Does the floor of the maxillary sinus affect tooth movement for premolar extraction space closure?

OBJECTIVE: The study investigated orthodontic tooth movement by comparing various horizontal and angular measures of the teeth having different sinus-root relationship (SRR) of patients undergoing first premolar extraction treatment protocols. MATERIALS AND METHODS: This retrospective cross-sectional study included 45 Taiwanese adult patients, classified as the control group (n = 15) and the sinus group (n = 30) according to SRR. The control group had type I SRR (sinus floor above the level connecting the buccal and palatal root apices), whereas the sinus group included patients with type V SRR (the buccal and palatal root displayed apical protrusion into the sinus floor). Morphology was identified using pretreatment orthopantomograms. Lateral cephalometric measurements were conducted before treatment (T1) and at debonding (T2). RESULTS: Post debonding, there were no statistically significant difference in the two groups. However, the incisors in the control group became marginally more upright than those of the sinus group, and the molars demonstrated tipping movement with minimal anchorage loss in the sinus group than in the control group. The total treatment time was not significantly different between the 2 groups. CONCLUSION: The study revealed that the sinus-root relationship does not affect the orthodontic tooth movement. However, a more extensive 3-D study with larger sample size is strongly recommended before coming to any conclusion. CLINICAL RELEVANCE: The lining of the floor of the maxillary sinus does not affect the orthodontic tooth movement.

Does cleft lip and palate affect the severity of malocclusion?

OBJECTIVE: The purpose of this study was to evaluate the 3D anatomical features of unilateral (UCLP) and bilateral (BCLP) complete cleft lip and palate with those of skeletal Class III dentofacial deformities. MATERIALS AND METHODS: In total, 92 patients were divided into cleft and noncleft groups. The cleft group comprised 29 patients with UCLP and 17 patients with BCLP. The noncleft group comprised 46 patients with Class III dentofacial deformities. 3D anatomical landmarks were identified and the corresponding measurements were made on the cone-beam computed tomography (CBCT). RESULTS: The differences between the affected and unaffected sides of the patients with UCLP were nonsignificant. The differences between the patients with UCLP and BCLP were nonsignificant except for the SNA angle. Significant differences between the patients with clefts and Class III malocclusion were identified for the SNA, A-N perpendicular, and A-N Pog line, indicating that the maxillae of the patients in the cleft group were more retrognathic and micrognathic. Relative to the noncleft group patients, the cleft group patients had a significantly smaller ramus height. CONCLUSION: The affected and unaffected sides of the patients with UCLP did not exhibit significant differences. The maxillae of the patients with UCLP were significantly more retrognathic than those of the patients with BCLP. The maxillae and mandibles of the patients in the cleft group were more micrognathic and retropositioned relative to those of the noncleft Class III patients. CLINICAL RELEVANCE: The maxillary and mandibular findings indicated greater deficiencies in the patients with UCLP or BCLP than in those with skeletal Class III malocclusion. Appropriate surgical design should be administered.

Extensive Gingivoperiosteoplasty Versus Secondary Alveolar Bone Grafting in Patients With Complete Bilateral Cleft Lip and Palate During the Mixed Dentition Period: A Retrospective Outcome Analysis.

BACKGROUND: The concept of gingivoperiosteoplasty (GPP) in the mixed dentition stage as compared with secondary alveolar bone grafting (ABG) in management of alveolar cleft has not been much discussed upon. The authors present the experience with extensive GPP and ABG in the mixed dentition stage in complete bilateral alveolar cleft cases. METHODS: A retrospective review of nonsyndromic patients with complete bilateral alveolar cleft operated on with either GPP or ABG (iliac crest) in the mixed dentition stage with at least 1-year follow-up was performed. Dental occlusal radiographs were evaluated for level of bone gain using Bergland and Witherow scales. Statistical evaluation of clinical success and procedure-related complications was conducted using χ2 test and odds ratio. RESULTS: Twenty-four patients in the GPP group and 20 in the ABG group were comparatively studied. Clinical success rate as indicated by Bergland scales I and II (87.5% in GPP vs 82.5% in ABG; P = 0.731), complication rate (20.83% in GPP vs 30% in ABG; P = 0.484), and status of canine eruption showed no significant differences in clinical outcomes in both groups. CONCLUSIONS: The technique of extensive GPP as described by authors shows equal efficacy to secondary ABG for management of bilateral alveolar clefts during the mixed dentition period.

Effects of maxillary advancement on maxillary incisor display in patients with skeletal Class III malocclusion and cleft lip and palate.

INTRODUCTION: The information on the hard- and soft-tissue factors correlated with tooth display after LeFort I osteotomy, especially in the surgery-first approach (SFA), are limited. This study aimed to correlate different parameters with the maxillary incisor display in patients with skeletal Class III malocclusion and those with cleft lip and palate (CLP) in SFA. METHODS: This study consisted of 35 patients with skeletal Class III malocclusion and 32 with cleft deformities who had undergone orthognathic surgery. Pretreatment and posttreatment lateral cephalometric analysis were obtained. Maxillary incisor display was measured in photographs. The intraclass correlation coefficient was used to assess the intraexaminer repeatability. The Student t test was used to compare the maxillary incisor display between 2 groups. Analysis of covariance was performed with pretreatment measurement as covariates, and the important determinants for maxillary incisor display were identified by adjusting the baseline measurements. RESULTS: The mean increase of maxillary advancement at point A was 5.25 mm and 1.28 mm downward movement for skeletal Class III malocclusion, whereas it was 4.59 mm advancement and 2.16 mm downward movement for patients with CLP. The resulting maxillary incisor display was 2.86 mm for skeletal Class III malocclusion and 2.56 mm for patients with CLP. The covariates for maxillary incisor display before intervention was significantly associated with the maxillary incisor display after intervention (P <0.001). However, the interaction effect of groups was not seen (P = 0.933). The horizontal position of A, vertical position of ANS, and upper lip length were the most predictable parameters (P <0.001, P <0.001, P = 0.048, respectively) for maxillary incisor display in both groups. CONCLUSIONS: Horizontal position of point A, vertical position of ANS, and upper lip length are the most important determinants for maxillary incisor display for patients with skeletal Class III malocclusion and those with CLP.

Assessment of Palatal Plane and Occlusal Plane for Determining Anteroposterior Jaw Relation.

INTRODUCTION: Sagittal jaw relationship is an important parameter for orthodontic treatment planning. Angular and linear measurements both have been proposed and used in orthodontic cephalometrics to assess the sagittal jaw relationships. However, angular measurement has been questioned over the years for its reliability as a result of changes in facial height, jaw inclination and the variable positions of Nasion. So, the objective of our study was to assess the linear anteroposterior jaw relation in a sample of Nepali population using occlusal (Wits appraisal) and palatal planes as reference lines. METHODS: A descriptive cross-sectional study was conducted using the lateral cephalogram of 101 individuals visiting the Department of Orthodontics, Kantipur Dental College, Kathmandu, Nepal. Individuals with Class I skeletal relation were selected using convenience sampling method. Radiographs were standardised and traced. Occlusal and palatal planes were drawn that were bisected by the perpendicular lines from Point A and Point B. The linear distances between the intersections were measured to determine sagittal jaw relations. RESULTS: In Nepali individuals with normal ANB angle (3.05°±2.511°), the sagittal jaw relation with reference to occlusal (Wits appraisal) and palatal planes were found to be 0.203±3.343mm and 3.574±4.074mm respectively. CONCLUSIONS: Various methods has been proposed and used to assess the sagittal jaw relation and each method has its own strength and limitations. So, it is well advised to use additional cephalometric analysis whenever possible before arriving at any diagnosis and treatment plans.