The Maxillary Retrusion In Adult Cleft Lip And Palate:Measurement, Classification And Treatment

【Objective】：(一) Fundamental research(1) to investigate the anatomical features of maxillae in bilateral cleft lip and palate (BCLP) and patients with maxillary retrusion(2) to investigate the characteristics of the dentition of the patients with cleft lip and palate.(二) Clinical classificationTo classify the patients with cleft lip and palate who need orthognathic surgery and propose the corresponding operations.[Methods]:( 一) Fundamental research(1) characteristics of maxillary morphology in patients with bilateral cleft lip and palateCraniofacial measurements were carried out among 22 BCLP adult patients with maxillary retrusion (GB),24 adult patients in class Ⅲ (SNA<80°, ANB<0°) (GⅢ), and 32 normal controls (GN). The CT slice date was from the LightSpeed CT scanner using a high-resolution bone algorithm. The axial images were reconstructed into a 3D video model using Mimics, software, version 16.0. All statistical analyses were conducted by IBM SPSS Statistics software, version 20.0. The independent sample group t test was used to compare means of GU and GN, GU and GIII, GU and GB. The levels of significance were set at P<.05; In GB group, the interdental widths (M3W, M4W, M5W) were obviously more constrictive and from the anterior part up to the second premolar, the gap gradually narrowed (P<.01)(2) Space analysis in maxillary retrusion of adult patients with cleft lip and palateSpace analysis were carried out among 68 UCLP adult patients(GA) and 25 BCLP adult patients(GB) with maxillary retrusion,28 adult patients in class Ⅲ (SNA<80°, ANB<0°) (GC). All statistical analyses were conducted by IBM SPSS Statistics software, version 20.0. The independent sample group t test was used to compare teeth quantity, bone quantity and Space analysis of GA and GB, GA and GC, GB and GC. The levels of significance were set at P<.05.(二) Clinical classificationPatients were divided into two categories depended on the dental crowding. Class Ⅰ:the available space and necessary space is coordinated, space analysis≤4 mm (coordination or mild dental crowding). The forward distance of maxillary less than 6 mm was defined as Class Ⅰa, more than 6mm as Class Ⅰ b.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 Ha, not corrected defined as Class Ⅱb【Results】:(一) Fundamental research(1) the posterior part of the maxillary length (P3M-P6M⊥CP) and overall maxillary length (A1-P6M⊥CP) at the dental level were both significantly reduced (P<.01), while the anterior part of the maxillary length (A1-P3M⊥CP)was larger than in GC. The Proportion of the anterior part of the maxillary length (A1-P3M⊥CP/A1-CP) was larger(P>.05), While the proportion of posterior part of the maxillary of the (P3M-P6M⊥CP/A1-CP) was much smaller. There was no difference in the proportion of the overall maxillary length (A1-P3M⊥CP/A1-CP).The distances of A1⊥CP and P3M⊥CP were obviously smaller than in the GB group(P<.01), but there was no significant difference of the distance of P6M⊥CP. When the GB group Compared to the GⅢ group, there was no significant difference of the distances of P3M-CP and P6M-CP between (P>.05), while the A1⊥CP in the GⅢ group were significantly shorter(P<.01). The anterior part(A1-P3M⊥CP) is larger in GB group, the posterior part and overall maxillary length at the dental level (P3M-P6M⊥CP and A1-P6M⊥CP) had no difference between two groups (P>0.05);(2) Compared the GA group to the GC group, the teeth quantity the bone quantity, the available space and the necessary space were all significantly less in the GA group (P<.05). while Space analysis was much crowding in GA group(P<.05). When the GB group compared to the GC group, the teeth quantity and bone quantity is significantly less in the GA group (P<.05), and also the available space and necessary space. But Space analysis was much larger in GB group (P<.05). When the GA group compared to the GB group, bone quantity is significantly less in the GB group (P<.05), the teeth quantity, the available space, the necessary space and Space analysis had no significant difference(P>.05).(二) Clinical classificationFrom January 2005 to May 2015,121 patients with cleft lip and palate diagnosed as maxillary retrusion were treated by orthognathic surgery. Inclusion criteria: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 undergoing the treatment of orthodontic and orthognathic before; ④ having no other craniofacial malformation.93 patients were included. Class Ⅰa included 36 cases, Class I b included 28 cases. Class Ha included 23 cases, Class Ⅱb included 6 cases. Class Ⅰa were corrected by conventional orthognathic surgery. While Class Ib were corrected by Le Fort I Maxillary advancement using distraction osteogenesis. Class Ⅱawere repaired just by anterior maxillary distraction. While Class Ⅱb need to combine conventional orthognathic surgery with anterior maxillary distraction All the patients were satisfied with the treatment effect.[Conclusions]:( 一) Fundamental research(1) In summary, for the BCLP patients, the decreased prominence of maxillary complex could be caused by the shortened maxillary length and the posterior position of the maxillary body.Maxillary development insufficient is mainly occurred in the posterior part(2) The phenomenon of dental crowding often exists in the maxillary retrusion patients.Due to the lack of the development of maxilla and the existence of the cleft, the bone quantity is significantly less in the patients with cleft lip and palate.(二) Clinical classificationThe patients of cleft lip and palate with maxillary retrusion who need orthognathic surgery can be classified as the method mentioned above, and then take the appropriate operations.