Condylar resorption post mandibular distraction osteogenesis in craniofacial microsomia: A retrospective study.

The aim of this study was to investigate the characteristics of condylar resorption in craniofacial microsomia (CFM) patients following mandibular distraction osteogenesis (MDO). Patients with unilateral type-IIa and type-IIb CFM, who had completed MDO and mandibular distractor extraction (MDE), were recruited. The height and volume of the condyle were measured on three-dimension models created by the analysis of computed tomography (CT) data. Normality analysis was performed using the Shapiro-Wilk test. Data for the affected and unaffected sides were compared using the paired t-test or Wilcoxon signed-rank test. Data for both type-IIa and type-IIb CFM were compared using the independent-samples t-test or Mann-Whitney U test. The Pearson or Spearman correlation was used to determine the correlations of condylar resorption rate with related measurements. In total, 48 type-IIa and 48 type-IIb CFM patients were included. The condylar resorption rate in type-IIa CFM (0.35 ± 0.32) was significantly associated with the height of the condyle (r = 0.776, p < 0.001) and distraction distance (r = 0.447, p = 0.001), while the condylar resorption rate in type-IIb CFM (0.49 ± 0.46) was significantly associated with the height of the condyle (r = 0.924, p < 0.001). However, there was no significant difference in condylar resorption rate between type-IIa and type-IIb CFM (p = 0.075). In addition to occlusal changes, no other negative symptoms of the TMJ were observed with condylar resorption. Condylar resorption was evident in CFM patients following mandibular distraction osteogenesis, and the condylar resorption rate showed a relationship with distraction distance and condylar height.

Respiratory outcome of mandibular distraction osteogenesis on obstructive sleep apnea in craniofacial microsomia: A retrospective study.

This study aimed to evaluate the effect of mandibular distraction osteogenesis (MDO) on respiratory function in CFM patients with obstructive sleep apnea (OSA) according to polysomnography (PSG). This study retrospectively analyzed patients with CFM who underwent PSG before surgery and after completion of mandible distraction. Patients who met the inclusion criteria were selected. The Pediatric Sleep Questionnaire (PSQ) was used to assess patients' signs and symptoms related to OSA. The obstructive apnea-hypopnea index (OAHI) and lowest oxygen saturation (LSaO2) were imported into SPSS version 26.0. The Wilcoxon signed-rank test was used to assess the differences in PSG before and after MDO. Other data were described using descriptive statistics. A P-value less than 0.05 was considered statistically significant. A total of 25 unilateral CFM patients were included in this study. Most patients (72%) had mild OSA; moderate and severe OSA were 12% and 16%, respectively. Snoring (52%) was the most common symptom among these patients. After completion of mandibular distraction, snoring and other OSA-related symptoms were significantly improved. Twelve patients had normalized PSG and the severity of OSA improved significantly in 3 patients. The total effective rate of MDO for OSA was 60%. The statistical results showed that OAHI (P = 0.045) decreased and LSaO2 (P = 0.009) increased significantly compared to preoperative values. MDO can improve OSA-related symptoms in CFM patients. In addition, respiratory function was improved in most patients after MDO, based on PSG. CFM patients, especially those with OSA, can benefit from MDO.

Morphologic Changes of the Temporomandibular Joint in Pruzansky-Kaban Type IIa Hemifacial Microsomia Postmandibular Distraction Osteogenesis.

OBJECTIVE: Mandibular distraction osteogenesis (MDO) is a powerful tool for the correction of hemifacial microsomia (HFM). The temporomandibular joint (TMJ) is the focus of attention in the diagnosis and treatment of HFM. This observational retrospective cross-sectional study aimed to investigate morphologic changes in TMJ post-MDO in type IIa HFM. METHODS: We recruited 48 patients with unilateral type IIa HFM who had completed MDO and mandibular distractor extraction (MDE). Data relating to the length, distance, angle, and volume of the TMJ were measured on 3-dimension models created by the analysis of computed tomography data. Normality analysis was performed by using the Shapiro-Wilk test. Data were compared with the paired t test and Wilcoxon signed-ranks test. RESULTS: The spaces between the affected condyle and the affected glenoid fossa before MDO were all significantly larger than before MDE (P<0.05). The breadth of the affected glenoid fossa before MDO was significantly longer than before MDE (P<0.001). The height of the affected condyle before MDO was significantly longer than before MDE (P<0.001). The volume of the affected condyle before MDO was significantly larger than before MDE (P<0.001). The ratio between the volume of the affected condyle and unaffected condyle before MDO was 0.20±0.13. The ratio between the volume of the affected condyle before MDE and MDO was 0.65±0.32. The resorption rate of the affected condyle post-MDO was 0.35±0.32. CONCLUSION: Herein, we characterized anatomic changes of the TMJ in type- IIa HFM post-MDO. Condylar resorption and the compression of space between the condyle and the glenoid fossa on the affected side were 2 typical manifestations. Our findings enhanced the understanding of the application of MDO on HFM.

Three-Dimensional Measurement of the Temporomandibular Joint in Pruzansky-Kaban Type IIa Hemifacial Microsomia.

OBJECTIVE: This observational retrospective cross-sectional study aimed to investigate the morphological characteristics of the temporomandibular joint (TMJ) in type IIa hemifacial microsomia (HFM). METHODS: We recruited 88 patients with unilateral type IIa HFM. Data relating to the length, distance, and angle of the TMJ, were measured on 3-dimensional models created by the analysis of computed tomography data. Normality analysis was performed by using the Shapiro-Wilk test. Data were compared with the paired t test and Wilcoxon signed-rank test. RESULTS: The height, long axis, and short axis of the affected condyle were significantly shorter than the unaffected side ( P <0.001); the ratios were 0.41±0.15, 0.75±0.20, and 0.95±0.24, respectively. The spaces between the condyle and the glenoid fossa were significantly larger in affected TMJs ( P <0.001). The ratio between the ipsilateral and contralateral anterior space in the sagittal plane was 4.62±2.59; this was significantly different than the ratio of inner space (1.50±1.70), superior space (1.70±0.97), and lateral space (1.28±0.62) in the coronal plane ( P <0.001) and the ratio of superior space (1.43±1.05) and posterior space (1.47±0.98) in the sagittal plane ( P <0.001); there were no statistical differences between the 5 spaces ( P >0.05). The breadth and depth of the glenoid fossa were significantly shorter in affected TMJs ( P <0.001), the ratio of the breadth in the affected and unaffected glenoid fossa was between 0.5 and 1 and the depth of the affected glenoid fossa was almost half of that on the unaffected side. The ratio between the ipsilateral and contralateral height of the condyle was significantly different when compared with the length of the mandibular ramus ( P <0.001). The ratio between the ipsilateral height of the condyle and the length of the mandibular ramus was significantly different when compared with that of the contralateral side ( P <0.001). The height of the affected condyle were significantly different ( P =0.005) among different ages. CONCLUSIONS: We found that hypoplasia was more severe in terms of the height of the condyle than the long axis and short axis of the condyle. The degree of condyle deformity was more severe than the mandible. And the affected condyle still had growth potential in the vertical direction with age.

Mandibular Distraction Osteogenesis First for Children With Severe Unilateral Hemifacial Microsomia: Treatment Strategy and Outcomes.

ABSTRACT: The treatment for severe hemifacial microsomia (HFM), especially type III case, is extremely difficult. Mandibular distraction osteogenesis (MDO) was rarely used as the primary choice in the treatment of severe type cases. The authors sought to observe the short-term therapeutic outcomes of patients with severe unilateral HFM who underwent MDO first.A retrospective study of children underwent MDO or later received costochondral graft (CCG) for severe unilateral HFM from 2009 to 2019 was conducted. Cephalometric measurements and clinical variables were analyzed to evaluate the effectiveness of MDO first strategy for severe cases and compare disparity between Pruzansky-Kaban classification type IIb and type III groups.Thirty-six patients (23 males and 13 females) underwent MDO first for severe HFM were included for analysis in the present study. The average age at MDO was 8.33 ±â€Š2.03 years. At the last follow-up, MDO acquired significant improvement in mandibular height, maxillary cant, chin deviation, lip commissural line tilt, and clinical chin deviation (P < 0.05). Distraction results were stable during the short-term follow-up in terms of the mandibular height ratio and maxillary cant (P > 0.05).MDO is a proper primary method for suitable type IIb and type III HFM cases. MDO can immediately and significantly improve the facial skeleton deficiency, extend the associated soft tissue at the same time, and lay foundation for secondary surgery. MDO can achieve the downgrade of HFM deficiency severity. MDO followed by costochondral graft can get satisfactory esthetic and structural consequence for type III patients.