Sirikorn Techarudeewan & Chairat Charoemratrote

The objective of this study was to investigate the influence of short upper posterior dental height (S-UPD) on dental, skeletal, and soft tissue profile in different vertical facial patterns in skeletal Class I patients. Lateral cephalometric radiographs of 136 skeletal Class I patients were grouped according to UPD: normal UPD (N-UPD) (n=64) and S-UPD (n=72). The S-UPD group was categorized according to the divergent pattern (Frankfort-mandibular plane angle [FMA]): normodivergent (Normo) (20o≤ FMA≤ 28o) (n=32), hypodivergent (Hypo) (FMA<20o) (n=20), and hyperdivergent (Hyper) (FMA>28o) (n=20). The skeletal, dental, and soft tissue characteristics were compared among the groups and analyzed for correlations. The results indicated that SNA was not significantly different among the groups, but SNB was significantly less in Hyper/S-UPD. Anterior facial height (N-Me and ANS-Me) in S-UPD was shorter than N-UPD. Posterior facial height (S-Go and Ar-Go) was the least in Hyper/S-UPD. Dentoalveolar height in the S-UPD group was significantly shorter than N-UPD except for UADH in Hyper/S-UPD. A significant difference was found in the angulation and position of the lower incisors. The soft tissue parameters showed that the upper and lower lips were more protrusive to the E-line in Hyper/S-UPD. Lower facial height and upper and lower lip lengths were greater in Hyper/S-UPD among the S-UPD. Throat length was greatest in Hypo/S-UPD, and the lip-chin-throat angle was greatest in Hyper/S-UPD. Moreover, the correlation results were consistent with the findings. Decreased UPDH was found to be related to decreased UADH, LADH, and LPDH except for UADH in Hyper/S-UPD. The decreased dentoalveolar height parameters, which led to a decreased overall facial height in both skeletal and soft tissue aspects, primarily affected the lower facial height. However, divergence of the face was affected by the posterior facial height.

KEY WORDS: Upper posterior dental height; Dentoalveolar height; Facial height; Dental compensation; Divergence.

TECHARUDEEWAN, S. & CHAROEMRATROTE, C. The influence of short upper posterior dental height on dental, skeletal, and soft tissue profile in different vertical facial patterns in skeletal class I patients. Int. J. Morphol., 44(1):179-187, 2026.