Facial morphology and malocclusions Christian Bittner and Hans Pancherz

Giessen, West Germany The aim of this study was to determine whether sagittal and vertical aberrations in intermaxillary incisal tooth and jaw relationships were reflected in facial morphology. One hundred seventy-two children (79 girls and 93 boys), 12 to 14 years of age, were selected from the Orthodontic Department, University of Giessen. Pretreatment profile and frontal facial photographs as well as profile roentgenograms in centric occlusion for each child were made. The method consisted of (1) a personal appraisal of the existing incisal tooth and jaw relationship by visual inspection of facial photographs, (2) a validity assessment of these personal appraisals, and (3) a comparison of linear and angular measurements made from facial photographs and from lateral headfilms. The result of this investigation revealed that a large overjet and a Class II, Division 2 incisal tooth relationship were most often reflected in the face. A Class I11 incisal tooth relationship and an open bite, however, were difficult to detect. Sagittal maxillary and mandibular positions could only occasionally be determined on the basis of facial appearance, while a Class II jaw base relationship (large ANB angle) could easily be seen. The vertical jaw relationship (mandibular plane angle and anterior facial height index) could be determined with relatively high precision. When the measurements from the facial photographs were compared with those from the lateral headfilms, moderate to high correlations were found between skeletal and soft tissue readings: ANB angle (r = + 0.63), mandibular plane angle (r = +0.93), and anterior facial height index (r = +0.86). It was concluded that sagittal and vertical dental and skeletal intermaxillary malrelationships were only partly reflected in the face. (AM J ORTHOD DENTOFACORTHOP 1990;97:308-15.)

A n g l e , as early as 1907, I emphasized the importance of facial esthetics in orthodontic treatment. Since the days of Angle, a great deal of research has been done on soft tissue morphology and its changes during growth and orthodontic intervention. Various systems for the evaluation of facial esthetics have been introduced, 2"~5 and numerous articles have dealt with the question of how much impact orthodontic and surgical procedures have on soft tissue morphology. ~62~ However, no current literature deals with the question of how well tooth and jaw malrelationships can actually be assessed on the basis of facial features only. The aim of this study was to determine whether sagittal and vertical aberrations in intermaxillary incisal tooth and jaw relationships are reflected in facial morphology. SUBJECTS

From the total patient population of the Orthodontic Department at the University of Giessen, 172 children (93 boys and 79 girls), 12 to 14 years of age, were From Department of Orthodontics, University of Giessen 811113240

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selected. In the selection of the patients, the following requirements had to be met: (1) Black and white facial photographs (profile and frontal views), as well as profile cephalometric roentgenograms in centric occlusion, from before treatment had to be available. (2) On the photographs, the subjects' lips had to be closed. (3) All diagnostic records should be of high quality so that reliable analyses could be made. METHOD

The method consisted of (l) a personal appraisal of the existing incisal tooth and jaw relationships by visual inspection of facial photographs, (2) a validity assessment of these personal appraisals, and (3) a comparison of selected linear and angular measurements made from facial photographs and from profile roentgenograms. The personal appraisal of the facial photographs was performed by a group of seven investigators (four specialists in orthodontics and three postgraduate orthodontic students). The frontal and profile facial photographs (size, 7 x 8 cm) of the patients were originally oriented with the Frankfort plane horizontally. To eliminate any possible influence of this unnatural head posture on the personal appraisal, the photographs were

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Facial morphology and malocclusions 309

Table I. Validity rating scale of the personal appraisals of the existing incisal tooth and jaw relationships by visual inspection of facial photographs

Validity l ratings

I

Appraisals

Error score

Very high High

7 appraisals correct, or 6 correct and 1 single* error 6 appraisals correct and 1 double* error, or 5 correct and 2 single errors Moderate 4 appraisals correct and 3 single errors, or 5 correct and 1 double and 1 single error Low All results with more wrong appraisals than listed above

0-1 2 3 4-14

The possible error score by a group of seven investigators is given. *Taking overjet as an example, a single error implied that an existing large overjet was appraised as normal; a double error implied that a large overjet was appraised as small.

mounted in round paper frames (Fig. 1). Each investigator was handed a set of photographs o f each o f the children for evaluation. The investigator was asked to orient the photographs to what was thought to be the most pleasing head posture and to give an appraisal of the existing intermaxillary tooth and jaw relationships. In assessment o f the validity of the personal appraisals of the facial photographs with respect to the actual dentofacial conditions, existing in the subjects, average cephalometric values for white persons, plus or minus one standard deviation, were used as norms. In appraising the photographs, the investigators were told to rate the eight variables listed (the cephalometric norm values for each rating are given in parentheses):

1. Overjet Normal (0 to 5 mm)

Large (>5 mm)

Small (5 mm)

Open (85 °)

Retrognathic (SNA 83 °)

Retrognathic (SNB 5 °)

Class III (ANB < 0 °)

7. Verticaljaw relationship - Mandibular plane angle Normal (ML/FH 22' to 30 °)

High angle (ML/FH >30 °)

Low angle (ML/FH

Facial morphology and malocclusions.

The aim of this study was to determine whether sagittal and vertical aberrations in intermaxillary incisal tooth and jaw relationships were reflected ...
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