Three-dimensional Measurement of the Zygomatic-maxillary Complex in the Class III Malocclusion Patients with Maxillary Retrusion.

This study investigated the anatomic features of the zygomatic-maxillary complex in patients with maxillary retrusion without clefts. Individuals were grouped, and craniofacial measurements were performed for 21 individuals with skeletal Class III malocclusion with maxillary retrusion (CIII) and 48 individuals from the control group (CG). We evaluated the predetermined hard-tissue and soft-tissue points of the facial profile in each group. Independent sample t -tests were performed to determine the differences between groups (significance set at P <0.05). Multiple points on the midface, including the most posterior point on the contour of the maxillary alveolar process, lowest point of the zygomaticomaxillary suture, furthest point to the zygomatic self-base plane, superior point in the infraorbital foramen, and lowest point of the inferior margin of the orbit to the coronal plane were smaller in CIII than in CG (all P <0.05). The soft tissue thickness in these regions was significantly increased compared with that in the normal group. In summary, for class III malocclusion patients with maxillary retrusion, the deficiency in the midface gradually decreased going upward, with the deficiency at the maxillary alveolar level being the most serious. To some extent, soft tissues compensate for the deficiencies in the facial skeleton, and standard Le Fort I osteotomy advancement was sufficient to achieve a harmonious appearance.

Observation of Nasal Morphology in Unilateral Microform Cleft Lip Repaired by a Hidden Skin Incision.

BACKGROUND: Microform cleft lip is the mildest type of cleft lip without obvious defects of the upper lip. The nose deformities of microform cleft lip include flattened nostril rim, alar base asymmetry, and septal deviation. A hidden skin incision with nasal base muscle reconstruction was introduced in nose deformities of microform cleft lip. METHOD: To investigate the operative effect, we reviewed 21 patients with microform cleft lip treated with a hidden skin incision with nasal base muscle reconstruction from May 2020 to October 2022. Photogrammetric nasal morphometric measurements were compared preoperatively and six months postoperatively. The proportional value was obtained from the cleft and the noncleft sides, and paired t-test analysis was used to evaluate the surgical outcome. RESULT: Significant differences were found in all nasal morphologic measurements at 6 months postoperatively compared to preoperatively (p < 0.05). After surgery, the alar base and nostril were narrowed, while the lateral lip height was increased on the affected side. The height of the nostrils on the affected side was increased, and the nasal columella deviation was released. In addition, the ratio of the cleft-to-noncleft nostril area was closer to 1.0 after surgery. CONCLUSION: The unilateral microform cleft lip nasal deformity can be repaired through a small hidden incision. LEVEL OF EVIDENCE III: This journal requires that authors assign a level of evidence to each article. For a full description of these evidence-based medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

A 3-Dimensional Measurements of Bone and Airway Variables After Le Fort I Distraction Osteogenesis in Patients With Cleft Lip and/or Palate-Induced Midface Hypoplasia: A Retrospective Study.

The authors retrospectively analyzed the effects of Le Fort I advancement with distraction osteogenesis on skeletal and airway variables in patients with midfacial hypoplasia induced by cleft lip and/or palate using 3-dimensional computed tomography reconstructions. The authors enrolled 23 subjects with moderate-to-severe midface hypoplasia induced by cleft lip and palate who were treated with Le Fort I distraction osteogenesis (mean age, 19.22±3.48 y; male/female ratio, 20/3); computed tomography images (1 before distraction and another at completion of distraction) were acquired. A 3-dimensional craniometric findings and airway volumes for the nasal cavity, nasopharynx, velopharynx, and upper and lower oropharynx were compared before and after distraction. The relationships between craniofacial morphology and changes in airway volume were also assessed ( P <0.05 was considered significant). Significant increases were observed in airway volumes for the nasal cavity (13.85%), nasopharynx (50.82%), velopharynx (29.57%), and upper oropharynx (36.92%) ( P =0.007, P <0.001, P =0.023, and P <0.001, respectively), whereas no significant changes were observed for the lower oropharynx ( P =0.117). Maxillary horizontal advancement was positively correlated with the airway volumes of the nasopharynx and upper oropharynx after distraction osteogenesis ( rs =+0.451, P =0.031; rs =+0.548, P =0.007); however, no significant correlations were observed for the nasal cavity and velopharynx. The authors' finding indicate that despite rotation of the mandible along with the maxilla, this change does not impact airway volume at the mandibular level. Le Fort I distraction osteogenesis can be feasible for patients with cleft lip and palate-induced midface hypoplasia, with satisfactory appearance and occlusion. Long-term detailed follow-up of the patients postdistraction osteogenesis is warranted.

Three-Dimensional Measurement of the Zygomatic-Maxillary Complex in Unilateral Cleft Lip and Palate Patients With Maxillary Retrusion.

ABSTRACT: The purpose of this study was to investigate the anatomical features of the zygomatic-maxillary complex in unilateral cleft lip and palate (UCLP) patients with maxillary retrusion. Individuals were grouped and craniofacial measurements were carried out for 34 individuals in the UCLP with maxillary retrusion group (UMRG) and 50 from a control group (CG). The authors measured the length, width, and height of the maxilla and zygoma and also measured predetermined regions on the midface in each group. Independent sample group t tests were performed to determine differences between groups (with significance set at P < 0.05). Multiple points on the midface (the most posterior point on the contour of the maxillary alveolar process, lowest point of the zygomaticomaxillary suture, furthest point to the zygomatic self-base plane, superior point in the infraorbital foramen, and lowest point of the inferior margin of the orbit) to the coronal plane were smaller in the UMRG than in the CG (all results P < 0.05). In addition, the maxillary length was significantly reduced in the UMRG than in the CG (P < 0.05). In summary, for the UCLP patients with maxillary retrusion, the deficiency in the midface gradually reduced going upward, with the deficiency in the maxillary alveolar level the most serious. The zygoma was influenced to a lesser extent.

Muscle Flap Reconstruction Based on Muscle Tension Line Groups to Repair the Philtrum of Patients With Microform Cleft Lip or Secondary Cleft Lip.

ABSTRACT: The muscle flap reconstruction technique was developed based on the concept of muscle tension line groups, which elucidates how nasolabial muscle tension helps maintain the shape of the philtrum. To investigate the operative effect, we reviewed 43 patients with microform cleft lip and 102 patients with secondary cleft lip treated with muscle flap reconstruction between January 2018 and June 2020. The patients were scanned using the digital three-dimensional stereophotogrammetry face system pre- and post-operatively, and comparative analysis of three-dimensional (3D) images was used to highlight variations of the philtrum. Visual analog scales were used to assess surgical outcomes. More than 6 months after the surgery, comparative 3D images of 37 patients (86.04%) with microform cleft lip and 86 patients (84.31%) with secondary cleft lip showed visible improvement in the prominence of the affected column. In addition, visual analog scale scores showed that 38 microform cleft lip patients (88.37%) and 89 secondary cleft lip patients (87.25%) had a good appearance. The postoperative prominence of the philtral column in both groups improved significantly compared to before surgery (P < 0.001 and P < 0.001, respectively). There was no significant difference in scores for philtrum prominence pre- and post-operatively between the 2 groups (P > 0.05). Muscle flap reconstruction is an effective means to create the 3D configuration of the philtrum. The biomechanical properties of muscles play a vital role in the morphological maintenance of the philtrum.

Surgical Planning for Cleft Lip and/or Palate-Induced Moderate-to-Severe Midfacial Hypoplasia.

BACKGROUND: Distraction osteogenesis and conventional bimaxillary orthognathic surgery have been performed for the treatment of midfacial hypoplasia for a long time. However, the effect of these 2 techniques on the maxilla, mandible, and whole-facial profile is significantly different. In this study, we aimed to measure the pre- to post-treatment changes in maxillary prominence, mandible size, and facial length and compare them between these 2 techniques to inform selection of the best technique. METHODS: This single-center, retrospective study included 35 patients with a cleft lip and/or palate-induced midfacial hypoplasia; 25 were treated using rigid external distraction osteogenesis and 10 using bimaxillary orthognathic surgery. Three-dimensional measures of changes in facial structure were obtained from reconstructed computed tomography images and used to compare the effects of the 2 techniques. RESULTS: Satisfactory appearance and occlusion were achieved in all patients. Three-dimensional reconstruction of the craniofacial skeleton revealed significant maxillary advancement (P < 0.001), mandibular (clockwise) rotation (P < 0.001), and increased facial length (P < 0.001) after rigid external distraction osteogenesis and obvious shortening of the mandibular body (P < 0.001) after bimaxillary orthognathic surgery. CONCLUSION: Distraction osteogenesis can be selected as the first choice of treatment for cleft lip and/or palate-induced midfacial hypoplasia. A mandibular setback procedure can be performed as a second-stage surgery when severe temporomandibular joint complications develop with distraction osteogenesis. Bimaxillary orthognathic surgery results in an obvious shortening of the mandibular body, which is not a natural change in facial morphology. LEVEL OF EVIDENCE: Therapeutic III.

Temporomandibular joint dislocation in patients with cleft lip and palate after maxillary distraction osteogenesis: Three case reports.

INTRODUCTION: Distraction osteogenesis (DO) is a widely used for cleft and palate related maxillary hypoplasia. There has been little research on temporomandibular joint (TMJ) dislocation after maxillary DO. We present these 3 cases and analyze the possible causes for reference by other clinicians. PATIENT CONCERNS: In the late stages of maxillary DO, the patients gradually felt a decrease in mandibular mobility and suffered from limited mouth opening. Case 2 and 3 could open their mouth up to 1 and 2 fingers and Case 1 barely able to open her mouth at the completion of distraction. DIAGNOSIS: Case 1 and Case 3 were diagnosed as right TMJ dislocation and Case 2 had a TMJ dislocation on her left side. INTERVENTIONS: Patients with TMJ dislocation were repositioned with manipulation as soon as detected. OUTCOMES: There was no recurrence in all three cases during the postoperative follow-up period. CONCLUSIONS: Maxillary DO can sufficiently advance the maxilla in cleft lip and palate patients. Clinicians should be mindful of the TMJ dislocations that maxillary DO can exert on patients.

Horizontal Maxillary Osteotomy Stability Using Mandibular Outer Cortex Bone Grafts in Patients With Cleft Lip and Palate.

OBJECTIVE: To investigate horizontal maxillary osteotomy stability after using bone grafts for the treatment of patients with unilateral cleft lip and palate (UCLP). DESIGN: Retrospective cohort study. SETTING: Plastic surgery hospital. PATIENTS: Fifty-eight patients with UCLP and maxillary hypoplasia requiring a maxillary Le Fort I advancement of 6 to 9 mm. INTERVENTIONS: The test group (TG) was comprised of 28 patients who underwent mandibular outer cortex bone grafting in the gaps created by a modified Le Fort I osteotomy. The control group (CG) was comprised of 30 patients who underwent a Le Fort I osteotomy without bone grafts. MAIN OUTCOME MEASURES: Maxillary horizontal advancement (recorded during the operation using a Vernier caliper) and horizontal relapse at 12 months after surgery (based on a manual cephalometric analysis of pre- and postoperative lateral teleradiographs). RESULTS: In the TG, the mean maxillary horizontal advancement was 7.13 ±â€Š0.7 mm (range: 6.01-8.23 mm), and the mean postoperative horizontal relapse was 25.07 ±â€Š6.64%. In the CG, the mean maxillary horizontal advancement was 6.90 ±â€Š0.55 mm (range: 6.05-7.39 mm), and the mean postoperative horizontal relapse was 24.89 ±â€Š4.25%. There were no significant between-group differences in the mean horizontal relapses. CONCLUSION: The use of mandibular outer cortex bone grafts as physical barriers in patients with UCLP does not increase postoperative stability when the maxillary advancement is 6 to 9 mm.

Rigid External Distraction with Intranasal Bone-borne Traction Hooks for Midfacial Hypoplasia.

Rigid external distraction is currently performed to correct cases of severe maxillary hypoplasia. As an improvement of this technique, we propose the use of an intranasal bone-borne traction hook. This study is a retrospective chart review of the intranasal bone-borne traction hooks used in the treatment of severe maxillary hypoplasia. There were 110 patients treated with the hooks from 2005 to 2017. The maximum traction force was 7.75 kg, and there were few complications encountered during distraction. There were 76 patients who had the hooks removed under local anaesthesia. A cephalometric analysis was conducted in 56 patients. The average advancement of A-point was 9.9 ± 4.2 mm, 8.4 ± 2.5 mm, 11.0 ± 3.7 mm, 17.9 ± 4.4 mm for the trans-sutural distraction osteogenesis (DO), maxillary anterior segment DO, Le Fort I osteotomy DO and Le Fort III/II osteotomy DO, respectively. The average changes of sella-nasion-point A (SNA) were 8.89 ± 4.30 degrees, 8.21 ± 3.17 degrees, 10.49 ± 3.26 degrees, and 15.10 ± 4.00 degrees, respectively. The A point-nasion-B point (ANB) also showed increases in all procedures with P < 0.001. In conclusion, this technique sufficiently advances the midface and ensures the scars are concealed in the nasal base. The traction hook can bear a large traction force, causes minimal complications and is easily removed.

Characteristics of the Development of the Maxillae and Vomer in Patients With Bilateral Cleft Lip and Palate.

The aim of this study was to investigate the anatomical features of the maxillae and vomer in patients with bilateral cleft lip and palate (BCLP). Craniofacial measurements of 24 adult BCLP patients (GB) and 32 normal adult controls (GN) were carried out. We measured the width and length of the maxillae, their relative positions with respect to the coronal plane passing through the basion, and the volume, length, cross-sectional area, and mean width of the vomer. Between-group differences were assessed using independent-sample t tests. Finite element models (FEMs) were used to explore the bite forces acting on the bone by evaluating the distribution of stress and bone displacement. The mean vomer volume and width were significantly larger in the GB group than in the GN group (P = 0.000), whereas the length was significantly shorter (P = 0.000). The anterior maxillary length (A1-P3M⊥CP) was significantly larger in the GB group (P = 0.013), whereas the posterior maxillary length (P3M-P6M⊥CP) and overall maxillary length (A1-P6M⊥CP) at the dental level were significantly reduced (P < 0.01). In the BCLP FEM analysis, the maximum displacement was on the left premaxillary edge (0.2 mm), and high Mises stresses were found in the superior region of the vomer (22.4 Mpa), high tensile stresses in the inferior region (14.3 Mpa), and significant compressive stresses in the superior region (-24.7 Mpa). In summary, for BCLP patients, forward growth of the maxillae and vomer was inhibited during maxillary development, and the vomer was thicker and its volume was increased compared with the vomer in normal subjects.

[Classification and operation in the treatment of maxillary retrusion of adult patients with cleft lip and palate].

OBJECTIVE: To classify the patients with cleft lip and palate who need orthognathic surgery and to propose the corresponding operations. METHODS: From January 2005 to May 2015, 121 patients with cleft lip and palate diagnosed as maxillary retrusion were treated by orthognathic surgery. Inclusion criteriar: (1) male aged over 16, female aged over 14; (2) diagnosed as non-syndromic cleft lip and palate without systemic disease and other genetic diseases; (3) without previous orthodontic and orthognathic treatment; (4) having no other craniofacial malformation. Maxillary features and repaired types were recorded. RESULTS: 93 patients were included and divided into two categories depended on the dental crowding. Class I: the teeth quantity and bone quantity is coordinated, space analysis ≤ 4 mm (mild dental crowding). The forward distance of maxillary less than 6 mm was defined as Class I a (36 cases) more than 6 mm as Class I b (28 cases). Class II: the teeth quantity and bone quantity is not coordinated, space analysis > 4 mm ( moderate or severe dental crowding). After the simulation of distraction osteogenesis, the anterior crossbite was corrected defined as Class II a (23 cases), not corrected defined as Class II b (6 cases). Class I a were corrected by conventional orthognathic surgery. While Class I b were corrected by Le Fort I maxillary advancement using distraction osteogenesis. Class II a were repaired just by anterior maxillary distraction. While Class II b need to combine conventional orthognathic surgery with anterior maxillary distraction. All the patients were satisfied with the treatment effect. CONCLUSIONS: The patients of cleft lip and palate with maxillary retrusion who need orthognathic surgery can be classified as the method mentioned above, and then choose the appropriate operations.

Characteristics of Maxillary Morphology in Unilateral Cleft Lip and Palate Patients Compared to Normal Subjects and Skeletal Class III Patients.

This study is to investigate the anatomical features of maxillae in unilateral cleft lip and palate (UCLP) patients with maxillary retrusion. Additionally, the dissimilarities of retruded maxillae between the UCLP patients and the skeletal class III patients were compared. Craniofacial measurements were carried out among 32 UCLP adult patients with maxillary retrusion (GC), 24 adult patients in class III (SNA < 80°, ANB < 0°) patients (GIII), and 32 normal controls (GN). The authors measured the width and length of the maxillae, as well as their relative positions to the coronal plane passing through basion. The independent sample group t test was performed, and P < 0.05 was regarded as statistically significant. In the GC group, the anterior and posterior maxillary length (A1-P3M⊥CP and P3M-P6M⊥CP) and overall maxillary length (A1-P6M⊥CP) at the dental level, the interdental widths of the maxillae, the maxillary volume (GM), and the volume consisting of maxilla and maxillary sinus (GT) significantly reduced compared with the GN group (P < 0.05). The distances from the points on the maxillae to the coronal plane (A1⊥CP, P3M⊥CP, and P6M⊥CP) in the GC and GIII groups were smaller than those in the GN group (P < 0.05). In summary, for the UCLP patients, the decreased prominence of maxillary complex could be mainly caused by the shortened maxillary length; meanwhile, posterior position of the maxillary body may have some influence on the maxillary protrusion. While for the class III patients, maxillary retrusion was resulted from malposition and malmorphology on an equal basis.