromic cleft lip/palate, all with previous primary lip/palate surgeries and without previous osteotomies, were analyzed. Orthognathic surgery (OS) (n = 24) and maxillary distraction osteogenesis (n = 18) with anterior segmental osteotomies (segmental distraction osteogenesis [SD]), alveolar transport disc (TD), and midface total distraction osteogenesis (TDO) by modified Le Fort III osteotomy was done.The average of maxillary advancement for OS was 5.58 ± 0.83 mm, for SD 9.4 ± 0.89 mm, for TD 8.00 ± 1.00 mm, and for TDO was 8.13 ± 1.55 mm.In the presence of infraorbital and/or zygomatic hypoplasia, TDO was performed using skeletal anchorage, with the requirement of occlusal stability in dental cast in occlusion. In short maxillary arch without dental cast feasibility in occlusion, hypodontia/agenesis or absence of premaxilla, TD and SD was performed. There was only 1 mm of recurrence in 1 patient of each group. Changes in speech were detected in 2 patients in the OS group (8.3%). Orthognathic surgery can be indicated for advancements ≤7 mm not requiring orbito-zygomatic advancement, whereas distraction osteogenesis can be indicated for advances >8 mm with or without the need for orbito-zygomatic advancement, in addition with other dentoalveolar factors and velopharyngeal function.

One-Year Treatment Outcome of Profile Changes After Transcutaneous Maxillary Distraction Osteogenesis in Growing Children With Cleft Lip and Palate.

To evaluate the long-term stability of LeFort I osteotomy followed by distraction osteogenesis with a transcutaneous rigid external device for the treatment of severe maxillary hypoplasia in patients with cleft lip and palate. Nine patients with cleft lip and palate underwent rigid external distraction after a LeFort I osteotomy for maxillary advancement. Lateral cephalometric films were analyzed for assessment of treatment outcome and stability in 1 month, 6 months, and 1 year after distraction. Significant maxillary advancement was observed in the horizontal direction, with the anterior nasal spine (ANS) distance of the maxilla increasing by an average of 20.5 ± 5.1 mm after distraction. The ANS relapse rates in 6 months and 1 year were 8.7% and 12.8%, respectively. The mean inclination of upper incisors to the palatal plane was almost unchanged (before: 109.8° ± 6.6°; after: 108.9° ± 7.5°). The movement ratios at the nasal tip/ANS, soft tissue A point/A point, and the upper vermilion border/upper incisor edge were 0.36:1, 0.72:1, and 0.83:1, respectively. Considerable maxillary advancement was achieved with less change of incisors inclination after distraction. Moreover, the relapse rate after 1 year was minimal. The concave facial profile was improved as well as the facial balance and aesthetics.

Minimally-invasive anterior maxillary distraction technique in patients with cleft lip and palate and maxillary deficiency: an evaluation of 106 patients.

Our aim was to evaluate the feasibility of a minimally-invasive surgical technique for anterior maxillary distraction osteogenesis to correct maxillary hypoplasia in patients with clefts. A modified Y distractor was placed intraorally in 106 patients with cleft- associated maxillary deficiency to facilitate protraction of the maxilla. Subsequently the patients had an anterior maxillary osteotomy through a minimally invasive incision, followed by activation of the appliance at the rate of 0.8mm/day until positive overjet was achieved. The patient's lateral cephalograms were evaluated preoperatively (T1), after activation (T2), and one year postoperatively (T3). Collected data were assessed with the paired t test, and probabilities of < 0.001 were accepted as significant. A mean (SD) of 10.4 (2.58) mm anterior maxillary advancement was obtained in all patients after 10-13 days of distraction. The sella-nasion-point A (SNA) angle increased from 75.37° to 83.01°. When we compared the cephalometric variables at T1 and T2, the mean maxillary length and overjet at T2 were significantly higher (p<0.001). The comparison of mean values at T2 and T3 was not significant. Minimally invasive anterior maxillary distraction with the modified Y distractor resulted in changes after activation that were consistent one year postoperatively, making it a conservative, less traumatic, and effective treatment of cleft-related maxillary deficiency.

Skeletal stability in patients with clefts after large maxillary advancements using intraoral distraction.

Maxillary hypoplasia is a common outcome in patients with cleft lip and palate after surgical and orthodontic interventions, and maxillary distraction osteogenesis has become a useful procedure for patients with extensive maxillary deformities. The aim of this study was to evaluate long term (two years) stability after maxillary advancement of more than 10mm by distraction osteogenesis in cleft patients using internal devices. We organised a retrospective study on 42 patients with cleft lip and palate using cephalometric analysis before and after maxillary distraction osteogenesis and evaluated them for 24 months. Postoperative measurements showed a marked advancement with an increase of 13.3mm and 10.8° in the length of the maxilla (Co-A) and SNA, respectively, including a shift from Angle class III to class I in dental relations. Follow-up observations showed preservation of maxillary length with a relapse of only 6.0 % (mean (SD) 0.8 (0.7) mm) and 10% relapse in SNA angle (mean (SD)1.1 (1.4) °) one year postoperatively and a negligible regression at the two years' follow up. This large-scale study shows stable results of skeletal advancement using distraction osteogenesis, indicating safe and reliable outcomes among patients with cleft lip and palate.