All PhD Theses

C.A.M. Bongaarts

The effect of infant orthopedics from 4 years to 6 years of age in children with unilateral cleft lip and palate

08-07-2009

A scientific essay in Medical Sciences

DOCTORAL THESIS defended in public on 8th of July 2009

SUMMARY

Chapter 1 gives a short introduction to the topic of the thesis. The history of infant orthopedics is explained and its shortcomings and benefits. Because there are so many drawbacks of previous studies, no evidence based information was available. This was the reason to start Dutchcleft, a prospective randomized clinical trial in three cleft palate centers (Nijmegen, Amsterdam, and Rotterdam). The study started in 1993 and comprised 4 main subjects: (1) general aspects, (2) surgical and orthodontic aspects, (3) speech and language development, (4) cost - effectiveness. A child entered the study within two weeks after birth, and was randomly assigned to the IO+ (treatment with infant orthopedics) or IO-group (treatment without infant orthopedics). A total of 54 children from three cleft palate centers was included; 27 in each group. In two earlier thesis the short term results of the trial were presented. In the present thesis the midterm results for the orthodontic and surgical variables are presented.

In chapter 2 the effect of infant orthopedics (IO) on the occlusion of the deciduous dentition is described. Dental arch relationships were assessed at 4 and 6 years of age with the 5-year-old index, the Huddartscore, and with measurements of overjet, overbite, and sagittal occlusion. There were no significant differences found between the IO+ and IO-groups for the 5-year-old index, the Huddart-score, and for overjet, overbite, and sagittal occlusion.

Chapter 3 describes a study into the effect of IO on maxillary arch dimensions in the deciduous dentition. The maxillary arch dimensions were assessed on dental casts at 4 and 6 years of age with measurements for arch width, arch depth, arch length, arch form, and the vertical position of the lesser segment. Contact and collapse were also assessed. IO had no observable effect on the maxillary arch dimensions or on the contact and collapse scores in the deciduous dentition at the age of 4 and 6 years.

Facial appearance at 4 and 6 years of age was assessed and the results are described in chapter 4. Full face photographs and photographs showing only nose and mouth were scored. Ratings were performed on a VAS-scale by professionals and laymen. At 4 years of age the full face pictures of IO+ children were scored to be more attractive than full face pictures of IO- children. However, this difference had faded away at 6 years of age. At the age of 6, only professionals saw a significant difference on nasolabial photographs between IO+ and IO-. Regression analysis showed a minor effect of occlusion, lip revision, or type of nose reconstruction on the esthetic results. IO had a positive effect on full facial appearance of UCLP children at the age of 4 years, but at the age of 6, only professionals saw a positive effect of IO on the nasolabial photographs. This is for UCLP patients irrelevant since they deal with laymen in their daily life.

In chapter 5 the reliability of some cephalometric measurements in unilateral cleft lip and palate patients was tested. Measurements with A, ANS, and PNS, were compared to measurements performed with alternatives for these points: A1, A2, ANS1, ANS2, and PNS1. Cephalograms of children with complete UCLP (n=164), with a lateral head film taken at age 4 to 6 were used. Intra- and interobserver reliability for cephalometric measurements including A, ANS, PNS or their alternatives were calculated: Dahlberg errors, systematic errors and Pearson correlation coefficients. The measurements using ANS and PNS or their alternatives, were comparable. The systematic error between observers for measurements using A2 was less than for measurements using A or A1. The scatter plot of point A showed a slightly better distribution of the points than the plots of A1 and A2. Although the landmarks A, ANS and PNS are hard to trace in UCLP patients with tooth germs in the anterior maxilla, no better landmarks were found, but cephalometric studies using A, ANS and PNS in UCLP patients should be interpreted with caution.

In chapter 6 the effect of IO on facial growth of UCLP patients, aged 4 and 6 years was evaluated. Measurements were done on lateral headfilms made at 4 and 6 years of age to get cephalometric values representing soft tissue, hard tissue and dental structures. No differences were found between IO+ and IO-, except for two measurements; the interincisal angle was larger (4 years of age) and the mentolabial angle was smaller (6 years of age) in the IO+ group. It was concluded that facial growth measurements at age 4 and 6 gave no reason to perform IO in UCLP patients.

Finally, in chapter 7, the general discussion, some methodological issues regarding the results are discussed. It describes the strength and weaknesses of the studies done, and gives implications for treatment. The general discussion ends with suggestions for further research.