Objective : Condyle hypoplasia in temporomandibular joint(TMJ) is often observed in several radiographic views. Mandibular Condyle hypoplasia is frequently confused with osteoarthritis with bony changes in TMJ. This paper investigated clinical characteristics of mandibular condyle hypoplasia as compared with TMJ osteoarthritis.

Material and method : 276 patients with TMD were taken clinical and radiological examination and were divided into study group, 189 patients diagnosed with mandibular condyle hypoplasia, and control group, 87 patients diagnosed with TMJ osteoarthritis. And clinical features(Onset, Overjet, Overbite, Noise, Locking, NAS of noise, LOM, pain, MCO, and site of diagnosis and pain)of the two groups were compared.


Results :
1. Mandibular condyle hypoplasia and TMJ osteoarthritis were similar in many of the clinical features.
2. Mandibular condyle hypoplasia concordance rates of the radiographic diagnosis site and the pain site was significantly lower than TMJ osteoarthritis.
3. Bilateral mandibular condyle hypoplasia group had more occlusal discomfort, and clenching habits than unilateral mandibular condyle hypoplasia group.
4. Unilateral mandibular condyle hypoplasia group had more unilateral chewing habits and LOM than unilateral TMJ osteoarthritis group. Unilateral TMJ osteoarthritis group had more morning stiffness and higher concordance rates of the radiographic diagnosis site and the click sound site than unilateral mandibular condyle hypoplasia group.
5. Bilateral mandibular condyle hypoplasia group had more usual headaches and overjet than bilateral TMJ osteoarthritis group.

Conclusion :
Mandibular condyle hypoplasia has somewhat distinguishing clinical characteristics as compared with TMJ osteoarthritis.

KEY WORD : Mandibular condyle hypoplasia, TMJ osteoarthritis, unilateral chewing habits, clenching, morning stiffness