Martin A. van't Hof

Condylar remodelling and resorption after le Fort I and bimaxillary osteotomies in patients with anterior open bite

A sample of 259 patients with vertical maxillary hyperplasia, mandibular hypoplasia and anterior vertical open bite, collected from three different institutions, was analysed regarding temporomandibular joint (TMJ) sounds, condylar remodelling, and condylar resorption. All patients underwent Le Fort I osteotomies, and bilateral sagittal split advancement osteotomies were performed in 117 patients. Intraosseous wire fixation was used in 149 and rigid internal fixation in 110 patients. Cephalometric and orthopantomographic radiographs were available before surgery, immediately after surgery, one year postoperatively and at the latest follow up. The mean follow up was 69 months (range 20-210 months). The number of patients with TMJ sounds decreased from 38% to 31%. At the latest follow up 23.6% of the patients showed condylar remodelling, 7.7% unilateral condylar resorption and 7.7% bilateral condylar resorption. Condylar contours, as assessed on orthopantomographic radiographs, were classified as five different types. Condyles with preexisting radiological signs of osteoarthrosis or having a posterior inclination were at high risk for progressive resorption. Female patients with severe anterior open bite, high mandibular plane angle and a low posterior-to-anterior facial height ratio, who underwent a bimaxillary osteotomy, were prone to condylar resorption. Bone loss was predominantly found at the anterior site of the condyle. The incidence of condylar resorption was significantly higher after bimaxillary osteotomies (23%) than after only Le Fort I intrusion osteotomies (9%). Avoidance of intermaxillary fixation by using rigid internal fixation tended to reduce condylar changes, in particular in patients who underwent only a Le Fort I osteotomy. Rigid internal fixation in bimaxillary osteotomies resulted in condylar remodelling in 30% and progressive condylar resorption in 19% of the patients. Condylar changes were not significantly different after using either miniplate osteosynthesis or positional screws in bilateral sagittal split osteotomy procedures.

Stability of orthodontic treatment outcome: Follow-up until 10 years postretention

Dental casts of 1016 patients were evaluated for the long-term treatment outcome using the Peer Assessment Rating (PAR) index. The PAR index was measured at the pretreatment stage (n = 1016), directly posttreatment (n = 783), postretention (n = 942), 2 years postretention (n = 781), 5 years postretention (n = 821), and 10 years postretention (n = 564). The mean absolute change as well as the percentage of change per year (relapse) related to the postretention stage was calculated. An analysis of variance was applied to compare the mean change in the PAR between cases with and without a fixed retainer at the postretention stage and up to 10 years postretention. Drop-out analysis showed that more Class II Division 2 cases were lost to follow-up than cases of other Angle classes. The results indicate that 67% of the achieved orthodontic treatment result was maintained 10 years postretention. About half of the total relapse (as measured with the PAR index) takes place in the first 2 years after retention. All occlusal traits relapsed gradually over time but remained stable from 5 years postretention with the exception of the lower anterior contact point displacement, which showed a fast and continuous increase even exceeding the initial score. The presence of a fixed retainer had a positive effect on the PAR score. In cases with fixed retention, the relapse was 3.6 PAR points less at 5 years postretention and 4.6 points less at 10 years postretention. The results of this type of studies enable clinicians to inform their patients about treatment limitations in order to better meet their expectations.

Skeletal and dento-alveolar stability of Le Fort I intrusion osteotomies and bimaxillary osteotomies in anterior open bite deformities: A retrospective three-centre study

A sample of 267 patients with maxillary hyperplasia, a Class I or Class II/I occlusion and anterior vertical open bites, collected from three different institutions, was analysed regarding stability after surgical corrections. Skeletal and dento-alveolar stability of the maxilla, and positional changes of the mandible and of the incisors were evaluated. All patients underwent Le Fort I intrusion osteotomies and in 92 patients segmentation of the maxillae was performed. An additional bilateral sagittal split advancement osteotomy was performed in 123 patients. Intraosseous wire fixation was used in 153 patients and rigid internal fixation in 114 patients. Cephalometric radiographs were collected before orthodontic treatment, before surgery, immediately after surgery, one year postoperatively and at the latest follow up. The mean follow up was 69 months (range 20-210 months). It can be concluded that patients with anterior open bites, treated with a Le Fort I osteotomy in one-piece or in multi-segments, with or without bilateral sagittal split osteotomy, exhibited good skeletal stability of the maxilla. Rigid internal fixation produced the best maxillary and mandibular stability. The mean overbite at the longest follow up was 1.24 mm and a lack of overlap between opposing incisors was present in 19%. The overbite did not differ significantly between the different treatment procedures, probably due to compensatory movements of the mandibular and maxillary incisors.

Timing of Hard Palate Closure and Dental Arch Relationships in Unilateral Cleft Lip and Palate Patients: A Mixed-Longitudinal Study

In a mixed longitudinal study, dental arch relationships of 88 consecutive UCLP patients treated at the Nijmegen Cleft Palate Centre were evaluated using the Goslon Yardstick. On the basis of timing of hard palate closure, the patients were divided into four groups. Mean age of hard palate closure the patients were divided into four groups. Mean age of hard palate closure in group A (n = 18) was 1.5 years, in group B (n = 26) 4.6 years and in group C (n = 18) 9.4 years. In group D (n = 26, no patient older than 10 years) the hard palate was still open. Four stages of dental development were distinguished; deciduous dentition, early mixed dentition, late mixed dentition and permanent dentition. Reproducibility of scoring with the Goslon Yardstick was good for all stages of dental development. No differences in dental arch relationships were found between the four groups. In 86% of the cases, the dental arch relationships of UCLP patients treated in Nijmegen were acceptable. Pharyngeal flap surgery had minor unfavorable effects on dental arch relationships.

Infant orthopedics and facial appearance: a randomized clinical trial (Dutchcleft)

Objective: To study the effect of infant orthopedics on facial appearance. Design: Prospective two-arm randomized controlled trial in parallel with three participating academic cleft palate centers. Treatment allocation was concealed and performed by means of a computerized balanced allocation method. Setting: Cleft Palate Centers of Amsterdam, Nijmegen, and Rotterdam, the Netherlands. Patients: Infants with complete unilateral cleft lip and palate, no other malformations. Interventions: One group (IO+) wore passive maxillary plates during the first year, the other group (IO−) did not. Main Outcome Measure(s): Two metrical response modalities were used (i.e., visual analog scales and reference scores) to score facial appearance. Full face and cropped photographs were compared with reference photographs and were judged. The photographs were judged by 45 judges, 24 laypeople, and 21 professionals. Transformation of the scores into z scores was applied to compare and to pool both response modalities. The validity of each individual judge was evaluated, as was the reliability of the scales. Differences between the treatment groups were evaluated by means of t tests. Results: Photographs were available of 41 subjects, 21 with and 20 without infant orthopedics. No significant differences were found between groups. Mean z-score values for the full-face photographs were: group IO+ = 0.10 (SD = 0.73) and group IO− = −0.03 (SD = 0.48); for the cropped photographs were: group IO+ = 0.12 (SD = 0.71) and group IO− = −0.06 (SD = 0.55). Conclusions: Infant orthopedics have no effect on facial appearance.

The effect of infant orthopedics on the occlusion of the deciduous dentition in Children with complete unilateral cleft lip and palate (Dutchcleft)

Objective Evaluation of the effect of infant orthopedics (IO) on the occlusion of the deciduous dentition in patients with unilateral cleft lip and palate (UCLP). Design Prospective, two-arm, randomized, controlled clinical trial with three participating cleft palate centers (Dutchcleft). Setting Cleft Palate Centers of the University Medical Center Nijmegen, Academic Center of Dentistry Amsterdam, and Dijkzigt University Hospital Rotterdam, The Netherlands. Patients Children with complete UCLP (n = 54) were included. Interventions In a concealed allocation procedure, half of the patients was randomized to wear a plate till surgical closure of the soft palate (IO+), and the other half (IO−) did not have a plate. Mean Outcome Measures Dental arch relationships were assessed at 4 and 6 years of age with the 5-year-old index; the Huddart-score; and measurements of overjet, overbite, and sagittal occlusion. Results There were no significant differences found between the IO+ and IO− groups for the 5-year-old index; the Huddart-score; and overjet, overbite, and sagittal occlusion. Conclusions IO had no observable effect on the occlusion in the deciduous dentition at 4 and 6 years of age. Considering the occlusion only, there is no need to perform IO in children with UCLP.

Cost-effectiveness analysis of adjuvant physical or occupational therapy for patients with reflex sympathetic dystrophy☆☆☆

OBJECTIVE To study from a societal viewpoint the cost-effectiveness of adjuvant treatment for patients with reflex sympathetic dystrophy (RSD) of one upper extremity. DESIGN A two-center randomized clinical trial comparing pairwise physical therapy (PT), occupational therapy (OT), and control treatment (CT). PATIENTS One hundred thirty-five patients with RSD for less than 1 year participated. INTERVENTIONS PT and OT were given according to protocols. For CT, services by social workers were offered. MAIN OUTCOME MEASURES The Impairment-level Sum Score (ISS), the modified Greentest, and the Sickness Impact Profile (SIP) were used to determine effectiveness. Real medical costs, nonmedical costs, and productivity costs were distinguished and incremental cost-effectiveness ratios were calculated. Sensitivity analyses were performed on cost estimates. RESULTS The ISS, but not the Greentest and SIP, showed a significant difference between PT versus OT and CT. The mean adjuvant treatment costs were significantly higher for PT (Netherlands Guilders [NLG] 1,726) and OT (NLG 2,089) compared with CT (NLG 903). The mean total medical costs were not significantly different for the groups (PT, NLG 8,692; OT, NLG 13,023; and CT, NLG 7,888) (intention-to-treat analysis). The sensitivity analyses showed a moderate influence of the cost estimates. CONCLUSIONS PT results in clinically relevant improvement in RSD. Costs associated with adjuvant treatment are moderate compared to other medical costs. The incremental cost-effectiveness ratios of PT versus OT and CT were moderate or even dominant, thus PT was both more effective and less costly than its comparators.

Impaired resistance to oxidation of low density lipoprotein in cystic fibrosis: improvement during vitamin E supplementation.

Antioxidants such as vitamin E protect unsaturated fatty acids of LDL against oxidation. In the ex vivo model used, LDL was exposed to Cu2+ ions, a potent prooxidant capable of initiating the oxidation of LDL. The lag time, indicating the delay of conjugated diene formation in LDL due to antioxidant protection, was measured in 54 cystic fibrosis (CF) patients with plasma alpha-tocopherol levels below (Group A, n = 30) or above (Group B, n = 24) 15.9 mumol/L (mean - 2 SD of Swiss population). Patients were reevaluated after 2 months on 400 IU/d of oral RRR-alpha-tocopherol. In group A, alpha-tocopherol concentrations in LDL increased significantly from 3.2 +/- 1.6 mol/mol LDL to 8.2 +/- 2.8 mol/mol (P < 0.001) and lag times increased from 79 +/- 33 min to 126 +/- 48 min (P < 0.001), whereas in the vitamin E sufficient group B no further increase neither in LDL alpha-tocopherol concentrations or in lag times was observed. LDL oleic acid concentrations were higher, and linoleic acid concentrations were lower in patients than in controls. After efficient vitamin E supplementation, lag times were positively related to LDL alpha-tocopherol (P < 0.01) and negatively to LDL linoleic and arachidonic acid content (P < 0.001). The maximum rate of oxidation correlated positively with linoleic and arachidonic acid concentrations, as did the maximum conjugated diene absorbance. These results indicate that LDL resistance to oxidation is impaired in vitamin E deficient CF patients but can be normalized within 2 months when alpha-tocopherol is given in sufficient amounts. Linoleic and arachidonic acid content exhibit a major influence on the LDL resistance to oxidation.

Infant orthopedics in UCLP: effect on feeding, weight, and length: a randomized clinical trial (Dutchcleft)

Objective To study the effects of infant orthopedics (IO) on feeding, weight, and length. Design Prospective two-arm randomized controlled trial in three academic Cleft Palate Centers. Treatment allocation was concealed and performed by means of a computerized balanced allocation method. Setting Cleft Palate Centers of Amsterdam, Nijmegen, and Rotterdam, the Netherlands. Patients Infants with complete unilateral cleft lip and palate (UCLP), no other malformations. Interventions One group (IO+) wore passive maxillary plates during the first year of life, but the other group (IO−) did not. All other interventions were the same for both groups. Main Outcome Measures Bottle feeding velocity (mL/min) at intake, 3, 6, 15, and 24 weeks (T0 to T24); weight-for-age, length-for-age, and weight-for-length using z scores; reference values from the Netherlands’ third nationwide survey on growth. Results Feeding velocity increased with time from 2.9 to 13.2 mL/min in the IO− group and from 2.6 to 13.8 mL/min in the IO+ group; no significant differences were found between groups. Weight-for-age, length-for-age, and weight-for-length (z scores) did not differ significantly between groups, but overall the infants with unilateral cleft lip and palate in both groups had significantly lower mean z scores for weight-for-age and height-for-age than the reference during the first 14 months, and had lower mean values for weight-for-length after soft palate closure. Conclusion Infant orthopedics with the aim of improving feeding and consequent nutritional status in infants with unilateral cleft lip and palate can be abandoned.

Driving Forces for and Barriers to Nutrition Guidance Practices of Dutch Primary Care Physicians

Abstract Determinants of the nutrition guidance practices of primary care physicians (PCPs) were studied using a mail questionnaire developed on the basis of focus group discussions, in-depth interviews, and literature review. The questionnaire was sent to a nationwide random sample of 1000 PCPs (in practice for between 5 and 15 years).The net response rate was 64%. Multiple regression analysis was used to identify determinants of nutrition guidance practices. The independent variables studied were the perceived barriers to nutrition guidance practices, characteristics of the respondents, and nutrition attitudes and beliefs of PCPs. As determinants of nutrition guidance practices, we identified both perceived barriers (which exert a negative influence) and driving forces (which exert a positive influence).The driving forces observed in PCPs were an active interest in the effect of nutrition on health and disease, a basic level of nutrition knowledge, and positive attitudes towards nutrition guidance practices. Although perceived barriers can be strong, negative determinants of being involved in nutrition guidance practices, in future, it may become more important to stress the driving forces that positively determine the involvement of PCPs in nutrition guidance practices.