Sagittal maxillary growth pattern in unilateral cleft lip and palate patients with unrepaired cleft palate.

OBJECTIVE: The objective of the study was to examine the sagittal maxillary growth pattern during the mixed and permanent dentition in unilateral cleft lip and palate (UCLP) patients with unrepaired cleft palate. PATIENTS AND METHODS: A total of 30 nonsyndromic UCLP patients with unrepaired cleft palate were included, 15 of whom were in mixed dentition and 15 in permanent dentition.Cephalograms were analyzed and compared in the patients with UCLP who have operatively undergone repair with both the lip and palate as well as normal subjects. RESULTS: The UCLP patients with unrepaired cleft palate in mixed dentition showed decreased anterior-posterior length of the maxilla. The UCLP patients with unrepaired cleft palate in permanent dentition demonstrated an almost normal maxillary growth. The operated-on patients both in mixed and permanent dentitions showed maxillary retrusion as well as decreased maxillary length. CONCLUSIONS: There appears that there may be the potential normal maxillary growth in UCLP patients, and early surgical repair of the cleft palate may affect sagittal maxillary growth pattern in patients with cleft.

[Impact of maxillary sinus floor on the mesial movement of maxillary first molar].

PURPOSE: To investigate the impact of maxillary sinus floor on the mesial movement of maxillary first molar. METHODS: Orthodontic patients with maxillary first premolars extracted were selected. Their maxillary first molars were divided into case group and control group according to whether their roots were in contact with the maxillary sinus floor. The case group was further divided into three subtypes according to the depth of the root extruded into the maxillary sinus. A total of 64 maxillary first molars from 32 patients were enrolled in this study, including 34 in the case group (five in subtype Ⅱ, fourteen in subtype Ⅲ, and 15 in subtype Ⅳ) and 30 in the control group. The mesial movement distance of each root and crown and the inclination of each root long axis were measured, and resorption of each root was evaluated. SPSS 22.0 software package was used for data analysis. RESULTS: After orthodontic treatment, the mesial movement distance of roots from both groups were all lager than 2 mm. The mesial movement distance of the crown was not statistically different between the two groups (P＞0.05), while the mesial movement distance of the roots in the control group was significantly larger than in the case group（P＜0.05）. Inclined movement towards the mesial direction was found in both groups, and the inclination angle was significantly larger in the case group（P＜0.05）. The inclination angle of the first molars in the subtype Ⅳ was significantly larger than that in the subtype Ⅲ and the control group. Most of the maxillary first molars from both groups had no obvious root resorption（P＞0.05）. CONCLUSIONS: With the proper force system, maxillary first molars with roots extruded into the maxillary sinus floor can be moved mesialy with mild or no root resorption, while a larger inclination can be found compared with maxillary first molars without root extruding into the maxillary sinus floor. The deeper the root extruding into the maxillary sinus, the larger the inclination angle will be.

[Using Q methodology to investigate motives of seeking orthodontic treatment from parents' perspectives of cleft lip and/or palate patients].

PURPOSE: This study was aimed to use Q methodology to find out why parents of cleft lip and/or palate (CLP) patients want their children to undergo orthodontic treatment. METHODS: Q methodology involved five phases.①concourse, collecting all viewpoints from CLP patients' parents on seeking orthodontic treatment. ②Q sample, Selecting 36 items from the concourse. ③P sample, forty varieties of parents whose children were CLP patients and want to have braces. ④Q sort, participant- ranked statements (Q sample) in order of relative significance using an enforced distribution grid (Q grid). ⑤analysis: using PQMehtod 2.35 vision to analyze the data. RESTULTS: Three factors were identified as representing the most widespread views of the majority of the parents. Group 1 consisted of parents of 13 CLP patients marked as factor 1: responsibility as parents. The parents of 8 participants made up group 2 designated as factor 2: parents' anxiety for their children's wellbeing. Group 3 was made up of parents of 9 CLP patients marked as factor 3: oral function. The opinions of the remaining participants did not fit into any of the outlined three groups. CONCLUSIONS: Parents' motives to seek orthodontic treatment for their children are complicated. Most CLP patients' parents are categorized into three different groups. Understanding these motives will help orthodontists frame their treatment discussions with parents and improve cooperation of both patients and parents.

[Study of three-dimensional anatomical relationship between infrazygomatic crest and maxillary sinus for mini-screw insertion].

PURPOSE: To measure the thickness of the infrazygomatic(IZ) crest above the maxillary first molar and analyze its relationship with maxillary sinus as to derive clinical implications and provide guidance for placements of orthodontic mini-screw. METHODS: Thirty seven cone-beam CT(CBCT) images of infrazygomatic crest sites were collected from data of 19 adult inter-treatment orthodontic patients. Based on the relationship of maxillary sinus floor and mesiobuccal root of the maxillary first molar, the subjects were divided into high sinus floor group (n=13) and low sinus floor group (n=24). Both lengths of mesial and distal buccal root of the maxillary first molar were measured as a reference for mini-screw positioning. Statistical analysis of the data was conducted using SPSS 20.0 software package. RESULTS: IZ crest thickness above the maxillary first molar in high sinus group was larger than that in low sinus group, and the thickness decreased as the measurement moved towards the skull base in both groups. Lengths of mesial and distal buccal root of the maxillary first molar were (12.62±0.55)mm and (12.30±0.48)mm respectively in male patients alongside (11.53±0.24)mm and (11.15±0.26)mm respectively in female patients. CONCLUSIONS: Our data indicated pre-insertion evaluation of the appropriate level of maxillary sinus floor should be performed before placement of mini-screw using CBCT. In order to avoid injury to the mesiobuccal root of the maxillary first molar and enhance the stability of inserted miniscrew, positions for miniscrew implant insertion should be over 13.62 mm in Chinese male patients and 12.53 mm in female patients at the vertical level from buccal CEJ.

[Maxillary protraction with and without maxillary expansion on unilateral cleft lip and palate model: a finite element analysis].

PURPOSE: The aim of this finite element study was to investigate biomechanical effects of maxillary protraction with and without maxillary expansion on unilateral cleft lip and palate(UCLP)model before and after alveolar bone graft (ABG). METHODS: Orthopedic force (30° downward and forward to the occlusal plane, 5N/side) with expansion and without expansion were loaded on models before ABG, and after ABG respectively. Initial displacement and sutural stress were analyzed by using ANSYS12.0 software. RESULTS: The amount of displacement at the cleft side was larger than that at the non-cleft side before ABG, a more symmetrical pattern was obtained after ABG. Regardless of ABG, maxillary protraction with maxillary expansion exhibited more evident forward displacement of maxilla. The sutural stress values after maxillary protraction with maxillary expansion were significantly higher than without expansion. CONCLUSIONS: Analysis of these results showed that maxillary protraction with expansion could presumably promote the orthopedic effects of the facemask on UCLP patients, and more uniform force would obtain after ABG.

[Clinical analysis of two-phase treatment of 35 cases with Angle Class II division 1 malocclusion].

PURPOSE: To evaluate the clinical value of the two-phase treatment of Angle Class II division 1 malocclusion. METHODS: Thirty five cases with Class II division 1 malocclusion were treated with two-phase treatment(Twin-block functional appliance and fixed appliance).Lateral cephalograms were taken before and after treatment for each patient. The results were analyzed with paired t test using SPSS11.0 software package. RESULTS: After treatment ,the bite relation of molars ,the overbite and overjet and soft tissue profile were improved. ANB angle,U1-SN,OB,OJ,UL-E,ULP were decreased respectively(P<0.01). SNB, C(o)-G(o),G(o)-G(n),C(o)-G(n) were increased respectively(P<0.01). L1-Mp and FH-MP were increased, too(P<0.05). CONCLUSIONS: Twin-block functional appliance possesses the orthopedic effects on Angle Class II division 1 malocclusion.It limits the maxillary growth forward and promotes the mandibular growth by repositioning the mandible forward.These may contribute to a harmonious relationship of upper and lower jaws and a better profile.

Sagittal maxillary growth in patients with unoperated isolated cleft palate.

OBJECTIVE: To examine the sagittal maxillary growth during mixed and permanent dentition in patients with unoperated isolated cleft palate. PATIENTS: A total of 41 patients with nonsyndromic unoperated isolated cleft palate, 16 with mixed dentition and 25 with permanent dentition. MAIN OUTCOME MEASURES: Cephalograms were analyzed to compare these patients with those with isolated cleft palate who had been repaired operatively as well with normal individuals. RESULTS: The unoperated patients in mixed dentition showed reduced anterior-posterior length of the maxilla. In adults with unoperated isolated cleft palate with permanent dentition, the measurements showed maxillary retrusion as well as reduction in the anterior-posterior maxillary length. CONCLUSION: Sagittal growth of the maxilla appears to be inhibited in patients with unoperated isolated cleft palate, which became more severe with age.

[Evaluation of bone volume of alveolar cleft before and after bone graft].

OBJECTIVE: The aim of this study was to evaluate the changing of alveolar cleft bone volume before and after bone graft. METHODS: 11 complete unilateral alveolar cleft patients were scanned with dental CT before bone graft surgery and 3 months after surgery. Matlab7.0 software was used to calculate the bone volume of alveolar cleft before bone graft and bone bridge volume after bone graft. The method was clockwise identify the irregular area of alveolar cleft by several points at different vertical level, then calculated the irregular area of alveolar cleft and the volume of alveolar cleft using Matlab7.0 software. The volume of implant bone was evaluated with same method after 3 months surgery. The ratio of graft bone bridge volume and alveolar cleft volume was calculated. RESULTS: The maximum ratio of bone bridge volume and alveolar cleft volume was 114.99%, the minimum ratio was 13.36%. The average ratio was 71.80%, coefficient variation was 47.987. CONCLUSION: Bone bridge volume after bone graft is varying.

[APDI and ODI estimated from substitute palate plane].

PURPOSE: The substitute palate plane was defined at the cephalometrics of noncleft patients. APDI and ODI were estimated from substitute PP. It is expected that the APDI and ODI estimated from PP (APDI',ODI')can be extended to the cleft patients to illustrate the anteroposterior and vertical relationship between maxilla and mandible. METHODS: The cephalometrics of 30 patients of C-I,C-II and C-III were traced and so were in 30 patients of normal overbite,deep overbite and open bite. The substitute palate plane(PP') was defined. The inclination of the PP to the FH, APDI and ODI, the inclination of the substitute PP to the FH,APDI' and ODI' were measured. The APDI and APDI' of C-I, C-II and C-III patients were compared,The ODI and ODI' of normal overbite, deep overbite and open bite patients were also compared by group t test. RESULTS: There was no significant difference between APDI and APDI' in C-I, C-II and C-III patients and also no significant difference between ODI and ODI' in normal overbite,deep overbite and open bite patients. It is showed the higher the ODI',the deeper the overbite. And the higher the APDI', the more mesial the molar relationship. CONCLUSIONS: The APDI and ODI estimated from substitute PP can be used as an important criterion to judge the vertical and anteroposterior development of the the maxilla, especially in palate clefts patients.

[Study of fluoride released from fluoride-releasing adhesives].

OBJECTIVE: To study the fluoride release ability of two kinds of fluoride-releasing composite resin adhesives made in China. METHODS: Test samples of fluoride-releasing composite resin adhesives I and II were prepared, and fluoride ion concentrations were measured with a No.720 fluoride ion-sensitive electrode. RESULTS: Fluoride ions were released from both of the fluoride-releasing composite resin adhesives. The concentration declined sharply after first 24 hours and maintained at a low level for about 21 days. The initial fluoride ions concentration of adhesive II was higher than adhesive I. CONCLUSION: Both of the fluoride-releasing composite resin adhesives had the ability of releasing fluoride. Adhesive II seemed better.