4.上下顎較常發生外生贅骨(exostoses)的位置為下列何者?
(A)上顎頰側後方(buccal sides of the posterior maxillary segments)
(B)上顎頰側前方(buccal sides of the anterior maxillary segments)
(C)下顎舌側後方(lingual sides of the posterior mandibular segments)
(D)下顎舌側前方(lingual sides of the anterior mandibular segments)